Redox imbalance and IL-17 responses in memory CD4⁺ T cells from patients with psoriasis

All stages of the inflammatory process involved in T cell-mediated chronic skin disorders like psoriasis are affected by redox imbalance. On the other hand, Th17 cells have a critical role in the pathogenesis of psoriasis. In this study, we evaluated redox status in memory CD4 + T cells and plasma of patients with psoriasis and its correlation with IL-17 response. To this end, memory T cells were isolated from 10 patients with psoriasis and 10 controls. Intracellular Glutathione (GSH), reactive oxygen species (ROS) and superoxide as well as IL-17 were measured using flow cytometry. Plasma total anti-oxidant capacity (TAC) was quantified by ferric reducing ability of plasma (FRAP) assay. The expression of catalase (CAT), superoxide dismutase 1(SOD1), superoxide dismutase 2 (SOD2), nuclear factor, erythroid 2 like 2 (NFE2L2) and cytochrome b-245 beta chain (CYBB) genes were analysed using real-time PCR. Our results showed an increased intracellular ROS production in memory CD4 + T cells of patients compared to controls, (P = 0.04). Furthermore, a significant decrease in expression of catalase gene was found in patients, (P = 0.02). However, no significant differences were observed for intracellular GSH, IL-17 and TAC levels between patients and controls. Also, no correlation was seen between the intracellular IL-17 level and intracellular ROS, GSH and catalase gene expression levels. Collectively, we found an increased ROS production in stimulated memory T cells of patients that could be due to reduced expression of catalase gene. However, it seems that these redox abnormalities have no relationship with IL-17 response in memory T cells.