Details of a Researcher - Fujii, Hideki

Papers - Fujii, Hideki

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Immunological detection of severe acute respiratory syndrome coronavirus by monoclonal antibodies.

Ohnishi, K., Sakaguchi, M., Kaji, T., Akagawa, K., Taniyama, T., Kasai,M., Tsunetsugu-Yokota, Y., Ohshima, M., Yamamoto, K., Takasuka, N., Hashimoto, S., Ato, M., Fujii, H., Takahashi, Y., Morikawa, S., Ishii, K., Sata, T., Takagi, H., Itamura, S., Odagiri, T, Miyamura, T., Kurane, I., Tashiro, M., Kurata, T., Yoshikura, H. and Takemori, T

Jpn. J Infect. Dis. 58 ( 2 ) 88-94 - 94 2005.04

Research paper (scientific journal), Single Work, ISSN 1344-6304

In order to establish immunological detection methods for severe acute respiratory syndrome coronavirus (SARS-CoV), we established monoclonal antibodies directed against structural components of the virus. B cell hybridomas were generated from mice that were hyper-immunized with inactivated SARS-CoV virion. By screening 2,880 generated hybridomas, we established three hybridoma clones that secreted antibodies specific for nucleocapsid protein (N) and 27 clones that secreted antibodies specific for spike protein (S). Among these, four S-protein specific antibodies had in vitro neutralization activity against SARS-CoV infection. These monoclonal antibodies enabled the immunological detection of SARS-CoV by immunofluorescence staining, Western blot or immunohistology. Furthermore, a combination of monoclonal antibodies with different specificities allowed the establishment of a highly sensitive antigen-capture sandwich ELISA system. These monoclonal antibodies would be a useful tool for rapid and specific diagnosis of SARS and also for possible antibody-based treatment of the disease.

Double-Stranded RNA Poly(I:C) Combined with Mucosal Vaccine Protects against Influenza Virus Infection.

Ichinohe T, Watanabe I, Ito S, Fujii H, Moriyama M, Tamura S, Takahashi H, Sawa H, Chiba J, Kurata T, Sata T, Hasegawa H.

J Virol. 79 ( 5 ) 2910-2919 - 2919 2005.03

Research paper (scientific journal), Joint Work, Accepted

A subcutaneously injected UV-inactivated SARS coronavirus vaccine elicits systemic humoral immunity in mice

Takasuka N, Fujii H, Takahashi Y, Kasai M, Morikawa S, Itamura S, Ishii K, Sakaguchi M, Ohnishi K, Ohshima M, Hashimoto S, Odagiri T, Tashiro M, Yoshikura H, Takemori T, Tsunetsugu-Yokota Y.

Int Immunol. 16 ( 10 ) 1423-1430 2004.10

Research paper (scientific journal), Joint Work, Accepted

2-methacryloyloxyethyl phosphorylcholine polymer treatment prevents Candida albicans biofilm formation on acrylic resin.

Adityakrisna Yoshi Putra Wigianto, Yuichi Ishida, Yuki Iwawaki, Takaharu Goto, Megumi Watanabe, Kazumitsu Sekine, Kenichi Hamada, Keiji Murakami, Hideki Fujii, Tetsuo Ichikawa

Journal of prosthodontic research 2022.10

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted

PURPOSE: We aimed to evaluate the effectiveness of photoreactive 2-methacryloyloxyethyl phosphorylcholine (MPC) in inhibiting Candida albicans biofilm formation on polymethyl methacrylate (PMMA) and assess its mechanism and need for re-application by evaluating its interaction with salivary mucin and durability during temperature changes. METHODS: PMMA discs were used as specimens. The MPC coating was applied using the spray and cure technique for the treatment groups, whereas no coating was applied to the control. The MPC treatment (MT) groups were further differentiated based on the number of thermal cycles involved (0, 1000, 2500, and 5000). The optical density was measured to assess mucin adsorption (MA). Contact angle (CA) was calculated to evaluate surface hydrophilicity. The presence of MPC components on the PMMA surface was assessed using X-ray photoelectron spectroscopy (XPS). C. albicans biofilms were evaluated qualitatively (scanning electron microscope images) and quantitatively (colony-forming units (CFUs)). Statistical analysis was conducted using two-way analysis of variance and Tukey's multiple comparison test. RESULTS: MA rate and CA increased significantly in the MT groups, which exhibited significantly fewer CFUs and thinner biofilms than those of the control group. Based on the XPS, MA, and CFU evaluations, the durability and efficacy of the MPC coating were considered stable up to 2500 thermal cycles. Additionally, a significant interaction was observed between mucin concentration and MPC efficacy. CONCLUSIONS: The photoreactive MPC coating, which was resistant to temperature changes for approximately 3 months, effectively prevented C. albicans biofilm formation by modifying surface hydrophilicity and increasing mucin adsorption.

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Porphyromonas gingivalis Outer Membrane Vesicles Stimulate Gingival Epithelial Cells to Induce Pro-Inflammatory Cytokines via the MAPK and STING Pathways

Yuta Uemura, Yuka Hiroshima, Ayano Tada, Keiji Murakami, Kaya Yoshida, Yuji Inagaki, Tomomi Kuwahara, Akikazu Murakami, Hideki Fujii, Hiromichi Yumoto

Biomedicines (MDPI AG) 10 ( 10 ) 2643 - 2643 2022.10

Research paper (scientific journal), Joint Work, Accepted, ISSN 2227-9059

Porphyromonas gingivalis (Pg) is a keystone pathogen associated with chronic periodontitis and produces outer membrane vesicles (OMVs) that contain lipopolysaccharide (LPS), gingipains, and pathogen-derived DNA and RNA. Pg-OMVs are involved in the pathogenesis of periodontitis. Pg-OMV-activated pathways that induce the production of the pro-inflammatory cytokines, interleukin (IL)-6, and IL-8 in the human gingival epithelial cell line, OBA-9, were investigated. The role of mitogen-activated protein kinase (MAPK) and nuclear factor (NF)-κB in levels of Pg-OMV-induced pro-inflammatory cytokines was investigated using Western blot analysis and specific pathway inhibitors. Pg-OMVs induced IL-6 and IL-8 production via the extracellular signal-regulated kinase (Erk) 1/2, c-Jun N-terminal kinase (JNK), p38 MAPK, and NF-κB signaling pathways in OBA-9 cells. In addition, the stimulator of interferon genes (STING), an essential innate immune signaling molecule, was triggered by a cytosolic pathogen DNA. Pg-OMV-induced IL-6 and IL-8 mRNA expression and production were significantly suppressed by STING-specific small interfering RNA. Taken together, these results demonstrated that Pg-OMV-activated Erk1/2, JNK, p38 MAPK, STING, and NF-κB signaling pathways resulting in increased IL-6 and IL-8 expression in human gingival epithelial cells. These results suggest that Pg-OMVs may play important roles in periodontitis exacerbation by stimulating various pathways.

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Regulatory roles of fibronectin and integrin α5 in reorganization of the actin cytoskeleton and completion of adipogenesis.

Uetaki M, Onishi N, Oki Y, Shimizu T, Sugihara E, Sampetrean O, Watanabe T, Yanagi H, Suda K, Fujii H, Kano K, Saya H, Nobusue H

Molecular biology of the cell 33 ( 9 ) ar78 2022.08

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 1059-1524

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First reported case of Lachnoanaerobaculum gingivalis bacteremia in an acute myeloid leukemia patient with oral mucositis during high dose chemotherapy.

Naoto Okada, Akikazu Murakami, Masami Sato, Shingen Nakamura, Shiro Fujii, Kimiko Sogabe, Mamiko Takahashi, Asami Okada, Akane Abe, Hideki Fujii, Masahiro Abe, Momoyo Azuma, Keisuke Ishizawa

Anaerobe (Anaerobe) 76 102610 - 102610 2022.08

Research paper (scientific journal), Joint Work, Accepted, ISSN 10759964

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pruR and PA0065 Genes Are Responsible for Decreasing Antibiotic Tolerance by Autoinducer Analog-1 (AIA-1) in Pseudomonas aeruginosa.

Muhammad Reza Pahlevi, Keiji Murakami, Yuka Hiroshima, Akikazu Murakami, Hideki Fujii

Antibiotics (Basel, Switzerland) (Antibiotics) 11 ( 6 ) 2022.06

Research paper (scientific journal), Joint Work, Accepted, ISSN 2079-6382

Pseudomonas aeruginosa infection is considered a high-risk nosocomial infection and is very difficult to eradicate because of its tolerance to antibiotic treatment. A new compound, autoinducer analog-1 (AIA-1), has been demonstrated to reduce antibiotic tolerance, but its mechanisms remain unknown. This study aimed to investigate the mechanisms of AIA-1 in the antibiotic tolerance of P. aeruginosa. A transposon mutant library was constructed using miniTn5pro, and screening was performed to isolate high tolerant mutants upon exposure to biapenem and AIA-1. We constructed a deletion mutant and complementation strain of the genes detected in transposon insertion site determination, pruR and PA0066-65-64, and performed killing assays with antibiotics and AIA-1. Gene expression upon exposure to biapenem and AIA-1 and their relationship to stress response genes were analyzed. High antibiotic tolerance was observed in Tn5-pruR and Tn5-PA0065 transposon mutants and their deletion mutants, ΔpruR and ΔPA0066-65-64. Complemented strains of pruR and PA0066-65-64 with their respective deletion mutants exhibited suppressed antibiotic tolerance. It was determined that deletion of PA0066-65-64 increased rpoS expression, and PA0066-65-64 affects antibiotic tolerance via the rpoS pathway. Additionally, antibiotics and AIA-1 were found to inhibit pruR and PA0066-65-64. This study proposed that pruR and PA0066-65-64 are members of the antibiotic tolerance suppressors.

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Proton pump inhibitors affect capecitabine efficacy in patients with stage II-III colorectal cancer: a multicenter retrospective study.

Kitazume Y, Kawazoe H, Uozumi R, Yoshizawa T, Iihara H, Fujii H, Takahashi M, Arai T, Murachi Y, Sato Y, Mikami T, Hashiguchi K, Yamazaki T, Takahashi K, Fujita Y, Hosokawa Y, Morozumi I, Tsuchiya M, Yokoyama A, Hashimoto H, Yamaguchi M

Scientific reports 12 ( 1 ) 6561 2022.04

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted

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IgM to IgG Class Switching Is a Necessary Step for Pemphigus Phenotype Induction in Desmoglein 3-Specific B Cell Receptor Knock-in Mouse.

Hisashi Nomura, Naoko Wada, Hayato Takahashi, Yuko Kase, Jun Yamagami, Shohei Egami, Hisato Iriki, Miho Mukai, Aki Kamata, Hiromi Ito, Hideki Fujii, Tomoyuki Ishikura, Haruhiko Koseki, Takashi Watanabe, Taketo Yamada, Osamu Ohara, Shigeo Koyasu, Masayuki Amagai

Journal of immunology (Baltimore, Md. : 1950) (Journal of Immunology) 208 ( 3 ) 582 - 593 2022.02

Research paper (scientific journal), Joint Work, Accepted, ISSN 00221767

Pemphigus vulgaris is an autoimmune blistering disease caused by IgG targeting desmoglein 3 (Dsg3), an adhesion molecule of keratinocytes. Anti-Dsg3 IgG production is prevented in healthy individuals, but it is unclear how Dsg3-specific B cells are regulated. To clarify the immunological condition regulating Dsg3-specific B cells, a pathogenic anti-Dsg3 Ig (AK23) knock-in mouse was generated. AK23 knock-in B cells developed normally without undergoing deletion or acquiring an anergic phenotype in vivo. The knock-in B cells showed Ca2+ influx upon IgM cross-linking and differentiated into AK23-IgG+ B cells after LPS and IL-4 stimulation in vitro that induced a pemphigus phenotype after adoptive transfer into Rag2 -/- mice. However, the knock-in mouse itself produced AK23-IgM but little IgG without blisters in vivo. Dsg3 immunization and skin inflammation caused AK23-IgG production and a pemphigus phenotype in vivo. Furthermore, Fcgr2b deficiency or haploinsufficiency spontaneously induced AK23-IgG production and a pemphigus phenotype with poor survival rates in AK23 knock-in mice. To assess Fcgr2b involvement in Ig class-switch efficiency, postswitch transcripts of B cells were quantified and significantly higher in Fcgr2b -/- and Fcgr2b +/- mice than wild-type mice in a gene dose-dependent manner. Finally, RNA sequencing revealed reduced expression of FCGR2B and FcγRIIB-related genes in patient B cells. These results indicated that Dsg3-specific B cells do not spontaneously perform pathogenic class switching in vivo, and pemphigus phenotype induction was prevented under normal conditions. Attenuated FcγRIIB signaling is also one of the drivers for pathogenic class switching and is consistent with immunological features identified from clinical samples. This study unveiled a characteristic immune state silencing autoreactive B cells in mice.

