组织相容性抗原是细胞表面的蛋白分子,能激发受体的免疫系统对移植物的排斥反应。这种细胞表面蛋白被发现已近五十年,直到70年代免疫学家才懂得它们在T淋巴细胞介导的免疫反应中起重要作用。这种作用的分子本质,尤其是“组织相容性的限制性”现象,至今仍认识不清并存在争论。 T淋巴细胞,特别是辅助性T细胞,对许多免疫反应的启动起关键作用。辅助性T细胞与表面展示着外来抗原的抗原提呈细胞(anti-senpresenting cells)相互作用时被活化。辅 Histocompatibility Antigens are protein molecules on the cell surface that stimulate the recipient’s immune system to reject rejection of the graft. This cell surface protein was discovered for nearly fifty years until immunologists in the 1970s learned that they played an important role in T lymphocyte-mediated immune responses. The molecular nature of this role, and in particular the “limited compatibility of tissues,” is still unclear and controversial. T lymphocytes, especially helper T cells, play a key role in the initiation of many immune responses. Helper T cells are activated upon interaction with anti-senpresenting cells that exhibit foreign antigens on their surface. auxiliary