論文 - 吉村　昭彦

Prevention of allogeneic cardiac graft rejection by transfer of ex vivo expanded antigen-specific regulatory T-cells

Takasato Fumika, Morita Rimpei, Schichita Takashi, Sekiya Takashi, Morikawa Yasuhide, Kuroda Tatsuo, Niimi Masanori, Yoshimura Akihiko

PLoS ONE 9 （ 2 ）  2014年02月

　概要を見る

<p>The rate of graft survival has dramatically increased using calcineurin inhibitors, however chronic graft rejection and risk of infection are difficult to manage. Induction of allograft-specific regulatory T-cells (Tregs) is considered an ideal way to achieve long-term tolerance for allografts. However, efficient in vitro methods for developing allograft-specific Tregs which is applicable to MHC full-mismatched cardiac transplant models have not been established. We compared antigen-nonspecific polyclonal-induced Tregs (iTregs) as well as antigen-specific iTregs and thymus-derived Tregs (nTregs) that were expanded via direct and indirect pathways. We found that iTregs induced via the indirect pathway had the greatest ability to prolong graft survival and suppress angiitis. Antigen-specific iTregs generated ex vivo via both direct and indirect pathways using dendritic cells from F1 mice also induced long-term engraftment without using MHC peptides. In antigen-specific Treg transferred models, activation of dendritic cells and allograft-specific CTL generation were suppressed. The present study demonstrated the potential of ex vivo antigen-specific Treg expansion for clinical cell-based therapeutic approaches to induce lifelong immunological tolerance for allogeneic cardiac transplants. © 2014 Takasato et al.</p>

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Prevention of allogeneic cardiac graft rejection by transfer of ex vivo expanded antigen-specific regulatory T-cells

Takasato Fumika, Morita Rimpei, Schichita Takashi, Sekiya Takashi, Morikawa Yasuhide, Kuroda Tatsuo, Niimi Masanori, Yoshimura Akihiko

PLoS ONE 9 （ 2 ）  2014年02月

　概要を見る

<p>The rate of graft survival has dramatically increased using calcineurin inhibitors, however chronic graft rejection and risk of infection are difficult to manage. Induction of allograft-specific regulatory T-cells (Tregs) is considered an ideal way to achieve long-term tolerance for allografts. However, efficient in vitro methods for developing allograft-specific Tregs which is applicable to MHC full-mismatched cardiac transplant models have not been established. We compared antigen-nonspecific polyclonal-induced Tregs (iTregs) as well as antigen-specific iTregs and thymus-derived Tregs (nTregs) that were expanded via direct and indirect pathways. We found that iTregs induced via the indirect pathway had the greatest ability to prolong graft survival and suppress angiitis. Antigen-specific iTregs generated ex vivo via both direct and indirect pathways using dendritic cells from F1 mice also induced long-term engraftment without using MHC peptides. In antigen-specific Treg transferred models, activation of dendritic cells and allograft-specific CTL generation were suppressed. The present study demonstrated the potential of ex vivo antigen-specific Treg expansion for clinical cell-based therapeutic approaches to induce lifelong immunological tolerance for allogeneic cardiac transplants. © 2014 Takasato et al.</p>

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Macrophages and dendritic cells emerge in the liver during intestinal inflammation and predispose the liver to inflammation

Mikami Yohei, Mizuno Shinta, Nakamoto Nobuhiro, Hayashi Atsushi, Sujino Tomohisa, Sato Toshiro, Kamada Nobuhiko, Matsuoka Katsuyoshi, Hisamatsu Tadakazu, Ebinuma Hirotoshi, Hibi Toshifumi, Yoshimura Akihiko, Kanai Takanori

PLoS ONE 9 （ 1 ）  2014年01月

　概要を見る

<p>The liver is a physiological site of immune tolerance, the breakdown of which induces immunity. Liver antigen-presenting cells may be involved in both immune tolerance and activation. Although inflammatory diseases of the liver are frequently associated with inflammatory bowel diseases, the underlying immunological mechanisms remain to be elucidated. Here we report two murine models of inflammatory bowel disease: RAG-2^-/- mice adoptively transferred with CD4⁺CD45RB^high T cells; and IL-10 ^-/- mice, accompanied by the infiltration of mononuclear cells in the liver. Notably, CD11b^-CD11c^lowPDCA-1⁺ plasmacytoid dendritic cells (DCs) abundantly residing in the liver of normal wild-type mice disappeared in colitic CD4⁺CD45RB^high T cell-transferred RAG-2^-/- mice and IL-10^-/- mice in parallel with the emergence of macrophages (Mφs) and conventional DCs (cDCs). Furthermore, liver Mφ/cDCs emerging during intestinal inflammation not only promote the proliferation of naïve CD4⁺ T cells, but also instruct them to differentiate into IFN-γ-producing Th1 cells in vitro. The emergence of pathological Mφ/cDCs in the liver also occurred in a model of acute dextran sulfate sodium (DSS)-induced colitis under specific pathogen-free conditions, but was canceled in germ-free conditions. Last, the Mφ/cDCs that emerged in acute DSS colitis significantly exacerbated Fas-mediated hepatitis. Collectively, intestinal inflammation skews the composition of antigen-presenting cells in the liver through signaling from commensal bacteria and predisposes the liver to inflammation. © 2014 Mikami et al.</p>

