Requirements for the Differentiation of CD4^+ Cytotoxic T cells Specific to Mycobacterial Antigens

다국어 초록 (Multilingual Abstract)

The cytolytic activity of CD4^+ T cells, both buman and murine, has been clearly domonstrated in the immune response to mycobacterial infection and suggested to play a significant role in the protection and immunopathology. However, little is knows about the differentiation of CD4^+ CTL. In order to address this issue, we examined the influences of some factors on the generation of CD4^+ CTL specific to mycobacterial antigens. After 7 day's stimulation of PBMCs from healthy tuberculin reactors with mycobacterial antigens, the cytolytic activity of purified CD4^+ T cells toward autologous macrophages infected with mycobacteria was measured by ^51Cr release assay. Frist, we found that both of live M.tuberculosis and soluble antigens (ST-CF) induced the cytolytic activity of CD4+ T cells, although the inducibility of the former was slightly greater than the latter. Second, the cytolytic activity was maximally induced at the relatively low antigen concentration (0.2:1 bacteria:monocyte ratio or 0.5 μg/ml of ST-CF). Finally, in the presence of increasing amounts of neutralizing anti-IL-12 or anti-IFN-γ MoAb, the cytolytic activity of CD4^+ T cells was decreased in a dose-dependent manner. These results suggest that low dose of antigen its particulate type(live mycobacteria), IL-12, IFN-γ give some positive signals for the generation of CD4^+ CTL.

목차 (Table of Contents)

• Introduction
• Materials and Methods
• Results
• Discussion
• References