小胶质细胞表达OX40L对T细胞增殖与凋亡的影响  

Regulation of T cell proliferation and apoptosis by microglia via OX40L costimulatory pathway

作　　者：王艳艳[1] 李茂全[2] 宋敏[1] 白云[1] 

机构地区：[1]第三军医大学医学遗传学教研室,重庆400038 [2]成都医学院公共卫生学教研室

出　　处：《中华微生物学和免疫学杂志》2006年第9期805-811,共7页Chinese Journal of Microbiology and Immunology

基　　金：国家杰出青年科学基金海外青年学者合作研究基金资助项目(30228018)

摘　　要：目的鉴定免疫共刺激分子OX40配体(OX40 ligand,OX40L)在小胶质细胞上的表达,并探讨OX40L信号在小胶质细胞对中枢神经系统内T细胞增殖与凋亡中的作用。方法通过RT- PCR、免疫印迹和流式细胞术检测小胶质细胞株N9活化前后OX40L在mRNA和蛋白水平的表达变化,细胞免疫化学法鉴定原代小胶质细胞上OX40L表达情况。体外将小胶质细胞株N9与活化后T细胞共培养并阻断OX40L信号后,3H-TdR掺入实验和FITC-annexin-V／PI荧光染色方法分别检测T细胞的增殖和凋亡情况,ELISA检测T细胞分泌IL-2的水平。结果小胶质细胞株N9活化前后均有OX40L表达,其蛋白表达率由23％增加为94％;原代小胶质细胞活化后表达OX40L。小胶质细胞表达OX40L后显著增强了T细胞增殖和IL-2分泌,抑制了T细胞凋亡。结论小胶质细胞活化后表达OX40L分子,OX40L-OX40信号可促进活化后T细胞增殖,抑制其凋亡,从而可能在维持中枢神经系统内T细胞免疫应答效应中发挥重要作用。有助于了解中枢神经系统内固有细胞和T细胞的相互作用机制,进一步认识OX40L的表达及功能。Objective To detect the expression of costimulatory molecule OX40L on microglia and explore the role of OX40L in the proliferation and apoptosis of the T ceils in the central nervous system （CNS）. Methods Expression changes of OX40L mRNA and protein on N9 murine microglial cell line were tested by RT-PCR, Western blot and FACS. The expression of OX40L on primary murine microglia was assayed by immunocytochemistry. After activated T cells were co-cultured with irradiated N9 expressing OX40L and the OX40-OX40L signal pathway was blocked with a neutralizing anfi-OX40L McAb, the proliferation of T cells was measured by ^3H-TdR incorporation test, the T cells were labeled with FITC-annexin-Ⅴ/PI and assessed by FACS, and the secretion of IL-2 was quantified by ELISA. Results OX40L was detected on N9 cell line and it was significantly up-regulated after activation. Primary culture of microglia was successful with positive staining with OX40L after stimulated by LPS and mIFN-γ. OX40L expressed on N9 could promote the proliferation of T ceils and IL-2 secretion, and suppress the apoptosis of T cells. Conclusion We firstly found that OX40L was expressed on activated N9 cell line and primary routine microglia in vitro. OX40L on microglia could increase the proliferation of T cells, maintain the T cell response in the CARS, and suppress the T cells apoptesis, which may be one of the mechanisms. These results will help elucidate the molecular mechanisms of the interaction between resident cells in the CNS and T cells, and further understand the expression and function of cestimulatory molecule OX40L.

关 键 词：小胶质细胞 T淋巴细胞 共刺激分子 OX40L 中枢神经系统 

分 类 号：R392[医药卫生—免疫学]