Document Type : Original Article (s)
                            
                        
                                                    Authors
                            
                                                            
                                                                            1
                                                                        MSc Student, Department of Immunology, School of Medicine AND Student Research Committee, Isfahan University of Medical Sciences, Isfahan, Iran                                
                                                            
                                                                            2
                                                                        Assistant Professor, Department of Immunology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran                                
                                                            
                                                                            3
                                                                        Professor, Department of Immunology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran                                
                                                            
                                                                            4
                                                                        Associate Professor, Department of Internal Medicine, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran                                
                                                            
                                                                            5
                                                                        Associate Professor, Department of Biostatistics and Epidemiology, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran                                
                                                            
                                                                            6
                                                                        Associate Professor, Department of Pathology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran                                
                                                            
                                                                            7
                                                                        PhD Student, Department of Immunology, School of Medicine AND Student Research Committee, Isfahan University of Medical Sciences, Isfahan, Iran                                
                                                            
                                                                            8
                                                                        PhD Student, Department of Cellular and Molecular Biology, School of Basic Sciences, Islamic Azad University, Science and Research Branch, Tehran, Iran                                
                            
                                                
                        
                            Abstract
                            Background: T-lymphocytes are considered as the most important immune cells fighting against various cancers. These cells are activated by different co-stimulatory receptors such as natural killer group 2D (NKG2D) molecules. Besides being stimulated via antigen-specific T-cell receptors, T-lymphocytes are further activated by NKG2D molecules. Up to now, the expression of NKG2D molecules has not been studied in various stages of colorectal cancer. Methods: In this study, peripheral blood samples of 18, 15, 11, and 10 individuals were obtained in control, low-grade non-metastatic, high-grade non-metastatic, and metastatic groups, respectively. The ratio of NKG2D expressing T-cells and the mean florescent intensity of NKG2D on these cells were evaluated in study groups by flow cytometry. Findings: There was no significant difference among the patients of low-grade non-metastatic, high-grade non-metastatic, and metastatic groups in comparison with the control subjects. Conclusion: Regarding the role of NKG2D molecules in T-cell activation, further studies are needed to explain our findings of not significant difference between various stages of colorectal cancer and healthy controls. Keywords: Colorectal neoplasm, T-lymphocytes, Natural killer cell receptors