Effects of Gamma Irradiation on Proliferation and IL-5 Production of Peripheral Blood Lymphocytes

Gamma irradiation is routinely used for suppression of lymphocyte function in transfusion and transplantation procedures. In recent years, some investigators focused on the effects of ionizing radiation on special aspects of lymphocyte function and considered the possibility of its clinical application for treatment of some immunological disorders. In this study, we evaluated the effects of five different doses of &gamma-ray on proliferation and IL-5 production of peripheral blood lymphocytes. Lymphocytes were separated from blood and were treated with 5, 10, 20, 30 and 40 Gy irradiation (using a 137 Cs source) and then were cultured for 72 h in the presence of phytohemagglutinin (PHA). The proliferative response of samples was evaluated by MTT assay, and the supernatant of the cells was collected for IL-5 detection. The results showed that the ionizing radiation had a suppressive effect on lymphocyte proliferation. IL-5 production was affected in a dose-response manner, augmented in response to 5 and 10 Gy and reached to its peak value at 20 Gy. At 30 Gy, IL-5 production was diminished lower than peak value, but still remained higher than control baseline, and 40 Gy led to IL-5 values lower than baseline