scholarly journals ANXA2 enhances virus replication through negatively regulating cGAS-STING and RLRs-mediated signal pathway

2021 ◽  
Author(s):  
Mengdi Xue ◽  
Hongyang Liu ◽  
Zhaoxia Zhang ◽  
Chunying Feng ◽  
Kunli Zhang ◽  
...  

AbstractHost nucleic acid receptors can recognize the viral DNA or RNA upon virus infection, which further triggers multiple signal pathways to promote the translocation of the interferon regulatory factor 3 (IRF3) into nucleus and produce type I interferon (IFN), leading to the host antiviral response. Here, we report a novel negative regulator Annexin A2 (ANXA2) that regulates type I IFN production through multiple mechanisms. Ectopic expression of ANXA2 inhibited the production of type I IFN induced by DNA- and RNA viruses and enhanced virus replication, while knockout of ANXA2 expression enhanced the production of type I IFN and inhibited virus replication. Mechanistically, ANXA2 not only disrupted MDA5 recruiting MAVS, but also inhibited the interaction between MAVS and TRAF3 upon RNA virus infection. In addition, ANXA2 impacted the translocation of STING from endoplasmic reticulum to Golgi apparatus upon DNA virus infection. Interestingly, ANXA2 also inhibited IRF3 phosphorylation and nuclear translocation through competing with TANK-binds kinase 1 (TBK1) and inhibitor-κB kinase ε (IKKε) for binding to IRF3. Anxa2 deficiency in vivo increased the production of type I IFN, which resulted in suppression of encephalomyocarditis virus (EMCV) replication. Our findings reveal that ANXA2, as a negative regulator of type I IFN production, plays an important role in regulating the host antiviral responses.Author summaryAnnexin is a family of evolutionarily conserved multi-gene proteins, which are widely distributed in various tissues and cells of plants and animals. These proteins can reversibly bind to phospholipid membranes and to calcium ions (Ca2+). To date, several studies have confirmed that some members of the Annexin family regulate the antiviral innate immune response. Until now, regulation of the production of type I IFN by ANXA2 is not reported. In this study, ANXA2 were found to strongly inhibit the production of type I IFN, leading to increased virus replication while knockout of ANXA2 expression inhibited virus replication by increasing the amount of IFN. Compared with wild-type littermates, ANXA2 deficiency mice produced more type I IFN to inhibit virus replication. Our results provide methanistic insights into the novel role of ANXA2 in the antiviral innate immune responses.

2020 ◽  
pp. JVI.01590-20
Author(s):  
Yumei Han ◽  
Jingying Xie ◽  
Shujuan Xu ◽  
Yingjie Bi ◽  
Xiangrong Li ◽  
...  

Type I interferon (IFN) - mediated antiviral responses are critical at modulating host-virus responses and indeed viruses have evolved strategies to antagonize this pathway. Encephalomyocarditis virus (EMCV) is an important zoonotic pathogen, which causes myocarditis, encephalitis, neurological disease, reproductive disorders and diabetes in pigs. This study aims to understand how EMCV interacts with the IFN pathway. EMCV circumvents the type I IFN response by expressing proteins that antagonize cellular innate immunity. Here, we show that EMCV VP2 is a negative regulator of IFN-β pathway. This occurs via degrade of the MDA5-mediated cytoplasmic double stranded RNA (dsRNA) antiviral sensing pathway, RIG-I-like receptors (RLR) pathway. We showed that structural protein VP2 of EMCV interacts with MDA5, MAVS and TBK1 through its C-terminal. In addition, we found that EMCV VP2 could significantly degrade RLRs by the proteasomal and lysosomal pathways. For the first time, EMCV VP2 was shown to play an important role in EMCV evasion type I IFN signaling pathway. This study expands our understanding that EMCV utilize its capsid protein VP2 to evade from the host antiviral response.Importance Encephalomyocarditis virus is an important pathogen can cause encephalitis, myocarditis, neurological diseases, and reproductive disorders. It also causes huge economic loss for swine industry worldwide. Innate immune plays an important role in defending host from pathogen infection. Understanding pathogen microorganisms evading from host immune system is with great importance. Currently, whether EMCV evades the cytosolic RNA sensing and signaling are still poorly understood. In the present study, we found that viral protein VP2 antagonized RLR signaling pathway by degrading MDA5, MAVS and TBK1 proteins expression to facilitate viral replication in HEK293 cells. Findings in this study are identifying a new mechanism for EMCV evading the host's innate immune response, which provide new insights into the virus-host interaction and help develop new antiviral approaches against EMCV.