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Autoinducer Analogs Can Provide Bactericidal Activity to Macrolides in Pseudomonas aeruginosa through Antibiotic Tolerance Reduction.

Mizuki Abe, Keiji Murakami, Yuka Hiroshima, Takashi Amoh, Mayu Sebe, Keiko Kataoka, Hideki Fujii

Antibiotics (Basel, Switzerland) (Antibiotics) 11 ( 1 ) 2022.01

Research paper (scientific journal), Joint Work, Accepted

Macrolide antibiotics are used in treating Pseudomonas aeruginosa chronic biofilm infections despite their unsatisfactory antibacterial activity, because they display several special activities, such as modulation of the bacterial quorum sensing and immunomodulatory effects on the host. In this study, we investigated the effects of the newly synthesized P. aeruginosa quorum-sensing autoinducer analogs (AIA-1, -2) on the activity of azithromycin and clarithromycin against P. aeruginosa. In the killing assay of planktonic cells, AIA-1 and -2 enhanced the bactericidal ability of macrolides against P. aeruginosa PAO1; however, they did not affect the minimum inhibitory concentrations of macrolides. In addition, AIA-1 and -2 considerably improved the killing activity of azithromycin and clarithromycin in biofilm cells. The results indicated that AIA-1 and -2 could affect antibiotic tolerance. Moreover, the results of hydrocarbon adherence and cell membrane permeability assays suggested that AIA-1 and -2 changed bacterial cell surface hydrophobicity and accelerated the outer membrane permeability of the hydrophobic antibiotics such as azithromycin and clarithromycin. Our study demonstrated that the new combination therapy of macrolides and AIA-1 and -2 may improve the therapeutic efficacy of macrolides in the treatment of chronic P. aeruginosa biofilm infections.

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Optimizing antiemetic treatment for chemotherapy-induced nausea and vomiting in Japan: Update summary of the 2015 Japan Society of Clinical Oncology Clinical Practice Guidelines for Antiemesis.

Aogi K, Takeuchi H, Saeki T, Aiba K, Tamura K, Iino K, Imamura CK, Okita K, Kagami Y, Tanaka R, Nakagawa K, Fujii H, Boku N, Wada M, Akechi T, Iihara H, Ohtani S, Okuyama A, Ozawa K, Kim YI, Sasaki H, Shima Y, Takeda M, Nagasaki E, Nishidate T, Higashi T, Hirata K

International journal of clinical oncology 26 ( 1 ) 1 - 17 2021.01

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 1341-9625

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Clinical Significance of Carbapenem-Tolerant Pseudomonas aeruginosa Isolated in the Respiratory Tract.

Momoyo Azuma, Keiji Murakami, Rina Murata, Keiko Kataoka, Hideki Fujii, Yoichiro Miyake, Yasuhiko Nishioka

Antibiotics (Basel, Switzerland) 9 ( 9 ) 2020.09

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted

We often come across difficult to treat infections-even after administering appropriate antibiotics according to the minimal inhibitory concentration of the causative bacteria. Antibiotic tolerance has recently started to garner attention as a crucial mechanism of refractory infections. However, few studies have reported the correlation between clinical outcomes and antibiotic tolerance. This study aims to clarify the effect of antibiotic tolerance on clinical outcomes of respiratory tract infection caused by Pseudomonas aeuginosa (P. aeruginosa). We examined a total of 63 strains isolated from sputum samples of different patients and conducted a retrospective survey with the medical records of 37 patients with imipenem-sensitive P. aeruginosa infections. Among them, we selected 15 patients with respiratory infections, and they were divided into high-tolerance minimal bactericidal concentration for adherent bacteria (MBCAD)/minimal inhibitory concentration for adherent bacteria (MICAD) ≥ 32 (n = 9) group and low-tolerance MBCAD/MICAD ≤ 16 (n = 6) group for further investigations. The findings indicated that the high-tolerance group consisted of many cases requiring hospitalization. Chest computed tomography findings showed that the disease was more extensive in the high-tolerance group compared to the low-tolerance group. Regarding the bacterial phenotypic characterization, the high-tolerance group significantly upregulated the production of the virulence factors compared to the low-tolerance group. Our study provided evidence that carbapenem tolerance level is a potent prognostic marker of P. aeruginosa infections, and carbapenem tolerance could be a potential target for new antimicrobial agents to inhibit the progression of persistent P. aeruginosa infections.

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Suppressive effects of 2-methacryloyloxyethyl phosphorylcholine (MPC)-polymer on the adherence of Candida species and MRSA to acrylic denture resin.

Natsumi Fujiwara, Keiji Murakami, Kaya Yoshida, Shunsuke Sakurai, Yasusei Kudo, Kazumi Ozaki, Katsuhiko Hirota, Hideki Fujii, Maiko Suzuki, Yoichiro Miyake, Hiromichi Yumoto

Heliyon 6 ( 6 ) e04211 2020.06

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted

OBJECTIVES: The effects of 2-methacryloyloxyethyl phosphorylcholine (MPC)-polymer on the adherence of microorganisms such as non-Candida albicans Candida (NCAC) and methicillin-resistant Staphylococcus aureus (MRSA), frequently detected in oral infections in immunocompromised and/or elderly people, to denture resin material, are still unclear. Here, we report the effects of MPC-polymer on the adherence of C. albicans, NCAC, and MRSA to acrylic denture resin. METHODS: Sixteen strains of C. albicans, seven strains of C. glabrata, two strains of C. tropicalis, one strain of C. parapsilosis, and six strains of MRSA were used. We cultured the fungal/bacterial strains and examined the cell growth and adherence of fungi/bacteria to mucin-coated acrylic denture resin plates (ADRP) with or without MPC-polymer coating, by scanning electron microscopy. The cell surface hydrophobicity of the fungal/bacterial strains was measured by the adsorption to hydrocarbons. RESULTS: MPC-polymer did not affect the growth of all strains of Candida species and MRSA, but significantly suppressed adherence to ADRP in most strains of C. albicans and all strains of NCAC and MRSA. A significant positive correlation was found between cell hydrophobicity and the reduction rates of microbial adherence to ADRP treated with 5% of MPC-polymer. CONCLUSIONS: MPC-polymer treatment for acrylic resin material suppresses the adherence of C. albicans, NCAC and MRSA via their hydrophilicity interaction. CLINICAL SIGNIFICANCE: The application of MPC-polymer for denture hygiene is potent to prevent oral candidiasis, denture stomatitis and opportunistic infection, caused by Candida species and MRSA, via suppressing the adherence of those fungus/bacteria.

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The Pathogenic Factors from Oral Streptococci for Systemic Diseases.

Hiromichi Yumoto, Katsuhiko Hirota, Kouji Hirao, Masami Ninomiya, Keiji Murakami, Hideki Fujii, Yoichiro Miyake

International journal of molecular sciences 20 ( 18 ) 2019.09

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted

The oral cavity is suggested as the reservoir of bacterial infection, and the oral and pharyngeal biofilms formed by oral bacterial flora, which is comprised of over 700 microbial species, have been found to be associated with systemic conditions. Almost all oral microorganisms are non-pathogenic opportunistic commensals to maintain oral health condition and defend against pathogenic microorganisms. However, oral Streptococci, the first microorganisms to colonize oral surfaces and the dominant microorganisms in the human mouth, has recently gained attention as the pathogens of various systemic diseases, such as infective endocarditis, purulent infections, brain hemorrhage, intestinal inflammation, and autoimmune diseases, as well as bacteremia. As pathogenic factors from oral Streptococci, extracellular polymeric substances, toxins, proteins and nucleic acids as well as vesicles, which secrete these components outside of bacterial cells in biofilm, have been reported. Therefore, it is necessary to consider that the relevance of these pathogenic factors to systemic diseases and also vaccine candidates to protect infectious diseases caused by Streptococci. This review article focuses on the mechanistic links among pathogenic factors from oral Streptococci, inflammation, and systemic diseases to provide the current understanding of oral biofilm infections based on biofilm and widespread systemic diseases.

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Obesity worsens the outcome of influenza virus infection associated with impaired type I interferon induction in mice.

Ho Namkoong, Makoto Ishii, Hideki Fujii, Takahiro Asami, Kazuma Yagi, Shoji Suzuki, Shuhei Azekawa, Sadatomo Tasaka, Naoki Hasegawa, Tomoko Betsuyaku

Biochemical and biophysical research communications 513 ( 2 ) 405 - 411 2019.05

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted

Increasing evidence indicates that obesity is a risk factor for increased severity of influenza virus infection. However, its precise immunological mechanism is not fully understood. To investigate this, diet-induced obese (DIO) mice were established by feeding C57BL/6 male mice a high-fat diet for 16 weeks. DIO and lean control mice were infected intranasally with 3000 pfu of influenza A virus (IAV) (PR8/H1N1). Interestingly, we found adipose tissue located along the bronchus in naïve DIO mice. In addition, the Nos2 level was significantly higher and Arg1 level was significantly lower in lung macrophages of naïve DIO mice, consistent with an M1-skewed phenotype. The survival rate and body weight of DIO mice infected with IAV were significantly lower than those of lean control mice and associated with higher viral load in the lungs of DIO mice. Histopathological analysis demonstrated higher numbers of inflammatory cells in the lungs of DIO mice after IAV infection. Levels of cytokines, including TNF-α, IL-6, IL-10, and type I IFN (IFN-α and IFN-β), in bronchoalveolar lavage fluid (BALF) were altered after IAV infection; in particular, IFN-α and IFN-β levels were significantly suppressed in the BALF of DIO mice. In vitro, bone marrow-derived macrophages were stimulated with ligands of toll-like receptor (TLR) 7/8, a pattern recognition receptor for single-stranded RNA, and levels of TNF-α, IL-6, and IL-10 were similarly altered. In addition, levels of IFN-α and IFN-β were significantly lower in culture supernatants of alveolar macrophages sorted from naïve DIO mice and infected with IAV, compared to those in macrophages sorted from lean control mice. Collectively, these results suggest that macrophages may be the main contributors to poor outcomes of influenza virus infection in obesity.

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Clarithromycin expands CD11b+Gr-1+ cells via the STAT3/Bv8 axis to ameliorate lethal endotoxic shock and post-influenza bacterial pneumonia.

Ho Namkoong, Makoto Ishii, Hideki Fujii, Kazuma Yagi, Takahiro Asami, Takanori Asakura, Shoji Suzuki, Ahmed E Hegab, Hirofumi Kamata, Sadatomo Tasaka, Koji Atarashi, Nobuhiro Nakamoto, Satoshi Iwata, Kenya Honda, Takanori Kanai, Naoki Hasegawa, Shigeo Koyasu, Tomoko Betsuyaku

PLoS pathogens 14 ( 4 ) e1006955 2018.04

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted

Macrolides are used to treat various inflammatory diseases owing to their immunomodulatory properties; however, little is known about their precise mechanism of action. In this study, we investigated the functional significance of the expansion of myeloid-derived suppressor cell (MDSC)-like CD11b+Gr-1+ cells in response to the macrolide antibiotic clarithromycin (CAM) in mouse models of shock and post-influenza pneumococcal pneumonia as well as in humans. Intraperitoneal administration of CAM markedly expanded splenic and lung CD11b+Gr-1+ cell populations in naïve mice. Notably, CAM pretreatment enhanced survival in a mouse model of lipopolysaccharide (LPS)-induced shock. In addition, adoptive transfer of CAM-treated CD11b+Gr-1+ cells protected mice against LPS-induced lethality via increased IL-10 expression. CAM also improved survival in post-influenza, CAM-resistant pneumococcal pneumonia, with improved lung pathology as well as decreased interferon (IFN)-γ and increased IL-10 levels. Adoptive transfer of CAM-treated CD11b+Gr-1+ cells protected mice from post-influenza pneumococcal pneumonia. Further analysis revealed that the CAM-induced CD11b+Gr-1+ cell expansion was dependent on STAT3-mediated Bv8 production and may be facilitated by the presence of gut commensal microbiota. Lastly, an analysis of peripheral blood obtained from healthy volunteers following oral CAM administration showed a trend toward the expansion of human MDSC-like cells (Lineage-HLA-DR-CD11b+CD33+) with increased arginase 1 mRNA expression. Thus, CAM promoted the expansion of a unique population of immunosuppressive CD11b+Gr-1+ cells essential for the immunomodulatory properties of macrolides.

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Antibiofilm and Anti-Inflammatory Activities of Houttuynia cordata Decoction for Oral Care.

