Early Production of Type I Interferon during West Nile Virus Infection: Role for Lymphoid Tissues in IRF3-Independent Interferon Production

ABSTRACT Infection of cells with flaviviruses in vitro is reduced by pretreatment with small amounts of type I interferon (IFN-α/β). Similarly, pretreatment of animals with IFN and experiments using mice defective in IFN signaling have indicated a role for IFN in controlling flavivirus disease in vivo. These data, along with findings that flavivirus-infected cells block IFN signaling, suggest that flavivirus infection can trigger an IFN response. To investigate IFN gene induction by the very first cells infected during in vivo infection with the flavivirus West Nile virus (WNV), we infected mice with high-titer preparations of WNV virus-like particles (VLPs), which initiate viral genome replication in cells but fail to spread. These studies demonstrated a brisk production of IFN in vivo, with peak levels of over 1,000 units/ml detected in sera between 8 and 24 h after inoculation by either the intraperitoneal or footpad route. The IFN response was dependent on genome replication, and WNV genomes and WNV antigen-positive cells were readily detected in the popliteal lymph nodes (pLN) of VLP-inoculated mice. High levels of IFN mRNA transcripts and functional IFN were also produced in VLP-inoculated IFN regulatory factor 3 null (IRF3−/−) mice, indicating that IFN production was independent of the IRF3 pathways to IFN gene transcription, consistent with the IFN type produced (predominantly α).

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Interferon Regulatory Factor IRF-7 Induces the Antiviral Alpha Interferon Response and Protects against Lethal West Nile Virus Infection

Journal of Virology ◽

10.1128/jvi.00918-08 ◽

2008 ◽

Vol 82 (17) ◽

pp. 8465-8475 ◽

Cited By ~ 114

Author(s):

Stephane Daffis ◽

Melanie A. Samuel ◽

Mehul S. Suthar ◽

Brian C. Keller ◽

Michael Gale ◽

...

Keyword(s):

West Nile Virus ◽

Cortical Neurons ◽

Interferon Regulatory Factor ◽

Interferon Response ◽

Type I ◽

Type I Ifn ◽

Regulatory Factor ◽

West Nile

ABSTRACT Type I interferon (IFN-α/β) comprises a family of immunomodulatory cytokines that are critical for controlling viral infections. In cell culture, many RNA viruses trigger IFN responses through the binding of RNA recognition molecules (RIG-I, MDA5, and TLR-3) and induction of interferon regulatory factor IRF-3-dependent gene transcription. Recent studies with West Nile virus (WNV) have shown that type I IFN is essential for restricting infection and that a deficiency of IRF-3 results in enhanced lethality. However, IRF-3 was not required for optimal systemic IFN production in vivo or in vitro in macrophages. To begin to define the transcriptional factors that regulate type I IFN after WNV infection, we evaluated IFN induction and virus control in IRF-7−/− mice. Compared to congenic wild-type mice, IRF-7−/− mice showed increased lethality after WNV infection and developed early and elevated WNV burdens in both peripheral and central nervous system tissues. As a correlate, a deficiency of IRF-7 blunted the systemic type I IFN response in mice. Consistent with this, IFN-α gene expression and protein production were reduced and viral titers were increased in IRF-7−/− primary macrophages, fibroblasts, dendritic cells, and cortical neurons. In contrast, in these cells the IFN-β response remained largely intact. Our data suggest that the early protective IFN-α response against WNV occurs through an IRF-7-dependent transcriptional signal.

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Protection against West Nile Virus Infection in Mice after Inoculation with Type I Interferon-Inducing RNA Transcripts

PLoS ONE ◽

10.1371/journal.pone.0049494 ◽

2012 ◽

Vol 7 (11) ◽

pp. e49494 ◽

Cited By ~ 9

Author(s):

Miguel Rodríguez-Pulido ◽

Miguel A. Martín-Acebes ◽

Estela Escribano-Romero ◽

Ana-Belén Blázquez ◽

Francisco Sobrino ◽

...

