Initiation and Regulation of Antiviral Innate Immunity

项目来源

美国卫生和人类服务部基金(HHS)

项目主持人

SINGLETON, KENTNER L

项目受资助机构

BOSTON CHILDREN'S HOSPITAL

项目编号

5R01AI093589-09

立项年度

2019

立项时间

未公开

研究期限

未知 / 未知

项目级别

国家级

受资助金额

442500.00美元

学科

Biodefense; Emerging Infectious Diseases; Genetics; Infectious Diseases;

学科代码

未公开

基金类别

Non-SBIR/STTR RPGs

关键词

未公开

参与者

KAGAN, JONATHAN C

参与机构

NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES

项目标书摘要:? DESCRIPTION (provided by applicant): The goal of this proposal is to identify how interleukin-1 (IL-1) family cytokines induce the expression of interferons (IFNs) and IFN-stimulated genes (ISGs) to elicit an antiviral state in human cells. While the ability of pattern recognition receptrs (PRRs) to induce IFNs is well-recognized, cytokine receptors are not considered robust activators of IFN expression. Despite this view, several reports from the 1980s highlighted antiviral actions of IL-1, although the mechanisms underlying these activities have remained unclear. This proposal is founded on our discovery that IL-1 family members elicit the expression of Type I and Type III IFNs in primary human cells. While Type I IFNs are important regulators of immunity in all tissues, Type III IFNs are most critical at mucosal surfaces, where they are highly induced by viral infections (especially in humans). We recently identified the RIG-I/MAVS pathway as the principle means by which RNA viruses elicit Type III IFN expression in epithelial cells and hepatocytes, but the mechanisms by which IL-1 family members elicit similar antiviral responses is unclear. Explaining the importance and mechanisms of cytokine- and PRR-mediated antiviral responses will illuminate the complex regulatory events that promote host defense during infections. We hypothesize that an uncharacterized signal transduction pathway is activated by IL-1 family members to specifically promote an antiviral response. Moreover, we speculate that this antiviral pathway is most important during infections with viruses that prevent IFN expression or signaling. Under these conditions, inflammasome activation (or necrosis) results in the release of IL-1 family members that activate antiviral responses in uninfected neighboring cells. In contrast, during infections with less pathogenic viruses, the classic PRR-mediated IFN responses may be most critical to activate antiviral responses. This hypothesis prompts us to classify IL-1 family members as latent IFNs, whose main benefit may be to ensure that antiviral responses are induced in infected tissues, even during encounters with viruses that block IFN expression. In this proposal, we will explore key aspects of this hypothesis. Specifically, we will determine the genetic and biochemical basis for the antiviral IL-1 signaling pathway (Aim 1), determine the mechanism by which a key regulator of IL-1 induced antiviral responses, the transcription factor IRF1, is activated (Aim 2), and determine if the main function of IL-1 induced antiviral activity i to prevent the replication highly virulent viral pathogens (Aim 3). These studies will provide important insight into the relationship between cytokine receptors and PRRs, and their relative roles in controlling viral infections.

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  • 1.How Inflammasomes Inform Adaptive Immunity

    • 关键词:
    • inflammasomes; innate immunity; SMOC; TLR; adaptive immunity;CD4(+) T-CELLS; GAMMA-INDUCING FACTOR; LEISHMANIA-MAJOR INFECTION;RECEPTOR ACCESSORY PROTEIN; LEGIONELLA-PNEUMOPHILA INFECTION;PATTERN-RECOGNITION RECEPTORS; EXPERIMENTAL CEREBRAL MALARIA;SYSTEMIC-LUPUS-ERYTHEMATOSUS; PROMOTES TUMOR-GROWTH; IL-1 FAMILY-MEMBERS

