Immune Regulation

kao Koichi Ikuta, M.D., Ph.D. Professor  btn

The immune system has acquired sophisticated control mechanisms as a result of evolution through the war between host and microorganism. Cytokines are the molecules important for the immune system. Our laboratory aims to elucidate control mechanisms on development and response of the immune system by cytokines. We welcome young students with much enthusiasm and interest in immunology.

Research and Education

Interleukin-7 (IL-7) is a cytokine important for differentiation and maintenance of lymphocytes. Focusing on IL-7, our laboratory is now pursuing the following research projects.
(1) Function of IL-7 in differentiation, maturation, and response of immune cells: IL-7 is involved in regulation of T lymphocyte response. We are analyzing this process in relation with T cell metabolism.
(2) Control of DNA recombination of lymphocyte antigen receptor genes by IL-7: We are studying how the transcription factor STAT5 controls chromatin status by epigenetics and high-order chromatin structure.
(3) Regulation of IL-7 receptor expression: Expression of the IL-7 receptor is strictly regulated during developmental stages of lymphocytes. We are investigating this mechanism in relation with T cell receptor signals and the endocrine system.
(4) Visualization and function of IL-7- and IL-15-producing stromal cells: In addition to lymphocytes, lymphoid tissues contain stromal cells that form the microenvironment supporting development and response of lymphocytes. We aim to elucidate the immune microenvironment by analyzing cytokine-producing stromal cells (Figure 1).
In our laboratory, every graduate student will be involved in one of the projects and trained to acquire the ability to plan, accomplish, and publish one’s work, with the knowledge and techniques on molecular biology, cell biology, and immunology.

生田先生                          Figure 1. Dectection of IL-15 (CFP)-expressing cells in IL-15-CFP knock-in mouse
In the thymus (left), IL-15-expressing cells are detected in medulla. In the lymph node (right), IL-15-expressing cells are mainly detected in T cell zone, medulla, and blood vessels.

           r-098-21 Figure 2. Laboratory members

Recent Publications

1. Cui G, Hara T, Simmons S, Wagatsuma K, Abe A, Miyachi H, Kitano S, Ishii M, Tani-ichi S, and Ikuta K. (2014) Characterization of the interleukin-15 niche in primary and secondary lymphoid organs in vivo. Proc Natl Acad Sci USA, 111:1915-1920.
2. Shitara S, Hara T, Liang B, Wagatsuma K, Zuklys S, Hollander GA, Nakase H, Chiba T, Tani-ichi S, and Ikuta K. (2013) Interleukin-7 produced by thymic epithelial cells plays a major role in the development of thymocytes and TCRgd+ intraepithelial lymphocytes. J Immunol, 190:6173-6179.
3. Tani-ichi S, Shinba A, Wagatsuma K, Miyachi H, Kitano S, Imai K, Hara T, and Ikuta K. (2013) The interleukin-7 receptor controls development and maturation of late stages of thymocyte subpopulations. Proc Natl Acad Sci USA, 110:612-617.
4. Hara T, Shitara S, Imai K, Miyachi H, Kitano S, Yao H, Tani-ichi S, and Ikuta K. (2012) Identification of interleukin-7-producing cells in primary and secondary lymphoid organs using IL-7-GFP knock-in mice. J Immunol, 189:1577-1584.
5. Liang B, Hara T, Wagatsuma K, Zhang J, Maki K, Miyachi H, Kitano S, Yabe-Nishimura C, Tani-ichi S, and Ikuta K. (2012) Role of hepatocyte-derived IL-7 in maintenance of intrahepatic NK T and T cells and development of B cells in fetal liver. J Immunol, 189:4444-4450.


Professor: Koichi Ikuta
Assistant Professor: Shizue Tani-ichi, Takahiro Hara
TEL +81-75-751-4012
FAX +81-75-751-4810