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Enhancement of leptin receptor signaling by SOCS3 deficiency induces development of gastric tumors in mice

Inagaki-Ohara K., Mayuzumi H., Kato S., Minokoshi Y., Otsubo T., Kawamura Y. I., Dohi T., Matsuzaki G., Yoshimura A.

Oncogene 33 （ 1 ） 74 - 84 2014年01月

ISSN  0950-9232

　概要を見る

<p>Leptin acts on its receptor (ObR) in the hypothalamus to inhibit food intake and energy expenditure. Leptin and ObR are also expressed in the gastrointestinal tract; however, the physiological significance of leptin signaling in the gut remains uncertain. Suppressor of cytokine signaling 3 (SOCS3) is a key negative feedback regulator of ObR-mediated signaling in the hypothalamus. We now show that gastrointestinal epithelial cell-specific SOCS3 conditional knockout (T3b-SOCS3 cKO) mice developed gastric tumors by enhancing leptin production and the ObRb/signal transducer and activator of transcription 3 (STAT3) signaling pathway. All T3b-SOCS3 cKO mice developed tumors in the stomach but not in the bowels by 2 months of age, even though the SOCS3 deletion occurred in both the epithelium of stomach and bowels. The tumors developed in the absence of the inflammatory response and all cKO mice died within 6 months. These tumors displayed pathology and molecular alterations, such as an increase in MUC2 (Mucin 2, oligomeric mucus/gel-forming) and TFF3 (trefoil factor 3), resembling human intestinal-type gastric tumors. Administration of antileptin antibody to T3b-SOCS3 cKO mice reduced hyperplasia of gastric mucosa, which is the step of the initiation of gastric tumor. These data suggest that SOCS3 is an antigastric tumor gene that suppresses leptin overexpression and ObRb/STAT3 hyperactivation, supporting the hypothesis that the leptin/ObRb/STAT3 axis accelerates tumorigenesis and that it may represent a new therapeutic target for the treatment of gastric cancer. © 2014 Macmillan Publishers Limited.</p>

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Macrophages and dendritic cells emerge in the liver during intestinal inflammation and predispose the liver to inflammation

Mikami Yohei, Mizuno Shinta, Nakamoto Nobuhiro, Hayashi Atsushi, Sujino Tomohisa, Sato Toshiro, Kamada Nobuhiko, Matsuoka Katsuyoshi, Hisamatsu Tadakazu, Ebinuma Hirotoshi, Hibi Toshifumi, Yoshimura Akihiko, Kanai Takanori

PLoS ONE 9 （ 1 ）  2014年01月

　概要を見る

<p>The liver is a physiological site of immune tolerance, the breakdown of which induces immunity. Liver antigen-presenting cells may be involved in both immune tolerance and activation. Although inflammatory diseases of the liver are frequently associated with inflammatory bowel diseases, the underlying immunological mechanisms remain to be elucidated. Here we report two murine models of inflammatory bowel disease: RAG-2^-/- mice adoptively transferred with CD4⁺CD45RB^high T cells; and IL-10 ^-/- mice, accompanied by the infiltration of mononuclear cells in the liver. Notably, CD11b^-CD11c^lowPDCA-1⁺ plasmacytoid dendritic cells (DCs) abundantly residing in the liver of normal wild-type mice disappeared in colitic CD4⁺CD45RB^high T cell-transferred RAG-2^-/- mice and IL-10^-/- mice in parallel with the emergence of macrophages (Mφs) and conventional DCs (cDCs). Furthermore, liver Mφ/cDCs emerging during intestinal inflammation not only promote the proliferation of naïve CD4⁺ T cells, but also instruct them to differentiate into IFN-γ-producing Th1 cells in vitro. The emergence of pathological Mφ/cDCs in the liver also occurred in a model of acute dextran sulfate sodium (DSS)-induced colitis under specific pathogen-free conditions, but was canceled in germ-free conditions. Last, the Mφ/cDCs that emerged in acute DSS colitis significantly exacerbated Fas-mediated hepatitis. Collectively, intestinal inflammation skews the composition of antigen-presenting cells in the liver through signaling from commensal bacteria and predisposes the liver to inflammation. © 2014 Mikami et al.</p>

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Enhancement of leptin receptor signaling by SOCS3 deficiency induces development of gastric tumors in mice

Inagaki-Ohara K., Mayuzumi H., Kato S., Minokoshi Y., Otsubo T., Kawamura Y. I., Dohi T., Matsuzaki G., Yoshimura A.

