scholarly journals Measure and Countermeasure: Type I IFN (IFN-α/β) Antiviral Response against West Nile Virus

2009 ◽  
Vol 1 (5) ◽  
pp. 435-445 ◽  
Author(s):  
Stephane Daffis ◽  
Mehul S. Suthar ◽  
Michael Gale, Jr. ◽  
Michael S. Diamond
Keyword(s):  
West Nile Virus ◽  
Antiviral Response ◽  
Type I ◽  
Type I Ifn ◽  
West Nile ◽  
Ifn Alpha ◽  
Alpha Beta

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

2008 ◽  
Vol 82 (17) ◽  
pp. 8465-8475 ◽  
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.

scholarly journals West Nile Virus-Inclusive Single-Cell RNA Sequencing Reveals Heterogeneity in the Type I Interferon Response within Single Cells

2019 ◽  
Vol 93 (6) ◽  
Author(s):  
Justin T. O’Neal ◽  
Amit A. Upadhyay ◽  
Amber Wolabaugh ◽  
Nirav B. Patel ◽  
Steven E. Bosinger ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Single Cell ◽  
Type I Interferon ◽  
Single Cells ◽  
Antiviral Response ◽  
Viral Rna ◽  
Type I ◽  
Cell Level ◽  
West Nile ◽  
Viral Abundance

ABSTRACTWest Nile virus (WNV) is a neurotropic mosquito-borne flavivirus of global importance. Neuroinvasive WNV infection results in encephalitis and can lead to prolonged neurological impairment or death. Type I interferon (IFN-I) is crucial for promoting antiviral defenses through the induction of antiviral effectors, which function to restrict viral replication and spread. However, our understanding of the antiviral response to WNV infection is mostly derived from analysis of bulk cell populations. It is becoming increasingly apparent that substantial heterogeneity in cellular processes exists among individual cells, even within a seemingly homogenous cell population. Here, we present WNV-inclusive single-cell RNA sequencing (scRNA-seq), an approach to examine the transcriptional variation and viral RNA burden across single cells. We observed that only a few cells within the bulk population displayed robust transcription of IFN-β mRNA, and this did not appear to depend on viral RNA abundance within the same cell. Furthermore, we observed considerable transcriptional heterogeneity in the IFN-I response, with genes displaying high unimodal and bimodal expression patterns. Broadly, IFN-stimulated genes negatively correlated with viral RNA abundance, corresponding with a precipitous decline in expression in cells with high viral RNA levels. Altogether, we demonstrated the feasibility and utility of WNV-inclusive scRNA-seq as a high-throughput technique for single-cell transcriptomics and WNV RNA detection. This approach can be implemented in other models to provide insights into the cellular features of protective immunity and identify novel therapeutic targets.IMPORTANCEWest Nile virus (WNV) is a clinically relevant pathogen responsible for recurrent epidemics of neuroinvasive disease. Type I interferon is essential for promoting an antiviral response against WNV infection; however, it is unclear how heterogeneity in the antiviral response at the single-cell level impacts viral control. Specifically, conventional approaches lack the ability to distinguish differences across cells with varying viral abundance. The significance of our research is to demonstrate a new technique for studying WNV infection at the single-cell level. We discovered extensive variation in antiviral gene expression and viral abundance across cells. This protocol can be applied to primary cells orin vivomodels to better understand the underlying cellular heterogeneity following WNV infection for the development of targeted therapeutic strategies.

scholarly journals Human MicroRNA miR-532-5p Exhibits Antiviral Activity against West Nile Virus via Suppression of Host Genes SESTD1 and TAB3 Required for Virus Replication

2015 ◽  
Vol 90 (5) ◽  
pp. 2388-2402 ◽  
Author(s):  
Andrii Slonchak ◽  
Rory P. Shannon ◽  
Gabor Pali ◽  
Alexander A. Khromykh
Keyword(s):  
West Nile Virus ◽  
Antiviral Response ◽  
Human Cells ◽  
Hek293 Cells ◽  
Type I ◽  
Virus Infections ◽  
West Nile ◽  
Viral Pathogen ◽  
Host Genes

