Effects of low-doses ionizing radiation on IL-4, IFN-γ and TGF-β genes expression in spleen lymphocytes of BALB/C mice

Abstract

Introduction While the widespread application of ionizing radiation in diagnostic and therapeutic medical procedures is unavoidable, Effects of low doses of ionizing radiation LDIR (low doses of ionizing radiation) are not quite obvious. Moreover, it has been showed that LDIR could affect our immune system. Purpose The aim of this study was to appraise the effects of LDIR on the inflammation genes expression levels of the immune system. Materials and Methods Balb/C mice were exposed to 20, 50 and 100 mGy WBI by gamma rays from a Cobalt-60 source. Lymphocytes of their spleen were extracted 24 h after exposing the animal for gene expression analysis. IL-4, IFN- γ and TGF- β expression levels were examined by relative quantitative real-time PCR and IFN- γ /IL-4 ratio was evaluated. To compare means values of gene expression the independent samples T-test was performed. Results The results of this study are evident that low doses of gamma radiation can induce changes on the expression level of the investigated genes and IFN-/IL-4 ratio in Balb/C spleen lymphocytes. A significant reduction of IL-4, IFN- γ and TGF- β genes and an increase of IFN- γ /IL-4 ratio has been induced in the group with 20 mGy of LDIR, while IFN- γ /IL-4 ratio was not changed following to 50 and 100 mGy of gamma irradiation. Conclusion Our result revealed that 20 mGy dose of gamma radiation can activate protection mechanisms as apoptosis and therefore cause the reduction of investigated genes and immune response shifting to Th1 and thereupon humoral immunity. However no shift to immune response has been observed in the groups which have received doses of 50 and 100 mGy. These results may be of importance to radiation workers and autoimmune patients. Disclosure There is not any relationship that might lead to a conflict of interest. Mashhad University of Medical Sciences (MUMS) has financially supported this work.