Canine Influenza Virus is Mildly Restricted by Canine Tetherin Protein

Tetherin (BST2/CD317/HM1.24) has emerged as a key host-cell ·defence molecule that acts by inhibiting the release and spread of diverse enveloped virions from infected cells. We analysed the biological features of canine tetherin and found it to be an unstable hydrophilic type I transmembrane protein with one transmembrane domain, no signal peptide, and multiple glycosylation and phosphorylation sites. Furthermore, the tissue expression profile of canine tetherin revealed that it was particularly abundant in immune organs. The canine tetherin gene contains an interferon response element sequence that can be regulated and expressed by canine IFN-α. A CCK-8 assay showed that canine tetherin was effective in helping mitigate cellular damage caused by canine influenza virus (CIV) infection. Additionally, we found that the overexpression of canine tetherin inhibited replication of the CIV and that interference with the canine tetherin gene enhanced CIV replication in cells. The impact of canine tetherin on CIV replication was mild. However, these results elucidate the role of the innate immune factor, canine tetherin, during CIV infection for the first time.

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In VitroSusceptibility of Canine Influenza A (H3N8) Virus to Nitazoxanide and Tizoxanide

Veterinary Medicine International ◽

10.4061/2010/891010 ◽

2010 ◽

Vol 2010 ◽

pp. 1-5 ◽

Cited By ~ 8

Author(s):

Laura V. Ashton ◽

Robert L. Callan ◽

Sangeeta Rao ◽

Gabriele A. Landolt

Keyword(s):

Influenza Virus ◽

Influenza A ◽

The United States ◽

Canine Influenza Virus ◽

Valuable Adjunct ◽

Canine Influenza ◽

The Impact ◽

H3n8 Virus

Infection of dogs with canine influenza virus (CIV) is considered widespread throughout the United States following the first isolation of CIV in 2004. While vaccination against influenza A infection is a common and important practice for disease control, antiviral therapy can serve as a valuable adjunct in controlling the impact of the disease. In this study, we examined the antiviral activity of nitazoxanide (NTZ) and tizoxanide (TIZ) against three CIV isolatesin vitro. NTZ and TIZ inhibited virus replication of all CIVs with 50% and 90% inhibitory concentrations ranging from 0.17 to 0.21 μMand from 0.60 to 0.76 μM, respectively. These results suggest that NTZ and TIZ are effective against CIV and may be useful for treatment of canine influenza in dogs but further investigation of thein vivoefficacy against CIV as well as the drug's potential for toxicity in dogs is needed.

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Canine Interferon-Inducible Transmembrane Protein Is a Host Restriction Factor That Potently Inhibits Replication of Emerging Canine Influenza Virus

Frontiers in Immunology ◽

10.3389/fimmu.2021.710705 ◽

2021 ◽

Vol 12 ◽

Author(s):

Gang Lu ◽

Jiajun Ou ◽

Siqi Cai ◽

Zhiying Lai ◽

Lintao Zhong ◽

...

Keyword(s):

Influenza Virus ◽

Antiviral Activity ◽

Profile Analysis ◽

Transmembrane Protein ◽

Canine Influenza Virus ◽

Host Restriction ◽

Expression Profile Analysis ◽

Challenge Study ◽

Canine Influenza

Canine influenza virus (CIV) is an emerging virus that is associated with major hidden hazards to the canine population and public health. Until now, how canine uses its innate immunity to restrict CIV replication is seldomly investigated. Recently, studies on interferon-inducible transmembrane (IFITM) of several major hosts of influenza virus (human, chicken, duck, pig) indicated it can potently restrict the viral replication. Here, the gene locus of five previously annotated canine IFITM (caIFITM) genes was determined on chromosome 18 using multiple bioinformatics strategies, provisionally designated as caIFITM1, caIFITM2a, caIFITM2b, caIFITM3, and caIFITM5. An analysis on protein sequences between caIFITM and its homologs indicated they shared the same conserved amino acids important for the antiviral activity. Expression profile analysis showed that caIFITM was constitutively expressed in tissues and MDCK cell line. After treatment with interferon or infection with influenza virus, the expression level of caIFITM increased with different degrees in vitro. An animal challenge study demonstrated CIV infection resulted in upregulation of caIFITM in beagles. caIFITMs had a similar subcellular localization to their human homologs. caIFITM1 was present at the cell surface and caIFITM3 was present perinuclearly and colocalized with LAMP1-containing compartments. Finally, we generated A549 cell lines stably expressing caIFITM and challenged them with influenza virus. The result demonstrated caIFITM1, caIFITM2a, caIFITM2b, and caIFITM3 had a potent antiviral activity against influenza virus. Our study will help better understand the evolutional pattern of IFITM and its role in the host’s defense against virus infection.

