人外周血卡介苗(BCG)特异性中央型和效应型记忆CD4^+ T细胞的特征  

Characterization of memory T cells following stimulation with BCG

作　　者：范艳莹[1] 杨利桃[1] 李丽[1] 吴长有[1] 

机构地区：[1]中山大学基础医学院免疫学教研室,广州510080

出　　处：《中国免疫学杂志》2006年第5期403-406,共4页Chinese Journal of Immunology

基　　金：国家重点基础研究发展计划973资助项目(2001CB510007);国家自然科学基金(创新群体)资助项目(30321004)

摘　　要：目的:探讨正常人外周血BCG特异性记忆T细胞的特征。方法:分离PPD-和PPD+正常人PBMCs,与BCG进行培养,采用ELISA法检测细胞培养上清液中IFN-γ的水平,ELISPOT法检测分泌IFN-γ的细胞数,利用流式细胞仪在单个细胞水平上检测细胞表面分子及细胞内因子IFN-γ和IL-2的表达及其关系。结果:当BCG刺激后,PPD-正常人PBMCs不产生或只产生少量的IFN-γ,而PPD+者IFN-γ产生的量和细胞数均明显增加(P<0·05)。流式细胞检测分析的结果表明,当BCG刺激后,主要是CD4+而非CD8+T细胞表达IFN-γ和IL-2,两者相比具有显著差异。在CD4+T细胞中单独产生IFN-γ的细胞占大多数,其次为IFN-γ和IL-2双阳性细胞,只产生IL-2的细胞占少数。此外,85%~95%以上的CD4+IFN-γ+T细胞为CD45RO+,其中60%以上的细胞为CCR7+,其余的为CCR7-。同样地,80%~95%左右的细胞为CD62L-。结论:BCG可以诱导抗原特异性记忆CD4+T细胞的产生,其中大多数为中央型记忆CD4+T细胞,少数为效应记忆CD4+T细胞,提示其在预防和控制结核分枝杆菌感染中发挥重要作用。Objective： To elucidate the characterization of antigen-specific memory T cells from PPD^＋ individuals after stimulation with BCG in vitro, Methods：PBMCs were isolated from PPD^-/＋ normal human peripheral blood and stimulated with BCG, The level of IFN-γin the culture supematants was assayed by ELISA and the frequency of IFN-γ-preducinging cells was detected by ELISPOT. The subsets and frequency of cytokine-producing cells were determined at a single cell level by flow cytometry, Results： After stimulation with BCG, PBMCs from PPD^＋ but not PPD - individuals produced significantly high levels of IFN-γ in culture supematants detected by ELISA（P 〈 0. 05 ）, similar results were confirmed with the ELISPOT detection. Flow cytometric analysis indicated that BCG could induce IFN-γand IL-2 production predominantly by CD4^＋T cells but not by CD8^＋T cells. Further analysis suggested that 85% -95% CD4^＋IFN-γ^＋ cells were memory cells in which more than 60% of cells were effector memory（CCR7^＋）T cells and the rest of them were central memory T cells（ CCR7^- ）, In addition, 80% -95% of the cells were CD62L^-. Conclusion： BCG could induce the generation of antigen-specific effector/memory CD4^＋ T cells and maintained in vivo.

关 键 词：BCG 记忆T细胞 γ-干扰素 CCR7 CD62L 

分 类 号：R392[医药卫生—免疫学]