长期铅暴露对小鼠胸腺细胞亚群分化的影响

Influence of Long-term Exposure to Lead on Development of Thymus Cells Subsets in Mice

目的探讨铅暴露对小鼠胸腺细胞不同亚群的影响。方法将24只健康初断乳21日龄清洁级雄性KM小鼠随机分为4组,分别为对照(蒸馏水)组和低(200 mg/L)、中(400 mg/L)、高(800 mg/L)剂量乙酸铅染毒组,每组6只。采用自由饮水方式进行染毒,连续染毒12周。采用流式细胞技术检测小鼠外周血和胸腺内不同T细胞亚群的百分率。结果与对照组比较,中、高剂量乙酸铅染毒组小鼠外周血和胸腺中αβT细胞百分率和CD4+T细胞百分率明显降低,γδT细胞百分率明显增加(P<0.05),各剂量乙酸铅染毒组小鼠αβT/γδT值和CD4/CD8比例均明显下降(P<0.05);中、高剂量乙酸铅染毒组小鼠外周血中CD8+T细胞明显增加(<0.05),CD4+T细胞百分率明显下降(P<0.05),而在胸腺中CD4+T细胞和CD8+T细胞百分率均明显减少(P<0.05)。且随着乙酸铅染毒剂量的升高,小鼠外周血和胸腺αβT细胞百分率、CD4+T细胞百分率、αβT/γδT值以及胸腺CD4/CD8值均呈现下降,而外周血和胸腺γδT细胞百分率以及外周血CD8+T细胞百分率均呈现上升趋势。结论长期铅暴露可导致小鼠胸腺细胞亚群异常导致免疫损伤。

Objective To study the effects of acetate lead exposure on migration-related chemokine receptors in mice thymus. Methods A total of 24 healthy and cleanly male KM mice weaned at 21 days were randomly divided into four groups, control group（distilled water） and low（200 mg/L）, moderate（400 mg/L）, high（800 mg/L） dose of lead acetate exposure group. Lead exposure was conducted through drinking water for 12 weeks. The percentage of different T cell subsets in peripheral blood and thymus were detected by flow cytometry. Results Compared with the control group, the percentage of αβT cells and the percentage of CD4＋T cells was significantly lower in the peripheral blood and thymus of moderate and high doses group, rather the γδT cells percentage significantly increased （P〈0.05）. In moderate and high doses group, CD8＋T cell percentage increased significantly and the percentage of CD4＋T cells decreased significantly in the peripheral blood （P〈0.05）, the percentage of CD4＋T cells and CD8＋T cells were both increased significantly in thymus （P〈0.05）; With lead acetate dose increased,the percentages of αβT cells and CD4＋T cells,as well as the ratio of αβT/γδT and CD4/CD8 showed a downward trend in peripheral blood and thymus of mice,and the percentage of γδT ceils of peripheral blood and thymus, as the percentage of CDS＋T cells of peripheral blood presented an upward trend. Conclusion Chemokine receptors are involved in thymus immune injury of mice with long-term lead exposure.