X-ray irradiation selectively kills thymocytes of different stages and impairs the maturation of donor-derived CD4^+CD8^+ thymocytes in recipient thymus  

作　　者：Jinbo Li Hongquan Cai Jianliang Jin Qian Wang Dengshun Miao 

机构地区：[1]The Research Center for Bone and Stem Cells, Department of Human Anatomy, Nanjing Medical University, Nanjing, Jiangsu 210029, China [2]Department of Preventive Medieine, School of Public Health, Nanjing Medical University, Nanjing, Jiangsu 210029, China

出　　处：《The Journal of Biomedical Research》2012年第5期355-364,共10页生物医学研究杂志（英文版）

基　　金：supported by an operating grant(No.BK2008440) to DSM from the Science and Technology Department of Jiangsu province,China

摘　　要：The aim of the present study was to determine whether the sensitivity of thymocytes to X-ray radiation depends on their proliferative states and whether radiation impairs the maturation of donor-derived thymocytes in recipient thymus.We assigned 8-week-old C57BL/6J mice into three treatment groups：1） untreated;2） X-ray radiation;3） X-ray radiation plus bone marrow transplantation with donor bone marrow cells from transgenic mice express-ing enhanced green fluorescent protein（GFP） on a universal promoter.After 4 weeks,the size of the thymus,the number and proliferation of thymocytes and ratios of different stage thymocytes were analyzed by immunohisto-chemistry and flow cytometry.The results showed that：1） CD4＋CD8＋ thymocytes were more sensitive to X-ray radiation-induced cell death than other thymocytes;2） the proliferative capacity of CD4＋CD8＋ thymocytes was higher than that of other thymocytes;3） the size of the thymus,the number of thymocytes and ratios of thymo-cytes of different stages in irradiated mice recovered to the normal level of untreated mice by bone marrow trans-plantation;4） the ratio of GFP-positive CD4＋CD8＋ thymocytes increased significantly,whereas the ratio of GFP-positive CD4＋ or CD8＋ thymocytes decreased significantly.These results indicate that the degree of sensitivity of thymocytes to X-ray radiation depends on their proliferative states and radiation impairs the maturation of donor-derived CD4＋CD8＋ thymocytes in recipient thymus.The aim of the present study was to determine whether the sensitivity of thymocytes to X-ray radiation depends on their proliferative states and whether radiation impairs the maturation of donor-derived thymocytes in recipient thymus.We assigned 8-week-old C57BL/6J mice into three treatment groups：1） untreated;2） X-ray radiation;3） X-ray radiation plus bone marrow transplantation with donor bone marrow cells from transgenic mice express-ing enhanced green fluorescent protein（GFP） on a universal promoter.After 4 weeks,the size of the thymus,the number and proliferation of thymocytes and ratios of different stage thymocytes were analyzed by immunohisto-chemistry and flow cytometry.The results showed that：1） CD4＋CD8＋ thymocytes were more sensitive to X-ray radiation-induced cell death than other thymocytes;2） the proliferative capacity of CD4＋CD8＋ thymocytes was higher than that of other thymocytes;3） the size of the thymus,the number of thymocytes and ratios of thymo-cytes of different stages in irradiated mice recovered to the normal level of untreated mice by bone marrow trans-plantation;4） the ratio of GFP-positive CD4＋CD8＋ thymocytes increased significantly,whereas the ratio of GFP-positive CD4＋ or CD8＋ thymocytes decreased significantly.These results indicate that the degree of sensitivity of thymocytes to X-ray radiation depends on their proliferative states and radiation impairs the maturation of donor-derived CD4＋CD8＋ thymocytes in recipient thymus.

关 键 词：THYMUS radiation CD4^＋CD8^＋ thymocytes sensitivity donor cells 

分 类 号：Q255[生物学—细胞生物学] X591[环境科学与工程—环境工程]