寻常型天疱疮的Dsg3特异性抗体反应及其基因限制性

探讨寻常型天疱疮中的自身抗原桥粒芯蛋白（Dsg3)特异性抗体反应及其基因限制性，为自身免疫性疾病机制的研究提供依据。采用RT－PCR法克隆自身抗原Dsg3E1,E2,E3,E4,E5多肽片段的cDNA，定向插入表达载体PGEX－2T，导入大肠杆菌JM109中表达重组融合蛋白并经GST层析柱纯化，进一步经免疫印迹法与PV患者阳性血清反应；应用序列特异性引物聚合酶链式反应（SSP－PCR）技术对HLA－Ⅱ类等位基因进行特异性体外扩增，分析了天疱疮患者HLA基因的DR位点的DRB1、DQB1多态性。Dsg3 E1,E2和E4可与PV患者阳性血清反应，而不与疾病对照组、正常对照组反应。在10个PV患者中，均携带HLA的DR4或／和DR14抗原，有7个DRB1*0402,4个DRB1*1401,7个DQB1*0302,4个DQB1*0503.Dsg3 E1,E2和E4中包含抗体反应相关的抗原表位，HLA DRB1*0402t DQB1＊0302与PV发病中抗E4抗体反应密切相关。

Specific antibody response and immunogenetic factors of autoantigen Dsg3 in pemphigus vulgaris

To understand the molecular mechanism of autoimmune diseases by means of analyzing specific anti Dsg3 antibody response and immunogenetic factors in PV. Based on the sequence analysis of autoantigen Dsg3, five cDNAs fractions of Dsg3 were cloned and the five relevent Dsg3 GST fusion proteins induced by TPTG in E.coli. JM109 were purified., The epitopes of Dsg3 were analyzed by IBT. The patients' HLA DR alleles were analyzed by SSP PCR. Dsg3 E1, E2 and E4 reacted with PV patients' sera, but not with the controls. Among the 10 patients with PV, all had DR4 or DR14 antigen, 7DRB1*0402,4 DRB1*1401, 7 DQB1*0302, 4 DQB1*0503, Dsg3 E1, E2, E4 and E5 expressed the epitopes reactive to autoantibody response, DRB1*0402 and DQB1*0302 play important roles in antigen recognition in the pathogenesis of pemphigus vulgaris.