Abstract: Dong Juan, Wang Ying, Zhu Haiqin, Xu Renchao, Zheng Jie, Pan Meng*. *Department of Dermatology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China Corresponding author: Pan Meng, Email: panmeng@medmail.com.cn 【Abstract】 Objective To study the changes of antigen-specific T helper type 1 （Th1） cells and Th2 cells in patients with pemphigus vulgaris（PV） at different stages, so as to better understand the roles of autoreactive T cells in PV. Methods The DG3 （96 － 112） peptide was synthesized. Twenty-four patients with PV and 10 health checkup examinees were included in this study. Peripheral blood mononuclear cells （PBMCs） were obtained from the health checkup examinees and all the patients before treatment and seven patients about one month after treatment, and stimulated with the DG3 peptide of 10 mg/L for different durations. Then, enzyme-linked immunospot （ELISPOT） assay was performed to count the number of DG3-specific IFN-γ+ Th1 cells, IL-4+ Th2 cells and memory B cells. One-way analysis of variance （ANOVA） and t test were done to compare the number of cells between different groups, and Pearson correlation coefficient was used to evaluate the correlation among Th cells, memory B cells and anti-desmoglein 3 （Dsg3） antibody titers. Results In these patients, the male to female ratio was 1.67 ∶ 1, and the average age was （56.59 ± 14.66） years. Compared with the health check-up examinees, the patients with PV showed a higher absolute number of DG3-specific IFN-γ+ Th1 cells （420.18 ± 350.29 vs. 145.12 ± 86.56, t = 3.25, P < 0.05）, but a similar absolute number of specific IL-4+ Th2 cells （366.76 ± 192.44 vs. 335.88 ± 164.96, P > 0.05） per 5 × 105 PBMCs. The percentage of DG3-specific IL-4+ Th2 cells in Th2 cells was 37.03% ± 23.44%, and the percentage of IFN-γ+ Th1 cells was 23.62% ± 16.77% in peripheral blood of patients with PV. The number of DG3-specific IL-4+ Th2 cells per 5 × 105 PBMCs significantly decreased from 452.82 ± 199.29 before treatment to 241.68 ± 160.60 after treatment in seven patients （t = 2.48, P < 0.05）. There was no significant correlation between specific Th cells, memory B cells and anti-Dsg3 antibody titers （all P > 0.05）. Conclusions The peptide DG3 （96－112） has pathogenic epitopes which could be recognized by specific Th cells of patients with PV. Both antigen-specific IFN-γ+ Th1 cells and IL-4+ Th2 cells play certain roles in the pathogenesis of pemphigus vulgaris, and IL-4+ Th2 cells appear to be more important.

Key words: Pemphigus, Th1 cells, Th2 cells, Epitopes, T-lymphocyte, ELISPOT