ABSTRACTWest Nile virus (WNV) is a mosquito-transmitted flavivirus that naturally circulates between mosquitos and birds but can also infect humans, causing severe neurological disease. The early host response to WNV infection in vertebrates primarily relies on the type I interferon pathway; however, recent studies suggest that microRNAs (miRNAs) may also play a notable role. In this study, we assessed the role of host miRNAs in response to WNV infection in human cells. We employed small RNA sequencing (RNA-seq) analysis to determine changes in the expression of host miRNAs in HEK293 cells infected with an Australian strain of WNV, Kunjin (WNVKUN), and identified a number of host miRNAs differentially expressed in response to infection. Three of these miRNAs were confirmed to be significantly upregulated in infected cells by quantitative reverse transcription (qRT)-PCR and Northern blot analyses, and one of them, miR-532-5p, exhibited a significant antiviral effect against WNVKUNinfection. We have demonstrated that miR-532-5p targets and downregulates expression of the host genes SESTD1 and TAB3 in human cells. Small interfering RNA (siRNA) depletion studies showed that both SESTD1 and TAB3 were required for efficient WNVKUNreplication. We also demonstrated upregulation of mir-532-5p expression and a corresponding decrease in the expression of its targets, SESTD1 and TAB3, in the brains of WNVKUN-infected mice. Our results show that upregulation of miR-532-5p and subsequent suppression of the SESTD1 and TAB3 genes represent a host antiviral response aimed at limiting WNVKUNinfection and highlight the important role of miRNAs in controlling RNA virus infections in mammalian hosts.IMPORTANCEWest Nile virus (WNV) is a significant viral pathogen that poses a considerable threat to human health across the globe. There is no specific treatment or licensed vaccine available for WNV, and deeper insight into how the virus interacts with the host is required to facilitate their development. In this study, we addressed the role of host microRNAs (miRNAs) in antiviral response to WNV in human cells. We identified miR-532-5p as a novel antiviral miRNA and showed that it is upregulated in response to WNV infection and suppresses the expression of the host genes TAB3 and SESTD1 required for WNV replication. Our results show that upregulation of miR-532-5p and subsequent suppression of the SESTD1 and TAB3 genes represent an antiviral response aimed at limiting WNV infection and highlight the important role of miRNAs in controlling virus infections in mammalian hosts.

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

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.

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

2019 ◽  
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 ◽  
Antiviral Response ◽  
Type I ◽  
West Nile ◽  
Pre Treatment ◽  
And Function

ABSTRACTSeveral 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 pre-treatment 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 is impaired compared to wild-type (wt) cells. IFNβ pre-treatment was more effective in protecting against subsequent WNV infection in wt cells as compared to 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 ISGs following WNV infection or IFNβ 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 is dependent on TRIM6 activity. Overall, these results provide evidence that TRIM6 contributes to the antiviral response against WNV and identified VAMP8 as a novel regulator of 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.

scholarly journals West Nile Virus Noncoding Subgenomic RNA Contributes to Viral Evasion of the Type I Interferon-Mediated Antiviral Response

2012 ◽  
Vol 86 (10) ◽  
pp. 5708-5718 ◽  
Author(s):  
A. Schuessler ◽  
A. Funk ◽  
H. M. Lazear ◽  
D. A. Cooper ◽  
S. Torres ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Type I Interferon ◽  
Antiviral Response ◽  
Type I ◽  
West Nile ◽  
Subgenomic Rna ◽  
Viral Evasion

scholarly journals PKR and RNase L Contribute to Protection against Lethal West Nile Virus Infection by Controlling Early Viral Spread in the Periphery and Replication in Neurons

2006 ◽  
Vol 80 (14) ◽  
pp. 7009-7019 ◽  
Author(s):  
Melanie A. Samuel ◽  
Kevin Whitby ◽  
Brian C. Keller ◽  
Anantha Marri ◽  
Winfried Barchet ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Mortality Rate ◽  
Type I ◽  
Rnase L ◽  
Type I Ifn ◽  
Oligoadenylate Synthetase ◽  
West Nile ◽  
Peripheral Tissues ◽  
Viral Spread ◽  
Viral Burden

ABSTRACT West Nile virus (WNV) is a neurotropic, mosquito-borne flavivirus that can cause lethal meningoencephalitis. Type I interferon (IFN) plays a critical role in controlling WNV replication, spread, and tropism. In this study, we begin to examine the effector mechanisms by which type I IFN inhibits WNV infection. Mice lacking both the interferon-induced, double-stranded-RNA-activated protein kinase (PKR) and the endoribonuclease of the 2′,5′-oligoadenylate synthetase-RNase L system (PKR−/− × RL−/−) were highly susceptible to subcutaneous WNV infection, with a 90% mortality rate compared to the 30% mortality rate observed in congenic wild-type mice. PKR−/− × RL−/− mice had increased viral loads in their draining lymph nodes, sera, and spleens, which led to early viral entry into the central nervous system (CNS) and higher viral burden in neuronal tissues. Although mice lacking RNase L showed a higher CNS viral burden and an increased mortality, they were less susceptible than the PKR−/− × RL−/− mice; thus, we also infer an antiviral role for PKR in the control of WNV infection. Notably, a deficiency in both PKR and RNase L resulted in a decreased ability of type I IFN to inhibit WNV in primary macrophages and cortical neurons. In contrast, the peripheral neurons of the superior cervical ganglia of PKR−/− × RL−/− mice showed no deficiency in the IFN-mediated inhibition of WNV. Our data suggest that PKR and RNase L contribute to IFN-mediated protection in a cell-restricted manner and control WNV infection in peripheral tissues and some neuronal subtypes.