Yasuko Sekita, Keiji Murakami, Hiromichi Yumoto, Kouji Hirao, Takashi Amoh, Natsumi Fujiwara, Katsuhiko Hirota, Hideki Fujii, Takashi Matsuo, Yoichiro Miyake, Yoshiki Kashiwada

Evidence-based complementary and alternative medicine : eCAM 2017 2850947 - 2850947 2017

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted

Dental biofilms that form in the oral cavity play a critical role in the pathogenesis of several infectious oral diseases, including dental caries, periodontal disease, and oral candidiasis. Houttuynia cordata (HC, Saururaceae) is a widely used traditional medicine, for both internal and external application. A decoction of dried HC leaves (dHC) has long been consumed as a health-promoting herbal tea in Japan. We have recently reported that a water solution of HC poultice ethanol extract (wHCP) exerts antimicrobial and antibiofilm effects against several important oral pathogens. It also exhibits anti-inflammatory effects on human keratinocytes. In our current study, we examined the effects of dHC on infectious oral pathogens and inflammation. Our results demonstrated that dHC exerts moderate antimicrobial effects against methicillin-resistant Staphylococcus aureus (MRSA) and other oral microorganisms. dHC also exhibited antibiofilm effects against MRSA, Fusobacterium nucleatum (involved in dental plaque formation), and Candida albicans and inhibitory effects on interleukin-8, CCL20, IP-10, and GROα productions by human oral keratinocytes stimulated by Porphyromonas gingivalis lipopolysaccharide (a cause of periodontal disease), without cytotoxic effects. This suggests that dHC exhibits multiple activities in microorganisms and host cells. dHC can be easily prepared and may be effective in preventing infectious oral diseases.

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Corrigendum to 'Phagocytic cells contribute to the antibody-mediated elimination of pulmonary-infected SARS coronavirus' [Virology (2014) 157-168].

Fumihiko Yasui, Michinori Kohara, Masahiro Kitabatake, Tetsu Nishiwaki, Hideki Fujii, Chise Tateno, Misako Yoneda, Kouichi Morita, Kouji Matsushima, Shigeo Koyasu, Chieko Kai

Virology (ACADEMIC PRESS INC ELSEVIER SCIENCE BV) 499: 397 - 398 2016.12

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 0042-6822

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Histone Deacetylase Inhibition Protects Mice Against Lethal Postinfluenza Pneumococcal Infection.

Kazuma Yagi, Makoto Ishii, Ho Namkoong, Hideki Fujii, Takahiro Asami, Shoji Suzuki, Takanori Asakura, Kosuke Mizoguchi, Tetsuro Kamo, Sadatomo Tasaka, Satoshi Iwata, Steven L Kunkel, Naoki Hasegawa, Tomoko Betsuyaku

Critical care medicine 44 ( 10 ) e980-7 2016.10

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted

OBJECTIVES: Secondary bacterial pneumonia following influenza virus infection is associated with high mortality, but the mechanism is largely unknown. Epigenetic gene regulation appears to play key roles in innate and adaptive immunity. We hypothesized that histone acetylation, a major epigenetic mechanism associated with transcriptionally active chromatin, might contribute to the poor outcome of postinfluenza pneumonia. DESIGN: Prospective experimental study. SETTING: University research laboratory. SUBJECTS: C57BL/6 male mice. INTERVENTIONS: Mice were infected intranasally with 1.0 × 10 colony-forming units of Streptococcus pneumoniae, 7 days after intranasal inoculation with five plaque-forming units of influenza virus A/H1N1/PR8/34. The mice were intraperitoneally injected with the histone deacetylase inhibitor trichostatin A (1 mg/kg) or vehicle once a day from 1 hour after pneumococcal infection throughout the course of the experiment. The primary outcome was survival rate. MEASUREMENTS AND MAIN RESULTS: Trichostatin A significantly suppressed histone deacetylase activity and significantly improved the survival rate of mice (56.3%) after postinfluenza pneumococcal infection when compared with vehicle-treated mice (20.0%), which was associated with a significant decrease in the total cell count of the bronchoalveolar lavage fluid. The interleukin-1β level in the serum and the number of natural killer cells in the lungs were significantly lower in the trichostatin A-treated group. CONCLUSIONS: The histone deacetylase inhibitor trichostatin A protects mice against postinfluenza pneumonia possibly through multiple factors, including decreasing local cell recruitment into the lungs and suppressing systemic inflammation.

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Heat Shock Enhances the Expression of the Human T Cell Leukemia Virus Type-I (HTLV-I) Trans-Activator (Tax) Antigen in Human HTLV-I Infected Primary and Cultured T Cells.

Marie Kunihiro, Hideki Fujii, Takuya Miyagi, Yoshiaki Takahashi, Reiko Tanaka, Takuya Fukushima, Aftab A Ansari, Yuetsu Tanaka

Viruses 8 ( 7 ) 2016.07

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted

The environmental factors that lead to the reactivation of human T cell leukemia virus type-1 (HTLV-I) in latently infected T cells in vivo remain unknown. It has been previously shown that heat shock (HS) is a potent inducer of HTLV-I viral protein expression in long-term cultured cell lines. However, the precise HTLV-I protein(s) and mechanisms by which HS induces its effect remain ill-defined. We initiated these studies by first monitoring the levels of the trans-activator (Tax) protein induced by exposure of the HTLV-I infected cell line to HS. HS treatment at 43 °C for 30 min for 24 h led to marked increases in the level of Tax antigen expression in all HTLV-I-infected T cell lines tested including a number of HTLV-I-naturally infected T cell lines. HS also increased the expression of functional HTLV-I envelope gp46 antigen, as shown by increased syncytium formation activity. Interestingly, the enhancing effect of HS was partially inhibited by the addition of the heat shock protein 70 (HSP70)-inhibitor pifithlin-μ (PFT). In contrast, the HSP 70-inducer zerumbone (ZER) enhanced Tax expression in the absence of HS. These data suggest that HSP 70 is at least partially involved in HS-mediated stimulation of Tax expression. As expected, HS resulted in enhanced expression of the Tax-inducible host antigens, such as CD83 and OX40. Finally, we confirmed that HS enhanced the levels of Tax and gp46 antigen expression in primary human CD4⁺ T cells isolated from HTLV-I-infected humanized NOD/SCID/γc null (NOG) mice and HTLV-I carriers. In summary, the data presented herein indicate that HS is one of the environmental factors involved in the reactivation of HTLV-I in vivo via enhanced Tax expression, which may favor HTLV-I expansion in vivo.

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A Potential of an Anti-HTLV-I gp46 Neutralizing Monoclonal Antibody (LAT-27) for Passive Immunization against Both Horizontal and Mother-to-Child Vertical Infection with Human T Cell Leukemia Virus Type-I.

Hideki Fujii, Mamoru Shimizu, Takuya Miyagi, Marie Kunihiro, Reiko Tanaka, Yoshiaki Takahashi, Yuetsu Tanaka

Viruses 8 ( 2 ) 2016.02

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted

Although the number of human T-cell leukemia virus type-I (HTLV-I)-infected individuals in the world has been estimated at over 10 million, no prophylaxis vaccines against HTLV-I infection are available. In this study, we took a new approach for establishing the basis of protective vaccines against HTLV-I. We show here the potential of a passively administered HTLV-I neutralizing monoclonal antibody of rat origin (LAT-27) that recognizes epitopes consisting of the HTLV-I gp46 amino acids 191-196. LAT-27 completely blocked HTLV-I infection in vitro at a minimum concentration of 5 μg/mL. Neonatal rats born to mother rats pre-infused with LAT-27 were shown to have acquired a large quantity of LAT-27, and these newborns showed complete resistance against intraperitoneal infection with HTLV-I. On the other hand, when humanized immunodeficient mice were pre-infused intravenously with humanized LAT-27 (hu-LAT-27), all the mice completely resisted HTLV-I infection. These results indicate that hu-LAT-27 may have a potential for passive immunization against both horizontal and mother-to-child vertical infection with HTLV-I.

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Osteoprotegerin Regulates Pancreatic β-Cell Homeostasis upon Microbial Invasion.

Yukiko Kuroda, Kenta Maruyama, Hideki Fujii, Isamu Sugawara, Shigeru B H Ko, Hisataka Yasuda, Hidenori Matsui, Koichi Matsuo

PloS one 11 ( 1 ) e0146544 2016

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted

Osteoprotegerin (OPG), a decoy receptor for receptor activator of NF-κB ligand (RANKL), antagonizes RANKL's osteoclastogenic function in bone. We previously demonstrated that systemic administration of lipopolysaccharide (LPS) to mice elevates OPG levels and reduces RANKL levels in peripheral blood. Here, we show that mice infected with Salmonella, Staphylococcus, Mycobacteria or influenza virus also show elevated serum OPG levels. We then asked whether OPG upregulation following microbial invasion had an effect outside of bone. To do so, we treated mice with LPS and observed OPG production in pancreas, especially in β-cells of pancreatic islets. Insulin release following LPS administration was enhanced in mice lacking OPG, suggesting that OPG inhibits insulin secretion under acute inflammatory conditions. Consistently, treatment of MIN6 pancreatic β-cells with OPG decreased their insulin secretion following glucose stimulation in the presence of LPS. Finally, our findings suggest that LPS-induced OPG upregulation is mediated in part by activator protein (AP)-1 family transcription factors, particularly Fos proteins. Overall, we report that acute microbial infection elevates serum OPG, which maintains β-cell homeostasis by restricting glucose-stimulated insulin secretion, possibly preventing microbe-induced exhaustion of β-cell secretory capacity.

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Human T-cell leukemia virus type-I Tax induces the expression of CD83 on T cells

Yuetsu Tanaka, Mariko Mizuguchi, Yoshiaki Takahashi, Hideki Fujii, Reiko Tanaka, Takuya Fukushima, Takeaki Tomoyose, Aftab A. Ansari, Masataka Nakamura

RETROVIROLOGY (BIOMED CENTRAL LTD) 12 56 2015.07

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 1742-4690

Background: CD83, a cell surface glycoprotein that is stably expressed on mature dendritic cells, can be transiently induced on other hematopoietic cell lineages upon cell activation. In contrast to the membrane form of CD83, soluble CD83 appears to be immunosuppressive. In an analysis of the phenotype of leukemic CD4(+) T cells from patients with adult T-cell leukemia (ATL), we found that a number of primary CD4(+) T cells became positive for cell surface CD83 after short-term culture, and that most of these CD83(+) CD4(+) T cells were positive for human T-cell leukemia virus type-I (HTLV-I) Tax (Tax1). We hypothesized that Tax1 is involved in the induction of CD83.
Result: We found that CD83 was expressed selectively on Tax1-expressing human CD4(+) T cells in short-term cultured peripheral blood mononuclear cells (PBMCs) isolated from HTLV-I+ donors, including ATL patients and HTLV-I carriers. HTLV-I-infected T cell lines expressing Tax1 also expressed cell surface CD83 and released soluble CD83. CD83 can be expressed in the JPX-9 cell line by cadmium-mediated Tax1 induction and in Jurkat cells or PBMCs by Tax1 introduction via infection with a recombinant adenovirus carrying the Tax1 gene. The CD83 promoter was activated by Tax1 in an NF-kappa B-dependent manner. Based on a previous report showing soluble CD83-mediated prostaglandin E2 (PGE2) production from human monocytes in vitro, we tested if PGE2 affected HTLV-I propagation, and found that PGE2 strongly stimulated expression of Tax1 and viral structural molecules.
Conclusions: Our results suggest that HTLV-I induces CD83 expression on T cells via Tax1 -mediated NF-kappa B activation, which may promote HTLV-I infection in vivo.

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The neutralizing function of the anti-HTLV-1 antibody is essential in preventing in vivo transmission of HTLV-1 to human T cells in NOD-SCID/γcnull (NOG) mice.

Mineki Saito, Reiko Tanaka, Hideki Fujii, Akira Kodama, Yoshiaki Takahashi, Toshio Matsuzaki, Hiroshi Takashima, Yuetsu Tanaka

Retrovirology 11 74 - 74 2014.08

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted

BACKGROUND: Human T-cell leukemia virus type 1 (HTLV-1) causes both neoplastic and inflammatory diseases, including adult T-cell leukemia and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Because these life-threatening and disabling diseases are not yet curable, it is important to prevent new HTLV-1 infections. FINDINGS: In this study, we have established a simple humanized mouse model of HTLV-1 infection for evaluating prophylactic and therapeutic interventions. In this model, HTLV-1-negative normal human peripheral blood mononuclear cells (PBMCs) are transplanted directly into the spleens of severely immunodeficient NOD-SCID/γcnull (NOG) mice, together with mitomycin-treated HTLV-1-producing T cells. Using this model, we tested the efficacy of monoclonal antibodies (mAbs) specific to HTLV-1 as well as human IgG isolated from HAM/TSP patients (HAM-IgG) in preventing HTLV-1-infection. One hour before and 24 h after transplantation of the human cells, each antibody sample was inoculated intraperitoneally. On day 14, human PBMCs isolated from the mouse spleens were tested for HTLV-1 infection. Whereas fresh CD4-positive and CD8-positive T cells isolated from untreated mice or mice treated with isotype control mAb, HTLV-1 non-neutralizing mAbs to envelope gp46, gag p19, and normal human IgG were all infected with HTLV-1; the mice treated with either HTLV-1 neutralizing anti-gp46 mAb or HAM-IgG did not become infected. CONCLUSIONS: Our data indicate that the neutralizing function of the antibody, but not the antigen specificity, is essential for preventing the in vivo transmission of HTLV-1. The present animal model will also be useful for the in vivo evaluation of the efficacy of candidate molecules to be used as prophylactic and therapeutic intervention against HTLV-1 infection.

