Abstract: Objective To investigate the immunological effects of human keratin 17 (K17) on T lymphocytes from psoriatic patients.Methods Total RNA was extracted from the epidermis of psoriatic lesions,and mRNA was reversely transcribed to cDNA.The K17 gene was amplified by PCR and inserted into pGEX-4T-1 expression vector,and then K17 was expressed and purified.T cells were isolated and purified by gra-dient centrifugation and AET-SRBC (2-aminoethylosothiouronium bromide-treated sheep red blood cells) precipitation.MTT assay and direct cell counting method were used to detect the proliferation of T cells.The concentration of IFN-γ in culture supernatant was measured by ELISA.Results Compared with the control group,K17 significantly enhanced the proliferation of T cells from psoriatic patients and increased the expression level of IFN-γ(P<0.001 respectively).Conclusion K17 can enhance the function of T cells in psoriatic patients,and it may play a role as an autoantigen in the immunological pathogenesis of psoriasis.

Key words: Psoriasis, Keratin, Interferon typeⅡ