Expression of CD127 on T regulatory cells in psoriasis

Background: Psoriasis is a relapsing chronic inflammatory skin disease where Treg cells appeared to be impaired. CD4 + CD25 + FoxP3 + Treg cells play vital role in immune tolerance. Upon peripheral activation its functional capacity can be altered. Transcription factor Foxp3 is the accepted marker of Treg cell, but it cannot be used to isolate cells for functional studies. Among different functional markers, CD127 (IL-7Rα) a surface marker of activated T cell can be used to see the functional status of CD4 + CD25 + FoxP3 + Treg cells. Aim: The aim of the study was to provide an overview of the immune phenotype of Treg cells in peripheral blood of psoriasis patient with respect to healthy control, and to analyze their association with disease severity and duration. Materials and methods: This cross-sectional study comprising 35 psoriasis patients and 35 healthy controls. Demographical details were recorded, and severity was assessed by Psoriasis Area and Severity Index (PASI) scoring. Peripheral blood mononuclear cells were separated by Ficoll-Hypaque density centrifugation and circulating Treg cells were quantified by flowcytometric immunophenotyping. Results: Increased circulatory CD4 + CD25 + FoxP3 + Treg and CD4 + CD25 + FoxP3 + CD127 + /pTreg and decreased CD4 + CD25 + FoxP3 + CD127 - /tTreg cells were seen in psoriasis patients. CD4 + CD25 + FoxP3 + cells increased only with disease severity whereas CD4 + CD25 + FoxP3 + CD127 - /tTreg tends to increase with both disease severity and duration. Conclusion: These findings suggest that accumulation of peripherally activated dysfunctional regulatory cells contribute to pathology of psoriasis, which in turn supports the autoimmune model of disease pathogenesis. It will not only help to evaluate patients’ status more preciously but also pave novel ways for immune therapy.