新孢子虫感染小鼠巨噬细胞IFN-γ、TNF-α和IL-6分泌的变化

Induction of changes in IFN-γ,TNF-α,and IL-6 secretion in mouse macrophages with Neospora caninum

目的探讨新孢子虫感染早期引起小鼠巨噬细胞IFN-γ、TNF-α和IL-6分泌的变化,分析其对宿主细胞Th1/Th2免疫应答的影响。方法分离纯化新孢子虫速殖子,刺激小鼠腹腔巨噬细胞,分别于6、12、18、24、36h收集培养上清,用ELISA方法检测IFN-γ、TNF-α和IL-6分泌情况,分析虫体感染对宿主细胞Th1/Th2免疫应答的影响。结果新孢子虫感染小鼠巨噬细胞后IFN-γ的分泌量逐渐升高,前18h抑制IFN-γ的分泌,在18hIFN-γ分泌量约为450pg/ml;24h后IFN-γ分泌量明显升高,在24h达到约1 200pg/ml。新孢子虫感染后的36h内,TNF-α分泌量一直处于较高水平,均在1 200pg/ml以上;新孢子虫感染后前18hIL-6分泌量逐渐增多,18h时达到峰值4 000pg/ml以上,24h后开始下降到约为650pg/ml。结论新孢子虫感染早期小鼠巨噬细胞IFN-γ、TNF-α和IL-6的分泌呈现不同程度的变化。表明新孢子虫通过影响IFN-γ和IL-6的分泌调控宿主细胞从Th2向Th1类型免疫应答转变,感染后的前24h以Th2类型免疫应答为主,24h后向Th1类型免疫应答转变。

Objectives To investigate changes in IFN-7, TNFa, and IL-6 secretion in murine macrophages induced by infection with Neospora caninurn and to analyze the effect of Thl/Th2 on the immune response of host cells. Methods N. caninum tachyzoites were isolated and purified using density gradient centrifugation. Mouse peritoneal macrophages were stimulated with tachyzoites. The supernatant of the culture medium was collected 6, 12, 18, 24, and 36 h after stimulation, and IFN-＇/, TNF-a, and IL 6 production were detected using ELISA. The effect of the parasites on the Thl/ Th2 immune response of host cells was analyzed. Results Secretion of IFN-Y by macrophages infected with N. cani- nurn gradually increased. N. caninurn inhibited the secretion of IFN-＇/for up to 18 h post-infection. The secretion of IFN- y was less than 450 pg/ml 18 h post-infection. IFN y secretion increased significantly 24 h post-infection and peaked at a- bout 1,200 pg/ml 24 h post-infection. The level of TNF-a secretion was high （over 1,200 pg/ml） at different times after N. caninum infection. IL-6 secretion gradually increased for up to 18 h post-infection and peaked at over 4,000 pg/ml 18 h after infection. IL-6 secretion then began to decrease significantly, reaching about 650 pg/ml 24 h after N. caninum in- fection. Conclusion Infection with N. caninum induced changes in IFN-7, TNF-a and IL-6 secretion in mouse macro- phages during the early stages of infection, leading the host cell immune response to change from a Th2-type response during the first 24 h after N. caninum infection to a Thl-type response 24 h later.