IL-15Rα-/- dendritic cells primed CD4+ T cells into hyperproliferation and IL-10 overproduction upon restimulation

• Main Authors: Shih Cheih Lin, 林士傑
• Other Authors: T. S. Wu
• Format: Others
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/70786057055507799376

碩士 === 長庚大學 === 生物醫學研究所 === 98 === IL-15 transpresentation has been demonstrated indispensable for the development and homeostasis of CD8+ T cells, natural killer cells, and natural killer dendritic cells. Yet, its role for CD4+ T cells has never been elucidated. We here demonstrated that compared with their wild type (wt) counterparts primed in wt mice, IL-15Rα-/- CD4+ T cells primed in IL-15Rα-/- mice were hyperproliferated and produced enhanced amounts of IL-10 upon restimulation. This phenomenon also applied to alternative immunization route and antigen. Results from subsequent substitution of TCR transgenic CD4+ T cells for endogenous IL-15Rα-/- CD4+ T cells further revealed that the observed hyperproliferation and enhanced IL-10 production was independent of in vivo primed CD4+ T cells, but was attributed to the IL-15Rα-/- microenvironment. Direct in vitro stimulation of CD4+ T cells by IL-15Rα-/- dendritic cells (DCs) in the presence of cognate antigen resulted in effector cells that were hyperproliferation and overproduced IL-10 upon restimulation. Our results suggested that CD4+ T cells hyperproliferated and generated enhanced IL-10 production during restimulation when they were primed by IL-15Rα-/- DCs. These results lead us to speculate that IL-15 transpresentation plays a major role in adequate CD4+ T cell priming. In the absence of IL-15 transpresentation, CD4+ T cells differentiate into a state where the proliferation and overall IL-10 production would be enhanced upon restimulated.