Abstract:

Sun Xiuwen, Li Bing, Zhang Weigang, Dang Erle, Jin Liang, Wang Gang. Department of Dermatology, Xijing Hospital, Fourth Military Medical University, Xi′an 710032, China Corresponding author: Wang Gang, Email: xjwgang@fmmu.edu.cn 【Abstract】 Objective To investigate the distribution and proportion of CD8α+α+ T cells in lesions and peripheral blood of patients with psoriasis, and to assess their roles in the pathogenesis of psoriasis. Methods An immunofluorescence assay was performed to observe the distribution of CD8α+α+ T cells in lesions of 5 patients with progressive psoriasis vulgaris and normal skin of 5 healthy human controls. Flow cytometry was conducted to determine the proportion of CD8α+α+ T cells, and to measure the expressions of interferon （IFN）-γ and tumor necrosis factor （TNF）-α in peripheral blood from 10 patients with progressive psoriasis vulgaris and 8 healthy human controls. Statistical analysis was carried out by t test with GraphPad Prism software. Results A massive infiltrate mainly composed of CD8α+α+ T cells but not CD8α+β+ T cells was observed in the upper dermis of lesions from the 5 patients with psoriasis, while there was no infiltrate of CD8α+β+ or CD8α+α+ T cells in the normal skin of 5 healthy human controls. Flow cytometry revealed that the proportion of CD8α+α+ T cells was significantly higher in peripheral blood from 10 patients with psoriasis than in that from 8 healthy human controls （26.47% ± 12.99% vs. 9.12% ± 4.80%, t = 3.96, P < 0.001）. Significant differences were also noted between the psoriatic patients and healthy human controls in the percentage of cells secreting IFN-γ （47.36% ± 19.38% vs. 13.44% ± 9.21%, t = 4.54, P < 0.001） and cells secreting TNF-α （54.14% ± 21.14% vs. 34.03% ± 17.22%, t = 2.17, P < 0.05） in peripheral blood CD8α+α+ T cells. Conclusions Both the distribution and proportion of CD8α+α+ T cells are increased in lesions and peripheral blood from patients with psoriasis, suggesting that CD8α+α+ T cells may be the main subgroup of CD8+ T cells that contribute to the pathogenesis of psoriasis.