SARS康复者M抗原特异性记忆性T细胞免疫应答的探讨  

Memory T cell response specific to SARS-CoV M peptides in PBMCs from recovered SARS patients

作　　者：杨利桃[1] 朱兆玲[1] 刘惠萍[2] 李刚[3] 黄子通[4] Richard A.Koup Robert T.Bailer 吴长有[1] 

机构地区：[1]中山大学基础医学院免疫学教研室 [2]中国人民解放军第458医院全军肝病中心 [3]中山大学附属三院 [4]中山大学附属二院 [5]Vaccine Research Center,NIAID/NIH,Bethesda,MD20892,USA

出　　处：《免疫学杂志》2006年第5期511-514,518,共5页Immunological Journal

基　　金：国家自然科学基金资助项目(30340012);广东省科技计划科技攻关引导项目(2003Z3-E0491);广东省教育厅联合赞助科技攻关项目;国家科技部973计划(4108000)资助

摘　　要：目的探讨SARS患者康复后,外周血单个核细胞(PBMCs)中是否存在SARS-CoVM抗原特异性T细胞。方法从完全康复期SARS患者和健康人外周血中分离PBMCs,体外经M混合多肽刺激后,采用酶联免疫吸附试验(ELISA)、酶联免疫斑点试验(ELISpot)及流式细胞仪检测技术,分析抗原特异性T淋巴细胞的反应性。结果在未经任何抗原刺激的情况下,PBMCs几乎不分泌IFN-γ。当SARS-CoVM混合多肽刺激后,SARS康复期患者的PBMCs分泌大量的IFN-γ,并可检测出高频率的IFN-γ产生细胞。与健康刺激组及康复期SARS患者未刺激组相比,差异显著(P<0.05)。流式结果显示,SARS康复期患者PBMCs经M多肽刺激后,分别有0.11%CD4+和0.16%CD8+T淋巴细胞分泌IFN-γ。根据IFN-γ和IL-2的表达与否,可将CD4+T细胞分为三个亚群IFN-γ-IL-2+、IFN-γ+IL-2+和IFN-γ+IL-2-。结论SARS-CoV感染后,机体可以产生针对SARS-CoVM蛋白的抗原特异性细胞免疫反应,其免疫记忆可以在体内维持很长时间。Objective To elucidate the long-lasting memory T cell immune response specific to SARS-CoV M antigen in PBMCs from recovered SARS patients. Methods PBMCs were isolated from peripheral blood and cultured in the presence or absence of SARS-CoV M peptides. The level of IFN-γ in the culture supematants was examined by ELISA; the frequency of IFN-γ producing cells and subsets of IFN-γ producing cells were analyzed at the single cell level by ELISpot and flow cytometry, respectively. Resets The expressions of IFN-γ in recovered SARS patients and healthy donors were not different when PBMCs were stimulated with polyclonal stimuli （OKT3 ＋ anti-CD28）. However, high level of IFN-γ in culture supematants and high frequency of IFN-γ^＋ producing cells in PBMCs were detected by ELISA and ELISpot respectively when the PBMCs from recovered SARS patients were cultured with SARS-CoV M peptides in vitro, but not PBMCs from normal individuals. Further studies demonstrated that both CD4^＋ and CD8^＋ T cells could express IFN-γ （0.11% and 0.16%） upon stimulation with SARS-CoV M peptides in vitro. Based on the expression of IFN-γ and IL-2, CD4^＋ T cells could be divided into three subsets： IFN-γ^- IL-2^＋, IFN-γ^＋ IL-2^＋, and IFN-γ^＋ IL-2^-. Conclusion SARS-CoV M-specific memory T cells persist for more than one year in vivo and display the capacity to secrete IFN-γ and IL-2 upon subsequent stimulation with SARS-CoV M peptides in vitro.

关 键 词：严重急性呼吸综合征(SARS) M抗原多肽 记忆性T细胞 IFN-γ 

分 类 号：R392[医药卫生—免疫学]