人类抗原加工相关转运体结构和功能的研究进展

在人类获得性免疫中,为了有效的激活细胞毒T淋巴细胞,MHC-I抗原肽复合体在细胞表面的表达甚为关健.这一过程涉及到多种蛋白的共同参与,如MHC-I、抗原加工相关转运体(TAP)、蛋白酶体和各种分子伴侣如Tapasin,ERp57,钙网蛋白等等.而负责运输抗原肽,并把它负载到MHC-I分子上的是TAP,这一步受阻,将导致细胞表面MHC-I类分子的低表达或不表达,严重影响免疫监视.

Recent advances on the structure and function of the transporter associated with antigen processing

It is pivotal to express of the MHC-I-poptide complexes on the cell surface for effective activating cytotoxic T lymphocytes(CTLs)in the process of adaptive immune response.There are several components working together during this process including major histocompatibility complex class Ⅰ molecules(MHC-I),the transporter associated with antigen processing(TAP),proteasome,ERp57,tapasin and calreticulin,etc.The most important component is TAP by which antigen poptides are transloeated into endoplasmic reticulum (ER)lumen from cytosol and then loaded onto MHC-I.If this step was obstructed,it would cause MHC-Ipeptide deficiency and failed immune surveillance.The structure and function of TAP and the relationship between TAP and diseases are reviewed here.