MHC II类分子表达调控的研究进展

MHCII类分子提呈经过加工的抗原给CD4 T淋巴细胞 ,在诱发免疫反应中起重要作用。MHCII类分子不正常表达会引起严重的免疫缺陷疾病 ,如裸淋巴细胞综合征 (BLS)等。目前已识别出四种不同的MHCII调控基因。这些基因分别编码RFXANK、RFX5、RFXAP和CIITA。其中 ,前三个是RFX复合物的亚基 ,RFX是一种结合于所有MHCII类基因启动子上的泛式表达的因子。CIITA是MHCII类分子表达的主要调控因子 ,其严密调控的表达模式决定了MHCII类分子表达的细胞特异性 ,及能否被诱导且在何种水平上表达。本文着重介绍近年来国内外对MHCII类分子表达及其调控研究的新进展

Research progress on regulation of class II MHC expression

Class II MHC antigens play a critical role in the induction of immune responses through presentation of processed antigen to CD4 T lymphocytes. The absence of MHC II normal expression results in severe primary immunodeficiency diseases, such as the bare lymphocyte syndrome (BLS). Four different MHC II regulatory genes have been identified. These genes encode RFXANK, RFX5, RFXAP and CIITA. The first three are subunits of RFX, a ubiquitously expressed factor that binds to the promoters of all MHC II genes. CIITA is the master control factor for MHC II expression. The highly regulated expression pattern of CIITA ultimately dictates the cell type specificity, induction and level of MHC II expression. This review focuses on reseach progress on regulation of class II MHC expression in recent years.