Oncogene 33 （ 1 ） 74 - 84 2014年01月

ISSN  0950-9232

　概要を見る

<p>Leptin acts on its receptor (ObR) in the hypothalamus to inhibit food intake and energy expenditure. Leptin and ObR are also expressed in the gastrointestinal tract; however, the physiological significance of leptin signaling in the gut remains uncertain. Suppressor of cytokine signaling 3 (SOCS3) is a key negative feedback regulator of ObR-mediated signaling in the hypothalamus. We now show that gastrointestinal epithelial cell-specific SOCS3 conditional knockout (T3b-SOCS3 cKO) mice developed gastric tumors by enhancing leptin production and the ObRb/signal transducer and activator of transcription 3 (STAT3) signaling pathway. All T3b-SOCS3 cKO mice developed tumors in the stomach but not in the bowels by 2 months of age, even though the SOCS3 deletion occurred in both the epithelium of stomach and bowels. The tumors developed in the absence of the inflammatory response and all cKO mice died within 6 months. These tumors displayed pathology and molecular alterations, such as an increase in MUC2 (Mucin 2, oligomeric mucus/gel-forming) and TFF3 (trefoil factor 3), resembling human intestinal-type gastric tumors. Administration of antileptin antibody to T3b-SOCS3 cKO mice reduced hyperplasia of gastric mucosa, which is the step of the initiation of gastric tumor. These data suggest that SOCS3 is an antigastric tumor gene that suppresses leptin overexpression and ObRb/STAT3 hyperactivation, supporting the hypothesis that the leptin/ObRb/STAT3 axis accelerates tumorigenesis and that it may represent a new therapeutic target for the treatment of gastric cancer. © 2014 Macmillan Publishers Limited.</p>

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A bidirectional crosstalk between iNKT cells and adipocytes mediated by leptin modulates susceptibility for T cell mediated hepatitis

Venken Koen, Seeuws Sylvie, Zabeau Lennart, Jacques Peggy, Decruy Tine, Coudenys Julie, Verheugen Eveline, Windels Fien, Catteeuw Dominiek, Drennan Michael, Van Calenbergh Serge, Lambrecht Bart N., Yoshimura Akihiko, Tavernier Jan, Elewaut Dirk

Journal of Hepatology 60 （ 1 ） 175 - 182 2014年01月

ISSN  0168-8278

　概要を見る

<p>Background &amp; Aims Immunometabolism is an emerging field of clinical investigation due to the obesity epidemic worldwide. A reciprocal involvement of immune mediators in the body energy metabolism has been recognized for years, but is only partially understood. We hypothesized that the adipokine leptin could provide an important modulator of iNKT cells. Methods The expression of leptin receptor (LR) on resting and activated iNKT cells was measured by flow cytometry. FACS-sorted hepatic iNKT cells were stimulated with anti-CD3/CD28Ab coated beads in the absence or presence of a neutralizing anti-leptin Ab. Furthermore, we evaluated the outcome of LR blocking nanobody treatment in ConA induced hepatitis and towards metabolic parameters in WT and iNKT cell deficient mice. Results The LR is expressed on iNKT cells and leptin suppresses iNKT cell proliferation and cytokine production in vitro. LR deficient iNKT cells are hyper-responsive further enforcing the role of leptin as an important inhibitor of iNKT cell function. Consistently, in vivo blockade of LR signaling exacerbated ConA hepatitis in wild-type but not in iNKT cell deficient mice, through both Janus kinase (JAK)2 and mitogen-activated protein kinase (MAPK) dependent mechanisms. Moreover, LR inhibition altered fat pad features and was accompanied by insulin resistance, only in wild-type mice. Curiously, this interaction was strictly dependent on MAPK mediated LR signaling in iNKT cells and uncoupled from the more central effects of leptin. Conclusions Our data support a new concept of immune regulation by which leptin protects towards T cell mediated hepatitis via modulation of iNKT cells. © 2013 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.</p>