2018 ◽  
Author(s):  
Esther Francisco ◽  
Mehul Suthar ◽  
Michael Gale ◽  
Amy B. Rosenfeld ◽  
Vincent R. Racaniello

AbstractViral infections are sensed by pattern recognition receptors that trigger an innate immune response through the expression of interferons (IFNs) and other cytokines. Most RNA viruses are sensed by the RIG-I like receptors (RLR)s. The contributions of these receptors to sensing viruses of thePicornaviridaefamily were investigated. Encephalomyocarditis virus (EMCV) and Coxsackievirus B3 (CVB3), picornaviruses of theCardiovirusandEnterovirusgenera, are detected by both MDA5 and RIG-I in bone marrow derived macrophages. In macrophages from wild type mice, type I IFN is produced early after infection; IFNβ synthesis is reduced in the absence of each sensor, while IFNα production is reduced in the absence of MDA5. EMCV and CVB3 do not replicate in murine macrophages, and their detection is different in murine embryonic fibroblasts (MEFs), in which the viruses replicate to high titers. In MEFs RIG-I was essential for the expression of type I IFNs but contributes to increased yields of CVB3, while MDA5 inhibited CVB3 replication but in an IFN independent manner. These observations demonstrate that innate sensing of similar viruses by RLRs depends upon the cell type.ImportanceEnteroviruses such as Coxsackieviruses are the most common human respiratory pathogens. The host’s innate immune response, in particular that modulated by the production of type I and III interferons, is thought to restrict picornavirus infection. Two cytoplasmic proteins, MDA5 and RIG-I, are critical for initiating the early innate immune response against these viruses. Mutations within MDA5 encoding gene have been associated with the development of severe enterovirus associated respiratory illnesses in healthy children. To further understand how the innate immune response dependent upon MDA5 and Rig-I is initiated during picornavirus infection, macrophages from mice lacking MDA5 or RIG-I were infected with Coxsackievirus B3 (CVB3) and a related animal virus. RIG-I is essential for type I IFN production during CVB3 infection; when MDA5 is present, viral titers are reduced by an IFN-independent pathway. These observations demonstrate that innate sensing of viruses by MDA5 and RIG-I depends upon the cell type.


2021 ◽  
Vol 17 (9) ◽  
pp. e1009901
Author(s):  
Min Zhao ◽  
Yaolin Zhang ◽  
Xiqin Yang ◽  
Jiayang Jin ◽  
Zhuo Shen ◽  
...  

Neddylation, an important type of post-translational modification, has been implicated in innate and adapted immunity. But the role of neddylation in innate immune response against RNA viruses remains elusive. Here we report that neddylation promotes RNA virus-induced type I IFN production, especially IFN-α. More importantly, myeloid deficiency of UBA3 or NEDD8 renders mice less resistant to RNA virus infection. Neddylation is essential for RNA virus-triggered activation of Ifna gene promoters. Further exploration has revealed that mammalian IRF7undergoes neddylation, which is enhanced after RNA virus infection. Even though neddylation blockade does not hinder RNA virus-triggered IRF7 expression, IRF7 mutant defective in neddylation exhibits reduced ability to activate Ifna gene promoters. Neddylation blockade impedes RNA virus-induced IRF7 nuclear translocation without hindering its phosphorylation and dimerization with IRF3. By contrast, IRF7 mutant defective in neddylation shows enhanced dimerization with IRF5, an Ifna repressor when interacting with IRF7. In conclusion, our data demonstrate that myeloid neddylation contributes to host anti-viral innate immunity through targeting IRF7 and promoting its transcriptional activity.


