TNF对结核杆菌感染小鼠的保护作用及机制的研究

目的 :研究肿瘤环死因子 (TNF)对结核杆菌感染小鼠的保护作用及部分作用机制。方法 :小鼠给予不同剂量的基因重组TNF ,2 4h后感染结核杆菌H37Rv株 ,观察半数死亡时间 ,并测定巨噬细胞的吞噬活性、杀菌功能及NK细胞杀伤活性。结果 :高剂量TNF(1× 10 4 U/只 )缩短感染小鼠半数死亡时间 ,适当剂量 (2× 10 3U/只、5 0 0U/只 )能延长感染小鼠半数死亡时间 ;TNF能提高巨噬细胞的吞噬百分率及吞噬指数 ;提高巨噬细胞的杀菌功能 ;能增强NK细胞的杀伤活性。结论 :适当剂量的TNF对结核杆菌感染小鼠具有保护作用 ,其机制可能与增强MΦ的吞噬杀伤活性及NK细胞的杀伤活性有关。

The Protective Effects and Mechanism of TNF on Mycobacterium Tuberculosis Infected Mice

Objective: To study the protective effects and mechanism of TNF on mice infected by mycobacterium tuberculosis H 37 Rv strain.Methods: The mice were injected with TNF 24 hours before infected by mycobacterium tuberculosis H 37 Rv strain. Time of fifty percent death(T 50 ), phagocytic activity of macrophage and the natural killing activity of NK cells were observed. Results: High dosage of TNF(1×10 4 U per mouse) shortened T 50 while adequate dosage(2×10 3 U per mouse;500 U per mouse) prolonged T 50 . TNF increased the phagocytic rate and index of macrophage and the bactericidial activity of macrophage. It also promoted the killing activity of NK cells. Conclusion: Adequate dosage of TNF can protect the infected mice. It may be related with the enhancement of phagocytic activity of macrophage and the killing activity of NK cells.