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Protective role of JAK/STAT signaling against renal fibrosis in mice with unilateral ureteral obstruction

Koike Kiyomi, Ueda Seiji, Yamagishi Sho ichi, Yasukawa Hideo, Kaida Yusuke, Yokoro Miyuki, Fukami Kei, Yoshimura Akihiko, Okuda Seiya

Clinical Immunology 150 （ 1 ） 78 - 87 2014年01月

ISSN  1521-6616

　概要を見る

<p>Inflammation is involved in renal fibrosis, a final common pathway for kidney diseases. To clarify how JAK/STAT/SOCS system was involved in renal fibrosis, UUO was induced in BALB/c or SOCS3^+/- mice in the presence or absence of JAK inhibitor-incorporated nanoparticle (pyridine6-PGLA). UUO increased pSTAT3 and subsequently elevated SOCS3 levels in the obstructed kidneys. pSTAT3 levels were further increased in SOCS3^+/- mice. UUO-induced renal fibrosis was markedly suppressed in SOCS3^+/- mice, while it was aggravated by pre-treatment with pyridine6-PGLA. Although there were no differences in renal mRNA levels of TGF-β and collagens between wild and SOCS3^+/- mice, MMP-2 activity was enhanced in SOCS3^+/- UUO mice. Activated MMP-2 was completely suppressed by pyridine6-PGLA-pre-treatment. TNF-α one of JAK/STAT activators, increased pSTAT3 levels and subsequently induced MMP-2 activation in proximal tubular cells. These results suggest that JAK/STAT3 signaling may play a role in repair process of renal fibrosis in UUO partly via MMP-2 activation. © 2013 Elsevier Inc.</p>

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A bidirectional crosstalk between iNKT cells and adipocytes mediated by leptin modulates susceptibility for T cell mediated hepatitis

Venken Koen, Seeuws Sylvie, Zabeau Lennart, Jacques Peggy, Decruy Tine, Coudenys Julie, Verheugen Eveline, Windels Fien, Catteeuw Dominiek, Drennan Michael, Van Calenbergh Serge, Lambrecht Bart N., Yoshimura Akihiko, Tavernier Jan, Elewaut Dirk

Journal of Hepatology 60 （ 1 ） 175 - 182 2014年01月

ISSN  0168-8278

　概要を見る

<p>Background &amp; Aims Immunometabolism is an emerging field of clinical investigation due to the obesity epidemic worldwide. A reciprocal involvement of immune mediators in the body energy metabolism has been recognized for years, but is only partially understood. We hypothesized that the adipokine leptin could provide an important modulator of iNKT cells. Methods The expression of leptin receptor (LR) on resting and activated iNKT cells was measured by flow cytometry. FACS-sorted hepatic iNKT cells were stimulated with anti-CD3/CD28Ab coated beads in the absence or presence of a neutralizing anti-leptin Ab. Furthermore, we evaluated the outcome of LR blocking nanobody treatment in ConA induced hepatitis and towards metabolic parameters in WT and iNKT cell deficient mice. Results The LR is expressed on iNKT cells and leptin suppresses iNKT cell proliferation and cytokine production in vitro. LR deficient iNKT cells are hyper-responsive further enforcing the role of leptin as an important inhibitor of iNKT cell function. Consistently, in vivo blockade of LR signaling exacerbated ConA hepatitis in wild-type but not in iNKT cell deficient mice, through both Janus kinase (JAK)2 and mitogen-activated protein kinase (MAPK) dependent mechanisms. Moreover, LR inhibition altered fat pad features and was accompanied by insulin resistance, only in wild-type mice. Curiously, this interaction was strictly dependent on MAPK mediated LR signaling in iNKT cells and uncoupled from the more central effects of leptin. Conclusions Our data support a new concept of immune regulation by which leptin protects towards T cell mediated hepatitis via modulation of iNKT cells. © 2013 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.</p>

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Protective role of JAK/STAT signaling against renal fibrosis in mice with unilateral ureteral obstruction

Koike Kiyomi, Ueda Seiji, Yamagishi Sho ichi, Yasukawa Hideo, Kaida Yusuke, Yokoro Miyuki, Fukami Kei, Yoshimura Akihiko, Okuda Seiya

