Type I IFN Triggers RIG-I/TLR3/NLRP3-dependent Inflammasome Activation in Influenza A Virus Infected Cells

The NS1 protein of the influenza A virus plays a critical role in regulating several biological processes in cells, including the type I interferon (IFN) response. We previously profiled the cellular factors that interact with the NS1 protein of influenza A virus and found that the NS1 protein interacts with proteins involved in RNA splicing/processing, cell cycle regulation, and protein targeting processes, including 14-3-3ε. Since 14-3-3ε plays an important role in RIG-I translocation to MAVS to activate type I IFN expression, the interaction of the NS1 and 14-3-3ε proteins may prevent the RIG-I-mediated IFN response. In this study, we confirmed that the 14-3-3ε protein interacts with the N-terminal domain of the NS1 protein and that the NS1 protein inhibits RIG-I-mediated IFN-β promoter activation in 14-3-3ε-overexpressing cells. In addition, our results showed that knocking down 14-3-3ε can reduce IFN-β expression elicited by influenza A virus and enhance viral replication. Furthermore, we found that threonine in the 49 th amino acid position of the NS1 protein plays a role in the interaction with 14-3-3ε. Influenza A virus expressing C-terminus-truncated NS1 with T49A mutation dramatically increases IFN-β mRNA in infected cells and causes slower replication than that of virus without the T-to-A mutation. Collectively, this study demonstrates that 14-3-3ε is involved in influenza A virus-initiated IFN-β expression and that the interaction of the NS1 protein and 14-3-3ε may be one of the mechanisms for inhibiting type I IFN activation during influenza A virus infection. IMPORTANCE Influenza A virus is an important human pathogen causing severe respiratory disease. The virus has evolved several strategies to dysregulate the innate immune response and facilitate its replication. We demonstrate that the NS1 protein of influenza A virus interacts with the cellular chaperone protein 14-3-3ε, which plays a critical role in RIG-I translocation that induces type I IFN expression, and that NS1 protein prevents RIG-I translocation to mitochondrial membrane. The interaction site for 14-3-3ε is the RNA-binding domain (RBD) of the NS1 protein. Therefore, this research elucidates a novel mechanism by which the NS1 RBD mediates IFN-β suppression to facilitate influenza A viral replication. Additionally, the findings reveal the antiviral role of 14-3-3ε during influenza A virus infection.

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MicroRNA-132-3p suppresses type I IFN response through targeting IRF1 to facilitate H1N1 influenza A virus infection

Bioscience Reports ◽

10.1042/bsr20192769 ◽

2019 ◽

Vol 39 (12) ◽

Author(s):

Fangyi Zhang ◽

Xuefeng Lin ◽

Xiaodong Yang ◽

Guangjian Lu ◽

Qunmei Zhang ◽

...

Keyword(s):

Influenza A Virus ◽

Peripheral Blood ◽

Influenza A ◽

Expression Profiles ◽

Protein A ◽

H1n1 Influenza ◽

Type I ◽

Dependent Manner ◽

Type I Ifn

Abstract Increasing evidence has indicated that microRNAs (miRNAs) have essential roles in innate immune responses to various viral infections; however, the role of miRNAs in H1N1 influenza A virus (IAV) infection is still unclear. The present study aimed to elucidate the role and mechanism of miRNAs in IAV replication in vitro. Using a microarray assay, we analyzed the expression profiles of miRNAs in peripheral blood from IAV patients. It was found that miR-132-3p was significantly up-regulated in peripheral blood samples from IAV patients. It was also observed that IAV infection up-regulated the expression of miR-132-3p in a dose- and time-dependent manner. Subsequently, we investigated miR-132-3p function and found that up-regulation of miR-132-3p promoted IAV replication, whereas knockdown of miR-132-3p repressed replication. Meanwhile, overexpression of miR-132-3p could inhibit IAV triggered INF-α and INF-β production and IFN-stimulated gene (ISG) expression, including myxovirus protein A (MxA), 2′,5′-oligoadenylate synthetases (OAS), and double-stranded RNA-dependent protein kinase (PKR), while inhibition of miR-132-3p enhanced IAV triggered these effects. Of note, interferon regulatory factor 1 (IRF1), a well-known regulator of the type I IFN response, was identified as a direct target of miR-132-3p during HIN1 IAV infection. Furthermore, knockdown of IRF1 by si-IRF1 reversed the promoting effects of miR-132-3p inhibition on type I IFN response. Taken together, up-regulation of miR-132-3p promotes IAV replication by suppressing type I IFN response through its target gene IRF1, suggesting that miR-132-3p could represent a novel potential therapeutic target of IAV treatment.

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Hemagglutinin of Influenza A Virus Antagonizes Type I Interferon (IFN) Responses by Inducing Degradation of Type I IFN Receptor 1

Journal of Virology ◽

10.1128/jvi.02749-15 ◽

2015 ◽

Vol 90 (5) ◽

pp. 2403-2417 ◽

Cited By ~ 41

Author(s):

Chuan Xia ◽

Madhuvanthi Vijayan ◽

Curtis J. Pritzl ◽

Serge Y. Fuchs ◽

Adrian B. McDermott ◽

...

