The roles of gammadelta T cells in host defense aginst bacterial infection

γδ T 细胞在宿主防御细菌感染中的作用

基本信息

批准号：
02454191
负责人：
YOSHIKAI Yasunobu
金额：
$ 4.29万
依托单位：
Nagoya University (1991-1992)Kyushu University (1990)
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1992
项目状态：
已结题

项目摘要

T cells recognize nominal antigens in the context of self-MHC antigens by T cell receptor(TcR) which is composed of alpha and beta chains. Another type of TcR, which is composed of gamma and delta chains has also identified. At least a significant fraction of gamma/delta T cells are reported to be specialized to recognize epitopes on mycobacterial antigens, suggesting that the gamma/delta bearing T cells may participate in immune surveillance against invasion with the various pathogens.To elucidate a potential role of the gamma/delta T cells in host-defense against bacterial infection,we examined the kinetics of gamma/delta T cells and their ligands during intraperitoneal infections with Listeria monocytogenes, Salmonella chorelaesuis and BCG.During infection with such intracellular bacteria, TcR gamma/delta T cells specific for 65kd hsp precede TcR alpha/beta T cells specific for bacterial antigens in appearance. The gamma/delta T cells provide a first line of defense against the infection by recognizing exogenous and endogenous 65 kd hsp on infected cells and producing cytokines such as gammaIFN. Our results suggest that the hsp- specific gamma/delta T cells respond quickly to antigenically diverse pathogens before antigen-specific alpha/beta T cells expand clonally, and they play a role in covering the gap between the phagocytic system and highly evolved immune response mediated by alpha/beta T cells.

T细胞在由α和β链组成的T细胞受体（TCR）的自我MHC抗原的背景下识别名义抗原。也确定了由伽马和三角洲链组成的另一种类型的TCR。据报道，至少有很大一部分γ/delta T细胞专门识别分枝杆菌抗原的表位，这表明γ/delta轴承T细胞可能会参与免疫监视，以防止患有各种病原体的入侵。在针对细菌感染的宿主防御性的伽马/三角细胞中，我们检查了γ/三角洲T细胞的动力学及其在腹膜内感染单核细胞增生李斯特氏蛋白酶的过程中，单核细胞增生李斯特氏菌，沙门氏菌葡萄球菌和BCG。对65KD HSP的T细胞先于TCRα/βT细胞在外观中针对细菌抗原特异的TCR细胞。通过识别受感染细胞的外源和内源性65 kD HSP并产生诸如γFN等细胞因子的外源和内源性65 kD HSP，伽马/三角洲T细胞通过识别外源和内源性65 kD HSP提供了对感染的第一道防线。我们的结果表明，在抗原特异性α/βT细胞之前，HSP-特异性γ/delta T细胞对抗原多样性的病原体迅速反应，并且它们在覆盖吞噬系统和高度演化的免疫反应介导的差距方面发挥了作用由alpha/beta T细胞。