Clinical Immunology 150 （ 1 ） 78 - 87 2014年01月

ISSN  1521-6616

　概要を見る

<p>Inflammation is involved in renal fibrosis, a final common pathway for kidney diseases. To clarify how JAK/STAT/SOCS system was involved in renal fibrosis, UUO was induced in BALB/c or SOCS3^+/- mice in the presence or absence of JAK inhibitor-incorporated nanoparticle (pyridine6-PGLA). UUO increased pSTAT3 and subsequently elevated SOCS3 levels in the obstructed kidneys. pSTAT3 levels were further increased in SOCS3^+/- mice. UUO-induced renal fibrosis was markedly suppressed in SOCS3^+/- mice, while it was aggravated by pre-treatment with pyridine6-PGLA. Although there were no differences in renal mRNA levels of TGF-β and collagens between wild and SOCS3^+/- mice, MMP-2 activity was enhanced in SOCS3^+/- UUO mice. Activated MMP-2 was completely suppressed by pyridine6-PGLA-pre-treatment. TNF-α one of JAK/STAT activators, increased pSTAT3 levels and subsequently induced MMP-2 activation in proximal tubular cells. These results suggest that JAK/STAT3 signaling may play a role in repair process of renal fibrosis in UUO partly via MMP-2 activation. © 2013 Elsevier Inc.</p>

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Aryl hydrocarbon receptor plays protective roles in cona-induced hepatic injury by both suppressing IFN-γ expression and inducing IL-22

Abe Hiromi, Kimura Akihiro, Tsuruta Sanae, Fukaya Tomohiro, Sakaguchi Ryota, Morita Rimpei, Sekiya Takashi, Shichita Takashi, Chayama Kazuaki, Fujii-Kuriyama Yoshiaki, Yoshimura Akihiko

International Immunology 26 （ 3 ） 129 - 137 2014年

ISSN  0953-8178

　概要を見る

<p>The aryl hydrocarbon receptor (AhR), a ligand-activated nuclear transcription factor, is known to mediate the toxic and carcinogenic effects of various environmental pollutants, while AhR has been shown to protect animals from various types of tissue injury. ConA-induced hepatitis is known as a mouse model of acute liver injury. Here, we found a protective role of AhR in ConA-induced hepatitis. AhR is induced in the liver during ConA-induced hepatitis, and Ahr^-/- mice were highly sensitive to this model. Bone marrow chimera experiments indicate that Ahr^-/- hematopoietic cells are responsible for hypersensitivity to ConA-induced hepatitis. We found that IFN-γ from invariant NKT cells was up-regulated and IL-22 from innate lymphoid cells (ILCs) was abolished in Ahr^-/- mice. In addition, IL-22 production was still observed in Rag2^-/- mice but it was severely reduced in Ahr^-/-Rag2^-/- mice. ConA-induced IL-22 production was also dependent on retinoic acid-related orphan receptor γt. These results show that AhR has crucial protective roles in ConA-induced liver injury via promoting IL-22 production from ILCs and suppressing IFN-γ expression from NKT cells. © The Japanese Society for Immunology. 2013. All rights reserved.</p>

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Aryl hydrocarbon receptor protects against bacterial infection by promoting macrophage survival and reactive oxygen species production

Kimura Akihiro, Abe Hiromi, Tsuruta Sanae, Chiba Sayuri, Fujii-Kuriyama Yoshiaki, Sekiya Takashi, Morita Rimpei, Yoshimura Akihiko

International Immunology 26 （ 4 ） 209 - 220 2014年

ISSN  0953-8178

　概要を見る

<p>Aryl hydrocarbon receptor (AhR) is crucial for various immune responses. The relationship between AhR and infection with the intracellular bacteria Listeria monocytogenes (LM) is poorly understood. Here, we show that in response to LM infection, AhR is required for bacterial clearance by promoting macrophage survival and reactive oxygen species (ROS) production. AhR-deficient mice were more susceptible to listeriosis, and AhR deficiency enhances bacterial growth in vivo and in vitro. On the other hand, pro-inflammatory cytokines were increased in AhR-deficient macrophages infected with LM despite enhanced susceptibility to LM infection in AhR-deficient mice. Subsequent studies demonstrate that AhR protects against macrophage cell death induced by LM infection through the induction of the antiapoptotic factor, the apoptosis inhibitor of macrophages, which promotes macrophage survival in the setting of LM infection. Furthermore, AhR promotes ROS production for bacterial clearance. Our results demonstrate that AhR is essential to the resistance against LM infection as it promotes macrophage survival and ROS production. This suggests that the activation of AhR by its ligands may be an effective strategy against listeriosis. © The Japanese Society for Immunology. 2013. All rights reserved.</p>

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Spred-2 deficiency exacerbates lipopolysaccharide-induced acute lung inflammation in mice

Xu Yang, Ito Toshihiro, Fushimi Soichiro, Takahashi Sakuma, Itakura Junya, Kimura Ryojiro, Sato Miwa, Mino Megumi, Yoshimura Akihiko, Matsukawa Akihiro