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Elimination of Human T Cell Leukemia Virus Type-1-Infected Cells by Neutralizing and Antibody-Dependent Cellular Cytotoxicity-Inducing Antibodies Against Human T Cell Leukemia Virus Type-1 Envelope gp46

Yuetsu Tanaka, Yoshiaki Takahashi, Reiko Tanaka, Akira Kodama, Hideki Fujii, Atsuhiko Hasegawa, Mari Kannagi, Aftab A. Ansari, Mineki Saito

AIDS RESEARCH AND HUMAN RETROVIRUSES (MARY ANN LIEBERT, INC) 30 ( 6 ) 542 - 552 2014.06

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 0889-2229

Human T cell leukemia virus type-1 (HTLV-1) is prevalent worldwide with foci of high prevalence. However, to date no effective vaccine or drug against HTLV-1 infection has been developed. In efforts to define the role of antibodies in the control of HTLV-1 infection, we capitalized on the use of our previously defined anti-gp46 neutralizing monoclonal antibody (mAb) (clone LAT-27) and high titers of human anti-HTLV-1 IgG purified from HAM/TSP patients (HAM-IgG). LAT-27 and HAM-IgG completely blocked syncytium formation and T cell immortalization mediated by HTLV-1 in vitro. The addition of these antibodies to cultures of CD8(+) T cell-depleted peripheral blood mononuclear cells (PBMCs) from HAM/TSP patients at the initiation of culture not only decreased the numbers of Tax-expressing cells and the production of HTLV-1 p24 but also inhibited the spontaneous immortalization of T cells. Coculture of in vitro-HTLV-1-immortalized T cell lines with autologous PBMCs in the presence of LAT-27 or HAM-IgG, but not an F(ab) 2 fragment of LAT-27 or non-neutralizing anti-gp46 mAbs, resulted in depletion of HTLV-1-infected cells. A 24-h Cr-51 release assay showed the presence of significant antibody-dependent cellular cytotoxicity (ADCC) activity in LAT-27 and HAM-IgG, but not F(ab) 2 of LAT-27, resulting in the depletion of HTLV-1-infected T cells by autologous PBMCs. The depletion of natural killer (NK) cells from the effector PBMCs reduced this ADCC activity. Altogether, the present data demonstrate that the neutralizing and ADCC-inducing activities of anti-HTLV-1 antibodies are capable of reducing infection and eliminating HTLV-1-infected cells in the presence of autologous PBMCs.

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Phagocytic cells contribute to the antibody-mediated elimination of pulmonary-infected SARS coronavirus.

Fumihiko Yasui, Michinori Kohara, Masahiro Kitabatake, Tetsu Nishiwaki, Hideki Fujii, Chise Tateno, Misako Yoneda, Kouichi Morita, Kouji Matsushima, Shigeo Koyasu, Chieko Kai

Virology (ACADEMIC PRESS INC ELSEVIER SCIENCE BV) 454-455: 157 - 68 2014.03

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted

While the 2002-2003 outbreak of severe acute respiratory syndrome (SARS) resulted in 774 deaths, patients who were affected with mild pulmonary symptoms successfully recovered. The objective of the present work was to identify, using SARS coronavirus (SARS-CoV) mouse infection models, immune factors responsible for clearing of the virus. The elimination of pulmonary SARS-CoV infection required the activation of B cells by CD4(+) T cells. Furthermore, passive immunization (post-infection) with homologous (murine) anti-SARS-CoV antiserum showed greater elimination efficacy against SARS-CoV than that with heterologous (rabbit) antiserum, despite the use of equivalent titers of neutralizing antibodies. This distinction was mediated by mouse phagocytic cells (monocyte-derived infiltrating macrophages and partially alveolar macrophages, but not neutrophils), as demonstrated both by adoptive transfer from donors and by immunological depletion of selected cell types. These results indicate that the cooperation of anti-SARS-CoV antibodies and phagocytic cells plays an important role in the elimination of SARS-CoV.

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Influenza A whole virion vaccine induces a rapid reduction of peripheral blood leukocytes via interferon-α-dependent apoptosis.

Manabu Ato, Yoshimasa Takahashi, Hideki Fujii, Shu-ichi Hashimoto, Tomohiro Kaji, Shigeyuki Itamura, Yoshinobu Horiuchi, Yoshichika Arakawa, Masato Tashiro, Toshitada Takemori

Vaccine 31 ( 17 ) 2184 - 90 2013.04

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted

Infection with single strand RNA (ssRNA) viruses, such as influenza A virus, is known to induce protective acquired immune responses, including the production of neutralizing antibodies. Vaccination also causes a reduction in the number of peripheral blood leukocytes (PBL) shortly after inoculation, a result which may have undesirable adverse effects. The cellular mechanisms for this response have not been elucidated so far. Here we report that formalin-inactivated influenza A whole virus vaccine (whole virion) induces a significant decrease in PBL in mice 5-16 h after administration, whereas an ether-split vaccine (HA split) made from the same influenza virus strain does not induce a similar loss of PBL. Concordant with this reduction in the number of PBL, a rapidly induced and massive production of interferon (IFN)-α is observed when mice are injected with whole virion, but not with HA split vaccines. The role of Toll-like receptors (TLR), which are involved in signal transduction of influenza virus, and the subsequent induction of IFNα were confirmed using mice lacking TLR7, MyD-88, or IFNα/β receptor. We further demonstrated that the observed PBL loss is caused by apoptosis in an IFNα-dependent manner, and not by leukocyte redistribution due to chemokine signaling failure. These findings indicate that RNA-encapsulated whole virion vaccines can rapidly induce a loss of leukocytes from peripheral blood by apoptosis, which may modulate the subsequent immune response.

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Modulation of murine macrophage TLR7/8-mediated cytokine expression by mesenchymal stem cell-conditioned medium.

Takahiro Asami, Makoto Ishii, Hideki Fujii, Ho Namkoong, Sadatomo Tasaka, Kenichi Matsushita, Ken Ishii, Kazuma Yagi, Hiroshi Fujiwara, Yohei Funatsu, Naoki Hasegawa, Tomoko Betsuyaku

Mediators of inflammation 2013 264260 - 264260 2013

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted

Increasing evidence suggests that mesenchymal stem cells (MSCs) play anti-inflammatory roles during innate immune responses. However, little is known about the effect of MSCs or their secretions on the ligand response of Toll-like receptor (TLR) 7 and TLR8, receptors that recognize viral single-stranded RNA (ssRNA). Macrophages play a critical role in the innate immune response to ssRNA virus infection; therefore, we investigated the effect of MSC-conditioned medium on cytokine expression in macrophages following stimulation with TLR7/8 ligands. After stimulation with TLR7/8 ligand, bone marrow-derived macrophages cultured with MSCs or in MSC-conditioned medium expressed lower levels of tumor necrosis factor (TNF) α and interleukin (IL) 6 and higher levels of IL-10 compared to macrophages cultured without MSCs or in control medium, respectively. The modulations of cytokine expression were associated with prostaglandin E2 (PGE2) secreted by the MSCs. PGE2 enhanced extracellular signal-related kinase (ERK) signaling and suppressed nuclear factor- κ B (NF- κ B) signaling. Enhanced ERK signaling contributed to enhanced IL-10 production, and suppression of NF- κ B signaling contributed to the low production of TNF- α . Collectively, these results indicate that MSCs and MSC-conditioned medium modulate the cytokine expression profile in macrophages following TLR7/8-mediated stimulation, which suggests that MSCs play an immunomodulatory role during ssRNA virus infection.

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Cutting edge: mTORC1 in intestinal CD11c+ CD11b+ dendritic cells regulates intestinal homeostasis by promoting IL-10 production.

Masashi Ohtani, Takayuki Hoshii, Hideki Fujii, Shigeo Koyasu, Atsushi Hirao, Satoshi Matsuda

Journal of immunology (Baltimore, Md. : 1950) 188 ( 10 ) 4736 - 40 2012.05

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted

The mammalian target of rapamycin (mTOR) controls cell growth and survival through two distinct complexes called mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). Although several reports have suggested the involvement of mTORC1 in development and function of dendritic cells (DCs), its physiological roles remain obscure. We therefore established mTORC1 signal-deficient mice lacking Raptor, an essential component of mTORC1 signal, specifically in DC lineage (referred to here as Raptor(DC-/-)). Raptor(DC-/-) mice exhibited cell expansion in specific subsets of DCs such as splenic CD8(+) DCs and intestinal CD11c(+)CD11b(+) DCs. We also found that impaired mTORC1 signal resulted in the suppression of IL-10 production along with enhanced CD86 expression in intestinal CD11c(+)CD11b(+) DCs and that Raptor(DC-/-) mice were highly susceptible to dextran sodium sulfate-induced colitis. Our results uncover mTORC1-mediated anti-inflammatory programs in intestinal CD11c(+)CD11b(+) DCs to limit the intestinal inflammation.

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Desmoglein 3-specific CD4(+) T cells induce pemphigus vulgaris and interface dermatitis in mice.

Hayato Takahashi, Michiyoshi Kouno, Keisuke Nagao, Naoko Wada, Tsuyoshi Hata, Shuhei Nishimoto, Yoichiro Iwakura, Akihiko Yoshimura, Taketo Yamada, Masataka Kuwana, Hideki Fujii, Shigeo Koyasu, Masayuki Amagai

Journal of Clinical Investigation (AMER SOC CLINICAL INVESTIGATION INC) 121 ( 9 ) 3677 - 3688 2011.08

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 0021-9738

Pemphigus vulgaris (PV) is a severe autoimmune disease involving blistering of the skin and mucous membranes. It is caused by autoantibodies against desmoglein 3 (Dsg3), an adhesion molecule critical for maintaining epithelial integrity in the skin, oral mucosa, and esophagus. Knowing the antigen targeted by the autoantibodies renders PV a valuable model of autoimmunity. Recently, a role for Dsg3-specific CD4(+) T helper cells in autoantibody production was demonstrated in a mouse model of PV, but whether these cells exert cytotoxicity in the tissues is unclear. Here, we analyzed 3 Dsg3-specific TCRs using transgenic mice and retrovirus induction. Dsg3-specific transgenic (Dsg3H1) T cells underwent deletion in the presence of Dsg3 in vivo. Dsg3H1 T cells that developed in the absence of Dsg3 elicited a severe pemphigus-like phenotype when cotransferred into immunodeficient mice with B cells from Dsg3(-/-) mice. Strikingly, in addition to humoral responses, T cell infiltration of Dsg3-expressing tissues led to interface dermatitis, a distinct form of T cell-mediated autoimmunity that causes keratinocyte apoptosis and is seen in various inflammatory/autoimmune skin diseases, including paraneoplastic pemphigus. The use of retrovirally generated Dsg3-specific T cells revealed that interface dermatitis occurred in an IFN-γ- and TCR avidity-dependent manner. This model of autoimmunity demonstrates that T cells specific for a physiological skin-associated autoantigen are capable of inducing interface dermatitis and should provide a valuable tool for further exploring the immunopathophysiology of T cell-mediated skin diseases.

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HIV-1 Nef impairs multiple T-cell functions in antigen-specific immune response in mice.

Hideki Fujii, Manabu Ato, Yoshimasa Takahashi, Kaori Otake, Shu-ichi Hashimoto, Tomohiro Kaji, Yasuko Tsunetsugu-Yokota, Mikako Fujita, Akio Adachi, Toshinori Nakayama, Masaru Taniguchi, Shigeo Koyasu, Toshitada Takemori

International Immunology (OXFORD UNIV PRESS) 23 ( 7 ) 433 - 441 2011.06

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 0953-8178

The viral protein Nef is a key element for the progression of HIV disease. Previous in vitro studies suggested that Nef expression in T-cell lines enhanced TCR signaling pathways upon stimulation with TCR cross-linking, leading to the proposal that Nef lowers the threshold of T-cell activation, thus increasing susceptibility to viral replication in immune response. Likewise, the in vivo effects of Nef transgenic mouse models supported T-cell hyperresponse by Nef. However, the interpretation is complicated by Nef expression early in the development of T cells in these animal models. Here, we analyzed the consequence of Nef expression in ovalbumin-specific/CD4(+) peripheral T cells by using a novel mouse model and demonstrate that Nef inhibits antigen-specific T-cell proliferation and multiple functions required for immune response in vivo, which includes T-cell helper activity for the primary and memory B-cell response. However, Nef does not completely abrogate T-cell activity, as defined by low levels of cytokine production, which may afford the virus a replicative advantage. These results support a model, in which Nef expression does not cause T-cell hyperresponse in immune reaction, but instead reduces the T-cell activity, that may contribute to a low level of virus spread without viral cytopathic effects.

