抗原提呈相关转运体基因多态性与慢性HBV感染研究进展

Transporter associated with antigen processing gene polymorphism and chronic HBV infection

抗原提呈相关转运体（TAP）在内源性抗原提呈过程中有重要作用，负责内源性抗原从胞浆到内质网腔的转运。TAP是由TAP1基因和TAP2基因编码的TAP1和TAP2组成的异二聚体。TAP基因具有多态性。乙型肝炎病毒（HBV）作为细胞内抗原，主要是经过内源性抗原加工和提呈途径而启动免疫应答的，TAP1／TAP2基因多态性的改变造成了分子结构异常，则会出现抗原呈递的功能障碍，抗原提呈不能有效进行，HBV抗原肽不能被细胞毒细胞识别而清除，则形成HBV的慢性持续感染。

The transporter associated with antigen processing （TAP） plays a pivotal role in the presentation of intracellular antigen by translocating intracellular antigenic peptides from the cytosol into the lumen of endoplasmic reticulum （ER）. TAP is a heterodimer of TAP1 and TAP2 protein encoded by TAP1 and TAP2 genes. Both genes exhibit genetic polymorphisms. Hepatitis B Vivus （HBV） antigens, as an intracellular antigens, antigens are presented mainly, through the endogenous antigen processing and presenting ways to activate the immune response. The polymorphisms located at TAP1/TAP2 gene coding regions may result in the structural and functional changes of TAP1/TAP2 complex, which subsequently interferes with the HBV peptide translocation, and leads to the chronically persistent infection of HBV because HBV peptide can not be recognized and removed by CTL. Here, the structure, function, and gene polymorphism of TAP, and its relationship with HBV chronic infection are reviewed.