结核分枝杆菌对巨噬细胞抗原呈递功能的抑制作用  

Mycobacterium tuberculosis inhibits antigen presentation in macrophages

作　　者：王翠妮[1] 徐薇[1] 熊思东[1] 

机构地区：[1]复旦大学免疫生物学研究所,复旦大学上海医学院免疫学系,上海200032

出　　处：《微生物与感染》2009年第3期132-136,184,共6页Journal of Microbes and Infections

基　　金：国家"十一.五"重大项目(2008zx10003011;2009zx10004-104);国家高技术研究发展计划(863)资助项目(2006AA02Z403);国家自然科学基金(30772020);上海市科技项目(064319024;07QA14005)

摘　　要：本文旨在通过观察结核分枝杆菌刺激后巨噬细胞抗原呈递功能的变化,探讨结核分枝杆菌的免疫逃逸机制。在体外,结核分枝杆菌刺激巨噬细胞24h后,用流式细胞仪检测γ干扰素(IFN-γ)诱导的主要组织相容性复合物(MHC)Ⅱ类分子、CD86和CD80的表达变化;酶联免疫吸附试验(ELISA)检测巨噬细胞的抗原呈递功能;反转录-聚合酶链反应检测巨噬细胞CⅡTA及其启动子PⅠ、PⅢ和PⅣ的mRNA水平。结果发现,结核分枝杆菌抑制IFN-γ诱导的巨噬细胞表面MHCⅡ类分子和CD86的表达,且呈剂量依赖性,但CD80的表达变化不明显;抗原呈递功能明显降低;结核分枝杆菌刺激后巨噬细胞CⅡTA及其启动子PⅠ、PⅢ和PⅣ的mRNA水平显著降低。提示结核分枝杆菌可能通过降低CⅡTA及其启动子PⅠ、PⅢ和PⅣ的mRNA水平,抑制IFN-γ诱导的巨噬细胞MHCⅡ类分子的表达;结核分枝杆菌可降低巨噬细胞CD86的表达,抑制IFN-γ诱导的巨噬细胞抗原呈递功能。The present study was aimed to investigate major histocompatibility complex Ⅱ （MHC Ⅱ） antigen presentation induced by interferon-γ （ IFN-γ ） in macrophages after exposure to Mycobacterium tuberculosis （ M. tuberculosis ）. The expressions of MHC 11 , CD86, and CD80 on macrophages, after exposure to M. tuberculosis for 24 h prior to the addition of IFN-γ, were detected by flow cytometry. The mRNA levels of C ⅡTA, P Ⅰ ,PⅢ and PIV were assayed by reverse transeriptase-polymerase chain reaction. MHC Ⅱ antigen presentation was detected by enzymelinked immunosorbent assay （ELISA）. The results showed that M. tuberculosis inhibited the expressions of MHC Ⅱ and CD86 but not CD80 induced by IFN-γ on macrophages. The ability of antigen presentation was also inhibited. The mRNA levels of C ⅡTA, P Ⅰ , PⅢ and PⅣ induced by IFN-γ were also decreased. It suggests that M. tuberculosis inhibits MHC Ⅱ antigen presentation induced by IFN-γ on macrophages.

关 键 词：结核分枝杆菌 抗原呈递 Γ干扰素 

分 类 号：R392[医药卫生—免疫学]