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Diet-induced adipose tissue inflammation and liver steatosis are prevented by DPP-4 inhibition in diabetic mice.

Jun Shirakawa, Hideki Fujii, Kei Ohnuma, Koichiro Sato, Yuzuru Ito, Mitsuyo Kaji, Eri Sakamoto, Megumi Koganei, Hajime Sasaki, Yoji Nagashima, Kikuko Amo, Kazutaka Aoki, Chikao Morimoto, Eiji Takeda, Yasuo Terauchi

Diabetes 60 ( 4 ) 1246 - 57 2011.04

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted

OBJECTIVE: Diet composition alters the metabolic states of adipocytes and hepatocytes in diabetes. The effects of dipeptidyl peptidase-4 (DPP-4) inhibition on adipose tissue inflammation and fatty liver have been obscure. We investigated the extrapancreatic effects of DPP-4 inhibition on visceral fat and the liver. RESEARCH DESIGN AND METHODS: We investigated diet-induced metabolic changes in β-cell-specific glucokinase haploinsufficient (Gck(+/-)) diabetic mice. We challenged animals with a diet containing a combination of sucrose and oleic acid (SO) or sucrose and linoleic acid (SL). Next, we assessed the effects of a DPP-4 inhibitor, des-fluoro-sitagliptin, on adipose tissue inflammation and hepatic steatosis. RESULTS: The epididymal fat weight and serum leptin level were significantly higher in Gck(+/-) mice fed SL than in mice fed SO, although no significant differences in body weight or adipocyte size were noted. Compared with SO, SL increased the numbers of CD11c(+) M1 macrophages and CD8(+) T-cells in visceral adipose tissue and the expression of E-selectin, P-selectin, and plasminogen activator inhibitor-1 (PAI-1). DPP-4 inhibition significantly prevented adipose tissue infiltration by CD8(+) T-cells and M1 macrophages and decreased the expression of PAI-1. The production of cytokines by activated T-cells was not affected by DPP-4 inhibition. Furthermore, DPP-4 inhibition prevented fatty liver in both wild-type and Gck(+/-) mice. DPP-4 inhibition also decreased the expressions of sterol regulatory element-binding protein-1c, stearoyl-CoA desaturase-1, and fatty acid synthase, and increased the expression of peroxisome proliferator-activated receptor-α in the liver. CONCLUSIONS: Our findings indicated that DPP-4 inhibition has extrapancreatic protective effects against diet-induced adipose tissue inflammation and hepatic steatosis.

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Langerhans cell antigen capture through tight junctions confers preemptive immunity in experimental staphylococcal scalded skin syndrome

Takeshi Ouchi, Akiharu Kubo, Mariko Yokouchi, Takeya Adachi, Tetsuro Kobayashi, Daniela Y. Kitashima, Hideki Fujii, Björn E. Clausen, Shigeo Koyasu, Masayuki Amagai, Keisuke Nagao

The Journal of Experimental Medicine (Rockefeller University Press) 208 ( 13 ) 2607 - 2613 2011

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 0022-1007

Epidermal Langerhans cells (LCs) extend dendrites through tight junctions (TJs) to survey the skin surface, but their immunological contribution in vivo remains elusive. We show that LCs were essential for inducing IgG(1) responses to patch-immunized ovalbumin in mice that lacked skin dendritic cell subsets. The significance of LC-induced humoral responses was demonstrated in a mouse model of staphylococcal scalded skin syndrome (SSSS), a severe blistering disease in which the desmosomal protein Dsg1 (desmoglein1) is cleaved by Staphylococcus aureus-derived exfoliative toxin (ET). Importantly, ET did not penetrate TJs, and patch immunization did not alter epidermal integrity. Nevertheless, neutralizing anti-ET IgG(1) was induced after patch immunization and abolished upon LC depletion, indicating that antigen capture through TJs by LCs induced humoral immunity. Strikingly, the ET-patched mice were protected from developing SSSS after intraperitoneal ET challenge, whereas LC-depleted mice were susceptible to SSSS, demonstrating a vital role for LC-induced IgG(1) in systemic defense against circulating toxin in vivo. Therefore, LCs elicit humoral immunity to antigens that have not yet violated the epidermal barrier, providing preemptive immunity against potentially pathogenic skin microbes. Targeting this immunological process confers protection with minimal invasiveness and should have a marked impact on future strategies for development of percutaneous vaccines.

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Thymoproteasome Shapes Immunocompetent Repertoire of CD8(+) T Cells

Takeshi Nitta, Shigeo Murata, Katsuhiro Sasaki, Hideki Fujii, Adiratna Mat Ripen, Naozumi Ishimaru, Shigeo Koyasu, Keiji Tanaka, Yousuke Takahama

IMMUNITY (CELL PRESS) 32 ( 1 ) 29 - 40 2010.01

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 1074-7613

How self-peptides displayed in the thymus contribute to the development of immunocompetent and self-protective T cells is largely unknown. In contrast, the role of thymic self-peptides in eliminating self-reactive T cells and thereby preventing autoimmunity is well established. A type of proteasome, termed thymoproteasome, is specifically expressed by thymic cortical epithelial cells (cTECs) and is required for the generation of optimal cellularity of CD8(+) T cells. Here, we show that cTECs displayed thymoproteasome-specific peptide-MHC class I complexes essential for the positive selection of major and diverse repertoire of MHC class I-restricted T cells. CD8(+) T cells generated in the absence of thymoproteasomes displayed a markedly altered T cell receptor repertoire that was defective in both allogeneic and antiviral responses. These results demonstrate that thymoproteasome-dependent self-peptide production is required for the development of an immunocompetent repertoire of CD8(+) T cells.

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Innate production of T(H)2 cytokines by adipose tissue-associated c-Kit(+)Sca-1(+) lymphoid cells.

Kazuyo Moro, Taketo Yamada, Masanobu Tanabe, Tsutomu Takeuchi, Tomokatsu Ikawa, Hiroshi Kawamoto, Jun-ichi Furusawa, Masashi Ohtani, Hideki Fujii, Shigeo Koyasu

Nature (NATURE PUBLISHING GROUP) 463 ( 7280 ) 540 - 544 2009.12

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 0028-0836

Innate immune responses are important in combating various microbes during the early phases of infection. Natural killer (NK) cells are innate lymphocytes that, unlike T and B lymphocytes, do not express antigen receptors but rapidly exhibit cytotoxic activities against virus-infected cells and produce various cytokines(1,2). Here we report a new type of innate lymphocyte present in a novel lymphoid structure associated with adipose tissues in the peritoneal cavity. These cells do not express lineage (Lin) markers but do express c-Kit, Sca-1 (also known as Ly6a), IL7R and IL33R. Similar lymphoid clusters were found in both human and mouse mesentery and we term this tissue 'FALC' (fat-associated lymphoid cluster). FALC Lin(-)c-Kit(+)Sca-1(+) cells are distinct from lymphoid progenitors(3) and lymphoid tissue inducer cells(4). These cells proliferate in response to IL2 and produce large amounts of T(H)2 cytokines such as IL5, IL6 and IL13. IL5 and IL6 regulate B-cell antibody production and self-renewal of B1 cells(5-7). Indeed, FALC Lin(-)c-Kit(+)Sca-1(+) cells support the self-renewal of B1 cells and enhance IgA production. IL5 and IL13 mediate allergic inflammation and protection against helminth infection(8,9). After helminth infection and in response to IL33, FALC Lin(-)c-Kit(+)Sca-1(+) cells produce large amounts of IL13, which leads to goblet cell hyperplasia-a critical step for helminth expulsion. In mice devoid of FALC Lin(-)c-Kit(+)Sca-1(+) cells, such goblet cell hyperplasia was not induced. Thus, FALC Lin(-)c-Kit(+)Sca-1(+) cells are T(H)2-type innate lymphocytes, and we propose that these cells be called 'natural helper cells'.

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Critical roles of NK and CD8(+) T cells in central nervous system Listeriosis.

Toshiyuki Hayashi, Shigenori Nagai, Hideki Fujii, Yukiko Baba, Eiji Ikeda, Takeshi Kawase, Shigeo Koyasu

Journal of Immunology (AMER ASSOC IMMUNOLOGISTS) 182 ( 10 ) 6360 - 6368 2009.05

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 0022-1767

Listeria monocytogenes (LM) causes a life-threatening infectious disease affecting the brain of humans and domestic animals. Unfortunately, no adequate murine models for CNS listeriosis exist. Using intraparenchymal injection, we have established a new murine model for CNS listeriosis. Injection of a small volume of bacterial suspension limits the bacteria to the brain parenchyma with no leakage into the ventricular system. This new method enabled us to investigate the progression of and recovery from listerial brain infection, revealing roles for both innate and adaptive immune cells in CNS listeriosis. In the early phase of CNS listeriosis, INK cell-derived IFN-gamma is a critical cytokine in the limitation of bacterial growth by the host defense. During the later phase, CD8(+) but not CD4(+) T cells play a critical role and LM-specific CD8(+) T cells kill LM-infected microglia. Thus, innate and adaptive immune responses combine to successfully eliminate bacteria from the brain. The Journal of Immunology, 2009, 182: 6360-6368.

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PI3K is a negative regulator of IgE production.

Tomomitsu Doi, Kunie Obayashi, Takashi Kadowaki, Hideki Fujii, Shigeo Koyasu

International Immunology (OXFORD UNIV PRESS) 20 ( 4 ) 499 - 508 2008.02

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 0953-8178

The production of IgE, a main player in allergic disorders such as asthma and atopic dermatitis, is strictly regulated and the serum concentrations of IgE are normally kept at a much lower level than other isotypes. We found that mice deficient for the p85α regulatory subunit of class IA phosphoinositide 3-kinase (PI3K) produced increasing amounts of serum IgE. Purified p85α(-/-) B cells produced more IgE than wild-type B cells in vitro in response to anti-CD40 mAb and IL-4. PI3K inhibitors wortmannin and IC87114 enhanced IgE production by wild-type B cells stimulated with anti-CD40 mAb and IL-4. Under the same condition, antigen receptor cross-linking induced the expression of inhibitor of differentiation-2 and suppressed the expression of activation-induced cytidine deaminase and class switch recombination (CSR) in a PI3K-dependent manner. IgE production was also suppressed in a concentrated cell culture condition, which was completely reversed by PI3K inhibition. The selective suppression of IgE production by PI3K was also observed at a protein level after CSR. Our results indicate that PI3K negatively regulates IgE production at both CSR and protein levels.

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Effect of prostatic neuropeptides on invasion and migration of PC-3 prostate cancer cells.

O Nagakawa, M Ogasawara, H Fujii, K Murakami, J Murata, H Fuse, I Saiki

Cancer letters 133 ( 1 ) 27 - 33 1998.11

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 0304-3835

We investigated the effect of various neuropeptides present in the prostate, including calcitonin gene-related peptide (CGRP), gastrin-releasing peptide (GRP), substance P (SP), neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP), calcitonin (CT), leucine-enkephalin (L-ENK), glucagon and parathyroid hormone-related protein (PTH-rP), on the invasion of PC-3 prostate cancer cells through a reconstituted basement membrane (Matrigel) using a Transwell cell culture chamber assay. Both CGRP and GRP increased the invasive capacity of tumor cells, whereas SP inhibited it. On the other hand, VIP, CT, L-ENK, NPY, glucagon and PTH-rP had no significant effect. Both CGRP and GRP also increased the haptotactic migration of tumor cells to fibronectin, but SP inhibited it. These three neuropeptides had no effect on either adhesion to fibronectin and laminin or on the gelatinolytic activities of MMP-9 in gelatin zymography, nor did they affect the growth of tumor cells at concentrations used in this study. These results indicate that both GRP and CGRP increased the invasive potential of PC-3 cells probably through enhancement of cell motility, while SP inhibited the invasiveness through suppression of motile response.

Anti-metastatic and immunomodulating properties of the water extract from Celosia argentea seeds.

