1 September 2011
skin inflammation, immune regulation, CD8+ T cells, immune modulation, TH, T helper cells, Foxp3, forkhead box protein 3, GFP, green fluorescent protein, RA, retinoic acid, DC, dendritic cell, Sp, spleen, CFSE, carboxyfluorescein diacetate, succinimidyl ester, CHS, contact hypersensitivity, DNFB, 2,4-dinitro-1-fluorobenzene, PBMC, peripheral blood mononuclear cells, CD, cluster of differentiation, CTLA, cytotoxic T-lymphocyte antigen, GITR, glucocorticoid-induced tumor necrosis factor receptor, TGF, transforming growth factor, IL, interleukin, TNF-β, tumor necrosis factor-β, IFN-γ, interferon-γ, PASI, Psoriasis Area and Severity Index
CD8 + regulatory T cells appear impaired in number and/or function in some autoimmune diseases. However, the role of CD8 + regulatory T cells in the pathogenesis of skin inflammation and psoriasis remains unknown. In this study, we set out to analyze the capability of CD8 + regulatory T cells to inhibit skin inflammation in a murine model and to determine the frequency of CD8 + regulatory T cells in patients with psoriasis. We demonstrate that murine fully competent CD8 + regulatory T cells can be induced by stimulating naïve CD8 + T cells in the presence of TGF-β and retinoic acid (RA). Importantly, in vitro induced CD8 + regulatory T cells significantly suppressed skin inflammation in vivo. Furthermore, we found that the frequency of regulatory CD8 +CD25 +Foxp3 + T cells is decreased in peripheral blood but increased in lesional psoriatic skin of patients with psoriasis. Thus, our study suggests a previously unappreciated role of CD8 +CD25 + Foxp3 + T cells in skin disorders, and induction of these cells in vitro may be an effective immunotherapy for skin inflammation.