PLoS ONE 9 （ 9 ） e108914 2014年

　概要を見る

<p>BACKGROUND: Acute respiratory distress syndrome (ARDS) is a severe and life-threatening acute lung injury (ALI) that is caused by noxious stimuli and pathogens. ALI is characterized by marked acute inflammation with elevated alveolar cytokine levels. Mitogen-activated protein kinase (MAPK) pathways are involved in cytokine production, but the mechanisms that regulate these pathways remain poorly characterized. Here, we focused on the role of Sprouty-related EVH1-domain-containing protein (Spred)-2, a negative regulator of the Ras-Raf-extracellular signal-regulated kinase (ERK)-MAPK pathway, in lipopolysaccharide (LPS)-induced acute lung inflammation.</p><p>METHODS: Wild-type (WT) mice and Spred-2(-/-) mice were exposed to intratracheal LPS (50 µg in 50 µL PBS) to induce pulmonary inflammation. After LPS-injection, the lungs were harvested to assess leukocyte infiltration, cytokine and chemokine production, ERK-MAPK activation and immunopathology. For ex vivo experiments, alveolar macrophages were harvested from untreated WT and Spred-2(-/-) mice and stimulated with LPS. In in vitro experiments, specific knock down of Spred-2 by siRNA or overexpression of Spred-2 by transfection with a plasmid encoding the Spred-2 sense sequence was introduced into murine RAW264.7 macrophage cells or MLE-12 lung epithelial cells.</p><p>RESULTS: LPS-induced acute lung inflammation was significantly exacerbated in Spred-2(-/-) mice compared with WT mice, as indicated by the numbers of infiltrating leukocytes, levels of alveolar TNF-α, CXCL2 and CCL2 in a later phase, and lung pathology. U0126, a selective MEK/ERK inhibitor, reduced the augmented LPS-induced inflammation in Spred-2(-/-) mice. Specific knock down of Spred-2 augmented LPS-induced cytokine and chemokine responses in RAW264.7 cells and MLE-12 cells, whereas Spred-2 overexpression decreased this response in RAW264.7 cells.</p><p>CONCLUSIONS: The ERK-MAPK pathway is involved in LPS-induced acute lung inflammation. Spred-2 controls the development of LPS-induced lung inflammation by negatively regulating the ERK-MAPK pathway. Thus, Spred-2 may represent a therapeutic target for the treatment of ALI.</p>

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Signal-transducing adaptor protein-2 regulates macrophage migration into inflammatory sites during dextran sodium sulfate induced colitis

Fujita Natsuko, Oritani Kenji, Ichii Michiko, Yokota Takafumi, Saitoh Norimitsu, Okuzaki Daisuke, Sekine Yuichi, Kon Shigeyuki, Muromoto Ryuta, Saitoh Kodai, Yoshimura Akihiko, Matsuda Tadashi, Kanakura Yuzuru

European Journal of Immunology 44 （ 6 ） 1791 - 1801 2014年

ISSN  0014-2980

　概要を見る

<p>Signal-transducing adaptor protein-2 (STAP-2) was cloned as a c-fms/M-CSF receptor interacting protein. STAP-2 is an adaptor protein carrying pleckstrin homology and Src homology 2 like domains, as well as a YXXQ motif. STAP-2 has been indicated to have an ability to bind and modulate a variety of signaling and transcriptional molecules. Especially, our previous in vitro studies showed that STAP-2 is crucial for immune and/or inflammatory responses. Here, we have investigated the role of STAP-2 in intestinal inflammation in vivo. The disruption of STAP-2 attenuates dextran sodium sulfate induced colitis via inhibition of macrophage recruitment. To study whether hematopoietic or epithelial cell derived STAP-2 is required for this phenomenon, we generated BM chimeric mice. STAP-2-deficient macrophages impair the ability of CXCL12-induced migration. Intriguingly, STAP-2 also regulates production of proinflammatory chemokines and cytokines such as CXCL1 and TNF-α from intestinal epithelial cells. Therefore, STAP-2 has a potential to regulate plural molecular events during pathological inflammatory responses. Furthermore, our findings not only indicate that STAP-2 is important in regulating intestinal inflammation, but also provide new insights toward the development of novel therapeutic approaches. © 2014 WILEY-VCH Verlag GmbH &amp; Co. KGaA, Weinheim.</p>

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SOCS1 and regulation of regulatory T cells plasticity

