IFN-γ活化小鼠腹腔巨噬细胞抗弓形虫作用的剂量相关性及其与TNF-α的协同作用

目的：揭示IFN－γ抗弓形虫作用的剂量相关性及TNF－α对IFN－γ是否存在协同作用。方法：本实验体外以不同剂量IFN－γ单独或与TNF－α联合刺激昆明鼠腹腔巨噬细胞，观察其对入侵的RH株速殖子的作用及培养上清中NO的水平。结果：随着IFN－γ剂量的增大，巨噬细胞抗虫作用增强，培养上清中NO水平增高；虫体入侵后24hNO水平与细胞内虫体数呈显著负相关。结论：IFN－γ可激活巨噬细胞抑制和杀灭入侵的弓形虫，并与剂量有关，TNF－α对此有协同作用，NO是抗虫作用中重要的效应因子。

Correlation between the dose and the anti-Toxoplasma effect of activated mouse macrophages induced by IFN-gamma and the synergism between IFN-gamma and TNF-alpha]

AIM: To find out the dose dependence of the anti-Toxoplasma effect induced by IFN-gamma and to determine the possible synergistic activity between TNF-alpha and IFN-gamma. METHODS: The in vitro effect of cultivated mouse peritoneal macrophages activated by IFN-gamma alone or IFN-gamma combined with different doses of TNF-alpha on the intracellular tachyzoites of RH strains and the nitric oxide (NO) level in the culture medium supernatant were simultaneously determined. RESULTS: With the increase in the dose of IFN-gamma, the anti-Toxoplasma effect was augmented and the NO level was enhanced. At 24 hours after tachyzoite invasion, a significant reversed correlation was demonstrated between the NO level and the number of intracellular parasites. CONCLUSION: The anti-Toxoplasma effect of macrophages activated by IFN-gamma appears to be dose-dependent and TNF-alpha acts synergitically with IFN-gamma in the activation of macrophages. The production of reactive NO could be an important effector in the IFN-gamma primed anti-Toxoplasma action.