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PLASMACYTOID DENDRITIC CELLS FUNCTION IN HIV INFECTION

Clinical & Investigative Medicine ◽

10.25011/cim.v31i4.4808 ◽

2008 ◽

Vol 31 (4) ◽

pp. 13

Author(s):

Martin Hyrcza ◽

Mario Ostrowski ◽

Sandy Der

Keyword(s):

Dendritic Cells ◽

Influenza Virus ◽

Hiv Infection ◽

Gene Transcription ◽

Sendai Virus ◽

Plasmacytoid Dendritic Cells ◽

Type I Interferons ◽

Interferon Response ◽

Type I ◽

Type I Ifn

Plasmacytoid dendritic cells (pDCs) are innate immune cells able to produce large quantities of type I interferons (IFN) when activated. Human immunodeficiency virus (HIV)-infected patients show generalized immune dysfunction characterized in part by chronic interferon response. In this study we investigated the role of dendritic cells inactivating and maintaining this response. Specifically we compared the IFN geneactivity in pDCs in response to several viruses and TLR agonists. We hypothesized that 1) the pattern of IFN gene transcription would differ in pDCs treated with HIV than with other agents, and 2) that pDCs from patients from different stages of disease would respond differently to the stimulations. To test these hypotheses, we obtained pDCs from 15 HIV-infected and uninfected individuals and treated freshly isolated pDCs with either HIV (BAL strain), influenza virus (A/PR/8/34), Sendai virus (Cantell strain), TLR7 agonist(imiquimod), or TLR9 agonist (CpG-ODN) for 6h. Type I IFN gene transcription was monitored by real time qPCRfor IFNA1, A2, A5, A6, A8,A17, B1, and E1, and cytokine levels were assayed by Cytometric Bead Arrays forTNF?, IL6, IL8, IL10, IL1?, and IL12p70. pDC function as determined by these two assays showed no difference between HIV-infected and uninfected patients or between patients with early or chronic infection. Specifically, HIV did notinduce type I IFN gene expression, whereas influenza virus, Sendai virus and imiquimod did. Similarly, HIV failed to induce any cytokine release from pDCs in contrast to influenza virus, Sendai virus and imiquimod, which stimulatedrelease of TNF?, IL6, or IL8. Together these results suggest that the reaction of pDCs to HIV virus is quantitatively different from the response to agents such as virus, Sendai virus, and imiquimod. In addition, pDCs from HIV-infected persons have responses similar to pDCs from uninfected donors, suggesting, that the DC function may not be affected by HIV infection.

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Evolution of the hemagglutinin gene of H3N8 canine influenza virus in dogs

Virus Genes ◽

10.1007/s11262-014-1102-8 ◽

2014 ◽

Vol 49 (3) ◽

pp. 393-399 ◽

Cited By ~ 7

Author(s):

Heidi L. Pecoraro ◽

Susi Bennett ◽

Miranda E. Spindel ◽

Gabriele A. Landolt

Keyword(s):

Influenza Virus ◽

Canine Influenza Virus ◽

Hemagglutinin Gene ◽

Canine Influenza

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Quantitative Proteome Analysis of Atg5-Deficient Mouse Embryonic Fibroblasts Reveals the Range of the Autophagy-Modulated Basal Cellular Proteome

mSystems ◽

10.1128/msystems.00481-19 ◽

2019 ◽

Vol 4 (6) ◽

Cited By ~ 1

Author(s):

Kiran Bala Sharma ◽

Manish Sharma ◽

Suruchi Aggarwal ◽

Amit Kumar Yadav ◽

Shinjini Bhatnagar ◽

...