Takahashi Reiko, Yoshimura Akihiko

Journal of immunology research 2014   943149 2014年

　概要を見る

<p>Several reports have suggested that natural regulatory T cells (Tregs) lose Forkhead box P3 (Foxp3) expression and suppression activity under certain inflammatory conditions. Treg plasticity has been studied because it may be associated with the pathogenesis of autoimmunity. Some studies showed that a minor uncommitted Foxp3(+) T cell population, which lacks hypomethylation at Treg-specific demethylation regions (TSDRs), may convert to effector/helper T cells. Suppressor of cytokine signaling 1 (SOCS1), a negative regulator of cytokine signaling, has been reported to play an important role in Treg cell integrity and function by protecting the cells from excessive inflammatory cytokines. In this review, we discuss Treg plasticity and maintenance of suppression functions in both physiological and pathological settings. In addition, we discuss molecular mechanisms of maintaining Treg plasticity by SOCS1 and other molecules. Such information will be useful for therapy of autoimmune diseases and reinforcement of antitumor immunity. </p>

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Role of inflammatory cytokines in brain ischemia

Yoshimura Akihiko

Therapeutic Research 35 （ 9 ） 801 - 803 2014年

ISSN  0289-8020

Aryl hydrocarbon receptor plays protective roles in cona-induced hepatic injury by both suppressing IFN-γ expression and inducing IL-22

Abe Hiromi, Kimura Akihiro, Tsuruta Sanae, Fukaya Tomohiro, Sakaguchi Ryota, Morita Rimpei, Sekiya Takashi, Shichita Takashi, Chayama Kazuaki, Fujii-Kuriyama Yoshiaki, Yoshimura Akihiko

International Immunology 26 （ 3 ） 129 - 137 2014年

ISSN  0953-8178

　概要を見る

<p>The aryl hydrocarbon receptor (AhR), a ligand-activated nuclear transcription factor, is known to mediate the toxic and carcinogenic effects of various environmental pollutants, while AhR has been shown to protect animals from various types of tissue injury. ConA-induced hepatitis is known as a mouse model of acute liver injury. Here, we found a protective role of AhR in ConA-induced hepatitis. AhR is induced in the liver during ConA-induced hepatitis, and Ahr^-/- mice were highly sensitive to this model. Bone marrow chimera experiments indicate that Ahr^-/- hematopoietic cells are responsible for hypersensitivity to ConA-induced hepatitis. We found that IFN-γ from invariant NKT cells was up-regulated and IL-22 from innate lymphoid cells (ILCs) was abolished in Ahr^-/- mice. In addition, IL-22 production was still observed in Rag2^-/- mice but it was severely reduced in Ahr^-/-Rag2^-/- mice. ConA-induced IL-22 production was also dependent on retinoic acid-related orphan receptor γt. These results show that AhR has crucial protective roles in ConA-induced liver injury via promoting IL-22 production from ILCs and suppressing IFN-γ expression from NKT cells. © The Japanese Society for Immunology. 2013. All rights reserved.</p>

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Aryl hydrocarbon receptor protects against bacterial infection by promoting macrophage survival and reactive oxygen species production

Kimura Akihiro, Abe Hiromi, Tsuruta Sanae, Chiba Sayuri, Fujii-Kuriyama Yoshiaki, Sekiya Takashi, Morita Rimpei, Yoshimura Akihiko

International Immunology 26 （ 4 ） 209 - 220 2014年

ISSN  0953-8178

　概要を見る

<p>Aryl hydrocarbon receptor (AhR) is crucial for various immune responses. The relationship between AhR and infection with the intracellular bacteria Listeria monocytogenes (LM) is poorly understood. Here, we show that in response to LM infection, AhR is required for bacterial clearance by promoting macrophage survival and reactive oxygen species (ROS) production. AhR-deficient mice were more susceptible to listeriosis, and AhR deficiency enhances bacterial growth in vivo and in vitro. On the other hand, pro-inflammatory cytokines were increased in AhR-deficient macrophages infected with LM despite enhanced susceptibility to LM infection in AhR-deficient mice. Subsequent studies demonstrate that AhR protects against macrophage cell death induced by LM infection through the induction of the antiapoptotic factor, the apoptosis inhibitor of macrophages, which promotes macrophage survival in the setting of LM infection. Furthermore, AhR promotes ROS production for bacterial clearance. Our results demonstrate that AhR is essential to the resistance against LM infection as it promotes macrophage survival and ROS production. This suggests that the activation of AhR by its ligands may be an effective strategy against listeriosis. © The Japanese Society for Immunology. 2013. All rights reserved.</p>

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Spred-2 deficiency exacerbates lipopolysaccharide-induced acute lung inflammation in mice