2021 ◽  
Vol 118 (26) ◽  
pp. e2100383118
Author(s):  
Yongzhi Chen ◽  
Xuqiu Lei ◽  
Zhaozhao Jiang ◽  
Katherine A. Fitzgerald

Type I interferons (IFNs) are innate immune cytokines required to establish cellular host defense. Precise control of IFN gene expression is crucial to maintaining immune homeostasis. Here, we demonstrated that cellular nucleic acid–binding protein (CNBP) was required for the production of type I IFNs in response to RNA virus infection. CNBP deficiency markedly impaired IFN production in macrophages and dendritic cells that were infected with a panel of RNA viruses or stimulated with synthetic double-stranded RNA. Furthermore, CNBP-deficient mice were more susceptible to influenza virus infection than were wild-type mice. Mechanistically, CNBP was phosphorylated and translocated to the nucleus, where it directly binds to the promoter of IFNb in response to RNA virus infection. Furthermore, CNBP controlled the recruitment of IFN regulatory factor (IRF) 3 and IRF7 to IFN promoters for the maximal induction of IFNb gene expression. These studies reveal a previously unrecognized role for CNBP as a transcriptional regulator of type I IFN genes engaged downstream of RNA virus–mediated innate immune signaling, which provides an additional layer of control for IRF3- and IRF7-dependent type I IFN gene expression and the antiviral innate immune response.


Viruses ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 261
Author(s):  
Wei Liu ◽  
Yilin Jin ◽  
Wanwan Zhang ◽  
Yangxi Xiang ◽  
Peng Jia ◽  
...  

The RIG-I-like receptors (RLRs) signaling pathway is essential for inducing type I interferon (IFN) responses to viral infections. Meanwhile, it is also tightly regulated to prevent uncontrolled immune responses. Numerous studies have shown that microRNAs (miRNAs) are essential for the regulation of immune processes, however, the detailed molecular mechanism of miRNA regulating the RLRs signaling pathway remains to be elucidated. Here, our results showed that miR-202-5p was induced by red spotted grouper nervous necrosis virus (RGNNV) infection in zebrafish. Overexpression of miR-202-5p led to reduced expression of IFN 1 and its downstream antiviral genes, thus facilitating viral replication in vitro. In comparison, significantly enhanced levels of IFN 1 and antiviral genes and significantly low viral burden were observed in the miR-202-5p-/- zebrafish compared to wild type zebrafish. Subsequently, zebrafish tripartite motif-containing protein 25 (zbTRIM25) was identified as a target of miR-202-5p in both zebrafish and humans. Ectopic expression of miR-202-5p suppressed zbTRIM25-mediated RLRs signaling pathway. Furthermore, we showed that miR-202-5p inhibited zbTRIM25-mediated zbRIG-I ubiquitination and activation of IFN production. In conclusion, we demonstrate that RGNNV-inducible miR-202-5p acts as a negative regulator of zbRIG-I-triggered antiviral innate response by targeting zbTRIM25. Our study reveals a novel mechanism for the evasion of the innate immune response controlled by RGNNV.


2017 ◽  
Vol 474 (12) ◽  
pp. 2051-2065 ◽  
Author(s):  
Li Huang ◽  
Tao Xiong ◽  
Huibin Yu ◽  
Quan Zhang ◽  
Kunli Zhang ◽  
...  

