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目的 研究铜绿假单胞菌野生菌株PAO1和单、双突变菌株(PA-△lasI、PA-△rhlI、PA-△lasI/rhlI)诱导巨噬细胞产生抗菌肽LL-37的作用及影响.方法 采用免疫磁珠法分选人外周血CD14 +单核细胞,经重组人粒-单核细胞集落刺激因子诱导分化为巨噬细胞,以不同浓度的PAO1、PA-△lasI、PA-△rhlI、PA-△lasI/rhlI处理巨噬细胞,ELISA法检测不同作用时间下巨噬细胞产生LL-37的浓度.结果 ELISA显示不同浓度PAO1、PA-△lasI、PA-△rhlI、PA-△lasI/rhlI诱导巨噬细胞在12 h开始分泌抗菌肽,呈诱导性表达,24 h或48 h达高峰,72 h下降逐渐消失,呈现剂量-时间依赖性,以PA-△lasI/rhlI∶ 巨噬细胞=100∶ 1时LL-37最高,达到(1.631 2±0.277 0)ng/mL.结论 抗菌肽LL-37呈诱导性表达,具有时间依赖性和浓度依赖性.双突变菌株更利于巨噬细胞产生LL-37,逃逸宿主免疫防御,进而影响机体免疫系统对铜绿假单胞菌的清除作用.“,”Objective To study the effects of PAO1 and its mutant strains of Pseudomonas aeruginosa ( PA) on the production of antimicrobial peptide LL-37 in macrophages. Methods Immunomagnetic beads method was applied for isolation of human peripheral blood CD14 + monocytes. Recombinant human granulocyte monocyte set colony stimulating factor was used for the induced-differentiation of macrophages. Different concentrations of PAO1, PA-△lasI, PA-△rhlI and PA-△lasI /rhlI were used to process the macrophages. The enzyme linked immunosorbent assay ( ELISA) method was used for the assessment of antimicrobial peptide LL-37 concentrations produced by PA-induced macrophage. Results Different concentrations of PAO1-, PA-△lasI-, PA-△rhlI-and PA-△lasI /rhlI-induced macrophages began to secrete antimicrobial peptides at 12 h, reached peak at 24 h or 48 h, and gradually declined until disappeared at 72 h, in dose-time-dependent manners. LL-37 was highest in the PA-ΔlasI / rhlI: macrophages =100∶ 1( 1. 631 2 ± 0. 277 0) ng /mL. Conclusion The antimicrobial peptide LL-37 is induced in time-dependent and concentration-dependent manners. Double mutant strain is more conducive for macrophages to produce LL-37, helping PA escape the host immune defense.