一氧化氮通过激活缺氧诱导因子-1α和抑制核因子κB来调节巨噬细胞对感染的反应。
Nitric Oxide Modulates Macrophage Responses to Infection through Activation of HIF-1α and Repression of NF-κB.
作者信息
Braverman Jonathan, Stanley Sarah A
机构信息
Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720; and.
Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720; and
出版信息
J Immunol. 2017 Sep 1;199(5):1805-1816. doi: 10.4049/jimmunol.1700515. Epub 2017 Jul 28.
IFN-γ is essential for control of infection in vitro and in vivo. However, the mechanisms by which IFN-γ controls infection remain only partially understood. One of the crucial IFN-γ target genes required for control of is inducible NO synthase (iNOS). Although NO produced by iNOS is thought to have direct bactericidal activity against , the role of NO as a signaling molecule has been poorly characterized in the context infection. In this study, we found that iNOS broadly regulates the macrophage transcriptome during infection, activating antimicrobial pathways while also limiting inflammatory cytokine production. The transcription factor hypoxia inducible factor-1α (HIF-1α) was recently shown to be critical for IFN-γ-mediated control of infection. We found that HIF-1α function requires NO production, and that HIF-1α and iNOS are linked by a positive feedback loop that amplifies macrophage activation. Furthermore, we found that NO inhibits NF-κB activity to prevent hyperinflammatory responses. Thus, NO activates robust microbicidal programs while also limiting damaging inflammation. IFN-γ signaling must carefully calibrate an effective immune response that does not cause excessive tissue damage, and this study identifies NO as a key player in establishing this balance during infection.
干扰素-γ对于体外和体内感染的控制至关重要。然而,干扰素-γ控制感染的机制仍仅被部分理解。控制感染所需的关键干扰素-γ靶基因之一是诱导型一氧化氮合酶(iNOS)。虽然iNOS产生的一氧化氮被认为对[病原体名称未给出]具有直接杀菌活性,但在感染背景下,一氧化氮作为信号分子的作用尚未得到充分表征。在本研究中,我们发现iNOS在[病原体名称未给出]感染期间广泛调节巨噬细胞转录组,激活抗菌途径,同时也限制炎性细胞因子的产生。转录因子缺氧诱导因子-1α(HIF-1α)最近被证明对干扰素-γ介导的[病原体名称未给出]感染控制至关重要。我们发现HIF-1α的功能需要一氧化氮的产生,并且HIF-1α和iNOS通过一个正反馈环相连,该正反馈环放大巨噬细胞的激活。此外,我们发现一氧化氮抑制核因子-κB活性以防止过度炎症反应。因此,一氧化氮激活强大的杀菌程序,同时也限制有害炎症。干扰素-γ信号传导必须仔细校准一种不会导致过度组织损伤的有效免疫反应,并且本研究确定一氧化氮是在[病原体名称未给出]感染期间建立这种平衡的关键因素。