MHCⅡ类分子在向CD4+T细胞提呈经过加工的抗原和诱发免疫反应中起重要作用。MHCⅡ类分子异常表达会引起裸淋巴细胞综合征等严重的免疫缺陷性疾病。目前已知CⅡTA是决定MHCⅡ类分子表达的主要调节因子。此外CⅡTA还影响着自身免疫性疾病、感染性疾病、肿瘤排斥、移植耐受等。因此,Ⅱ类反式激活蛋白作为影响诸多基因的单体蛋白,在干预MHCⅡ类分子提呈抗原途径上是理想的药物治疗靶点。 MHC class II molecules play an important role in presenting processed antigens and inducing immune responses to CD4 + T cells. Aberrant expression of MHC class II molecules can cause severe immunodeficiency diseases such as bare-cell syndrome. It is currently known that CIITA is the main regulatory factor that determines the expression of MHC class II molecules. In addition C Ⅱ TA also affects autoimmune diseases, infectious diseases, tumor rejection, transplant tolerance and so on. Therefore, class II transactivator protein as a single protein that affects many genes is an ideal target for drug therapy in the intervention of MHC class II antigen presenting pathways.