Keyword(s):

West Nile Virus ◽

Virus Infection ◽

Type I Interferon ◽

West Nile Virus Infection ◽

Type I ◽

West Nile ◽

Rna Transcripts

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VAMP8 contributes to TRIM6-mediated type-I interferon antiviral response during West Nile virus infection

10.1101/484469 ◽

2018 ◽

Author(s):

Colm Atkins ◽

Sarah van Tol ◽

Preeti Bharaj ◽

Ricardo Rajsbaum ◽

Alexander N. Freiberg

Keyword(s):

West Nile Virus ◽

Type I Interferon ◽

Treatment Options ◽

A549 Cells ◽

Febrile Illness ◽

West Nile Virus Infection ◽

Antiviral Response ◽

Type I ◽

West Nile ◽

Pre Treatment

ABSTRACTMembers of the tripartite motif (TRIM) family of E3 ubiquitin ligases regulate immune pathways including the antiviral type I interferon (IFN-I) system. Previously, we demonstrated that TRIM6 is involved in IFN-I induction and signaling. In absence of TRIM6 function, optimal IFN-I signaling is reduced, allowing increased replication of interferon-sensitive viruses. Despite numerous mechanisms to restrict vertebrate host’s IFN-I response, West Nile Virus (WNV) replication is sensitive to pre-treatment with IFN-I. However, the regulators and products of the IFN-I pathway important in regulating WNV replications are incompletely defined. Consistent with WNV’s sensitivity to IFN-I, we found that in TRIM6 knockout (TRIM6 KO) A549 cells WNV replication is significantly increased. Additionally, induction of Ifnb mRNA was delayed and the expression of several IFN-stimulated genes (ISGs) was reduced in TRIM6 KO cells. IFNβ pre-treatment was more effective in protecting against subsequent WNV infection in wt cells, indicating that TRIM6 contributes to the establishment of an IFN-induced antiviral response against WNV. Using next generation sequencing, we identified potential factors involved in this TRIM6-mediated antiviral response. One identified gene, VAMP8, is a soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNARE) in the vesicle-associated membrane protein subfamily. Knockdown of VAMP8 resulted in reduced STAT1 phosphorylation and impaired induction of several ISGs following WNV infection or IFNβ treatment. Therefore, VAMP8 is a novel gene involved in the regulation of IFN-I signaling, and its expression is dependent on TRIM6 function. Overall, these results indicate that TRIM6 contributes to the antiviral response against WNV by regulating the IFN-I system.IMPORTANCEWNV is a mosquito-borne flavivirus that poses threat to human health across large discontinuous areas throughout the world. Infection with WNV results in febrile illness, which can progress to severe neurological disease. Currently, there are no approved treatment options to control WNV infection. Understanding the cellular immune responses that regulate viral replication is important in diversifying the resources available to control WNV. Here we show that the elimination of TRIM6 in human cells results in an increase in WNV replication and alters the expression and function of other components of the IFN-I pathway through VAMP8. Dissecting the interactions between WNV and host defenses both informs basic molecular virology and promotes the development of host- and viral-targeted antiviral strategies.

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VAMP8 Contributes to the TRIM6-Mediated Type I Interferon Antiviral Response during West Nile Virus Infection

Journal of Virology ◽

10.1128/jvi.01454-19 ◽

2019 ◽

Vol 94 (2) ◽

Cited By ~ 5

Author(s):

Sarah van Tol ◽

Colm Atkins ◽

Preeti Bharaj ◽

Kendra N. Johnson ◽

Adam Hage ◽

...

Keyword(s):