Keyword(s):

Signaling Pathway ◽

Influenza A Virus ◽

Influenza A ◽

Type I Interferon ◽

Innate Immune ◽

Host Cells ◽

Type I ◽

Type I Ifn ◽

Type I Ifns ◽

Ha Protein

ABSTRACTInfluenza A virus (IAV) employs diverse strategies to circumvent type I interferon (IFN) responses, particularly by inhibiting the synthesis of type I IFNs. However, it is poorly understood if and how IAV regulates the type I IFN receptor (IFNAR)-mediated signaling mode. In this study, we demonstrate that IAV induces the degradation of IFNAR subunit 1 (IFNAR1) to attenuate the type I IFN-induced antiviral signaling pathway. Following infection, the level of IFNAR1 protein, but not mRNA, decreased. Indeed, IFNAR1 was phosphorylated and ubiquitinated by IAV infection, which resulted in IFNAR1 elimination. The transiently overexpressed IFNAR1 displayed antiviral activity by inhibiting virus replication. Importantly, the hemagglutinin (HA) protein of IAV was proved to trigger the ubiquitination of IFNAR1, diminishing the levels of IFNAR1. Further, influenza A viral HA1 subunit, but not HA2 subunit, downregulated IFNAR1. However, viral HA-mediated degradation of IFNAR1 was not caused by the endoplasmic reticulum (ER) stress response. IAV HA robustly reduced cellular sensitivity to type I IFNs, suppressing the activation of STAT1/STAT2 and induction of IFN-stimulated antiviral proteins. Taken together, our findings suggest that IAV HA causes IFNAR1 degradation, which in turn helps the virus escape the powerful innate immune system. Thus, the research elucidated an influenza viral mechanism for eluding the IFNAR signaling pathway, which could provide new insights into the interplay between influenza virus and host innate immunity.IMPORTANCEInfluenza A virus (IAV) infection causes significant morbidity and mortality worldwide and remains a major health concern. When triggered by influenza viral infection, host cells produce type I interferon (IFN) to block viral replication. Although IAV was shown to have diverse strategies to evade this powerful, IFN-mediated antiviral response, it is not well-defined if IAV manipulates the IFN receptor-mediated signaling pathway. Here, we uncovered that influenza viral hemagglutinin (HA) protein causes the degradation of type I IFN receptor subunit 1 (IFNAR1). HA promoted phosphorylation and polyubiquitination of IFNAR1, which facilitated the degradation of this receptor. The HA-mediated elimination of IFNAR1 notably decreased the cells' sensitivities to type I IFNs, as demonstrated by the diminished expression of IFN-induced antiviral genes. This discovery could help us understand how IAV regulates the host innate immune response to create an environment optimized for viral survival in host cells.

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Sphingosine 1-Phosphate Lyase Enhances the Activation of IKKε To Promote Type I IFN–Mediated Innate Immune Responses to Influenza A Virus Infection

The Journal of Immunology ◽

10.4049/jimmunol.1601959 ◽

2017 ◽

Vol 199 (2) ◽

pp. 677-687 ◽

Cited By ~ 8

Author(s):

Madhuvanthi Vijayan ◽

Chuan Xia ◽

Yul Eum Song ◽

Hanh Ngo ◽

Caleb J. Studstill ◽

...

Keyword(s):

Virus Infection ◽

Immune Responses ◽

Influenza A Virus ◽

Influenza A ◽

Innate Immune ◽

Type I ◽

Type I Ifn ◽

Innate Immune Responses ◽

Sphingosine 1 Phosphate ◽

Influenza A Virus Infection

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Long noncoding RNA TSPOAP1 antisense RNA 1 negatively modulates type I IFN signaling to facilitate influenza A virus replication

Journal of Medical Virology ◽

10.1002/jmv.25483 ◽

2019 ◽

Cited By ~ 4

Author(s):

Qi Wang ◽

Daining Zhang ◽

Wenjing Feng ◽

Yidi Guo ◽

Xiaoning Sun ◽

...

