Hiroshi Kiyono

Publications (3)20.7 Total impact

• Article: Ecto-Nucleoside Triphosphate Diphosphohydrolase 7 Controls Th17 Cell Responses through Regulation of Luminal ATP in the Small Intestine.

  Takashi Kusu, Hisako Kayama, Makoto Kinoshita, Seong Gyu Jeon, Yoshiyasu Ueda, Yoshiyuki Goto, Ryu Okumura, Hiroyuki Saiga, Takashi Kurakawa, Kayo Ikeda, [......], Jun-Ichi Nishimura, Yasunobu Arima, Koji Atarashi, Kenya Honda, Masaaki Murakami, Jun Kunisawa, Hiroshi Kiyono, Meinoshin Okumura, Masahiro Yamamoto, Kiyoshi Takeda
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  ABSTRACT: Extracellular ATP is released from live cells in controlled conditions, as well as dying cells in inflammatory conditions, and, thereby, regulates T cell responses, including Th17 cell induction. The level of extracellular ATP is closely regulated by ATP hydrolyzing enzymes, such as ecto-nucleoside triphosphate diphosphohydrolases (ENTPDases). ENTPDase1/CD39, which is expressed in immune cells, was shown to regulate immune responses by downregulating the ATP level. In this study, we analyzed the immunomodulatory function of ENTPDase7, which is preferentially expressed in epithelial cells in the small intestine. The targeted deletion of Entpd7 encoding ENTPDase7 in mice resulted in increased ATP levels in the small intestinal lumen. The number of Th17 cells was selectively increased in the small intestinal lamina propria in Entpd7(-/-) mice. Th17 cells were decreased by oral administration of antibiotics or the ATP antagonist in Entpd7(-/-) mice, indicating that commensal microbiota-dependent ATP release mediates the enhanced Th17 cell development in the small intestinal lamina propria of Entpd7(-/-) mice. In accordance with the increased number of small intestinal Th17 cells, Entpd7(-/-) mice were resistant to oral infection with Citrobacter rodentium. Entpd7(-/-) mice suffered from severe experimental autoimmune encephalomyelitis, which was associated with increased numbers of CD4(+) T cells producing both IL-17 and IFN-γ. Taken together, these findings demonstrate that ENTPDase7 controls the luminal ATP level and, thereby, regulates Th17 cell development in the small intestine.
  The Journal of Immunology 12/2012; · 5.79 Impact Factor
• Article: Dietary folic Acid promotes survival of foxp3+ regulatory T cells in the colon.

  Makoto Kinoshita, Hisako Kayama, Takashi Kusu, Tomoyuki Yamaguchi, Jun Kunisawa, Hiroshi Kiyono, Shimon Sakaguchi, Kiyoshi Takeda
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  ABSTRACT: Dietary compounds as well as commensal microbiota contribute to the generation of a unique gut environment. In this study, we report that dietary folic acid (FA) is required for the maintenance of Foxp3(+) regulatory T cells (Tregs) in the colon. Deficiency of FA in the diet resulted in marked reduction of Foxp3(+) Tregs selectively in the colon. Blockade of folate receptor 4 and treatment with methotrexate, which inhibits folate metabolic pathways, decreased colonic Foxp3(+) Tregs. Compared with splenic Tregs, colonic Tregs were more activated to proliferate vigorously and were highly sensitive to apoptosis. In colonic Tregs derived from mice fed with a FA-deficient diet, expression of anti-apoptotic molecules Bcl-2 and Bcl-xL was severely decreased. A general reduction of peripheral Tregs was induced by a neutralizing Ab against IL-2, but a further decrease by additional FA deficiency was observed exclusively in the colon. Mice fed with an FA-deficient diet exhibited higher susceptibility to intestinal inflammation. These findings reveal the previously unappreciated role of dietary FA in promotion of survival of Foxp3(+) Tregs that are in a highly activated state in the colon.
  The Journal of Immunology 08/2012; 189(6):2869-78. · 5.79 Impact Factor
• Source

  Available from: Hirokazu Tsuji

  Article: Probiotic Bifidobacterium breve induces IL-10-producing Tr1 cells in the colon.

  Seong Gyu Jeon, Hisako Kayama, Yoshiyasu Ueda, Takuya Takahashi, Takashi Asahara, Hirokazu Tsuji, Noriko M Tsuji, Hiroshi Kiyono, Ji Su Ma, Takashi Kusu, Ryu Okumura, Hiromitsu Hara, Hiroki Yoshida, Masahiro Yamamoto, Koji Nomoto, Kiyoshi Takeda
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  ABSTRACT: Specific intestinal microbiota has been shown to induce Foxp3(+) regulatory T cell development. However, it remains unclear how development of another regulatory T cell subset, Tr1 cells, is regulated in the intestine. Here, we analyzed the role of two probiotic strains of intestinal bacteria, Lactobacillus casei and Bifidobacterium breve in T cell development in the intestine. B. breve, but not L. casei, induced development of IL-10-producing Tr1 cells that express cMaf, IL-21, and Ahr in the large intestine. Intestinal CD103(+) dendritic cells (DCs) mediated B. breve-induced development of IL-10-producing T cells. CD103(+) DCs from Il10(-/-), Tlr2(-/-), and Myd88(-/-) mice showed defective B. breve-induced Tr1 cell development. B. breve-treated CD103(+) DCs failed to induce IL-10 production from co-cultured Il27ra(-/-) T cells. B. breve treatment of Tlr2(-/-) mice did not increase IL-10-producing T cells in the colonic lamina propria. Thus, B. breve activates intestinal CD103(+) DCs to produce IL-10 and IL-27 via the TLR2/MyD88 pathway thereby inducing IL-10-producing Tr1 cells in the large intestine. Oral B. breve administration ameliorated colitis in immunocompromised mice given naïve CD4(+) T cells from wild-type mice, but not Il10(-/-) mice. These findings demonstrate that B. breve prevents intestinal inflammation through the induction of intestinal IL-10-producing Tr1 cells.
  PLoS Pathogens 05/2012; 8(5):e1002714. · 9.13 Impact Factor