Keyword(s):

Cell Adhesion ◽

Inflammatory Response ◽

Transforming Growth Factor ◽

Proteome Analysis ◽

Interferon Response ◽

Type I ◽

Mouse Embryonic Fibroblasts ◽

Embryonic Fibroblasts ◽

The Impact

ABSTRACT Basal autophagy is crucial for maintenance of cellular homeostasis. ATG5 is an essential protein for autophagosome formation, and its depletion has been extensively used as a tool to disrupt autophagy. Here, we characterize the impact of Atg5 deficiency on the cellular proteome of mouse embryonic fibroblasts (MEFs). Using a tandem mass tagging (TMT)-based quantitative proteomics analysis, we observe that 14% of identified proteins show dysregulated levels in atg5−/− MEFs. These proteins were distributed across diverse biological processes, such as cell adhesion, development, differentiation, transport, metabolism, and immune responses. Several of the upregulated proteins were receptors involved in transforming growth factor β (TGF-β) signaling, JAK-STAT signaling, junction adhesion, and interferon/cytokine-receptor interactions and were validated as autophagy substrates. Nearly equal numbers of proteins, including several lysosomal proteins and enzymes, were downregulated, suggesting a complex role of autophagy/ATG5 in regulating their levels. The atg5−/− MEFs had lower levels of key immune sensors and effectors, including Toll-like receptor 2 (TLR2), interferon regulatory factor 3 (IRF3), IRF7, MLKL, and STAT1/3/5/6, which were restored by reexpression of ATG5. While these cells could efficiently mount a type I interferon response to the double-stranded RNA (dsRNA) mimic poly(I·C), they were compromised in their inflammatory response to the bacterial pathogen-associated molecular patterns (PAMPs) lipopolysaccharide (LPS) and Pam3CSK4. Transcriptional activation and secretion of interleukin-6 (IL-6) in these cells could be recovered by ATG5 expression, supporting the role of autophagy in the TLR2-induced inflammatory response. This study provides a key resource for understanding the effect of autophagy/ATG5 deficiency on the fibroblast proteome. IMPORTANCE Autophagy performs housekeeping functions for cells and maintains a functional mode by degrading damaged proteins and organelles and providing energy under starvation conditions. The process is tightly regulated by the evolutionarily conserved Atg genes, of which Atg5 is one such crucial mediator. Here, we have done a comprehensive quantitative proteome analysis of mouse embryonic fibroblasts that lack a functional autophagy pathway (Atg5 knockout). We observe that 14% of the identified cellular proteome is remodeled, and several proteins distributed across diverse cellular processes with functions in signaling, cell adhesion, development, and immunity show either higher or lower levels under autophagy-deficient conditions. These cells have lower levels of crucial immune proteins that are required to mount a protective inflammatory response. This study will serve as a valuable resource to determine the role of autophagy in modulating specific protein levels in cells.

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Role of CARD Region of MDA5 Gene in Canine Influenza Virus Infection

Viruses ◽

10.3390/v12030307 ◽

2020 ◽

Vol 12 (3) ◽

pp. 307 ◽

Cited By ~ 1

Author(s):

Cheng Fu ◽

Shaotang Ye ◽

Yongbo Liu ◽

Shoujun Li

Keyword(s):

