Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 12 3 2013 09 15 228 235 EN Jian-guo Li Department of Respirology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Respiratory Disease Research Institute of Sun Yat-Sen University, Guangzhou, Guangdong province, People’s Republic of China Yong-xun Zhuan-sun Department of Respirology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Respiratory Disease Research Institute of Sun Yat-Sen University, Guangzhou, Guangdong province, People’s Republic of China Bing Wen Department of Respirology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Respiratory Disease Research Institute of Sun Yat-Sen University, Guangzhou, Guangdong province, People’s Republic of China Hao Wu Department of Emergency, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Respiratory Disease Research Institute of Sun Yat-Sen University, Guangzhou, Guangdong province, People’s Republic of China Feng-ting Huang Department of Gastroenterology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Respiratory Disease Research Institute of Sun Yat-Sen University, Guangzhou, Guangdong province, People’s Republic of China Hridaya bibhu Ghimire Department of Respirology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Respiratory Disease Research Institute of Sun Yat-Sen University, Guangzhou, Guangdong province, People’s Republic of China Pi-xin Ran Department of Respirology, The First Affiliated Hospital of Guang Zhou Medical College, Guangzhou, Guangdong province, People’s Republic of China 2015 10 16 Up-regulation of CD4+CD25+CD127low/- regulatory T cells (Tregs) is a new target in the treatment of asthma. Human bone marrow mesenchymal stem cells can up-regulate CD4+CD25+CD127low/- regulatory T cells in vitro,  meanwhile, heme oxygenase-1 (HO-1) plays an important role in the development and maintenance of CD4+CD25+ regulatory T cells. However the mechanism has not yet been adequately understood. Hence, we wondered what effect of Heme Oxygenase-1 made on regulation of CD4+CD25+CD127low/-  regulatory T cells mediated by mesenchymal stem cells. Peripheral blood mononuclear cells isolated from asthmatic patients and healthy controls were co-cultured with human bone marrow mesenchymal stem cells which were pretreated with Hemin (the revulsive of Heme Oxygenase-1), Protoporphyrin Ⅸ zinc (the inhibitor of Heme Oxygenase-1) and saline. The expression of Heme Oxygenase-1 in MSCs was enhanced by Hemin and inhibited by Protoporphyrin  zinc in vitro. Overexpression of Heme Oxygenase-1 elevated the proportion of CD4+CD25+CD127low/- regulatory T cells in CD4+ T cells, meanwhile, inhibition of Heme Oxygenase-1 decreased the proportion of CD4+CD25+CD127low/- regulatory T cells in CD4+ T cells as compared with mesenchymal stem cells alone. Taken together, these data demonstrated that Heme Oxygenase-1 contributed to the up-regulation of CD4+CD25+CD127low/- regulatory T cells mediated by mesenchymal stem cells in asthma. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/508 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/508/530