金黄色葡菌球菌刺激巨噬细胞对JNK活化和Th1/Th2型细胞因子分泌的影响

Effects of Staphylococcus aureus on the activation of JNK and secretion of Th1/Th2 cytokines in murine macrophage

目的探讨金黄色葡萄球菌(简称金葡菌)刺激小鼠巨噬细胞系RAW264.7对c-Jun氨基末端激酶(JNK)信号通路活化及其对Th1/Th2型细胞因子表达的影响。方法体外培养小鼠单核巨噬细胞系RAW264.7细胞,以金葡菌的感染复数(MOI)值为10(金葡菌∶细胞=10∶1)刺激RAW264.7细胞,设置时间点为0.5、1.0、1.5、2.0 h。Western blot检测金葡菌刺激后RAW264.7细胞JNK磷酸化水平,ELISA法检测各时间点RAW264.7细胞上清液中白介素-5(IL-5)和干扰素-γ(IFN-γ)的表达水平。结果金葡菌刺激RAW264.7细胞后JNK磷酸化水平显著升高,在0.5 h最明显(P<0.01);细胞上清液中IFN-γ水平在金葡菌刺激后0.5、1.0 h显著升高(P<0.01),而在1.5、2.0 h逐渐恢复到正常水平(P>0.05);IL-5水平在金葡菌刺激后1.0 h时开始升高(P<0.05),并在1.5、2.0 h显著升高(P<0.01);另外IL-5/IFN-γ在1.0、1.5、2.0 h时差异均有统计学意义(P<0.01)。结论金葡菌刺激小鼠巨噬细胞系RAW264.7细胞能够活化JNK通路,并影响Th1/Th2型细胞因子的表达。

Objective To investigate the effects on c-Jun amino-terminal kinase （JNK） expression and Th1/Th2 cytokines secretion from mouse macrophage cell line RAW264.7 stimulated by Staphylococcus aureus （S. aureus）. Methods RAW264.7 cells were cultured in vitro, then were stimulated by S. aureus at a multiplicity of infection （MOI） of 10 （S. aureus ： cells = 10 ： 1） for 0. 5, 1. 0, 1.5 and 2.0 h respectively. The protein expression of p- JNK was analyzed by Western blot, the levels of interleukin-5 （IL-5） and interferon-γ （IFN-γ） in the supernatants of each group were analyzed by ELISA. Results After stimulating by S. aureus, the level of JNK phosphorylation was significantly increased and was maximized at 0. 5 h （P 〈 0. 01 ） ;the level of IFN-γ/was significantly increased at 0. 5, 1.0 h （P 〈 0. 01 ）, but back to normal level at 1.5 and 2. 0 h （P 〉 0. 05） ; IL-5 began to increase at 1.0 h and 1.5 h （ P 〈 0. 05 ）, and was significantly higher at 2. 0 h （P 〈 0. 01 ） ; additionally, the ratio of IL-5/IFN-γ was significantly increased at 1.0, 1.5 and 2.0 h （P 〈 0.01）. Conclusion S. aureus stimulation activates JNK signaling and regulates the balance of Th1/Th2 cytokines in murine macrophages.