Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 11 3 2012 09 15 217 223 EN Azadeh Mottaghi Department of Nutrition and Biochemistry, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. Eisa Salehi Department of Immunology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran Hashem Sezavar Department of Internal Medicine, Division of Cardiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Seyed Ali Keshavarz Department of Nutrition and Biochemistry, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Mohammad Reza Eshraghian Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Nima Rezaei Research Center for Immunodeficiencies, Pediatrics Center of Excellence, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran AND  Department of Immunology, Molecular Immunology Research Center; School of Medicine,Tehran University of Medical Sciences, Tehran, Iran Leili Rejali Cellular and Molecular Biology, Medical Branch, Tehran Azad University, Tehran, Iran Ali-Akbar Saboor-Yaraghi Department of Nutrition and Biochemistry, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran 2015 10 16 Atherosclerosis is a chronic inflammatory condition that affects the arterial wall. Oxidized low- density lipoprotein (ox-LDL) seems to have an important role in atherosclerotic plaque formation. This study was performed to investigate the effects of ox-LDL as well as PHA on proliferation and gene expression of  peripheral blood  mononuclear  cells (PBMCs) in patients with atherosclerosis compared  to  healthy controls. Proliferation of  PBMCs was assessed by BrdU assay, while gene expression was assessed by real-time PCR. Both PHA and ox-LDL significantly induced proliferation of PBMCs of patients and controls. PBMCs  from  controls  showed  significantly higher  proliferation  when  stimulated  with  ox-LDL compared to patients. Expression of TGF-β was significantly lower in PBMCs from patients compared to healthy controls (p<0.001). Following simulation with PHA, TGF-β and Foxp3 gene expression levels in patients and controls were significantly decreased (p<0.001). Expression of Foxp3 in PBMCs treated with ox-LDL was significantly decreased in patients and controls. Decreased expression of TGF-β and Foxp3 genes after ox-LDL stimulation may be due to more sensitivity of Treg cells than effector T cells to ox-LDL. Presence of ox-LDL within atheroma could be associated with the diminished population of Treg cells in the atherosclerotic patients. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/560 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/560/481