Y Hayakawa, H Fujii, K Hase, Y Ohnishi, R Sakukawa, S Kadota, T Namba, I Saiki

Biological & pharmaceutical bulletin 21 ( 11 ) 1154 - 9 1998.11

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 0918-6158

We have investigated the anti-metastatic effect of Celosia argentea seed extracts (CAE), which have traditionally been used as a therapeutic drug for eye and hepatic diseases in China and Japan. Intraperitoneal (i.p.) administration of CAE for 7 d before tumor inoculation significantly inhibited liver metastasis caused by intraportal injection of colon 26-L5 carcinoma cells in a dose-dependent manner. CAE also showed concentration dependent mitogenic activity on BALB/c whole splenocytes, whereas incubation of the non-adherent fraction of splenocytes with CAE did not induce this activity. CAE has the ability to induce interleukin (IL)-12 production from macrophages in vitro. Following i.p. administration of CAE the maximal levels of IL-12 and interferon (IFN)-gamma production in serum were achieved at 2-3 and 6 h, respectively. Experiments using macrophage- or NK cell-deficient mice revealed that CAE-induced IL-12 in serum was not mediated by macrophages and that IFN-gamma production was mainly dependent on natural killer (NK) cells. Since CAE was inactive when the contributions of macrophages were removed in our system, its inhibitory mechanism is likely to be mainly associated with the activation of macrophages to an anti-metastatic state rather than NK cells. CAE administration resulted in increased production of IL-2, IFN-gamma and decreased production of a Th2 cytokine (IL-4) from splenocytes stimulated by PMA and A23187. Thus, the anti-metastatic effect by CAE is based on its immunomodulating properties including induction of cytokines such as IL-12, IL-2 and IFN-gamma leading to a Th1 dominant immune state and activating macrophages to the tumoricidal state. This may provide a basis for the inhibition of cancer metastasis.

Inhibition of tumor invasion and metastasis by calcium spirulan (Ca-SP), a novel sulfated polysaccharide derived from a blue-green alga, Spirulina platensis.

T Mishima, J Murata, M Toyoshima, H Fujii, M Nakajima, T Hayashi, T Kato, I Saiki

Clinical & experimental metastasis 16 ( 6 ) 541 - 50 1998.08

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 0262-0898

We have investigated the effect of calcium spirulan (Ca-SP) isolated from a blue-green alga, Spirulina platensis, which is a sulfated polysaccharide chelating calcium and mainly composed of rhamnose, on invasion of B16-BL6 melanoma, Colon 26 M3.1 carcinoma and HT-1080 fibrosarcoma cells through reconstituted basement membrane (Matrigel). Ca-SP significantly inhibited the invasion of these tumor cells through Matrigel/fibronectin-coated filters. Ca-SP also inhibited the haptotactic migration of tumor cells to laminin, but it had no effect on that to fibronectin. Ca-SP prevented the adhesion of B16-BL6 cells to Matrigel and laminin substrates but did not affect the adhesion to fibronectin. The pretreatment of tumor cells with Ca-SP inhibited the adhesion to laminin, while the pretreatment of laminin substrates did not. Ca-SP had no effect on the production and activation of type IV collagenase in gelatin zymography. In contrast, Ca-SP significantly inhibited degradation of heparan sulfate by purified heparanase. The experimental lung metastasis was significantly reduced by co-injection of B16-BL6 cells with Ca-SP. Seven intermittent i.v. injections of 100 microg of Ca-SP caused a marked decrease of lung tumor colonization of B16-BL6 cells in a spontaneous lung metastasis model. These results suggest that Ca-SP, a novel sulfated polysaccharide, could reduce the lung metastasis of B16-BL6 melanoma cells, by inhibiting the tumor invasion of basement membrane probably through the prevention of the adhesion and migration of tumor cells to laminin substrate and of the heparanase activity.

A new pseudo-peptide analogue of the Arg-Gly-Asp (RGD) sequence inhibits liver metastasis of colon 26-L5 carcinoma cells.

Y Ohnishi, H Fujii, K Murakami, T Sakamoto, K Tsukada, M Fujimaki, M Kojima, I Saiki

Cancer letters 124 ( 2 ) 157 - 63 1998.02

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 0304-3835

We have investigated the effect of the pseudo-peptide analogue (FC-336) of the Arg-Gly-Asp (RGD) sequence in a liver metastasis model by the inoculation of a highly liver-metastatic cell line of colon 26 carcinoma (colon 26-L5) into the portal vein of BALB/c mice. The intraportal injection of colon 26-L5 cells with FC-336 resulted in a marked suppression of liver metastatic colonies in a dose-dependent manner and it reduced the liver weights to a normal level. However, the co-injection of tumor cells with a high dose of RGDS tetrapeptide led to a slight inhibition of liver metastasis. The multiple i.v. administration of FC-336 after tumor inoculation as well as the injection of FC-336 with tumor cells caused significant inhibition of experimental metastasis in the liver. The multiple i.v. administration of the RGDS peptide did not show any inhibitory activity. FC-336 significantly enhanced the survival rate of mice compared with untreated controls when injected intraportally with tumor cells or when intravenously administered after tumor inoculation. Zymography analysis showed that FC-336 inhibited the degradation of gelatin substrate by matrix metalloproteinases (MMPs) produced by colon 26-L5 cells, while RGDS peptide did not affect the enzymatic degradation. These findings clearly indicate that the pseudo-peptides of the RGD sequence (FC-336) have a potent inhibitory activity on liver metastasis of colon 26-L5 carcinoma cells.

Vaccination with B7-1+ tumor and anti-adhesion therapy with RGD pseudo-peptide (FC-336) efficiently induce anti-metastatic effect.

H Fujii, M Inobe, Y Hayakawa, F Kimura, M Murakami, Y Onishi, I Azuma, T Uede, I Saiki

Clinical & experimental metastasis 16 ( 2 ) 141 - 8 1998.02

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 0262-0898

We have previously shown that expression of costimulatory ligand B7-1 on MHC class I+ tumor cells (B16-BL6 melanoma) resulted in marked reduction of lung metastasis caused by i.v. injection into immunocompetent syngeneic mice and led to induction of immunity to the challenge by the parental B7-1 negative tumor. Here we investigated the effectiveness of irradiated B7-1 transfected tumor cells as a vaccine on established tumor metastasis and whether or not expression of B7-1 molecule on tumor cells in combination with administration of anti-adhesion peptide FC-336 can augment the antimetastatic efficacy. Immunization with X-irradiated B7-1 transfectants after i.v. injection of B7-1- parental B16-BL6 cells was effective in inhibiting lung metastasis. We also found that vaccination with irradiated B7-1 transfectants after excision of primary tumor on day 21 resulted in significant inhibition of spontaneous lung metastasis by intrafootpad injection of viable parental B16-BL6 melanoma, as compared with the untreated control. However, immunizing twice with mock transfectants did not affect inhibition of spontaneous lung metastasis of wild-type tumors. On the other hand, multiple administration of a pseudo-peptide of RGD sequence (FC-336) after tumor inoculation inhibited spontaneous lung metastasis through the interference of tumor invasion, migration and adhesion. Combined treatment of B7-1 transfected tumor vaccine and anti-adhesive therapy with FC-336 led to the augmentation of the antimetastatic effect in both experimental and spontaneous metastasis models, as compared with either treatment alone. B7-1- and FC-336-mediated inhibition of tumor metastasis may be mediated by different mechanisms at various steps of metastasis, based on the regulation (promotion or inhibition) of tumor interaction with host cells and components.

Oral administration of a Kampo (Japanese herbal) medicine Juzen-taiho-to inhibits liver metastasis of colon 26-L5 carcinoma cells.

Y Ohnishi, H Fujii, Y Hayakawa, R Sakukawa, T Yamaura, T Sakamoto, K Tsukada, M Fujimaki, S Nunome, Y Komatsu, I Saiki

Japanese journal of cancer research : Gann 89 ( 2 ) 206 - 13 1998.02

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 0910-5050

We have investigated the inhibitory effect of oral administration of Juzen-taiho-to, a Kampo Japanese herbal medicine, on liver metastasis by the inoculation of a liver-metastatic variant (L5) of murine colon 26 carcinoma cells into the portal vein. Oral administration of Juzen-taiho-to for 7 days before tumor inoculation resulted in dose-dependent inhibition of liver tumor colonies and significant enhancement of survival rate as compared with the untreated control, without side effects. We also found that liver metastasis of L5 cells was enhanced in BALB/c mice pretreated with anti-asialo GM1 serum or 2-chloroadenosine, and in BALB/c nu/nu mice, compared to normal mice. This indicates that NK cells, macrophages, and T-cells play important roles in the prevention of metastasis of tumor cells. Juzen-taiho-to significantly inhibited the experimental liver metastasis of colon 26-L5 cells in mice pretreated with anti-asialo GM1 serum and untreated normal mice, whereas it did not inhibit metastasis in 2-chloroadenosine-pretreated mice or T-cell-deficient nude mice. Oral administration of Juzen-taiho-to activated peritoneal exudate macrophages (PEM) to become cytostatic against the tumor cells. These results show that oral administration of Juzen-taiho-to inhibited liver metastasis of colon 26-L5 cells, possibly through a mechanism mediated by the activation of macrophages and/or T-cells in the host immune system. Thus, Juzen-taiho-to may be efficacious for the prevention of cancer metastasis.

A new pseudo-peptide of Arg-Gly-Asp (RGD) with inhibitory effect on tumor metastasis and enzymatic degradation of extracellular matrix.

H Fujii, N Nishikawa, H Komazawa, M Suzuki, M Kojima, I Itoh, A Obata, K Ayukawa, I Azuma, I Saiki

Clinical & experimental metastasis 16 ( 1 ) 94 - 104 1998.01

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 0262-0898

A series of pseudo-peptide analogs of the Arg-Gly-Asp (RGD) sequence of fibronectin have been synthesized, and their anti-metastatic effects in mice and inhibitory effects on tumor cell invasion in vitro have been examined. The partially modified retro pseudo-peptide of RGD, Rrev-COCH2CO-D (FC-63), was more effective in inhibiting tumor metastasis than the original RGDS peptide. Replacement of the malonyl moiety of FC-63 with a carboxyethylene linkage (Rrev-COCH2CH2-D, FC-303 ) achieved more potent inhibition of lung metastasis of melanoma cells than FC-63. Among the analogs, FC-336, a p-xylylendiamine derivative having two FC-303 moieties, showed the most potent inhibitory effect on experimental lung metastasis produced by i.v. co-injection with B16-BL6 melanoma or colon 26 M3.1 cells in a dose-dependent manner. Multiple administrations of FC-336 after tumor inoculation also showed efficient therapeutic potency against spontaneous lung metastasis of B16-BL6 melanoma in mice. Furthermore, FC-336 effectively inhibited the invasion, migration and adhesion of tumor cells in vitro, but its inhibitory effects were not more than those of RGDS peptide. Zymography analysis revealed that FC-336 inhibited the degradation of gelatin substrate by matrix metalloproteinases (MMPs) produced by tumor cells, while the RGDS peptide did not affect the enzymatic degradation. These findings indicate that the pseudo-peptides of the RGD sequence, possessing the inhibitory property of the degradation by MMPs differently from original RGD-containing peptides, may be advantageous and useful in preventing tumor metastasis.

LEA-1/ICAM-1 interaction is essentially involved in the pathogenesis of delayed-type hypersensitivity-induced liver injury to picryl chloride.

Q Xu, J Jiang, J Cao, F Wu, H Fujii, I Saiki

Life sciences 62 ( 15 ) 1281 - 92 1998

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 0024-3205

The kinetics of lymphocyte function associated antigen 1 (LFA-1) expression on spleen cells (SPC) and liver non-parenchymal cells (NPC), and intercellular adhesion molecule 1 (ICAM-1) expression on hepatocytes (HC) was examined in acute liver injury mice induced by a DTH reaction to picryl chloride (PCl). The peak expression of LFA-1 on SPC was seen at 6 hr after eliciting liver injury, and then that of LFA-1 on NPC and ICAM-1 on HC appeared at 12 hr. Thereafter, the serum ALT elevation reached to a peak at 18 hr. A splenectomy before the PCl elicitation significantly reduced the ALT elevation. Both SPC and NPC from liver injury mice induced a remarkable release of ALT from HC in vitro, in parallel with their LFA-1 expression. The pre-treatment of NPC or SPC with anti-LFA-1 mAb, irrespective of the presence of complement, completely blocked the ALT release. Also, when HC was prebound with anti-ICAM-1 mAb, neither NPC nor SPC showed a cytotoxicity against the HC. Furthermore, the treatment of NPC with either anti-Thy1.2 or anti-CD4 mAb in the presence but not absence of complement, showed a complete abolishment of ALT release. Anti-CD8 mAb plus complement also tended to inhibit ALT release. The twofold increase in CD4+ LFA-1+ and mild increase in CD8+ LFA-1+ populations were also confirmed in NPC at 12 hr. These results suggest that PCl elicitation in liver may trigger an increased expression of LFA-1 on SPC and NPC and ICAM-1 on HC. LFA-1/ICAM-1 interaction between liver-infiltrating NPC, mainly including CD4+ and CD8+ T cells, and HC may be an essential step for the hepatocyte damage in PCl-DTH liver injury.

Anti-invasive activity of synthetic serine protease inhibitors and its combined effect with a matrix metalloproteinase inhibitor.

