scholarly journals Human DNA-PK activates a STING-independent DNA sensing pathway

2020 ◽  
Vol 5 (43) ◽  
pp. eaba4219 ◽  
Author(s):  
Katelyn Burleigh ◽  
Joanna H. Maltbaek ◽  
Stephanie Cambier ◽  
Richard Green ◽  
Michael Gale ◽  
...  

Detection of intracellular DNA by the cGAS-STING pathway activates a type I interferon-mediated innate immune response that protects from virus infection. Whether there are additional DNA sensing pathways, and how such pathways might function, remains controversial. We show here that humans—but not laboratory mice—have a second, potent, STING-independent DNA sensing pathway (SIDSP). We identify human DNA-dependent protein kinase (DNA-PK) as the sensor of this pathway and demonstrate that DNA-PK activity drives a robust and broad antiviral response. We show that the E1A oncoprotein of human adenovirus 5 and the ICP0 protein of herpes simplex virus 1 block this response. We found heat shock protein HSPA8/HSC70 as a target for inducible phosphorylation in the DNA-PK antiviral pathway. Last, we demonstrate that DNA damage and detection of foreign DNA trigger distinct modalities of DNA-PK activity. These findings reveal the existence, sensor, a specific downstream target, and viral antagonists of a SIDSP in human cells.

2019 ◽  
Author(s):  
Katelyn Burleigh ◽  
Joanna H. Maltbaek ◽  
Stephanie Cambier ◽  
Richard Green ◽  
Michael Gale ◽  
...  

SummaryDetection of intracellular DNA by the cGAS-STING pathway activates a type I interferon-mediated innate immune response that protects from virus infection and can be harnessed to promote anti-tumor immunity. Whether there are additional DNA sensing pathways, and how such pathways might function, remains controversial. We show here that humans – but not mice – have a second, potent, STING-independent DNA sensing pathway that is blocked by the E1A viral oncogene of human adenovirus 5. We identify human DNA-PK as the sensor of this pathway and demonstrate that DNA-PK kinase activity drives a robust and broad antiviral response. We discover that the heat shock protein HSPA8/HSC70 is a unique target of DNA-PK. Finally, we demonstrate that detection of foreign DNA and DNA damage trigger distinct modalities of DNA-PK activity. These findings reveal the existence, sensor, unique target, and viral antagonists of a STING-independent DNA sensing pathway (SIDSP) in human cells.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
David Shahnazaryan ◽  
Rana Khalil ◽  
Claire Wynne ◽  
Caroline A. Jefferies ◽  
Joan Ní Gabhann-Dromgoole ◽  
...  

AbstractHerpes simplex keratitis (HSK), caused by herpes simplex virus type 1 (HSV-1) infection, is the commonest cause of infectious blindness in the developed world. Following infection the virus is initially suspended in the tear film, where it encounters a multi-pronged immune response comprising enzymes, complement, immunoglobulins and crucially, a range of anti-viral and pro-inflammatory cytokines. However, given that HSV-1 can overcome innate immune responses to establish lifelong latency throughout a susceptible individual’s lifetime, there is significant interest in understanding the mechanisms employed by HSV-1 to downregulate the anti-viral type I interferon (IFN) mediated immune responses. This study aimed to investigate the interactions between infected cell protein (ICP)0 and key elements of the IFN pathway to identify possible novel targets that contribute to viral immune evasion. Reporter gene assays demonstrated the ability of ICP0 to inhibit type I IFN activity downstream of pathogen recognition receptors (PRRs) which are known to be involved in host antiviral defences. Further experiments identified interferon regulatory factor (IRF)7, a driver of type I IFN, as a potential target for ICP0. These findings increase our understanding of the pathogenesis of HSK and suggest IRF7 as a potential therapeutic target.


2021 ◽  
Vol 17 (9) ◽  
pp. e1009950
Author(s):  
Nikhil Sharma ◽  
Chenyao Wang ◽  
Patricia Kessler ◽  
Ganes C. Sen

STING is a nodal point for cellular innate immune response to microbial infections, autoimmunity and cancer; it triggers the synthesis of the antiviral proteins, type I interferons. Many DNA viruses, including Herpes Simplex Virus 1 (HSV1), trigger STING signaling causing inhibition of virus replication. Here, we report that HSV1 evades this antiviral immune response by inducing a cellular microRNA, miR-24, which binds to the 3’ untranslated region of STING mRNA and inhibits its translation. Expression of the gene encoding miR-24 is induced by the transcription factor AP1 and activated by MAP kinases in HSV1-infected cells. Introduction of exogenous miR-24 or prior activation of MAPKs, causes further enhancement of HSV1 replication in STING-expressing cells. Conversely, transfection of antimiR-24 inhibits virus replication in those cells. HSV1 infection of mice causes neuropathy and death; using two routes of infection, we demonstrated that intracranial injection of antimiR-24 alleviates both morbidity and mortality of the infected mice. Our studies reveal a new immune evasion strategy adopted by HSV1 through the regulation of STING and demonstrates that it can be exploited to enhance STING’s antiviral action.


