Abstract: Objective To study the effects of recombinant chimeric toxin Dsg3EC_1-2PE40 on T and B cells from PV patients. Methods The recombinant protein Dsg3EC_1-2PE40 was expressed on BL21TrxB (DE3) cells, then identified and purified. ELISPOT assay was used to detect and quantitate autoantibody-producing B cells in different concentrations of recombinant chimeric toxin, and MTT assay and ³H-TdR assay to observe the metabolism and proliferation of T cells from PV patients in vitro. Results The purity of expressed protein Dsg3EC_1-2PE40 was up to 80%. The number of anti-Dsg3 antibody-producing B cells in PBMC from PV patients decreased by 40% with treatment of Dsg3EC_1-2PE40, which was significantly lower (P<0.01) than those with treatment of Dsg3EC_1-2. Compared with Dsg3EC_1-2, Dsg3EC_1-2PE40 markedly inhibited the metabolism and proliferation of T cells from PV patients (P<0.01). Conclusions Recombinant chimeric toxin Dsg3EC_1-2PE40 can reduce the number of anti-Dsg3 antibody-producing B cells and inhibit or kill T cells from PV patients in vitro.

Key words: Pemphigus, Immunotoxins, Desmoglein