TRAF family member-associated NF-κB activator (TANK) is a scaffold protein that assembles into the interferon (IFN) regulator factor 3 (IRF3)-phosphorylating TANK-binding kinase 1 (TBK1)–(IκB) kinase ε (IKKε) complex, where it is involved in regulating phosphorylation of the IRF3 and IFN production. However, the functions of TANK in encephalomyocarditis virus (EMCV) infection-induced type I IFN production are not fully understood. Here, we demonstrated that, instead of stimulating type I IFN production, the EMCV-HB10 strain infection potently inhibited Sendai virus- and polyI:C-induced IRF3 phosphorylation and type I IFN production in HEK293T cells. Mechanistically, EMCV 3C protease (EMCV 3C) cleaved TANK and disrupted the TANK–TBK1–IKKε–IRF3 complex, which resulted in the reduction in IRF3 phosphorylation and type I IFN production. Taken together, our findings demonstrate that EMCV adopts a novel strategy to evade host innate immune responses through cleavage of TANK.


2021 ◽  
Vol 22 (6) ◽  
pp. 3090
Author(s):  
Toshimasa Shimizu ◽  
Hideki Nakamura ◽  
Atsushi Kawakami

Sjögren’s syndrome (SS) is a systemic autoimmune disease characterized by chronic inflammation of the salivary and lacrimal glands and extra-glandular lesions. Adaptive immune response including T- and B-cell activation contributes to the development of SS. However, its pathogenesis has not yet been elucidated. In addition, several patients with SS present with the type I interferon (IFN) signature, which is the upregulation of the IFN-stimulated genes induced by type I IFN. Thus, innate immune responses including type I IFN activity are associated with SS pathogenesis. Recent studies have revealed the presence of activation pattern recognition receptors (PRRs) including Toll-like receptors, RNA sensor retinoic acid-inducible gene I and melanoma differentiation-associated gene 5, and inflammasomes in infiltrating and epithelial cells of the salivary glands among patients with SS. In addition, the activation of PRRs via the downstream pathway such as the type I IFN signature and nuclear factor kappa B can directly cause organ inflammation, and it is correlated with the activation of adaptive immune responses. Therefore, this study assessed the role of the innate immune signal pathway in the development of inflammation and immune abnormalities in SS.


Blood ◽  
2013 ◽  
Vol 122 (15) ◽  
pp. 2591-2599 ◽  
Author(s):  
Simon Heidegger ◽  
David Anz ◽  
Nicolas Stephan ◽  
Bernadette Bohn ◽  
Tina Herbst ◽  
...  

Key Points Systemic virus infection leads to rapid disruption of the Peyer’s patches but not of peripheral lymph nodes. Virus-associated innate immune activation and type I IFN release blocks trafficking of B cells to Peyer’s patches.


2009 ◽  
Vol 83 (23) ◽  
pp. 12399-12406 ◽  
Author(s):  
Vineet D. Menachery ◽  
David A. Leib

ABSTRACT The type I interferon (IFN) cascade is critical in controlling viral replication and pathogenesis. Recognition pathways triggered by viral infection rapidly induce the type I IFN cascade, often in an IFN regulatory factor 3 (IRF-3)-dependent fashion. This dependence predicts that loss of IRF-3 would render early recognition pathways inoperative and thereby impact virus replication, but this has not been observed previously with herpes simplex virus type 1 (HSV-1) in vitro. In this study, HSV-1-infected IRF-3−/− bone marrow-derived dendritic cells (BMDCs) and macrophages supported increased HSV replication compared to control cells. In addition, IRF-3-deficient BMDCs exhibited delayed type I IFN synthesis compared to control cells. However, while IFN pretreatment of IRF-3−/− BMDCs resulted in reduced virus titers, a far greater reduction was seen after IFN treatment of wild-type cells. This suggests that even in the presence of exogenously supplied IFN, IRF-3−/− BMDCs are inherently defective in the control of HSV-1 replication. Together, these results demonstrate a critical role for IRF-3-mediated pathways in controlling HSV-1 replication in cells of the murine immune system.


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