Th1型和Th2型细胞因子对人中性粒细胞吞噬结核杆菌活性的影响

Effects of Th1 and Th2 cytokines on the phagocytosis of Mycobacterium tuberculosis by human neutrophils

目的 建立用流式细胞术检测人外周血中性粒细胞（PMNs）吞噬结核分枝杆菌（Mtb）的方法 ,并探讨Th1和Th2型细胞因子对PMNs吞噬Mtb活性的影响.方法 运用抗酸染色、激光共聚焦显微镜观察人PMNs吞噬Mtb,并用流式细胞术检测人PMNs对FTTC标记Mtb的吞噬活性.外周血预先分别与IL-2、IFN-γ、GM-CSF和IL-4等细胞因子孵育,再加FTTC标记Mtb后,用流式细胞术检测PMNs对Mtb吞噬率,并与对照组比较吞噬率的变化.结果 抗酸染色和激光共聚焦显微镜均能观测到人PMNs吞噬Mtb.用流式细胞术检测健康人外周血PMNs对Mtb的吞噬率在5 min时为47%,15～20 min达到平台期,为66%～72%.外周血预先加IL-2或IFN-γ作用后,PMNs对Mtb的吞噬率可分别增加76.7%和75.2%;而预先加IL-4作用后,吞噬率降低31.7%.结论 IL-2和IFN-γ对PMNs吞噬Mtb功能有增强作用,而IL-4有降低作用,表明Th1型和Th2型细胞因子参与调节PMNs抗结核杆菌感染的免疫作用.

Objective To establish a flowcytometry method for detecting phagocysis of Mycobacterium tuberculosis（Mth） by the human peripheral blood neutrophils（ PMNs）, and to explore the effects of Thl and Th2 cytokine on phagocytotic activity of PMNs. Methods By using acid-fast staining the phagocytosis of Mtb by human neutrophil was observed by microscopy, and the phagocytosis of FTTC labeled Mtb by human neutrophils was detected under confocal microscope. The whole fresh peripheral blood of healthy adults was incubated with FTTC labeled Mtb and the phagocytosis were measured by flow cytometry. The altered phagocytosis of FTTC-Mtb by neutrophils pretreated with IL-2, IFN-γ, GM-CSF or IL-4 were measured. Results Human peripheral blood neutrophils activity of Mtb phagocytosis was observed by acid-fast staining and confocal microscope. The percentage of phagocytosis of Mtb was dependent on the time of incubation with Mtb. The percentages were 47% at 5 min and reached plateau about 66% ～72% at 15 min to 20 min.Pretreatment with different concentrations of IL-2 or IFN-γincreased the phagocytosis of Mtb by 76.7% and 75.2%, respectively; but pretreatment with IL-4 decreased the phagocytosis by 31.7%. Conclusion IL-2and IFN-γcan increase phagocytosis of Mth by neutrophils; while IL-4 can reduced neutrophil activity of phagocytosis of Mtb by human neutrophils, and demonstrate that Th1/Th2 type cytokins involve in regulating the acitvities of neutrophils anti-Mtb infection.