Keyword(s):

Influenza A Virus ◽

Virus Replication ◽

Long Noncoding Rna ◽

Antisense Rna ◽

Noncoding Rna ◽

Influenza A ◽

Type I ◽

Type I Ifn

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Defective interfering influenza A virus protects in vivo against disease caused by a heterologous influenza B virus

Journal of General Virology ◽

10.1099/vir.0.034132-0 ◽

2011 ◽

Vol 92 (9) ◽

pp. 2122-2132 ◽

Cited By ~ 27

Author(s):

Paul D. Scott ◽

Bo Meng ◽

Anthony C. Marriott ◽

Andrew J. Easton ◽

Nigel J. Dimmock

Keyword(s):

Influenza A Virus ◽

Influenza A ◽

Influenza Viruses ◽

Influenza B Virus ◽

Influenza B ◽

Type I ◽

Type I Ifn ◽

B Virus ◽

The Family

Influenza A and B viruses are major human respiratory pathogens that contribute to the burden of seasonal influenza. They are both members of the family Orthomyxoviridae but do not interact genetically and are classified in different genera. Defective interfering (DI) influenza viruses have a major deletion of one or more of their eight genome segments, which renders them both non-infectious and able to interfere in cell culture with the production of infectious progeny by a genetically compatible, homologous virus. It has been shown previously that intranasal administration of a cloned DI influenza A virus, 244/PR8, protects mice from various homologous influenza A virus subtypes and that it also protects mice from respiratory disease caused by a heterologous virus belonging to the family Paramyxoviridae. The mechanisms of action in vivo differ, with homologous and heterologous protection being mediated by probable genome competition and type I interferon (IFN), respectively. In the current study, it was shown that 244/PR8 also protects against disease caused by a heterologous influenza B virus (B/Lee/40). Protection from B/Lee/40 challenge was partially eliminated in mice that did not express a functional type I IFN receptor, suggesting that innate immunity, and type I IFN in particular, are important in mediating protection against this virus. It was concluded that 244/PR8 has the ability to protect in vivo against heterologous IFN-sensitive respiratory viruses, in addition to homologous influenza A viruses, and that it acts by fundamentally different mechanisms.

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FAT10 Is Critical in Influenza A Virus Replication by Inhibiting Type I IFN

The Journal of Immunology ◽

10.4049/jimmunol.1501563 ◽

2016 ◽

Vol 197 (3) ◽

pp. 824-833 ◽

Cited By ~ 10

Author(s):

Yanli Zhang ◽

Jun Tang ◽

Ning Yang ◽

Qiang Liu ◽

Qingchao Zhang ◽

...

Keyword(s):

Influenza A Virus ◽

Virus Replication ◽

Influenza A ◽

Type I ◽

Type I Ifn

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Influenza a virus NS1 resembles a TRAF3-interacting motif to target the RNA sensing-TRAF3-type I IFN axis and impair antiviral innate immunity

Journal of Biomedical Science ◽

10.1186/s12929-021-00764-0 ◽

2021 ◽

Vol 28 (1) ◽

Author(s):

Chun-Yang Lin ◽

Meng-Cen Shih ◽

Hung-Chun Chang ◽

Kuan-Jung Lin ◽

Lin-Fang Chen ◽

...

Keyword(s):

Influenza A Virus ◽

Influenza A ◽

Ex Vivo ◽

Antiviral Response ◽

Mutant Virus ◽

Luciferase Reporter ◽

Common Mechanism ◽

Type I ◽

Type I Ifn

Abstract Background Influenza A virus (IAV) evolves strategies to counteract the host antiviral defense for establishing infection. The influenza A virus (IAV) non-structural protein 1 (NS1) is a key viral factor shown to counteract type I IFN antiviral response mainly through targeting RIG-I signaling. Growing evidence suggests that viral RNA sensors RIG-I, TLR3, and TLR7 function to detect IAV RNA in different cell types to induce type I IFN antiviral response to IAV infection. Yet, it remains unclear if IAV NS1 can exploit a common mechanism to counteract these RNA sensing pathways to type I IFN production at once, then promoting viral propagation in the host. Methods Luciferase reporter assays were conducted to determine the effect of NS1 and its mutants on the RIG-I and TLR3 pathways to the activation of the IFN-β and NF-κB promoters. Coimmunoprecipitation and confocal microscopic analyses were used to the interaction and colocalization between NS1 and TRAF3. Ubiquitination assays were performed to study the effect of NS1 and its mutants on TRAF3 ubiquitination. A recombinant mutant virus carrying NS1 E152A/E153A mutations was generated by reverse genetics for biochemical, ex vivo, and in vivo analyses to explore the importance of NS1 E152/E153 residues in targeting the RNA sensing-TRAF3-type I IFN axis and IAV pathogenicity. Results Here we report that NS1 subverts the RIG-I, TLR3, and TLR7 pathways to type I IFN production through targeting TRAF3 E3 ubiquitin ligase. NS1 harbors a conserved FTEE motif (a.a. 150-153), in which the E152/E153 residues are critical for binding TRAF3 to block TRAF3 ubiquitination and type I IFN production by these RNA sensing pathways. A recombinant mutant virus carrying NS1 E152A/E153A mutations induces higher type I IFN production ex vivo and in vivo, and exhibits the attenuated phenotype in infected mice, indicating the importance of E152/E153 residues in IAV pathogenicity. Conclusions Together our work uncovers a novel mechanism of IAV NS1-mediated immune evasion to promote viral infection through targeting the RNA sensing-TRAF3-type I IFN axis.

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