T Ikeda, K Murakami, Y Hayakawa, H Fujii, M Ohkoshi, I Saiki

Anticancer research 18 ( 6A ) 4259 - 65 1998

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 0250-7005

Tumor invasion into the extracellular matrix (ECM) and basement membrane (BM) is a crucial step of tumor metastasis. In order to investigate the possible therapeutic procedure for the tumor invasion, we investigated the anti-invasive activities of several synthetic serine protease inhibitors. FOY-305, a serine protease inhibitor, showed no cytotoxic activity against human HT-1080 fibrosarcoma cells at concentrations ranging from 0.1 to 100 micrograms/ml, while its analogs ONO-3403 and FO-349 showed slight cytotoxic activities at the concentration of 100 micrograms/ml. These compounds inhibited the activity of urokinase-type plasminogen activator (u-PA) which is one of serine proteases and considered to be associated with tumor invasion and metastasis in fibrin zymography. FOY-305 more potently inhibited the invasion of HT-1080 cells into the reconstituted BM Matrigel, as well inhibited u-PA activity, compared with ONO-3403 and FO-349. These results suggest that the anti-invasive activity of these compounds is consistent with their anti-fibrinolytic activities. In addition, the combined treatment of FOY-305 with FC-336 processing anti-invasive and anti-MMP properties resulted in marked enhancement of anti-invasive activity. In conclusion, FOY-305 inhibited the invasion of tumor cells through interference with the u-PA activity of tumor cells, and this inhibitory activity was augmented by the combination with a MMP inhibitor.

Antimetastatic effect by Juzen-taiho-to in the liver metastasis model of colon 26-L5 carcinoma

Ohnishi Y, Fujii H, Kimura F, Hayakawa Y, Sakukawa R, Murata J, Sakamoto T, Tazawa K, Fujimaki M, Saiki I

Biotherapy 12 ( 1 ) 187 - 189 1998

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted

Effect of anti-adhesion therapy by a new pseudo-peptide of arg-gly-asp (RGD) on tumor metastasis

Ohnishi Y, Fujii H, Murata J, Sakamoto T, Tazawa K, Fujimaki M, Saiki I

Jpn J Gastroenterological Surgery 31 ( 4 ) 1004 - 1009 1998

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted

Antimetastatic and antitumor effect of a recombinant human tissue inhibitor of metalloproteinases-2 in murine melanoma models.

T Oku, N Ata, K Yonezawa, H Tokai, H Fujii, A Shinagawa, E Ohuchi, I Saiki

Biological & pharmaceutical bulletin 20 ( 8 ) 843 - 9 1997.08

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 0918-6158

Tumor metastasis into distinct organs and tissues, of which many patients with malignancies die, is regulated in multiple steps. Using a murine metastasis model, in which highly metastatic B16-BL6 melanoma cells were inoculated i.v. into syngeneic C57BL/6 mice, the administration of a recombinant human tissue inhibitor of metalloproteinases-2 (r-hTIMP-2) once a day on days -1 to 3 after the implantation significantly inhibited the formation of metastatic foci in the lungs. The antimetastatic effect of r-hTIMP-2 was detected irrespective of administration route [i.v., i.p., s.c., and i.m. routes] and in a dose-dependent manner. The i.m.-injection of r-hTIMP-2 during the early phase after tumor inoculation is suggested to be essential for antimetastasis. In another model using spontaneously metastasing B16-BL6 cells, multiple i.m.-injections of r-hTIMP-2 also resulted in a reduced but not statistically significant number of pulmonary metastases. In addition to these antimetastatic effects, a slight inhibitory effect on tumor cell growth was observed in vitro and in vivo. In conclusion, the antimetastasis by r-hTIMP-2 may be due to inhibition of the degradation of the extracellular matrix by matrix metalloproteinases (MMPs) and, in part, to the suppression of the tumor cell growth.

Alpha-melanocyte-stimulating hormone blocks invasion of reconstituted basement membrane (Matrigel) by murine B16 melanoma cells.

J Murata, K Ayukawa, M Ogasawara, H Fujii, I Saiki

Invasion & metastasis 17 ( 2 ) 82 - 93 1997

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 0251-1789

We have examined the effect of alpha-melanocyte-stimulating hormone (alpha-MSH) on invasive ability of murine melanoma cell lines with different metastatic potential in a Matrigel invasion assay. alpha-MSH potently blocked the invasion of B16-BL6 cells with highly metastatic potential in a concentration-dependent manner, whereas it was less effective in inhibiting the invasion of weakly metastatic B16-F1 cells. Pretreatment of B16-BL6 cells with alpha-MSH resulted in a decrease of the adhesiveness to fibronectin and laminin substrates in a time-dependent fashion. As assessed by zymographic analysis, alpha-MSH partially inhibited the production of matrix metalloproteinase (MMP)-2 and -9 from both cell lines to a similar degree without affecting the degradative activity of these MMPs. alpha-MSH was more potent in inhibiting the migration of B16-BL6 cells towards both fibronectin- and laminin-coated substrates than that of B16-F1 cells. The growth and morphology of B16-BL6 cells were not changed after a 7-day incubation with alpha-MSH. The number of lung tumor colonies markedly decreased when B16-BL6 cells were coinjected intravenously with 10(-6) M alpha-MSH. However, alpha-MSH had no effect on the experimental lung metastases by B16-F1 cells. These results suggest that alpha-MSH suppressed the invasive and metastatic properties of B16 melanoma cells, and the degree of inhibition was associated with metastatic potential of B16 melanoma cells.

Antimetastatic effect by vaccination of tumor cells transfected with B7- 1 (CD80) gene

Ohnishi Y, Fujii H, Inobe M, Kimura F, Murata J, Murakami M, Uede T, Sakamoto T, Tazawa K, Fujimaki M, Saiki I

Biotherapy 11 ( 5 ) 621 - 622 1997

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted

Characterization of a liver metastatic variant of murine colon 26 carcinoma cells.

Y Ohnishi, T Sakamoto, H Fujii, F Kimura, J Murata, K Tazawa, M Fujimaki, Y Sato, M Kondo, Y Une, J Uchino, I Saiki

Tumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine 18 ( 2 ) 113 - 22 1997

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 1010-4283

Intraportal vein injection of highly metastatic L5 cells consistently resulted in liver metastases (increases in the number of tumor colonies in the liver), whereas inoculation of P cells rarely did. L5 cells invaded the basement membrane Matrigel in greater numbers than did P cells, suggesting that the metastatic potential of L5 cells is partly related to enhanced invasive properties. The enhanced adhesion of L5 cells to fibronectin-, laminin- and Matrigel-coated substrates, as well as their haptotactic migration to fribronectin, may be associated with the preferential expression of VLA-2 and VLA-4 integrins on the surface of these cells detected by flow cytometry. Gelatin zymograms showed that the degradative activity of 72-kD gelatinases was greater in L5 cells than P cells. These results indicate that, in addition to adhesiveness and motility, the invasive ability of L5 cells may also be attributed to enhanced gelatinolytic activity. L5 cells grew more rapidly than P cells in vitro. Thus, an experimental model using highly metastatic colon 26 L5 cells would be useful for analyzing the molecular mechanism of liver metastasis and for evaluating the efficacy of treatment of occult micrometastases which may already have been disseminated at the time of surgery.

Application of liposomes for cancer metastasis

Oku N, Koike C, Tokudome Y, Okada S, Nishikawa N, Tsukada H, Kiso M, Hasegawa A, Fujii H, Murata J, Saiki I

Advance Drug Delivery Review 24 215 - 223 1997

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted

Inhibitory effect of a traditional Chinese medicine, Juzen-taiho-to, on progressive growth of weakly malignant clone cells derived from murine fibrosarcoma.

Y Ohnishi, H Fujii, F Kimura, T Mishima, J Murata, K Tazawa, M Fujimaki, F Okada, M Hosokawa, I Saiki

Japanese journal of cancer research : Gann 87 ( 10 ) 1039 - 44 1996.10

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 0910-5050

We have investigated the inhibitory effect of oral administration of Juzen-taiho-to, a Kampo (Chinese herbal) medicine, on progressive growth of a mouse fibrosarcoma. Spontaneously regressive QR-32 tumor cells were able to grow progressively in vivo when coimplanted s.c. with a foreign body, gelatin sponge, whereas QR-32 cells alone gradually grew for over 15 days after inoculation and thereafter regressed for up to 25 days. Oral administration of Juzen-taiho-to (40 mg/day/mouse) for 7 days after inoculation of QR-32 cells with gelatin sponge resulted in significant inhibition of tumor growth and prolongation of the survival of the tumor-bearing mice. This growth-inhibitory effect of Juzen-taiho-to observed on day 25 was dose-dependent over the dose range from 4 to 40 mg/day. Treatment with Juzen-taiho-to for 7 days before tumor inoculation with gelatin sponge also significantly suppressed tumor growth examined on day 25, as did the administration of bismuth subnitrate, which is well known to induce metallothionein, an antioxidant. On the other hand, inoculation of progressed tumor cells (QRsP) resulted in growth without gelatin sponge, leading to death in syngeneic mice. Administration of Juzen-taiho-to for 7 days after inoculation of QRsP cells resulted in a decrease of the tumor growth and prolongation of the survival of mice, but the effect was less than that on the growth of QR-32 regressor tumor after coimplantation with gelatin sponge. These results suggest that the inhibitory effect of Juzen-taiho-to is partly associated with prevention of gelatin sponge-elicited progressive growth, probably mediated by endogenous factors including antioxidant substances, in addition to the augmentation of host-mediated antitumor activity.

Synthesis and biological properties of partially modified retro and retro-inverso pseudo peptides of Arg-Gly-Asp (RGD)

Nishikawa N, Komazawa H, Orikasa A, Yoshikane M, Yamaguchi J, Kojima M, Ono M, Itoh I, Azuma I, Fujii H, Murata J, Saiki I

Bioorg. Med. Chem. Lett. 6 ( 22 ) 2725 - 2728 1996.06

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted

Vaccination of tumor cells transfected with the B7-1 (CD80) gene induces the anti-metastatic effect and tumor immunity in mice.

H Fujii, M Inobe, F Kimura, J Murata, M Murakami, Y Onishi, I Azuma, T Uede, I Saiki

International journal of cancer 66 ( 2 ) 219 - 24 1996.04

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 0020-7136

The present study demonstrates that the transfection of B7-1 or its variant MB7-2 genes into MHC class I+ tumor cells (B16-BL6 or K1735-M2 melanoma) resulted in the remarkable reduction of lung metastasis caused by i.v. injection into immunocompetent syngeneic mice. However, i.v. injection of the transfectants into T cell-deficient nude mice did not affect reduction of lung tumor colonies as compared with parental wild-type tumors, suggesting that such an inhibitory effect was closely associated with T cell-mediated responses. The reduced metastasis of B7+ tumor cells consequently led to the significant prolongation of survival. Expression of B7 on tumor cells did not influence the tumorigenicity in vivo and tumor cell invasion into basement membrane Matrigel in vitro. We also found that immunization of X-irradiated B7 transfectants was effective as a tumor vaccine for preventing lung metastasis caused by i.v. injection of B7- parental B16-BL6 cells but not against other syngeneic 3LL tumors. Thus, the B7-mediated anti-metastatic effect was tumor-specific. Vaccinations of irradiated B7+ tumor cells before and after surgical excision of the s.c. inoculated primary B7- tumors on day 21 achieved effectively the prevention of spontaneous lung metastasis. Our report that vaccination of irradiated B7+ tumor cells led to a therapeutic effect in an established tumor metastasis model clearly expands and confirms previous related observations.

Functional role of sialyl Lewis X and fibronectin-derived RGDS peptide analogue on tumor-cell arrest in lungs followed by extravasation.

I Saiki, C Koike, A Obata, H Fujii, J Murata, M Kiso, A Hasegawa, H Komazawa, H Tsukada, I Azuma, S Okada, N Oku

International journal of cancer 65 ( 6 ) 833 - 9 1996.03

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 0020-7136

Our study demonstrates that synthetic sialyl Lewis X (SLex) as a ligand for selectins and fibronectin-derived RGDS peptide analogue [Ar(DRGDS)3] inhibits lung metastases produced by i.v. co-injection of B16-BL6 melanoma cells. To investigate the inhibitory mechanisms in a living animal, we performed positron-emission tomography (PET) analysis after i.v. injection of [2-18F]2-fluoro-2v-deoxy-D-glucose-labeled tumor cells with or without liposomal SLex or Ar(DRGDS)3. The real-time PET measurement for the first 120 min, started immediately after injection, showed that tumor-cell arrest, i.e., accumulation in the target organ (lung) was remarkably inhibited by liposomal SLex, but not inhibited by Ar(DRGDS)3 or liposomal Me-SLex, which is not recognized by selectins. In contrast, Ar(DRGDS)3 inhibited the invasion of B16-BL6 cells into reconstituted basement membrane (Matrigel) following tumor arrest, whereas SLex- or Me-SLex-entrapped liposomes did not affect tumor invasion. In the metastatic processes containing tumor-cell lodgement and arrest in the target organ followed by extravasation (invasion), SLex resulted in the inhibition of initial arrest of tumor cells, presumably tumor-endothelium interaction, while Ar(DRGDS)3 achieved inhibition of tumor invasion into basement membrane at later steps of the cascade, consequently leading to inhibition of metastasis. Thus, tumor-cell arrest in lungs in the metastatic processes must be precisely and properly controlled by different adhesion molecules at different stages, which are similar to those observed in leukocyte-endothelium interaction.

