CTLA4Ig诱导免疫耐受的体外研究

目的 观察CTLA4Ig在诱导人外周血T细胞免疫耐受中的作用。方法 以结核菌素刺激人外周血淋巴细胞，观察不同剂量CTLA4Ig对外周血淋巴细胞增殖反应的影响；观察CTLA4Ig和CsA(环孢霉素A)对再次结核菌素刺激和非相关第三者APC细胞刺激淋巴细胞增殖反应的影响，IL-2的变化，以及外源性IL-2对免疫耐受诱导的影响。结果 CTLA4Ig抑制淋巴细胞增殖呈剂量依赖关系，20μg／ml时抑制作用最强；CTLA4Ig能诱导免疫耐受并与CsA有协同作用；外源性IL-2能抑制免疫耐受的诱导。结论 CTLA4Ig能抑制淋巴细胞的增殖和IL-2的分泌释放，CTLA4Ig和CsA联合应用能更彻底抑制淋巴细胞增殖和IL-2的分泌释放，并诱导免疫耐受；外源性IL-2能逆转免疫耐受。

Experimental study of immune tolerance induced by CTLA4Ig in vitro

Objective To study the roles of cytologic T lymphocyte-associated antigen 4 immunoglobulin ( CTLA4Ig) in the induction of human T cell immune tolerance. Methods The effects of different doses of CTLA4Ig on the human T cell proliferation induced by tuberculin as well as those of CTLA4Ig and cyclosporin A (CsA) on the human lymphocyte proliferation re-stimulated by tuberculin or by the third party antigen-presenting cells (APC) were observed. The changes of IL-2 and effect of IL-2 on the immune tolerance were also observed. Results Tuberculin-induced T cell proliferation was inhibited by CTLA4Ig in a dose-dependent manner. The inhibitory effect was the strongest when the dose of CTLA4Ig was 20 fig/ml. CTLA4Ig could induce the immune tolerance and had a cooperative effect with CsA, but IL-2 could inhibit the immune tolerance. Conclusion CTLA4Ig can inhibit T cell proliferation and IL-2 excretion. Combination of CTLA4Ig and CsA can completely inhibit T cell proliferation and IL-2 excretion but can induce immune tolerance. The immune tolerance can be reversed by IL-2.