ICOS/GL50信号在T细胞依赖性体液免疫应答中的作用

Role of ICOS/GL50 Signal in T Cell Dependent Humoral Immune Responses

研究ICOS/GL5 0信号在T细胞体外增殖、细胞因子分泌以及B细胞抗体分泌中的作用 ,进一步探讨该信号途径在机体体液免疫应答中的作用机制。采用3 H TdR检测GL5 0 L92 9转染细胞和特异性鼠抗人GL5 0单抗对T细胞体外增殖的作用 ;ELISA法检测GL5 0 L92 9转染细胞和抗人GL5 0单抗对T细胞分泌IL 2、IL 10以及ICOS L92 9转染细胞和特异性鼠抗人GL5 0单抗对PWM介导的B细胞分泌抗体的效应。结果提示GL5 0 L92 9转染细胞能够促进经抗CD3单抗活化的T细胞增值和分泌IL 10 ,而抗GL5 0单抗可以阻断这些效应。ICOS分子与B细胞上GL5 0分子的结合上调PWM介导的B细胞分泌抗体而抗GL5 0单抗则下调这一效应。这些表明 ,ICOS/GL5

To understand the role of ICOS/GL50 si gnal in T-cell dependent humoral immune responses by determining the signal function in T cell proliferation and cytokine secretion as well as B cell antibody production in vitro. GL50 and ICOS transfected L929 cells and the specific mouse-anti-human GL50 mAb were employed to study their impact on the proliferation of T cells in vitro by 3H-TdR measurements and on the cytokine secretion (IL-2 and IL-10) from anti-CD3 pretreated T cells and the antibody production from PWM-driven B cells by ELISA assay. Our results indicated that the stimulation GL50-L929 transfectants up regulated the vitro. Proliferat ion of preactivated T cells in absence of CD28 signaling, whose activation, however, furthered the proliferation enhancement, while the specific anti-GL50 mAb inhibited the T-cell proliferation. The treatment of GL50-L929 transfectants induced an enhanced production of IL-10, but not IL-2, from anti-CD3 experienced T cells while the IL-10 production was down regulated by anti-GL50 mAbs addition . The level of antibody secretion from PWM-driven B cells was upgraded in presence of ICOS-L929 stimulation. Anti-GL50 mAbs treatment, however, partly abrogated the up regulating effect. In conclusion, ICOS/CL50 signal played a key role in the secondary T cell dependent humoral immune responses.