CsA inhibits IL-22 production by memory CD4+ T cells from patients with psoriasis

Abstract

IL-22 is involved in psoriasis and exacerbates disease progression. Cyclosporine A (CsA) is an immunosuppressant drug that has been used in the treatment of psoriasis for more than 20 years. We determined IL-22 producing T cells and their phenotype, and demonstrated that IL-22 is mainly produced by CD4+ memory T cells not CD8+ T cells in peripheral blood from healthy adults. We compared Th17 and Th1 with the percentages of IL-22 producing CD4+ T cells, and demonstrated that Th1 is the majority Th subset in the blood, as the percentage of Th1 cells is significantly larger than the percentage of IL-22 producing CD4+ T cells or Th17 cells. We analyzed the correlation of IL-22, IL-17 and IFN-γ produced by CD4+ T cells from healthy adults, and confirmed that there is a subset of Th22 cells that does not produce IL-17 or IFN-γ. Furthermore, we observed that the percentage of IL-22 producing CD4+ T cells is elevated in psoriasis compared to healthy donors, and that the majority of these cells are memory CD4+ T cells. We also investigated the inhibitory effects of CsA on IL-22 production by CD4+ T cells from both healthy donors and patients with psoriasis. We observed that CsA inhibits the production of IL-22 by CD4+ T cells from healthy donors in a dose-dependent manner, and that it inhibits IL- 22, IFN-γ and IL-17 production by CD4+ T cells in psoriasis. The obtained results provide critical information regarding the clinical efficacies of CsA in the treatment of psoriasis.

Keywords

• CD4+ memory T cells
• Cyclosporine A
• IL-22
• psoriasis
• Th22 cells