Virology ◽  
2008 ◽  
Vol 374 (2) ◽  
pp. 487-494 ◽  
Author(s):  
Karen E. Johnson ◽  
Byeongwoon Song ◽  
David M. Knipe

2018 ◽  
Vol 92 (19) ◽  
Author(s):  
Hui Yuan ◽  
Jia You ◽  
Hongjuan You ◽  
Chunfu Zheng

ABSTRACT Type I interferons (IFNs), as major components of the innate immune system, play a vital role in host resistance to a variety of pathogens. Canonical signaling mediated by type I IFNs activates the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway through binding to the IFN-α/β receptor (IFNAR), resulting in transcription of IFN-stimulated genes (ISGs). However, viruses have evolved multiple strategies to evade this process. Here, we report that herpes simplex virus 1 (HSV-1) ubiquitin-specific protease (UL36USP) abrogates the type I IFN-mediated signaling pathway independent of its deubiquitinase (DUB) activity. In this study, ectopically expressed UL36USP inhibited IFN-β-induced activation of ISRE promoter and transcription of ISGs, and overexpression of UL36USP lacking DUB activity did not influence this effect. Furthermore, UL36USP was demonstrated to antagonize IFN-β-induced activation of JAKs and STATs via specifically binding to the IFNAR2 subunit and blocking the interaction between JAK1 and IFNAR2. More importantly, knockdown of HSV-1 UL36USP restored the formation of JAK1-IFNAR2 complex. These findings underline the roles of UL36USP-IFNAR2 interaction in counteracting the type I IFN-mediated signaling pathway and reveal a novel evasion mechanism of antiviral innate immunity by HSV-1. IMPORTANCE Type I IFNs mediate transcription of numerous antiviral genes, creating a remarkable antiviral state in the host. Viruses have evolved various mechanisms to evade this response. Our results indicated that HSV-1 encodes a ubiquitin-specific protease (UL36USP) as an antagonist to subvert type I IFN-mediated signaling. UL36USP was identified to significantly inhibit IFN-β-induced signaling independent of its deubiquitinase (DUB) activity. The underlying mechanism of UL36USP antagonizing type I IFN-mediated signaling was to specifically bind with IFNAR2 and disassociate JAK1 from IFNAR2. For the first time, we identify UL36USP as a crucial suppressor for HSV-1 to evade type I IFN-mediated signaling. Our findings also provide new insights into the innate immune evasion by HSV-1 and will facilitate our understanding of host-virus interplay.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Longzhen He ◽  
Baocheng Wang ◽  
Yuanyuan Li ◽  
Leqing Zhu ◽  
Peiling Li ◽  
...  

The innate immune response is the first line defense against viral infections. Novel genes involved in this system are continuing to emerge. SLC15A3, a proton-coupled histidine and di-tripeptide transporter that was previously found in lysosomes, has been reported to inhibit chikungunya viral replication in host cells. In this study, we found that SLC15A3 was significantly induced by DNA virus herpes simplex virus-1(HSV-1) in monocytes from human peripheral blood mononuclear cells. Aside from monocytes, it can also be induced by HSV-1 in 293T, HeLa cells, and HaCaT cells. Overexpression of SLC15A3 in 293T cells inhibits HSV-1 replication and enhances type I and type III interferon (IFN) responses, while silencing SLC15A3 leads to enhanced HSV-1 replication with reduced IFN production. Moreover, we found that SLC15A3 interacted with MAVS and STING and potentiated MAVS- and STING-mediated IFN production. These results demonstrate that SLC15A3 participates in anti-HSV-1 innate immune responses by regulating MAVS- and STING-mediated signaling pathways.


2016 ◽  
Vol 90 (19) ◽  
pp. 8661-8672 ◽  
Author(s):  
Maitreyi Shivkumar ◽  
Clara Lawler ◽  
Ricardo Milho ◽  
Philip G. Stevenson

ABSTRACTHerpes simplex virus 1 (HSV-1) enters mice via olfactory epithelial cells and then colonizes the trigeminal ganglia (TG). Most TG nerve endings are subepithelial, so this colonization implies subepithelial viral spread, where myeloid cells provide an important line of defense. The outcome of infection of myeloid cells by HSV-1in vitrodepends on their differentiation state; the outcomein vivois unknown. Epithelial HSV-1 commonly infected myeloid cells, and Cre-Lox virus marking showed nose and lung infections passing through LysM-positive (LysM+) and CD11c+cells. In contrast, subcapsular sinus macrophages (SSMs) exposed to lymph-borne HSV-1 were permissive only when type I interferon (IFN-I) signaling was blocked; normally, their infection was suppressed. Thus, the outcome of myeloid cell infection helped to determine the HSV-1 distribution: subepithelial myeloid cells provided a route of spread from the olfactory epithelium to TG neurons, while SSMs blocked systemic spread.IMPORTANCEHerpes simplex virus 1 (HSV-1) infects most people and can cause severe disease. This reflects its persistence in nerve cells that connect to the mouth, nose, eye, and face. Established infection seems impossible to clear. Therefore, we must understand how it starts. This is difficult in humans, but mice show HSV-1 entry via the nose and then spread to its preferred nerve cells. We show that this spread proceeds in part via myeloid cells, which normally function in host defense. Myeloid infection was productive in some settings but was efficiently suppressed by interferon in others. Therefore, interferon acting on myeloid cells can stop HSV-1 spread, and enhancing this defense offers a way to improve infection control.


Sign in / Sign up

Export Citation Format

Share Document