Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 14 6 2015 11 29 633 637 EN Mojgan Ghaedi Department of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Hayedeh Namdari Department of Immunology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran Parisa Rahimzadeh Department of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Sahar Morteza Gholi Department of Immunology, Tabriz University of Medical Sciences, International Campus (Aras), Jolfa, Tabriz, Iran Maryam Azimi Mohamadabadi Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Eisa Salehi Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran 2015 11 03 2015 11 03 An appropriate differentiation of distinct human CD4+ T cell subset is critical for manipulating these cells for using in immunity related diseases. Despite various attempts to clarify the role of different factors involved in Th17 differentiation, many crucial contradictions yet remained to be optimized. Although it has been shown that the differentiation of in-vitro Th17 cells culture conditions requires the presence of IL-1beta, IL-23, IL-2, IL-21, IL-6 and TGF-β, the optimum amount of TGF-β regulating in vitro human Th17 cell differentiation is still unclear. In the current study, a flow cytometric assay was used to evaluate the effect of different concentrations of TGF-β and a combination of IL-1beta, IL-23, IL-2 without using IL-6 on development of Interleukin (IL)-17–producing T helper (Th17) cells. According to our findings, 0.1 ng/ml of TGF-β significantly increases the expression of IL-17 in comparison to other concentrations of this cytokine. Results indicated the vital role of TGF-β cytokine in the polarization of human Th17 cells in vitro. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/648 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/648/582