免疫抑制剂对巨噬细胞Dectin-1和TLR2表达的影响

Effects of immunosuppressants on Dectin-1 and TLR2 expression in macrophages

目的:研究地塞米松、环磷酰胺、环孢素A和霉酚酸酯对小鼠RAW264.7巨噬细胞Dectin-1和TLR2受体表达的影响。方法:体外培养RAW264.7巨噬细胞,分别给予不同浓度的地塞米松、环磷酰胺、环孢素A和霉酚酸酯刺激细胞24 h,CCK-8检测RAW264.7细胞毒性作用,RT-PCR检测细胞Dectin-1和TLR2 mRNA表达情况,流式细胞术检测Dectin-1和TLR2蛋白水平变化。结果:不同剂量的地塞米松、环磷酰胺、环孢素A和霉酚酸酯作用细胞24 h后均对细胞表现出一定的毒性作用(P<0.05),且随着药物浓度增加毒性作用越大。地塞米松降低Dectin-1 mRNA和蛋白水平的表达,上调TLR2受体转录和翻译(P<0.05);环磷酰胺对巨噬细胞Dectin-1和TLR2的转录翻译无明显影响(P>0.05);霉酚酸酯和环孢素A能够同时下调Dectin-1、TLR2 mRNA和蛋白水平表达(P<0.05)。结论:不同免疫抑制剂对模式识别受体表达的调节作用具有差异性,通过选择性调节各自靶点PRRs的表达抑制机体对各种真菌病原体的免疫识别过程,同时也能够抑制巨噬细胞的生长增殖,共同介导免疫抑制功能。

Objective： To study the effects of dexamethasone,cyclophosphamide,cyclosporin A and mycophenolate mofetil on the expression of Dectin-1 and TLR2 receptor in RAW264. 7 cell line. Methods： In vitro culturing RAW264. 7 macrophages,the cells were given different doses of dexamethasone and cyclophosphamide,cyclosporin A and mycophenolate mofetilfor 24 h. The influence of different immunosuppresants on cell proliferation was detected by CCK-8 assay. Dectin-1,TLR2 mRNA and protein levels of change were detected with RT-PCR technique and flow cytometry. Results： CCK-8 cell proliferation toxicity experiment results showed that with the increase of the dose of dexamethasone,cyclophosphamide,Cyclosporin A and mycophenolate mofetil,the different degree of inhibition of RAW264. 7 cell proliferation in mice can be saw after the intervention of 24 h（ P〈0. 05）. After 24 h of dexamethasone stimulation,Dectin-1 mRNA and protein level decreased,TLR2 mRNA and protein levels elevated（ P〈0. 05）. However cyclophosphamide had no obvious influence on Dectin-1 and TLR2（ P〉0. 05）. Mycophenolate mofetil and cyclosporin A could both inhibit the expression of Dectin-1 and TLR2（ P〈0. 05）. Conclusion： There are significant differences among the regulatory functions of various immunosupressants on the expression of pattern recognition receptors. Different immunosuppressive agents exert their inhibitory effects on immune recognition process of fungal pathogens not only by selectively regulating their target PRRs expression,but also by inhibiting the growth and proliferation of macrophages.