West Nile Virus ◽

Type I Interferon ◽

Treatment Options ◽

A549 Cells ◽

Febrile Illness ◽

West Nile Virus Infection ◽

Antiviral Response ◽

Type I ◽

West Nile ◽

And Function

ABSTRACT Several members of the tripartite motif (TRIM) family of E3 ubiquitin ligases regulate immune pathways, including the antiviral type I interferon (IFN-I) system. Previously, we demonstrated that TRIM6 is involved in IFN-I induction and signaling. In the absence of TRIM6, optimal IFN-I signaling is reduced, allowing increased replication of interferon-sensitive viruses. Despite having evolved numerous mechanisms to restrict the vertebrate host’s IFN-I response, West Nile virus (WNV) replication is sensitive to pretreatment with IFN-I. However, the regulators and products of the IFN-I pathway that are important in regulating WNV replication are incompletely defined. Consistent with WNV’s sensitivity to IFN-I, we found that in TRIM6 knockout (TRIM6-KO) A549 cells, WNV replication is significantly increased and IFN-I induction and signaling are impaired compared to wild-type (wt) cells. IFN-β pretreatment was more effective in protecting against subsequent WNV infection in wt cells than TRIM6-KO, indicating that TRIM6 contributes to the establishment of an IFN-induced antiviral response against WNV. Using next-generation sequencing, we identified VAMP8 as a potential factor involved in this TRIM6-mediated antiviral response. VAMP8 knockdown resulted in reduced JAK1 and STAT1 phosphorylation and impaired induction of several interferon-stimulated genes (ISGs) following WNV infection or IFN-β treatment. Furthermore, VAMP8-mediated STAT1 phosphorylation required the presence of TRIM6. Therefore, the VAMP8 protein is a novel regulator of IFN-I signaling, and its expression and function are dependent on TRIM6 activity. Overall, these results provide evidence that TRIM6 contributes to the antiviral response against WNV and identify VAMP8 as a novel regulator of the IFN-I system. IMPORTANCE WNV is a mosquito-borne flavivirus that poses a threat to human health across large discontinuous areas throughout the world. Infection with WNV results in febrile illness, which can progress to severe neurological disease. Currently, there are no approved treatment options to control WNV infection. Understanding the cellular immune responses that regulate viral replication is important in diversifying the resources available to control WNV. Here, we show that the elimination of TRIM6 in human cells results in an increase in WNV replication and alters the expression and function of other components of the IFN-I pathway through VAMP8. Dissecting the interactions between WNV and host defenses both informs basic molecular virology and promotes the development of host- and virus-targeted antiviral strategies.

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The in vitro and in vivo antiviral properties of combined monoterpene alcohols against West Nile virus infection

Virology ◽

10.1016/j.virol.2016.04.021 ◽

2016 ◽

Vol 495 ◽

pp. 18-32 ◽

Cited By ~ 5

Author(s):

Adriana Pliego Zamora ◽

Judith H. Edmonds ◽

Maxwell J. Reynolds ◽

Alexander A. Khromykh ◽

Stephen J. Ralph

Keyword(s):

West Nile Virus ◽

Virus Infection ◽

West Nile Virus Infection ◽

West Nile

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E3 ligase Nedd4l promotes antiviral innate immunity by catalyzing K29-linked cysteine ubiquitination of TRAF3

Nature Communications ◽

10.1038/s41467-021-21456-1 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Peng Gao ◽

Xianwei Ma ◽

Ming Yuan ◽

Yulan Yi ◽

Guoke Liu ◽

...

Keyword(s):

Posttranslational Modifications ◽

Type I Interferon ◽

Zinc Fingers ◽

E3 Ligase ◽

Type I ◽

E3 Ligases ◽

Protein Posttranslational Modifications ◽

Antiviral Innate Immunity

AbstractUbiquitination is one of the most prevalent protein posttranslational modifications. Here, we show that E3 ligase Nedd4l positively regulates antiviral immunity by catalyzing K29-linked cysteine ubiquitination of TRAF3. Deficiency of Nedd4l significantly impairs type I interferon and proinflammatory cytokine production induced by virus infection both in vitro and in vivo. Nedd4l deficiency inhibits virus-induced ubiquitination of TRAF3, the binding between TRAF3 and TBK1, and subsequent phosphorylation of TBK1 and IRF3. Nedd4l directly interacts with TRAF3 and catalyzes K29-linked ubiquitination of Cys56 and Cys124, two cysteines that constitute zinc fingers, resulting in enhanced association between TRAF3 and E3 ligases, cIAP1/2 and HECTD3, and also increased K48/K63-linked ubiquitination of TRAF3. Mutation of Cys56 and Cys124 diminishes Nedd4l-catalyzed K29-linked ubiquitination, but enhances association between TRAF3 and the E3 ligases, supporting Nedd4l promotes type I interferon production in response to virus by catalyzing ubiquitination of the cysteines in TRAF3.

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