Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 17 3 2018 06 10 265 273 EN Mohsen Abdolmaleki Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Nazanin Mojtabavi Department of Immunology, Iran University of Medical Sciences, Tehran, Iran Mahdi Zavvar Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Mohammad Vaezi Hematology, Oncology and Stem Cell Transplantation Research Center, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran Farshid Noorbakhsh Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Mohammad Hossein Nicknam Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran AND Molecular Immunology Research Center, Tehran University of Medical Sciences, Tehran, Iran 2017 07 31 2017 09 04 T cell exhaustion is an immunosuppressive mechanism which occurs in chronic viral infections, solid tumors and hematologic malignancies. Exhausted T cell has increased the expression of inhibitory receptors, and functional impairment. In this study, we investigated the expression from some of those inhibitory receptors being Programmed death 1 (PD-1), T cell immunoglobulin and mucin domain containing molecules 3 (TIM-3) and CD244 on T cells from Iranian acute myeloid leukemia (AML) patients. Peripheral blood samples were collected from Iranian newly diagnosed AML patients and flow cytometric analysis was accomplished for cell surface expression of PD-1, TIM-3, and CD244 on T lymphocytes. Functionality and proliferation assay were done in the presence of anti-PD-1 and anti-CD244 blocking antibodies. Immunophenotyping of T cells showed a significant increase of PD-1 and CD244 expression on CD4+ and CD8+ T cells of AML patients. Whereas blockade of PD1 and CD244 increased the proliferation of CD4+ and CD8+ T lymphocytes of AML patients but IFN-γ production was not significantly increased. In conclusion, our data indicate that CD4+ and CD8+ T cells from AML patients appeared to be exhausted and blockade of some immune checkpoints can improve the proliferation of those cells. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/1594 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/1594/836