Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 14 2 2015 04 15 198 207 EN Kaiwen Wang The Central Laboratory, The First People's Hospital of Kunshan, Affiliated Hospital of Jiangsu University, Kunshan, 230251 China. Lei Shi The Central Laboratory, The First People's Hospital of Kunshan, Affiliated Hospital of Jiangsu University, Kunshan, 230251 China. Zongliang Yu The Central Laboratory, The First People's Hospital of Kunshan, Affiliated Hospital of Jiangsu University, Kunshan, 230251 China. Zhiyong Deng The Central Laboratory, The First People's Hospital of Kunshan, Affiliated Hospital of Jiangsu University, Kunshan, 230251 China. AoLin He The Central Laboratory, The First People's Hospital of Kunshan, Affiliated Hospital of Jiangsu University, Kunshan, 230251 China. Shasha Li The Central Laboratory, The First People's Hospital of Kunshan, Affiliated Hospital of Jiangsu University, Kunshan, 230251 China. Lei Liu The Central Laboratory, The First People's Hospital of Kunshan, Affiliated Hospital of Jiangsu University, Kunshan, 230251 China. 2015 10 16 Primary Sjögren's syndrome (pSS) is a common autoimmune disease involving abnormal Th17 activation. The aim of the current study was to investigate the immunosuppression effect of Cyclosporine A (Cys A), a potent immunosuppressor on the proliferation and activation of T cells, on the activation of Th17 cells. Blood samples from both inactive and active pSS patients as well as healthy controls were collected and serum and peripheral blood mononuclear cells (PBMCs) were collected and tested for IL-17 and RORγt expression. Subsequently, PBMCs were treated in vitro with Cys A in a series of doses and incubation time and the effect of Cys A on inhibiting Th17 activation was tested by measuring IL-17 and RORγt expression. IL-17 in both serum and PBMCs as well as RORγt in PBMCs from active pSS patients were significantly elevated on both the mRNA and protein levels comparing to those from both inactive pSS patients and healthy controlCys A in the final concentration of 80ng/ml and the treatment time of 24h showed strong inhibition effect on the expression of IL-17 and RORγt in PBMCs from active pSS patients. However, Cys A in various doses and incubation times did not show much impact on inhibiting IL-17 as well as RORγt expression in PBMCs from healthy donors and inactive pSS patients. Cys A possesses the capability in immunosuppressing the activation of Th17 cells, suggesting that Cys A may be a potential treatment for pSS and maybe other autoimmune diseases. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/394 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/394/443