    An immune response consists of a finely orchestrated interplay between initial recognition of potential microbial threats by the innate immune system and subsequent licensed adaptive immune neutralization. The initial recognition integrates environmental cues derived from pathogen-associated molecular patterns and cell-intrinsic damage-associated molecular patterns to contextualize the insult and inform a tailored adaptive response via T and B lymphocytes. While there are much data to support the role of transcriptional responses downstream of pattern recognition receptors in informing the adaptive immune response, markedly less attention has been paid to the role of post-translational responses to pathogen-associated molecular pattern and damage-associated molecular pattern recognition by the innate immune system, and how this may influence adaptive immunity. A well-characterized post-translational consequence of pattern recognition receptor signaling is the assembly of a multimeric signaling platform, termed the inflammasome, by members of the nucleotide-binding oligomerization domain (Nod), leucine-rich repeat-containing receptors (NLRB), and pyrin and HIN domain (PYHIN) families. Inflammasomes assemble in response to cytosolic perturbations, such as mitochondrial dysfunction and aberrant ion fluxes in the case of the canonical NLRP3 inflammasome or the presence of bacterial lipopolysaccharides in the case of the non-canonical inflammasome. Assembly of the inflammasome allows for the cleavage and activation of inflammatory caspases. These activated inflammatory caspases in turn cleave pro-form inflammatory cytokines into their mature bioactive species and lead to unconventional protein secretion and lytic cell death. In this review, we discuss evidence for inflammasome-mediated instruction and contextualization of infectious and sterile agents to the adaptive immune system. (C) 2017 Elsevier Ltd. All rights reserved.

    ...
  • 2.How Inflammasomes Inform Adaptive Immunity

    • 关键词:
    • inflammasomes; innate immunity; SMOC; TLR; adaptive immunity;CD4(+) T-CELLS; GAMMA-INDUCING FACTOR; LEISHMANIA-MAJOR INFECTION;RECEPTOR ACCESSORY PROTEIN; LEGIONELLA-PNEUMOPHILA INFECTION;PATTERN-RECOGNITION RECEPTORS; EXPERIMENTAL CEREBRAL MALARIA;SYSTEMIC-LUPUS-ERYTHEMATOSUS; PROMOTES TUMOR-GROWTH; IL-1 FAMILY-MEMBERS

    An immune response consists of a finely orchestrated interplay between initial recognition of potential microbial threats by the innate immune system and subsequent licensed adaptive immune neutralization. The initial recognition integrates environmental cues derived from pathogen-associated molecular patterns and cell-intrinsic damage-associated molecular patterns to contextualize the insult and inform a tailored adaptive response via T and B lymphocytes. While there are much data to support the role of transcriptional responses downstream of pattern recognition receptors in informing the adaptive immune response, markedly less attention has been paid to the role of post-translational responses to pathogen-associated molecular pattern and damage-associated molecular pattern recognition by the innate immune system, and how this may influence adaptive immunity. A well-characterized post-translational consequence of pattern recognition receptor signaling is the assembly of a multimeric signaling platform, termed the inflammasome, by members of the nucleotide-binding oligomerization domain (Nod), leucine-rich repeat-containing receptors (NLRB), and pyrin and HIN domain (PYHIN) families. Inflammasomes assemble in response to cytosolic perturbations, such as mitochondrial dysfunction and aberrant ion fluxes in the case of the canonical NLRP3 inflammasome or the presence of bacterial lipopolysaccharides in the case of the non-canonical inflammasome. Assembly of the inflammasome allows for the cleavage and activation of inflammatory caspases. These activated inflammatory caspases in turn cleave pro-form inflammatory cytokines into their mature bioactive species and lead to unconventional protein secretion and lytic cell death. In this review, we discuss evidence for inflammasome-mediated instruction and contextualization of infectious and sterile agents to the adaptive immune system. (C) 2017 Elsevier Ltd. All rights reserved.

    ...
  • 3.The Fly Way of Antiviral Resistance and Disease Tolerance

    Like humans, insects face the threat of viral infection. Despite having repercussions on human health and disease, knowledge gaps exist for how insects cope with viral pathogens. Drosophila melanogaster serves as an ideal insect model due to its genetic tractability. When encountering a pathogen, two major approaches to fight disease are resistance strategies and tolerance strategies. Disease resistance strategies promote the health of the infected host by reducing pathogen load. Multiple disease resistance mechanisms have been identified in Drosophila: RNA interference, Jak/STAT signaling, Toll signaling, IMD signaling, and autophagy. Disease tolerance mechanisms, in contrast, do not reduce pathogen load directly, but rather mitigate the stress and damage incurred by infection. The main benefit of tolerance mechanisms may therefore be to provide the host with time to engage antiviral resistance mechanisms that eliminate the threat. In this review, antiviral resistance mechanisms used by Drosophila will be described and compared to mammalian antiviral mechanisms. Disease tolerance will then be explained in a broader context as this is a burgeoning field of study.

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