A类Ⅰ型清道夫受体调节小鼠腹腔巨噬细胞抗肺炎克雷伯菌和铜绿假单胞菌感染

摘要

The aim of this study is to investigate the immune regulation function of scavenger receptor class A type I (SR‐AI) on macrophages for the treatment of two common pathogens of respiratory tract :Klebsiella pneumoniae (K . pneumoniae) and Pseudomonas aeruginosa ( P . aeruginosa) .The clinical isolates of K . pneumoniae and P . aeruginosa were collected .They were stained by fluorescent dyes and subjected to the peritoneal macrophages prepared from wide‐type (WT) and SR‐AI-/- mice respectively .The results showed that SR‐AI-/- macrophages had lower phagocytic ability to K . pneumoniae ,but higher phagocytic ability to P . aeruginosa than WT macrophages .Quantitative reverse transcriptase‐polymerase chain reaction (RT‐qPCR) was used to detect mRNA expressions of inflammatory cytokines . The results showed that the inflammatory reactions of SR‐A I-/- macrophages were significantly improved than WT macrophages after infection of K . pneumoniae and P . aeruginosa . The data suggest that SR‐AI could participate in the phagocytosis of K . pneumoniae by macrophages ,but not in the phagocytosis of P . aeruginosa .Besides , SR‐AI plays a role in downregulation of inflammatory reactions induced by infection of K . pneumoniae and P . aeruginosa .%本研究旨在探讨A类Ⅰ型清道夫受体（scavenger receptor class A type I ，SR‐AI）在呼吸道感染常见病原体肺炎克雷伯菌及铜绿假单胞菌感染过程中的免疫调节功能。以肺炎克雷伯菌和铜绿假单胞菌临床分离株与野生型小鼠和 SR‐A I－／－小鼠腹腔原代巨噬细胞互作，研究SR‐AI在吞噬和炎症反应中的作用。荧光染料染色菌体及检测胞内荧光强度，数据显示 SR‐A I敲除后巨噬细胞对肺炎克雷伯菌的吞噬能力下降，但对铜绿假单胞菌的吞噬能力升高。采用实时定量荧光聚合酶链反应检测相关炎症因子mRNA水平，发现 SR‐A I敲除后肺炎克雷伯菌和铜绿假单胞菌刺激巨噬细胞引发的炎症反应均增强。结果表明，SR‐AI参与巨噬细胞对肺炎克雷伯菌的吞噬，但不参与对铜绿假单胞菌的吞噬，且可能抑制了肺炎克雷伯菌和铜绿假单胞菌引发的炎症反应。