CD4^(+)CD25^(+) T regulatory(Treg)cells are critical in inducing and maintaining immunological self-tolerance as well as transplant tolerance.The effect of low doses of whole-body irradiation(WBI)on CD41CD251Foxp31 Tr...CD4^(+)CD25^(+) T regulatory(Treg)cells are critical in inducing and maintaining immunological self-tolerance as well as transplant tolerance.The effect of low doses of whole-body irradiation(WBI)on CD41CD251Foxp31 Treg cells has not been determined.The proportion,phenotypes and function of CD4^(+)CD25^(+) Treg cells were investigated 0.5,5 and 15 days after euthymic,thymectomized or allogeneic bone marrow transplanted C57BL/6 mice received 2-Gy c-rays of WBI.The 2-Gy WBI significantly enhanced the ratios of CD41CD251 Treg cells and CD4^(+)CD25^(+)Foxp3^(+) Treg cells to CD41 T cells in peripheral blood,lymph nodes,spleens and thymi of mice.The CD41CD251 Treg cells of the WBI-treated mice showed immunosuppressive activities on the immune response of CD4^(+)CD25^(+) T effector cells to alloantigens or mitogens as efficiently as the control mice.Furthermore,2-Gy c-ray WBI significantly increased the percentage of CD4^(+)CD25^(+)Foxp3^(+) Treg cells in the periphery of either thymectomized mice or allogeneic bone marrow transplanted mice.The in vitro assay showed that ionizing irradiation induced less cell death in CD4^(+)CD25^(+)Foxp3^(+) Treg cells than in CD4^(+)CD25^(+) T cells.Thus,a low dose of WBI could significantly enhance the level of functional CD41CD251Foxp31 Treg cells in the periphery of naive or immunized mice.The enhanced proportion of CD41CD251Foxp31 Treg cells in the periphery by a low dose of WBI may make hosts more susceptible to immune tolerance induction.展开更多
基金by grants from the Chinese Academy of Sciences(KJCX2-YW-L08,YZ)the National Natural Science Foundation,China(30630060,YZ).
文摘CD4^(+)CD25^(+) T regulatory(Treg)cells are critical in inducing and maintaining immunological self-tolerance as well as transplant tolerance.The effect of low doses of whole-body irradiation(WBI)on CD41CD251Foxp31 Treg cells has not been determined.The proportion,phenotypes and function of CD4^(+)CD25^(+) Treg cells were investigated 0.5,5 and 15 days after euthymic,thymectomized or allogeneic bone marrow transplanted C57BL/6 mice received 2-Gy c-rays of WBI.The 2-Gy WBI significantly enhanced the ratios of CD41CD251 Treg cells and CD4^(+)CD25^(+)Foxp3^(+) Treg cells to CD41 T cells in peripheral blood,lymph nodes,spleens and thymi of mice.The CD41CD251 Treg cells of the WBI-treated mice showed immunosuppressive activities on the immune response of CD4^(+)CD25^(+) T effector cells to alloantigens or mitogens as efficiently as the control mice.Furthermore,2-Gy c-ray WBI significantly increased the percentage of CD4^(+)CD25^(+)Foxp3^(+) Treg cells in the periphery of either thymectomized mice or allogeneic bone marrow transplanted mice.The in vitro assay showed that ionizing irradiation induced less cell death in CD4^(+)CD25^(+)Foxp3^(+) Treg cells than in CD4^(+)CD25^(+) T cells.Thus,a low dose of WBI could significantly enhance the level of functional CD41CD251Foxp31 Treg cells in the periphery of naive or immunized mice.The enhanced proportion of CD41CD251Foxp31 Treg cells in the periphery by a low dose of WBI may make hosts more susceptible to immune tolerance induction.
