Microbial co-infection alters macrophage polarization, phagosomal escape, and microbial killing:

Innate Immunity

Nikita HTrivedi¹ 

关键词: Francisella;    BCG;    co-infection;    macrophage;    IL-4;   

DOI  :  10.1177/1753425918760180

学科分类：生物科学（综合）

来源: Sage Journals

【 摘 要 】

Macrophages are important innate immune cells that respond to microbial insults. In response to multi-bacterial infection, the macrophage activation state may change upon exposure to nascent mediators, which results in different bacterial killing mechanism(s). In this study, we utilized two respiratory bacterial pathogens, Mycobacterium bovis (Bacillus Calmette Guẻrin, BCG) and Francisella tularensis live vaccine strain (LVS) with different phagocyte evasion mechanisms, as model microbes to assess the influence of initial bacterial infection on the macrophage response to secondary infection. Non-activated (M0) macrophages or activated M2-polarized cells (J774 cells transfected with the mouse IL-4 gene) were first infected with BCG for 24–48 h, subsequently challenged with LVS, and the results of inhibition of LVS replication in the macrophages was assessed. BCG infection in M0 macrophages activated TLR2-MyD88 and Mincle-CARD9 signaling pathways, stimulating nitric oxide (NO) production and enhanced killin...

【 授权许可】

CC BY