目的通过对梅毒螺旋体(treponema pallidum,TP)脂肽激活巨噬细胞产生细胞因子以及脂肽所诱导的免疫耐受对信号通路的影响进行研究,为进一步完善TP感染人体的免疫学过程,解释TP感染人体后引起的血清固定现象提供理论依据。方法不同浓度的TP脂肽刺激经PMA诱导THP-1细胞转化的巨噬细胞,利用酶联免疫吸附试验(ELISA)检测其分泌细胞因子的水平,并通过阻断CD14受体后,检测巨噬细胞对合成脂肽的反应能力以及合成脂肽耐受刺激后诱导巨噬细胞产生免疫耐受的能力。采用Western blot法检测细胞内的信号转导分子。结果 3种合成脂肽诱导巨噬细胞分泌白细胞介素(IL)-β及IL-8的能力随着脂肽浓度升高而递增。CD14受体阻断后,IL-1β及IL-8分泌水平均明显减少。合成脂肽经耐受后刺激的IL-1β及IL-8分泌水平明显低于直接刺激的细胞因子的水平。合成脂肽在耐受刺激下,其巨噬细胞内的信号转导分子toll样受体2(toll like receptor 2,TLR2)和核转录因子kappa B(NF-κB)P65的蛋白表达显著减少。结论 3种合成脂肽均能诱导巨噬细胞产生IL-1β及IL-8。合成脂肽通过激活巨噬细胞膜表面CD14受体分子,活化下游信号通路,从而诱导细胞因子产生。合成脂肽能够诱导巨噬细胞模型产生免疫耐受,其可能机制为通过TLR2激活下游NF-κB信号通路,减少炎性细胞因子产生。 OBJECTIVE: To study the effects of cytokines activated by macrophages activated by lipopeptide of treponema pallidum (TP) and immunological tolerance induced by lipopeptide on signal transduction pathways. To further improve the immunological process of human TP infection, TP Infected human body caused by serum fixation provides a theoretical basis. Methods Different concentrations of TP lipopeptide stimulated PMA-induced macrophages transformed with THP-1 cells. The level of secreted cytokines was measured by enzyme-linked immunosorbent assay (ELISA). After macrophages were blocked by blocking CD14 receptor, The ability of cells to synthesize lipopeptides, and the ability of synthetic lipopeptides to induce stimulation to induce macrophage immune tolerance. The signal transduction molecules in cells were detected by Western blot. Results The ability of three synthetic lipopeptides to induce the secretion of interleukin (IL) -β and IL-8 by macrophages increased with the increase of lipopeptide concentration. CD14 receptor block, IL-1β and IL-8 secretion were significantly reduced. The level of IL-1β and IL-8 secreted by the synthetic lipopeptide after being tolerated was significantly lower than that of the directly stimulated cytokines. The expression of TLR2 and NF-κB P65 in macrophages was significantly reduced by the synthetic lipopeptide. Conclusion All three synthetic lipopeptides can induce the production of IL-1β and IL-8 by macrophages. Synthetic lipopeptides induce the production of cytokines by activating CD14 receptor molecules on the surface of macrophage membranes and activating downstream signaling pathways. Synthetic lipopeptides can induce immune tolerance in macrophage model. The possible mechanism is that TLR2 activates the downstream NF-κB signaling pathway to reduce the production of inflammatory cytokines.