LIHGT-HVEM/LTbR途径缺陷诱导T细胞的失能

Induction of T cells anergy by the deficiency of LIGHT-HVEM/LTbR signal pathway

目的探讨LIGHT-HVEM/LTbR信号通路缺陷对T细胞应答的影响。方法以LIGHTKO小鼠为动物模型,制备脾脏单细胞悬液,加入抗CD3mAb和抗CD28mAb刺激。通过3H-TdR掺入法检测了细胞的增殖能力、ELISA和FACS分别检测了细胞培养上清和胞内IFN-gamma和IL-10的水平,并探讨了这些细胞对外源性rIL-2的反应性。结果与野生型的C57BL/6小鼠相比,LIGHTKO小鼠的脾细胞表现为低下的增殖活性(P<0.05);细胞培养上清中Th1细胞因子IFN-gamma的水平显著下降(P<0.05);与ELISA结果一致,FACS胞内染色结果表明,IFN-gamma阳性T细胞的百分率显著下降,而LIGHTKO小鼠脾细胞IL-10的产生却显著高于野生型的对照小鼠(P<0.01)。进一步的研究表明LIGHTKO小鼠这种缺陷的IFN-gamma产生主要与CD8+T细胞亚群有关,而CD4+T细胞亚群IFN-gamma的产生是正常的。外源性rIL-2的加入可使LIGHTKO小鼠T细胞恢复正常的增殖能力和IFN-gamma的产生。结论 LIGHT-HVEM/LTbR信号通路缺陷导致T细胞的失能。

To explore the effects of LIGHT-HVEM/LTbR signal pathway deficiency on the T cells response,LIGHT KO mice was used as an animal model in this study. Single cell suspension from the spleen was prepared and stimulated with purified anti-CD3 mAb plus anti-CD28 mAb in vitro. Then cell proliferation was determined by 3H-TdR incorporation,while the cultural supernatant and intracellular IFN-gamma and IL-10 levels were measured by ELISA and FACS,respectively. In contrast to WT C57BL/6 mice,cells from LIGHT KO mice showed impaired proliferation ability （P 0.05）,as well as decreased IFN-gamma production both in the cultural supernatant （P 0.05） and in the intracellular expression,but IL-10 production was significant higher than that of cells from WT C57BL/6 mice （P 0.01）. Further results showed that the defective IFN-gamma production in T cells of the LIGHT KO mice was associated mainly with CD8＋ T cells subpopulation,while the production of IFN-gamma in the CD4＋ T cells subpopulation was normal. The impaired proliferation and IFN-gamma production of cells from LIGHT KO mice can be restored by the addition of exogenous rIL-2. All the results suggest that the T cells show an anergic phenotype in the deficiency of LIGHT-HVEM/LTbR signal pathway.