[Decreased number and immune activity of splenic T lymphocytes in mice exposed to hypoxia at high altitude].

Objective To explore the changes of splenic T lymphocyte subsets and functions in mice under high-altitude hypoxic conditions. Methods After mice were exposed to an altitude of 400 m, 2200 m and 4200 m for 30 days, ELISA was used to detect the concentrations of interleukin-4 (IL-4) and interferon-γ (IFN-γ) in the cultured splenocyte supernatant; MTT assay was used to analyze the proliferation of splenic T lymphocytes; flow cytometry was performed to examine the alterations of splenic T lymphocyte subsets. Results After exposed to hypoxia for 30 days, in comparison with the control group (400 m), the spleen index of the mice increased significantly in both the 2200 m and 4200 m groups, and the spleen index of the 4200 m group was apparently higher than that of the 2200 m group; the concentration of IFN-γ in the splenocyte supernatant of the 4200 m and 2200 m groups significantly decreased, while the concentration of IL-4 had no obvious change. The proliferation of splenic T lymphocyte was reduced obviously in both the 2200 m and 4200 m groups, at the same time, the proliferation of T cells in the 4200 m group was markedly lower than that in the 2200 m group. The percentages of splenic CD3(+), CD4(+) and CD8(+) T lymphocytes decreased markedly in the 2200 m and 4200 m groups, among them, the number of CD4(+)T cells decreased significantly than CD8(+) T cells. In addition, CD3(+) and CD4(+) T lymphocyte percentages of the 4200 m group obviously decreased compared with the 2200 m group. Conclusion In mice exposed to hypoxia at an altitude of 4200 m and 2200 m for 30 days, the number of T lymphocyte subsets and the proliferation ability of T cells decrease, and the level of IFN-γ is decreased as well.