Influence of long-term lead exposure on the development of thymus cells subsets in mice
长期铅暴露对小鼠胸腺微环境阳性选择相关分子表达的影响

This study investigated the effect of long-term lead exposure on expression of positive selection associated molecules in the mouse thymus micro-environment. A total of 24 healthy 21-day-old male KM mice were randomly and evenly divided into four groups, labeled as control group (distilled water), low (200 mg·L-1), medium (400 mg·L-1), and high (800 mg·L-1) doses of lead acetate exposure group. Mice were continuously exposed to lead acetate in drinking water for 12 weeks. At the end of the exposure, the expression of positive selection associated membrane molecules on mouse thymocytes and thymic epithelial cells were assessed by flow cytometry. The results showed that the expression of CD4, CD8, CD28 and LFA-1 in mouse thymus cell from each dose of lead acetate exposure group significantly decreased in comparisonwith control group. Similarly, the expressions of H2-A, H2-K, B7 and ICAM-1 in thymic epithelial cells decreased significantly (p<0.05). Along with increasing doses of lead acetate, the expression of thymus cell membrane molecules CD4 and CD8, CD28, LFA-1 displayed a downward trend, and the expression of thymic epithelial cell membrane molecule H2-A, H2-K, B7 and ICAM-1 showed similar patterns.