저선량 감마선 노출에 의한 비장세포의 염증 유발 작용에 대한 연구

Abstract

Gamma irradiation (<TEX>${\gamma}IR$</TEX>) is widely used for radiotherapy as a treatment of cancer cells although it has a risk to damage normal cells. Inflammation is regarded as one of side effects of <TEX>${\gamma}IR$</TEX> while the effect of low dose of <TEX>${\gamma}IR$</TEX> on inflammation has not been researched well. Here, we investigated the inflammatory responses of low dose of <TEX>${\gamma}IR$</TEX> on murine spleen cells. It was evaluated if <TEX>${\gamma}IR$</TEX> affected the mitogen-induced lymphocyte proliferation, the regulation of various inflammatory cytokines (IFN-<TEX>${\gamma}$</TEX>, IL-2, IL-17, IL-4, IL-10), and the involvement of Ikaros and MAPK/NF-<TEX>${\kappa}B$</TEX> medicated mechanism. Exposure of <TEX>$^{137}Cs-{\gamma}IR$</TEX> below 2 Gy decreased the lymphocytes proliferative response to mitogens (LPS, ConA) except at the lowest dose, 0.05 Gy. IL-17, IL-2 and IL-4 mRNA increased at 0.5 and 2 Gy, but not altered at 0.05 Gy. IL-10, anti-inflammatory cytokine, increased only at 0.05 Gy. In regard to intracellular signaling, p-JNK, p-p38 and p-<TEX>$I{\kappa}B{\alpha}$</TEX> were not changed, whereas the activation of ERK and Ikaros increased at the lowest dose. These results suggest that exposure of <TEX>${\gamma}IR$</TEX> less than 0.5 Gy (or below 0.05 Gy) has beneficial effects as a radiation hormesis on immune function.