antigen-independent ifn-γ production by human na？ve cd4+ t cells activated by il-12 plus il-18antigen-independent ifn-γ生产由人类天真cd4 + t细胞激活il - 12 +的地震.pdfVIP

¨ Antigen-Independent IFN-c Production by Human Naıve CD4+ T Cells Activated by IL-12 Plus IL-18 1. 1. 1 1 1 Rachel B. Munk , Katsuki Sugiyama , Paritosh Ghosh *, Carl Y. Sasaki , Louis Rezanka , Kasturi 2 1 2 1 Banerjee , Hidenori Takahashi , Ranjan Sen , Dan L. Longo 1 Lymphocyte Cell Biology Unit, Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, United States of America, 2 Gene Regulation Section, Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, United States of America Abstract The role of T cells in innate immunity is not well defined. In this report, we show that a subset of human peripheral blood CD4+ T cells responds to IL-12 plus IL-18, but not to IL-12 or IL-18 alone, by producing IFN-c in the absence of any antigenic stimulation or cell proliferation. Intracellular staining reveals a small percentage of resting CD4+ T cells (0.5 to 1.5%) capable ¨ + + + of producing IFN-c in response to IL-12 plus IL-18. Interestingly, both naıve (CD45RA ) and memory (CD45RO ) CD4 populations were responsive to IL-12 plus IL-18 stimulation in producing IFN-c. The expression of IFN-cinduced by IL-12 and IL-18 is sensitive to rapamycin and SB203580, indicating the possible invol