Xu Yang, Ito Toshihiro, Fushimi Soichiro, Takahashi Sakuma, Itakura Junya, Kimura Ryojiro, Sato Miwa, Mino Megumi, Yoshimura Akihiko, Matsukawa Akihiro

PLoS ONE 9 （ 9 ） e108914 2014年

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<p>BACKGROUND: Acute respiratory distress syndrome (ARDS) is a severe and life-threatening acute lung injury (ALI) that is caused by noxious stimuli and pathogens. ALI is characterized by marked acute inflammation with elevated alveolar cytokine levels. Mitogen-activated protein kinase (MAPK) pathways are involved in cytokine production, but the mechanisms that regulate these pathways remain poorly characterized. Here, we focused on the role of Sprouty-related EVH1-domain-containing protein (Spred)-2, a negative regulator of the Ras-Raf-extracellular signal-regulated kinase (ERK)-MAPK pathway, in lipopolysaccharide (LPS)-induced acute lung inflammation.</p><p>METHODS: Wild-type (WT) mice and Spred-2(-/-) mice were exposed to intratracheal LPS (50 µg in 50 µL PBS) to induce pulmonary inflammation. After LPS-injection, the lungs were harvested to assess leukocyte infiltration, cytokine and chemokine production, ERK-MAPK activation and immunopathology. For ex vivo experiments, alveolar macrophages were harvested from untreated WT and Spred-2(-/-) mice and stimulated with LPS. In in vitro experiments, specific knock down of Spred-2 by siRNA or overexpression of Spred-2 by transfection with a plasmid encoding the Spred-2 sense sequence was introduced into murine RAW264.7 macrophage cells or MLE-12 lung epithelial cells.</p><p>RESULTS: LPS-induced acute lung inflammation was significantly exacerbated in Spred-2(-/-) mice compared with WT mice, as indicated by the numbers of infiltrating leukocytes, levels of alveolar TNF-α, CXCL2 and CCL2 in a later phase, and lung pathology. U0126, a selective MEK/ERK inhibitor, reduced the augmented LPS-induced inflammation in Spred-2(-/-) mice. Specific knock down of Spred-2 augmented LPS-induced cytokine and chemokine responses in RAW264.7 cells and MLE-12 cells, whereas Spred-2 overexpression decreased this response in RAW264.7 cells.</p><p>CONCLUSIONS: The ERK-MAPK pathway is involved in LPS-induced acute lung inflammation. Spred-2 controls the development of LPS-induced lung inflammation by negatively regulating the ERK-MAPK pathway. Thus, Spred-2 may represent a therapeutic target for the treatment of ALI.</p>

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Signal-transducing adaptor protein-2 regulates macrophage migration into inflammatory sites during dextran sodium sulfate induced colitis

Fujita Natsuko, Oritani Kenji, Ichii Michiko, Yokota Takafumi, Saitoh Norimitsu, Okuzaki Daisuke, Sekine Yuichi, Kon Shigeyuki, Muromoto Ryuta, Saitoh Kodai, Yoshimura Akihiko, Matsuda Tadashi, Kanakura Yuzuru

European Journal of Immunology 44 （ 6 ） 1791 - 1801 2014年

ISSN  0014-2980

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<p>Signal-transducing adaptor protein-2 (STAP-2) was cloned as a c-fms/M-CSF receptor interacting protein. STAP-2 is an adaptor protein carrying pleckstrin homology and Src homology 2 like domains, as well as a YXXQ motif. STAP-2 has been indicated to have an ability to bind and modulate a variety of signaling and transcriptional molecules. Especially, our previous in vitro studies showed that STAP-2 is crucial for immune and/or inflammatory responses. Here, we have investigated the role of STAP-2 in intestinal inflammation in vivo. The disruption of STAP-2 attenuates dextran sodium sulfate induced colitis via inhibition of macrophage recruitment. To study whether hematopoietic or epithelial cell derived STAP-2 is required for this phenomenon, we generated BM chimeric mice. STAP-2-deficient macrophages impair the ability of CXCL12-induced migration. Intriguingly, STAP-2 also regulates production of proinflammatory chemokines and cytokines such as CXCL1 and TNF-α from intestinal epithelial cells. Therefore, STAP-2 has a potential to regulate plural molecular events during pathological inflammatory responses. Furthermore, our findings not only indicate that STAP-2 is important in regulating intestinal inflammation, but also provide new insights toward the development of novel therapeutic approaches. © 2014 WILEY-VCH Verlag GmbH &amp; Co. KGaA, Weinheim.</p>

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