Kyushu University Academic Staff Educational and Research Activities Database
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Yasunobu Yoshikai Last modified date:2016.08.18



Graduate School
Undergraduate School
Other Organization


E-Mail
Homepage
http://www.bioreg.kyushu-u.ac.jp/kansenseigyo/home0.html
Phone
092-642-6972
Fax
092-642-6973
Academic Degree
Doctor of Medical Science
Field of Specialization
Immunology
Outline Activities
The host defense mechanisms against microbial infection are largely divided into two phases. Most of microorganisms are detected and destroyed within hours by innate immunity which preexist and are not antigen-specific. Innate immunity is mainly mediated by macrophages and neutrophils. Adaptive response is mediated by antigen-specific lymphocytes, which require several days for clonal expansion and differentiation of naive lymphocytes into effector cells. We have proposed a novel host defense mechanism termed " primitive immunity", which bridges the gap between innate and adaptive immunity in terms of the time sequence after infection. "Primitive immunityÅh, which is mediated by NK, NKT cells and gd T cells, can be activated by infection but does not generate lasting protective immunity. The "primitive immunity" serve not only to bridge the gap between innate and adaptive immunity but also to shape subsequent development of adaptive immunity against microbiral infection. We investigate the role of “primitive immunity” in microbial infection, tumor development and inflammatory diseases including allergy and autoimmunity.
Research
Research Interests
  • Infection and immunity
    keyword : bacteria, virus, fungus, tumor, allergy
    2011.04~2018.03.
  • Infection and Immunity
    keyword : bacteria, virus, fungus, tumor, allergy
    1977.04~2011.03Immunological system evolves during battle against various pathogens. Therefore, understanding host defense mechanism against microbial infection leads to elucidate whole immunological system. The host defense mechanisms against bacterial infection are largely divided into three phases. Most of microorganisms are detected and destroyed within hours by innate immunity which preexist and are not antigen-specific. Innate immunity is mainly mediated by phagocytes such as macrophages and neutrophils. "Primitive immunity?h can be activated by infection but does not generate lasting protective immunity. "Primitive immunity" serve not only to bridge the gap between innate and adaptive immunity but also to shape subsequent development of adaptive immunity against bacterial infection. There are several lines of evidence that NK, NKT cells, gd T cells and CD5B cells are involved in “primitive immunity” against bacterial infection. Adaptive response is mediated by antigen-specific lymphocytes, which require several days for clonal expansion and differentiation of naive lymphocytes into effector cells. During this period, specific immunological memory is established, providing long-lasting protection against re-infection. Th1 cells produce IFN-g which mediate cell-mediate immunity, while Th2 cells help B cell to produce antibody via IL-4, 5 ,6 production. Th3 cells producing TGF-b and contribute to oral tolerance and Tr1 cells producing IL-10 are responsible for termination of excessive immune inflammations. We investigate host defense mechanisms against microbial infection, tumor development and inflammatory diseases including allergy and autoimmunity to establish prophylactic and therapeutic approach to control these diseases..
Academic Activities
Papers
1. Nishimura H.. , Yajima T., Muta H., Podack E.R., Tani K., and Yoshikai Y., A novel role of CD30/CD30L signaling in the generation of long-lived memory CD8+T cells, J.Immunol, 175, 7, 175:4627-34., 2005.10.
2. Yajima T., Nishimura H., Sad S., Shen.H. , Kuwano H. and Yoshikai Y., Critical role of IL-15 in early activation of memory CD8+ CTL after re-infection., J.Immunol., 174:3590-7., 2005.03.
3. Nishimura H., Fujimoto A., Naoyuki T., Yajima T., Wajjwalku W, and Yoshikai Y., A novel autoregulatory mechanism for transcriptional activation of IL-15 gene by Non-secretable Isoform of IL-15 Generated by Alternative Splicing, FASEB J, 19, 1, 19:19-28, 2005, 2005.01.
4. Tagawa, T., Nishimura, H., Yajima, T., Hara, H., Kishihara, K., Matsuzaki, G., Yoshino,I., Maehara, Y. and Yoshikai. Y., Vdelta1-gamma delta T cells producing CC chemokines may bridge a gap between neutrophils and macrophages in innate immunity during Escherichia coli infection in mice, J. Immunol., 173:5156-5164, 2004.09.
5. Nishimura, H., Yajima, T., Naiki, Y., Tsunobuchi, H., Umemura, M., Itano, K.,Matsuguchi, T., Suzuki, M., Ohashi, P, M., and Yoshikai, Y.:, Differential roles of IL-15 mRNA isoforms generated by alternative splicing in immune responses in vivo., J. Exp. Med., 191:157-170, 2000., 2000.01.
Educational
Social
Professional and Outreach Activities
Immunostimulating food.