Effects Of High-altitude Hypoxia On Splenic T Lymphocyte Subsets And Function In Mice

Objective: To explore the changes of spleen T lymphocyte sunsets and functions in mice under high altitude hypoxic conditions.Methods: After exposing mice to an altitude of 400 m,2200 m and 4200 m for 30 days,we analyzed the concentration of IL-4 and IFN-? in the cultured splenocyte supernatant with ELISA kits;the proliferation of spleen T lymphocyte with MTT method;the alterations of spleen T lymphocyte subsets and its surface co-stimulatory molecules by using flow cytometry.Results: After exposing to hypoxia for 30 days,in comparison with the 400 m group,the spleen index of mice both in the 2200 m and 4200 m group increased significantly(P<0.05),meanwhile,the spleen index of the 4200 m group was also apparently higher(P<0.05)than the 2200 m group;the concentration of IFN-? in the splenocyte supernatant of the 4200 m and 2200 m group significantly decreased(P<0.05),while the concentration of IL-4 had no obvious change;the proliferation of spleen T lymphocytes reduced obviously(P<0.05)both in the 2200 m and 4200 m group,at the same time,the proliferation of T cells in 4200 m group was lower(P<0.05)than the 2200 m group;the percentages of splenic CD3+,CD4+ and CD8+ T lymphocytes in mice decreased markedly(P<0.05),in which CD4+ T cells level of declining is higher than CD8+ T cells;CD4+CD28+ T lymphocyte percentages also prominently decreased(P<0.05)while the CD8+CD28+ T lymphocyte had no obvious change,in addition,splenic CD3+,CD4+ and CD4+CD28+ T lymphocytes percentages of the 4200 m group obviously decreased(P<0.05)compared with the 2200 m group in mice.Conclusion: After exposing mice to hypoxia at high altitude environment,not only the number of spleen T lymphocyte subsets and the proliferation of T lymphocytes significantly reduced,but also the function of cytokines secretion in T cells changed,moreover,the activation of CD4+ T lymphocyte obviously decreased.Therefor,the celluar immune functions in mice was suppressed.