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Journal of Biomedicine and Biotechnology
Volume 2010 (2010), Article ID 641757, 8 pages
Review Article

Regulation of the Induction and Function of Cytotoxic T Lymphocytes by Natural Killer T Cell

Department of Informative Clinical Medicine, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu City 501-1194, Japan

Received 29 November 2009; Revised 14 February 2010; Accepted 9 March 2010

Academic Editor: Kim Klonowski

Copyright © 2010 Hiroyasu Ito and Mitsuru Seishima. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Cytotoxic T lymphocytes (CTLs) play a crucial role in the infections and the antitumor immunity. Induction and activation of antigen-specific CTLs is an important strategy in immunotherapy for various diseases, and several researchers have focused on the modulation of CTL induction and function. Natural killer T (NKT) cells are an important focus area of researchers studying immunomodulatory responses to tumors and infectious diseases. CD1d-restricted NKT cells consist of type I NKT cells and type II NKT cells. 𝛼 -galactosylceramide ( 𝛼 -GalCer)-activated type I NKT cells secrete both Th1 (e.g., IFN- 𝛾 ) and Th2 cytokines, affect the expression of costimulatory molecules in immune cells, and regulate the host immune system. Type II NKT cells, however, are stimulated by sulfatide, a self-glycolipid derived from myelin, and play an immunosuppressive role in animal model of autoimmune diseases. CTL generation, activation, and suppression are strongly affected by activated type I and type II NKT cells. Thus, the regulation of these NKT cells leads to the modification of CTL function. CTLs contribute to antimicrobial responses, antitumor immune and autoimmune responses. Understanding the role of NKT cells in the regulation of CTL generation, activation, and suppression enable the development of novel treatment strategies for these diseases.