Th1型相关细胞因子对人中性粒细胞吞噬功能的影响

Influence of Th1 type related cytokines on phagocytosis of human peripheral neutrophils

目的：用流式细胞术观察Th1型细胞因子IL-2和IFN-γ,以及Th1细胞诱导因子IL-12对人外周血中性粒细胞吞噬功能的影响。方法：用不同浓度异硫氰酸荧光素（FITC）在碳酸盐缓冲液（CB,pH9.5）和磷酸盐缓冲盐水（PBS,pH7.2）中标记大肠埃希菌和金黄色葡萄球菌（金葡菌）,流式细胞术检测细菌标记率。取新鲜健康成人外周血与标记细菌于37℃孵育5-20 min后,洗涤和溶血,用流式细胞术检测中性粒细胞吞噬百分率。或外周血预先分别与IL-2、IFN-γ及IL-12孵育2 h,再加标记细菌孵育5 min,流式细胞术检测中性粒细胞吞噬率,并与对照组比较计算吞噬增加比率。结果：FITC标记大肠埃希菌在碱性的CB中标记率较高,而金葡菌在中性的PBS标记率较高（P〈0.01）。健康人外周血中性粒细胞对大肠埃希菌和金葡菌的吞噬率在5 min时分别为45%和38%,15-20 min达到平台期,分别为86%-88%和83%-89%。外周血预先用IL-2（20u/ml）、IFN-γ（50 u/ml）或IL-12（30 u/ml）作用后,中性粒细胞对大肠埃希菌的吞噬率分别增加19%、19%和26%;对金葡菌的吞噬率分别增加25%、23%和35%。结论：Th1型细胞因子IL-2、IFN-γ及Th1型诱导细胞因子IL-12均能增强人中性粒细胞吞噬功能,Th1型细胞因子和IL-12均具有增强中性粒细胞功能的作用。

Objective：To observe the influence of Thl cytokines IL-2,IFN-γ,and Thl induced cytokine IL-12 on the phagocytosis of human peripheral blood neutrophils using flowcytometry. Methods： Escherichia coli （ E. coli ） and Staphylococcus aureus （ S. aureus ） were labeled with different concentrations of fluorescein isothiocyanate （FITC） in carbonate buffer （CB, pH 9.5 ） or phosphate buffer saline （ PBS,pH 7.2）. The FITC labeling rates of the two bacteria were measured by flowcytometry. The whole fresh peripheral blood of the healthy adults were incubated with FITC labeled bacteria for 5 min to 20 min at 37 %, followed by washing and lysing of red blood cells： The percentages of phagocytosis of bacteria by neutrophils were measured by flowcytometry. The whole blood was pretreated with IL-2（20 u/ml） ,IFN-γ（50 u/ml） or IL-12（30 u/ml） for 2 hours before incubation with FITC labeled bacteria for 5 min at 37 ℃. The increment of phagocytosis of bacteria by neutrophils was measured and calculated in comparison with control group. Results： The labeling rate of E. coli was higher in alkaline CB,and that of S. aureus was higher in PBS. The percentages of phagocytic neutrophils for E. coli and S. aureus at 5 min were 45% and 38%, respectively, and reached plateau at 15 min to 20 min, with the percentages of 86% -88% and 83% -89% for E. coli and S. aureus, respectively. Pretreated with IL-2 （20 u/ml）, IFN-γ（ 50 u/ml ） or IL-12 （30 u/ ml） ,the phagocytosis rates for E. coli by neutrophils increased by 19% , 19% , and 26%, respectively;and that for S. aureus increased by 25% ,23%, and 35%, respectively. Conclusions： Thl type cytokines IL-2, IFN-γ, and Thl induced cytokine IL-12 can increase human neutrophil phagocytosis,which demonstrates that Thl type related cytokines enhance the role of neutrophils in innate immunity.