Inhibition by galloylglucose (GG6-10) of tumor invasion through extracellular matrix and gelatinase-mediated degradation of type IV collagens by metastatic tumor cells.

N Ata, T Oku, M Hattori, H Fujii, M Nakajima, I Saiki

Oncology research 8 ( 12 ) 503 - 11 1996

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 0965-0407

Tumor invasion into extracellular matrix (ECM) and basement membrane (BM) is a crucial step in the complex multistage process that leads to metastasis formation. GG6-10 galloylglucose, isolated from Galla Rhois, inhibited the invasion of metastatic HT-1080 cells into a reconstituted BM, such as a Matrigel/fibronectin (FN)-coated filter, in a concentration-dependent fashion. GG6-10 affected neither the tumor cell adhesion and haptotactic migration to ECM components (Matrigel and FN), nor the growth of HT-1080 cells. The gelatin zymography revealed that GG6-10 was able to inhibit not only the degradation of gelatin mediated by matrix metalloproteinases (MMP)-2 and -9 in conditioned medium of HT-1080 tumor cells but also the production of MMP from the tumor cells in a concentration-dependent manner. MMP production is well known to be positively regulated by various cytokines, such as tumor necrosis factor-alpha (TNF-alpha). Thus, we examined the effect of GG6-10 on the TNF-alpha-mediated translation of the MMP-9 gene using HT-1080 cells transfected with the MMP-9 promoter linked to the luciferase gene as a reporter. Similarly to prednisolone, GG6-10 was found to inhibit the TNF-alpha-inducible promoter activity. In keeping with these results, GG6-10 might inhibit tumor cell invasion by inhibiting the gelatinolysis mediated by MMP-2 and -9 and interfering with the production of MMP via inhibiting transcription of the promoter for MMP.

Inhibition of tumor invasion and metastasis by peptidic mimetics of Arg-Gly Asp (RGD) derived from the cell recognition site of fibronectin.

H Fujii, N Nishikawa, H Komazawa, A Orikasa, M Ono, I Itoh, J Murata, I Azuma, I Saiki

Oncology research 8 ( 9 ) 333 - 42 1996

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 0965-0407

The partially modified retro- and retro-inverso peptides of the Arg-Gly Asp (RGD) sequence of fibronectin, in which the direction of the Arg residue is reversed and/or the chirality of the amino acid residue is inverted, i.e., mainly R(rev)-COCH2CO-D and DR(rev)-COCH2CO-D, have been synthesized to examine their antimetastatic effects in murine lung or liver metastasis models, as well as their inhibitory effect on tumor cell invasion in vitro. R(rev)-COCH2CO-D inhibited lung metastasis produced by i.v. coinjection with B16-BL6 melanoma more potently than did other pseudo-peptides or the original RGDS peptide. Rrev-COCH2CO-D also showed antimetastatic effects against several different types of tumor cells such as B16-BL6 melanoma, Colon26 M3.1 carcinoma, and L5178Y-ML25 lymphoma cells, in a dose-dependent manner, and multiple administrations had a therapeutic effect on spontaneous lung metastasis. The invasion of melanoma cells into reconstituted basement membrane Matrigel in vitro was suppressed by R(rev)-COCH2CO-D more effectively than by RGDS. These results indicate that the antimetastatic effect by R(rev)-COCH2CO-D was in part due to the inhibition of tumor invasion. The RGDS peptide decomposed when incubated with fresh plasma in vitro, whereas R(rev)-COCH2CO-D was not affected by this treatment. Thus, the reversion of the Arg-Gly linkage in the RGD sequence resulted in protease resistance leading to the retardation of the clearance of the peptide in vivo, and consequently augmented its antimetastatic and antiinvasive properties. Designed peptide analogues may provide various advantages and be useful for preventing cancer metastasis.

Antimetastatic activities of synthetic Arg-Gly-Asp-Ser (RGDS) and Arg-Leu-Asp-Ser (RLDS) peptide analogues and their inhibitory mechanisms.

H Fujii, H Komazawa, H Mori, M Kojima, I Itoh, J Murata, I Azuma, I Saiki

Biological & pharmaceutical bulletin 18 ( 12 ) 1681 - 8 1995.12

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 0918-6158

We have investigated the inhibitory effect of the N-terminal modified Arg-Gly-Asp-Ser (RGDS) analogues, AcDRGDS and AcDRLDS, on tumor cell adhesion to the components of extracellular matrix and basement membrane, and also tested the antimetastatic effect of their conjugates with trimesic acid, Ar(DRGDS)3 and Ar(DRLDS)3. AcDRGDS significantly inhibited tumor cell adhesion to fibronectin, vitronectin and RGDS substrates, but not to CS1 substrate which is a ligand for the alpha 4 beta 1 tumor surface integrin receptor. In contrast, AcDRLDS variant peptide significantly inhibited tumor cell adhesion to laminin, in addition to RGDS-mediated adhesion to fibronectin and vitronectin. AcDRLDS also inhibited tumor cell adhesion to CS1 as well as the RGDS sequence within the fibronectin molecule in a concentration-dependent manner, although the inhibitory effect was less than that of the CS1 (EILDV) peptide. Ar(DRLDS)3 inhibited the laminin- and fibronectin-mediated invasion and migration of tumor cells, whereas Ar(DRGDS)3 selectively inhibited fibronectin-mediated invasion and migration. Ar(DRGDS)3 and Ar(DRLDS)3 were much more effective in inhibiting experimental lung or liver metastases of various types of murine and human tumors than the original RGDS-containing peptides or Ar(COONa)3. Multiple administrations of Ar(DRGDS)3 or Ar(DRLDS)3 potently inhibited spontaneous lung metastasis produced by intra-footpad injection of B16-BL6 cells without affecting the primary tumor size at the time of surgical excision, as compared with RGDS peptide or untreated control. Thus, Ar(DRGDS)3 and Ar(DRLDS)3 substantially increased the exhibiting any antimetastatic effect of the peptides without direct cytotoxicity.

Role of the heparin-binding domain of chimeric peptides derived from fibronectin in cell spreading and motility.

J Yoneda, I Saiki, Y Igarashi, H Kobayashi, H Fujii, Y Ishizaki, F Kimizuka, I Kato, I Azuma

Experimental cell research 217 ( 1 ) 169 - 79 1995.03

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 0014-4827

Cellular responses to fibronectin (FN) are likely to have a complex molecular basis involving the interactions between multiple functional domains of FN and specific cell surface molecules. We have utilized several types of recombinant FN fragments and their chimeric fragments to examine the regulatory mechanisms of the spreading and chemotactic migration of HT1080 human fibrosarcoma cells on FN. The CH-271 fusion fragment, in which the cell-binding domain (C-274) of FN is adjacent to the heparin-binding domain (H-271), promoted cell spreading more efficiently than C-274, H-271, or their mixture (C-274 + H-271) over a 60-min incubation. The CH-271 variants containing various modules in the heparin-binding domain (CHV peptide) showed different promotion of cell migration, spreading, and vinculin accumulation at focal adhesion, respectively. The preincubation of the cells with heparitinase I resulted in significant inhibition of chemotactic migration to FN and its fragments containing the III13 and/or III14 modules of the heparin-binding domain. Additionally, migration to CH-271 was inhibited by the presence of the RGDS peptide in a concentration-dependent fashion. Thus, the spread and migration responses of HT1080 cells onto FN fusion peptides require the adjacent coexistence of cell- and heparin-binding domains and are mediated by the interactions between cell surface heparan sulfate and the heparin-binding domain, in concert with the interaction between cell surface integrin and the cell-binding domain. In conclusion, our present study demonstrated that fusion peptides of fibronectin can efficiently induce two signals from the cell-binding and heparin-binding domains required for the completion of cell spreading, the formation of focal contact, and motility at the early stage of the culture, suggesting that the III13 or III14 modules within the heparin-binding domain are responsible for the initiation of different cellular responses.

Combination of anti-cell adhesive synthetic Arg-Gly-Asp-Ser analogue and anticancer drug doxorubicin heightens their original antimetastatic activities.

H Komazawa, H Fujii, M Kojima, H Mori, M Ono, I Itoh, I Azuma, I Saiki

Oncology research 7 ( 7-8 ) 341 - 51 1995

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 0965-0407

A new compound containing the cell-adhesive Arg-Gly-Asp-Ser (RGDS) peptide was synthesized, i.e. tetrahydrofurantetracarboxylic acid (THFTCA)-RGDS conjugate [THFTCA- (RGDS)3, FC-243], and the inhibitory effect of FC-243 on lung metastasis of B16-BL6 melanoma in mice was examined in combination with or without the anticancer agent doxorubicin (DOX). FC-243 showed an inhibitory effect on lung metastasis of melanoma cells in a dose-dependent manner. A mixture of THFTCA and RGDS peptide or THFTCA alone did not show any inhibitory effect on experimental lung metastasis as compared with FC-243 on a molar basis. RGDS peptide, however, required a higher dose to obtain a sufficient antimetastatic effect. Intermittent IV administration of FC-243 after the inoculation of B16-BL6 cells caused significant inhibition of spontaneous lung metastasis as compared with multiple administration of RGDS or untreated control. The in vitro tumor invasion study showed that FC-243 as well as RGDS+THFTCA on a molar basis resulted in similar inhibition of the invasion of B16-BL6 cells into reconstituted basement membrane Matrigel. Combined treatment with FC-243 and DOX significantly inhibited lung metastasis of melanoma as compared with either treatment alone or the untreated control. Administrations of FC-243 and DOX in combination substantially prolonged the survival time of mice. These results demonstrate that combination therapy of the anti-cell adhesive FC-243 and the anticancer agent DOX, i.e. antiadhesion therapy and chemotherapy, is a new approach that offers enhanced inhibitory effects on tumor metastasis and invasion.

Inhibitory effect of recombinant fibronectin polypeptides on the adhesion of liver-metastatic lymphoma cells to hepatic sinusoidal endothelial cells and tumor invasion.

J Yoneda, I Saiki, H Kobayashi, H Fujii, Y Ishizaki, I Kato, M Kiso, A Hasegawa, I Azuma

Japanese journal of cancer research : Gann 85 ( 7 ) 723 - 34 1994.07

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted, ISSN 0910-5050

We have investigated the inhibitory mechanism of the initial arrest of L5178Y-ML25 lymphoma cells in a target organ (liver) by using recombinant fibronectin fragments with cell- and/or heparin-binding domains (C-274, H-271 or the fusion fragment CH-271). Pretreatment of hepatic sinusoidal endothelial (HSE) cell monolayers with lymphoma cells or their conditioned medium for 4 to 6 h resulted in the enhancement of lymphoma cell adhesion to HSE cell monolayer. The increased tumor adhesiveness was completely abolished by preincubation of the conditioned medium with anti interleukin-1 beta monoclonal antibody (mAb). Synthetic sialyl Le(x) (SLe(x)) as a ligand for endothelial cell leukocyte adhesion molecule-1 (ELAM-1) adhesion receptor and anti ELAM-1 mAb blocked the conditioned medium-induced enhancement of tumor-endothelial cell interaction, while pretreatment of the activated HSE cell monolayer with anti vascular cell adhesion molecule-1 (VCAM-1) mAb did not affect the enhanced tumor cell adhesion. These results indicate that tumor cell interaction with the stimulated HSE cells is mediated by ELAM-1 molecules on HSE cells. However, the expression of SLe(x) and SLe(a) on the tumor surface was not observed by flow cytometric analysis. ELAM-1-mediated enhancement of tumor cell adhesion to HSE monolayer was also inhibited in a concentration-dependent manner by CH-271 fusion polypeptide or the sulfated chitin derivative sulfated carboxymethyl-chitin, which can bind to the heparin-binding domain of CH-271. In addition, CH-271 inhibited not only tumor-endothelium interaction but also tumor cell invasion into reconstituted basement membrane Matrigel in vitro.

Inhibition of tumor cell invasion by ubenimex (bestatin) in vitro.

Saiki I, Murata J, Watanabe K, Fujii H, Abe F, Azuma I

Jpn. J. Cancer Res. 80 ( 9 ) 873 - 878 1989.09

Research paper (scientific journal), Joint Work, Lead author, Last author, Corresponding author, Accepted

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