Toll样配体(R-848)与IL-12对人NK细胞亚群IFN-γ产生的作用

目的:研究Toll样配体(R-848)与IL-12对人NK细胞IFN-γ产生的作用和细胞亚群分析。方法:分离人外周血PBMC和纯化的NK细胞,分别与R-848、IL-12或R-848和IL-12共同培养。利用ELISA法检测培养上清中IFN-γ的水平,再利用流式检测并分析产生IFN-γ的NK细胞亚群。结果:正常人PBMC分别与不同浓度的Toll样配体R-848、LPS、CpG培养后,均以剂量依赖的方式诱导IFN-γ的产生,但以R-848的效果最佳。细胞亚群分析的结果表明,R-848对CD4 T和CD8 T细胞IFN-γ的表达无明显作用,但显著地促进CD56 细胞表达IFN-γ。同样地,在IL-12刺激之下,CD56bright和CD56dimNK细胞表达IFN-γ。当R-848和IL-12与PBMC和纯化NK细胞孵育后,对CD56bright和CD56dimNK细胞IFN-γ的表达具有协同作用。结论:Toll样配体与NK细胞Toll样受体结合后,促进CD56brightNK细胞亚群IFN-γ的产生,而且Toll样配体与IL-12具有协同作用,提示Toll样受体与细胞因子在调控NK细胞的生物活性中发挥着十分重要的作用。

Effect of TLR ligand (R-848) and IL-12 on the production of IFN-γ by human NK cell subsets

AIM: To investigate the effect of the TLR ligand (R-848) and IL-12 on the production of IFN-gamma by human NK cell subsets. METHODS: PBMC or purified NK cells were isolated from normal human peripheral blood and cultured with R-848, IL-12 , R-848+ IL-12. The level of IFN-gamma in the culture supernatants was measured by ELISA. The cell subsets which produced IFN-gamma were detected and analyzed by flow cytometry(FCM). RESULTS: PBMC cultured with different concentrations of TLR ligands (R-848, LPS and CpG) could induce IFN-gamma production in a dose dependent manner. Among these three TLR ligands, R-848 was the best one in induction of IFN-gamma production by PBMC. FCM analysis indicated that R-848 could induce IFN-gamma expression by CD56(+) cells, but not CD4(+) or CD8(+) T cells. Similarly, IL-12 could stimulate NK cells to produce IFN-gamma. In addition, R-848 and IL-12 had synergistic effect on the production of IFN-gamma by PBMC and purified NK cells including CD56(bright) and CD56(dim) subsets. CONCLUSION: Engagement of TLR7/8 by R-848 stimulation with IL-12 could induce IFN-gamma production by CD56(bright) NK cells which indicated that TLRs and cytokines played an important role in the regulation of biologic function of NK cells.