Abstract
Autoantibody plays an important role in autoimmune diseases. We have reported that repeated 0.5-Gy gamma-irradiation attenuates the pathology in autoimmune disease models accompanied by suppression of autoantibody production. These observations raise an important question whether gamma-irradiation would suppress the antibody production against external antigen or not. Here, we investigated the effects of gamma-irradiation on antibody production in ovalubmin-immunized mice. Mice were immunized with ovalubmin, and exposed to 0.5-Gy gamma-rays per week. After the immunization with ovalubmin, we observed the increment of total serum IgG and IgE level. We found that 0.5-Gy gamma-irradiation further increased the ability of antibody production. Consistent with these results, higher levels of both ovalubmin-specific IgG and IgE were observed in irradiated mice compared with in non-irradiated mice. Furthermore, the percentage of plasma cells was increased by gamma-irradiation, whereas the percentage of B cell was not changed. Splenocytes-producing cytokines, which are involved in antibody production, were increased in ovalubmin-immunized mice, whereas further increments were observed in irradiated mice. These results indicate that repeated 0.5-Gy gamma-irradiation would enhance antibody production against external antigen rather than internal autoantigen.