Innate Immunity ◽

Influenza Virus ◽

Cytokine Production ◽

Influenza Virus Infection ◽

Luciferase Assay ◽

Canine Influenza Virus ◽

Card Domain ◽

Canine Influenza ◽

Receptor Family

MDA5 belongs to the RIG-I-like receptor family, which is involved in innate immunity. During viral infection, MDA5 generates an antiviral response by recognizing the ligand to activate interferon. However, the role and mechanism of MDA5 in canine influenza virus (CIV) infection are unclear. To understand the mechanism of canine MDA5-mediated innate immunity during CIV infection, we detected the distribution of MDA5 in beagles, and the structural prediction showed that MDA5 was mainly composed of a CARD domain, RD domain, and DExD/H helix structure. Moreover, we found that MDA5 inhibits CIV replication. Furthermore, in the dual luciferase assay, we revealed that the CARD region of MDA5 strongly activated the IFN-β promoter and mainly transmitted signals through the CARD region. Overexpression of the CARD region of MDA5 revealed that the MDA5-mediated signaling pathway could transmit signals by activating the IRF3/NF-κB and IRF3 promoters, promoting the expression of antiviral proteins and cytokine release, thereby inhibiting CIV replication. Upon silencing of MDA5, cytokine production decreased, while the replication ability of CIV was increased. Thus, this study revealed a novel mechanism by which MDA5 mediated CIV infection and provided new avenues for the development of antiviral strategies.

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Short communication: isolation and phylogenetic analysis of an avian-origin H3N2 canine influenza virus in dog shelter, China

Virus Genes ◽

10.1007/s11262-013-0882-6 ◽

2013 ◽

Vol 46 (3) ◽

pp. 554-557 ◽

Cited By ~ 4

Author(s):

Shuo Su ◽

Ziguo Yuan ◽

Jidang Chen ◽

Jiexiong Xie ◽

Huatao Li ◽

...

Keyword(s):

Phylogenetic Analysis ◽

Influenza Virus ◽

Short Communication ◽

Canine Influenza Virus ◽

Avian Origin ◽

Canine Influenza

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The Seroprevalence of Canine Influenza Virus H3N8 in Dogs Participating in a Flyball Tournament in Pennsylvania in 2010: A Follow-Up Study

Journal of Veterinary Internal Medicine ◽

10.1111/jvim.12047 ◽

2013 ◽

Vol 27 (2) ◽

pp. 367-370 ◽

Cited By ~ 2

Author(s):

C.A. Wiley ◽

M.C. Ottoson ◽

M.M. Garcia ◽

L.E. Wiley ◽

C.M. Otto

Keyword(s):

Influenza Virus ◽

Canine Influenza Virus ◽

Follow Up Study ◽

Canine Influenza

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Knockout of IRF7 Highlights its Modulator Function of Host Response Against Avian Influenza Virus and the Involvement of MAPK and TOR Signaling Pathways in Chicken

Genes ◽

10.3390/genes11040385 ◽

2020 ◽

Vol 11 (4) ◽

pp. 385

Author(s):

Tae Hyun Kim ◽

Colin Kern ◽

Huaijun Zhou

Keyword(s):

Influenza Virus ◽

Avian Influenza ◽

Avian Influenza Virus ◽

Signaling Pathways ◽

Cell Lines ◽

Host Response ◽

Antiviral Response ◽

Influenza Viruses ◽

Interferon Response ◽

Type I

Interferon regulatory factor 7 (IRF7) is known as the master transcription factor of the type I interferon response in mammalian species along with IRF3. Yet birds only have IRF7, while they are missing IRF3, with a smaller repertoire of immune-related genes, which leads to a distinctive immune response in chickens compared to in mammals. In order to understand the functional role of IRF7 in the regulation of the antiviral response against avian influenza virus in chickens, we generated IRF7-/- chicken embryonic fibroblast (DF-1) cell lines and respective controls (IRF7wt) by utilizing the CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9) system. IRF7 knockout resulted in increased viral titers of low pathogenic avian influenza viruses. Further RNA-sequencing performed on H6N2-infected IRF7-/- and IRF7wt cell lines revealed that the deletion of IRF7 resulted in the significant down-regulation of antiviral effectors and the differential expression of genes in the MAPK (mitogen-activated protein kinase) and mTOR (mechanistic target of rapamycin) signaling pathways. Dynamic gene expression profiling of the host response between the wildtype and IRF7 knockout revealed potential signaling pathways involving AP1 (activator protein 1), NF-κB (nuclear factor kappa B) and inflammatory cytokines that may complement chicken IRF7. Our findings in this study provide novel insights that have not been reported previously, and lay a solid foundation for enhancing our understanding of the host antiviral response against the avian influenza virus in chickens.

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