Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 8 1 2009 03 15 25 30 Abediankenari Saeid Department of Microbiology and Immunology, School of Medicine, Ghasemi Maryam 2 Department of Pathology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran 2015 10 01 Variety of positive as well as negative regulatory signals are provided by antigen presenting cell in particular by dendritic cells. In this research, we studied the capacity of dendritic cells to expand antigen-specific T regulatory cells.We also investigated the role of TGF-beta in induction inhibitory functions of dendritic cells in mixed leukocyte reactions. Dendritic cells were generated from blood CD14+ monocytes with granulocyte-Monocyte colony stimulating factor and interleukin-4 with or without TGF-beta (TGF-β-GM-DC or GM-DC). CD4+ T cell were isolated to assess lymphocyte proliferation by lymphocyte transformation test assay and the ratio of CD4+FOXp3+ CD25+ T cells were determined by fluorescene-activated cell sorter. T cell proliferation responses in GM-DC showed a significance antigen-specific proliferative response comparing with TGFβ-GM -DC. T Cell proliferation was inhibited in co-culture system containing DC-treated TGF-β. It can be suggested that the expsansion of T regulatory by TGF-β-GM-DC provides a means for antigen specific control of unwanted immune reactions. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/230 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/230/230