scholarly journals Bloom syndrome protein restrains innate immune sensing of micronuclei by cGAS

2019 ◽  
Vol 216 (5) ◽  
pp. 1199-1213 ◽  
Author(s):  
Matthieu Gratia ◽  
Mathieu P. Rodero ◽  
Cécile Conrad ◽  
Elias Bou Samra ◽  
Mathieu Maurin ◽  
...  
Keyword(s):  
Dna Damage ◽  
Immune Responses ◽  
Genome Instability ◽  
Bloom Syndrome ◽  
Innate Immune ◽  
Genome Integrity ◽  
Immune Sensing ◽  
Syndrome Protein ◽  
Innate Immune Sensing ◽  
Exonuclease Trex1

Cellular innate immune sensors of DNA are essential for host defense against invading pathogens. However, the presence of self-DNA inside cells poses a risk of triggering unchecked immune responses. The mechanisms limiting induction of inflammation by self-DNA are poorly understood. BLM RecQ–like helicase is essential for genome integrity and is deficient in Bloom syndrome (BS), a rare genetic disease characterized by genome instability, accumulation of micronuclei, susceptibility to cancer, and immunodeficiency. Here, we show that BLM-deficient fibroblasts show constitutive up-regulation of inflammatory interferon-stimulated gene (ISG) expression, which is mediated by the cGAS–STING–IRF3 cytosolic DNA–sensing pathway. Increased DNA damage or down-regulation of the cytoplasmic exonuclease TREX1 enhances ISG expression in BLM-deficient fibroblasts. cGAS-containing cytoplasmic micronuclei are increased in BS cells. Finally, BS patients demonstrate elevated ISG expression in peripheral blood. These results reveal that BLM limits ISG induction, thus connecting DNA damage to cellular innate immune response, which may contribute to human pathogenesis.

scholarly journals Battle Royale: Innate Recognition of Poxviruses and Viral Immune Evasion

Biomedicines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 765
Author(s):  
Huibin Yu ◽  
Ryan C. Bruneau ◽  
Greg Brennan ◽  
Stefan Rothenburg
Keyword(s):  
Immune Responses ◽  
Current Knowledge ◽  
Immune Defense ◽  
Innate Immune ◽  
Host Immune Responses ◽  
Antiviral Responses ◽  
Activation Of Transcription ◽  
Immune Sensing ◽  
Molecular Patterns ◽  
Innate Immune Sensing

Host pattern recognition receptors (PRRs) sense pathogen-associated molecular patterns (PAMPs), which are molecular signatures shared by different pathogens. Recognition of PAMPs by PRRs initiate innate immune responses via diverse signaling pathways. Over recent decades, advances in our knowledge of innate immune sensing have enhanced our understanding of the host immune response to poxviruses. Multiple PRR families have been implicated in poxvirus detection, mediating the initiation of signaling cascades, activation of transcription factors, and, ultimately, the expression of antiviral effectors. To counteract the host immune defense, poxviruses have evolved a variety of immunomodulators that have diverse strategies to disrupt or circumvent host antiviral responses triggered by PRRs. These interactions influence the outcomes of poxvirus infections. This review focuses on our current knowledge of the roles of PRRs in the recognition of poxviruses, their elicited antiviral effector functions, and how poxviral immunomodulators antagonize PRR-mediated host immune responses.

scholarly journals Special Issue: “Innate Immune Sensing of Viruses and Viral Evasion”

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 567
Author(s):  
Renate König ◽  
Carsten Münk
Keyword(s):  
Innate Immunity ◽  
Innate Immune ◽  
Special Issue ◽  
First Line ◽  
Review Articles ◽  
Immune Sensing ◽  
Innate Immune Sensing ◽  
Viral Evasion

In this Special Issue, a wide variety of original and review articles provide a timely overview of how viruses are recognized by and evade from cellular innate immunity, which represents the first line of defense against viruses [...]

scholarly journals The innate immune sensor Toll-like receptor 2 controls the senescence-associated secretory phenotype

2018 ◽  
Author(s):  
Priya Hari ◽  
Fraser R. Millar ◽  
Nuria Tarrats ◽  
Jodie Birch ◽  
Curtis J. Rink ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Innate Immune ◽  
Toll Like Receptor ◽  
Cycle Arrest ◽  
Secretory Phenotype ◽  
Immune Sensing ◽  
Molecular Patterns ◽  
Innate Immune Sensing

ABSTRACTCellular senescence is a stress response program characterised by a robust cell cycle arrest and the induction of a pro-inflammatory senescence-associated secretory phenotype (SASP) that is triggered through an unknown mechanism. Here, we show that during oncogene-induced senescence (OIS), the Toll-like receptor TLR2 and its partner TLR10 are key mediators of senescence in vitro and in murine models. TLR2 promotes cell cycle arrest by regulating the tumour suppressors p53-p21CIP1, p16INK4a and p15INK4b, and regulates the SASP through the induction of the acute-phase serum amyloids A1 and A2 (A-SAA) that, in turn, function as the damage associated molecular patterns (DAMPs) signalling through TLR2 in OIS. Finally, we found evidence that the cGAS-STING cytosolic DNA sensing pathway primes TLR2 and A-SAA expression in OIS. In summary, we report that innate immune sensing of senescence-associated DAMPs by TLR2 controls the SASP and reinforces the cell cycle arrest program in OIS.

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