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

2019 ◽  
Vol 94 (2) ◽  
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.

scholarly journals Early B-Cell Activation after West Nile Virus Infection Requires Alpha/Beta Interferon but Not Antigen Receptor Signaling

2008 ◽  
Vol 82 (22) ◽  
pp. 10964-10974 ◽  
Author(s):  
Whitney E. Purtha ◽  
Karen A. Chachu ◽  
Herbert W. Virgin ◽  
Michael S. Diamond
Keyword(s):  
West Nile Virus ◽  
B Cell ◽  
Cell Activation ◽  
Immunoglobulin M ◽  
Type I ◽  
B Cell Activation ◽  
West Nile ◽  
Beta Interferon ◽  
Alpha Beta ◽  
Β Receptor

ABSTRACT The B-cell response against West Nile virus (WNV), an encephalitic Flavivirus of global concern, is critical to controlling central nervous system dissemination and neurological sequelae, including death. Here, using a well-characterized mouse model of WNV infection, we examine the factors that govern early B-cell activation. Subcutaneous inoculation with a low dose of replicating WNV results in extensive B-cell activation in the draining lymph node (LN) within days of infection as judged by upregulation of the surface markers CD69, class II major histocompatibility complex, and CD86 on CD19+ cells. B-cell activation in the LN but not the spleen was dependent on signals through the type I alpha/beta interferon (IFN-α/β) receptor. Despite significant activation in the draining LN at day 3 after infection, WNV-specific B cells were not detected by immunoglobulin M enzyme-linked immunospot analysis until day 7. Liposome depletion experiments demonstrate that B-cell activation after WNV infection was not affected by the loss of F4/80+ or CD169+ subcapsular macrophages. Nonetheless, LN myeloid cells were essential for control of viral replication and survival from infection. Overall, our data suggest that the massive, early polyclonal B-cell activation occurring in the draining LN after WNV infection is immunoglobulin receptor and macrophage independent but requires sustained signals through the type I IFN-α/β receptor.

scholarly journals West Nile virus-inclusive single-cell RNA sequencing reveals heterogeneity in the type I interferon response within single cells

2018 ◽  
Author(s):  
Justin T. O’Neal ◽  
Amit A. Upadhyay ◽  
Amber Wolabaugh ◽  
Nirav B. Patel ◽  
Steven E. Bosinger ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Single Cell ◽  
Type I Interferon ◽  
Single Cells ◽  
Antiviral Response ◽  
Viral Rna ◽  
Type I ◽  
Cell Level ◽  
West Nile ◽  
Viral Abundance

ABSTRACTWest Nile virus (WNV) is a neurotropic mosquito-borne flavivirus of global importance. Neuroinvasive WNV infection results in encephalitis and can lead to prolonged neurological impairment or death. Type I interferon (IFN-I) is crucial for promoting antiviral defenses through the induction of antiviral effectors, which function to restrict viral replication and spread. However, our understanding of the antiviral response to WNV infection is mostly derived from analysis of bulk cell populations. It is becoming increasingly apparent that substantial heterogeneity in cellular processes exists among individual cells, even within a seemingly homogenous cell population. Here, we present WNV-inclusive single-cell RNA sequencing (scRNA-seq), an approach to examine the transcriptional variation and viral RNA burden across single cells. We observed that only a few cells within the bulk population displayed robust transcription of IFN-β mRNA, and this did not appear to depend on viral RNA abundance within the same cell. Furthermore, we observed considerable transcriptional heterogeneity in the IFN-I response, with genes displaying high unimodal and bimodal expression patterns. Broadly, IFN-stimulated genes negatively correlated with viral RNA abundance, corresponding with a precipitous decline in expression in cells with high viral RNA levels. Altogether, we demonstrated the feasibility and utility of WNV-inclusive scRNA-seq as a high-throughput technique for single-cell transcriptomics and WNV RNA detection. This approach can be implemented in other models to provide insights into the cellular features of protective immunity and identify novel therapeutic targets.IMPORTANCEWest Nile virus (WNV) is a clinically relevant pathogen responsible for recurrent epidemics of neuroinvasive disease. Type I interferon is essential for promoting an antiviral response against WNV infection; however, it is unclear how heterogeneity in the antiviral response at the single-cell level impacts viral control. Specifically, conventional approaches lack the ability to distinguish differences across cells with varying viral abundance. The significance of our research is to demonstrate a new technique for studying WNV infection at the single-cell level. We discovered extensive variation in antiviral gene expression and viral abundance across cells. This protocol can be applied to primary cells orin vivomodels to better understand the underlying cellular heterogeneity following WNV infection for the development of targeted therapeutic strategies.

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