RECOMBINANT EXPRESSION AND EPITOPE ANALYSIS OF AUTOANTIGEN Dsg3 IN PEMPHIGUS VULGARIS / 解放军医学杂志

ABSTRACT

The present study was to analyze the epitopes of autoantigen Dsg3 in pemphigus vulgaris (PV), and to elucidate the molecular mechanisms underlying autoimmune diseases. Based on the sequence analysis of autoantigen Dsg3 in Genbank five fragments of Dsg 3 cDNA (E1, E2, E3, E4, and E5) were cloned using RT PCR. Then PCR products were inserted into the expression vector pGEX 2T, and transformed into JM109 strain of E. coli. Dsg3 recombinant proteins were purified from the cell lysates. The epitopes of Dsg3 in PV patients were analyzed with five Dsg3 recombinant proteins by Western blot. The results showed that Dsg3 E1, E2 and E4 recombinant proteins reacted with PV patients′ sera, but not with control or normal sera. The dominant epitopes of Dsg3 in PV patients were different. The above data indicated that the epitopes of Dsg3 were located in E1, E2, and E4, which might play an important role in the pathogenesis of pemphigus vulgaris.