关键词: 高毒力肺炎克雷伯菌, 中性粒细胞, 吸入感染, 肺炎

Abstract: To explore the key role of neutrophils in the host response after hypervirulent K. pneumoniae sgh10 inhalation infection. Method In vivo elimination model of neutrophils was established by depleting lung tissue neutrophils in mice using monoclonal antibody anti-ly6g ( 10 mg / kg ) , and the model was evaluated by flow cytometry detection and immunofluorescence. Animals were divided into two groups, one injected with mAb and one injected with isotype control Ab at pre-infection, 24 and 48 h post infection to examine mouse survival, lung bacterial load, lung histopathology, cytokines as well as the effect of neutrophil depletion on other immune cells. Reslut The elimination effect of neutrophils was confirmed by flow cytometry and immunofluorescence assays. Depletion of neutrophils in vivo resulted in increased mortality, higher bacterial loads in the lungs, more severe lung injury and higher levels of pro-inflammatory cytokines in mice compared to controls. Furthermore, although neutrophil depleted mice are more susceptible to hypervirulent K. pneumoniae respiratory infection and cause up to 90% mortality, alterations in neutrophils did not significantly affect the levels of several other innate immune cells. Conclusion neutrophils played an important role in the host response of hypervirulent K. pneumoniae infection.

Key words: hypervirulent K. pneumoniae;neutrophils, inhalation infection, pneumonia