Mycobacterial infection induces higher interleukin-1? and dysregulated lung inflammation in mice with defective leukocyte NADPH oxidase.
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ABSTRACT: Granulomatous inflammation causes severe tissue damage in mycobacterial infection while redox status was reported to be crucial in the granulomatous inflammation. Here, we used a NADPH oxidase 2 (NOX2)-deficient mice (Ncf1-/-) to investigate the role of leukocyte-produced reactive oxygen species (ROS) in mycobacterium-induced granulomatous inflammation. We found poorly controlled mycobacterial proliferation, significant body weight loss, and a high mortality rate after M. marinum infection in Ncf1-/- mice. Moreover, we noticed loose and neutrophilic granulomas and higher levels of interleukin (IL)-1? and neutrophil chemokines in Ncf1-/- mice when compared with those in wild type mice. The lack of ROS led to reduced production of IL-1? in macrophages, whereas neutrophil elastase (NE), an abundant product of neutrophils, may potentially exert increased inflammasome-independent protease activity and lead to higher IL-1? production. Moreover, we showed that the abundant NE and IL-1? were present in the caseous granulomatous inflammation of human TB infection. Importantly, blocking of IL-1? with either a specific antibody or a recombinant IL-1 receptor ameliorated the pulmonary inflammation. These findings revealed a novel role of ROS in the early pathogenesis of neutrophilic granulomatous inflammation and suggested a potential role of IL-1 blocking in the treatment of mycobacterial infection in the lung.
SUBMITTER: Chao WC
PROVIDER: S-EPMC5724816 | biostudies-literature | 2017
REPOSITORIES: biostudies-literature
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