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Okajima M, Takenaka-Uema A, Fujii Y, Izumi F, Kojima I, Ozawa M, Naitou K, Suda Y, Nishiyama S, Murakami S, Horimoto T, Ito N, Shirafuji H, Yanase T, Masatani T. Differential role of NSs genes in the neurovirulence of two genogroups of Akabane virus causing postnatal encephalomyelitis. Arch Virol 2023; 169:7. [PMID: 38082138 DOI: 10.1007/s00705-023-05929-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 10/14/2023] [Indexed: 12/18/2023]
Abstract
Akabane virus (AKAV) is a member of the genus Orthobunyavirus, family Peribunyaviridae. In addition to AKAV strains that cause fetal Akabane disease, which is characterized by abortion in ruminants, some AKAV strains cause postnatal infection characterized by nonsuppurative encephalomyelitis in ruminants. Here, we focused on the NSs protein, a virulence factor for most viruses belonging to the genus Orthobunyavirus, and we hypothesized that this protein would act as a neurovirulence factor in AKAV strains causing postnatal encephalomyelitis. We generated AKAV strains that were unable to produce the NSs protein, derived from two different genogroups, genogroups I and II, and then examined the role of their NSs proteins by inoculating mice intracerebrally with these modified viruses. Our results revealed that the neurovirulence of genogroup II strains is dependent on the NSs protein, whereas that of genogroup I strains is independent of this protein. Notably, infection of primary cultured bovine cells with these viruses suggested that the NSs proteins of both genogroups suppress innate immune-related gene expression with equal efficiency. These results indicate differences in the determinants of virulence of orthobunyaviruses.
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Affiliation(s)
- Misuzu Okajima
- Joint Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Akiko Takenaka-Uema
- Laboratory of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Yuji Fujii
- Joint Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Fumiki Izumi
- Joint Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Isshu Kojima
- Joint Graduate School of Veterinary Medicine, Kagoshima University, Kagoshima, Japan
| | - Makoto Ozawa
- Joint Graduate School of Veterinary Medicine, Kagoshima University, Kagoshima, Japan
- Laboratory of Animal Hygiene, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan
- Transboundary Animal Diseases Research Center, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan
| | - Kiyotada Naitou
- Department of Basic Veterinary Science, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan
| | - Yuto Suda
- Kagoshima Research Station, National Institute of Animal Health, NARO, Kagoshima, Japan
| | - Shoko Nishiyama
- Laboratory of Zoonotic Diseases, Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan
| | - Shin Murakami
- Laboratory of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Taisuke Horimoto
- Laboratory of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Naoto Ito
- Joint Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
- Laboratory of Zoonotic Diseases, Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan
- Center for One Medicine Innovative Translational Research (COMIT), Gifu University, Gifu, Japan
| | - Hiroaki Shirafuji
- Kagoshima Research Station, National Institute of Animal Health, NARO, Kagoshima, Japan
| | - Tohru Yanase
- Kagoshima Research Station, National Institute of Animal Health, NARO, Kagoshima, Japan
| | - Tatsunori Masatani
- Joint Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan.
- Laboratory of Zoonotic Diseases, Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan.
- Center for One Medicine Innovative Translational Research (COMIT), Gifu University, Gifu, Japan.
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Zhang S, Zhang Y, Liu G, Wang C, Ji Y, Chen J, Hu C, Chen X, Guo A, Chen Y. The Safety and Protective Efficacy Evaluation of an Attenuated M. bovis-BoHV-1 Bivalent Vaccine in Rabbits. Vaccines (Basel) 2023; 11:1698. [PMID: 38006030 PMCID: PMC10674485 DOI: 10.3390/vaccines11111698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Revised: 10/31/2023] [Accepted: 11/05/2023] [Indexed: 11/26/2023] Open
Abstract
Bovine respiratory disease (BRD) is a global prevalent multifactorial infection primarily caused by viral and bacterial coinfections. In China, Mycoplasma bovis (M. bovis) and bovine herpesvirus type 1 (BoHV-1) are the predominant pathogens associated with BRD. Our previous study involved the development of attenuated M. bovis HB150 and BoHV-1 gG-/tk- vaccine strains, which were thoroughly assessed for their safety profiles and protective efficacy in cattle. In this study, we applied a combination of vaccines in varying ratios and used a rabbit model to determine the safety and protective efficacy. We used PCR/RT-PCR to detect the postimmunization and challenge shedding of M. bovis and BoHV-1. Additionally, we measured antibody titers and the expression of IFN-β and TNF-α to evaluate the humoral and cellular immune responses, respectively. Furthermore, we performed a histopathological analysis to assess lung damage. Our study provides evidence of the safety and effectiveness of the bivalent M. bovis-BoHV-1 vaccine in rabbits, particularly when applying a combination of 1.0 × 108 CFU of M. bovis HB150 and 1.0 × 106 TCID50 of the BoHV-1 gG-/tk- strain. The bivalent vaccine significantly enhanced both the long-term antibody immune response and cellular protection against the M. bovis and BoHV-1 challenge. These findings provide a valuable model for the potential application in cattle.
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Affiliation(s)
- Sen Zhang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (S.Z.)
- Hubei International Scientific and Technological Cooperation Base of Veterinary Epidemiology, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
- Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture and Rural Affair, Wuhan 430070, China
| | - Yisheng Zhang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (S.Z.)
- Hubei International Scientific and Technological Cooperation Base of Veterinary Epidemiology, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
| | - Guoxing Liu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (S.Z.)
- Hubei International Scientific and Technological Cooperation Base of Veterinary Epidemiology, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
| | - Chen Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (S.Z.)
- Hubei International Scientific and Technological Cooperation Base of Veterinary Epidemiology, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
- Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture and Rural Affair, Wuhan 430070, China
| | - Yan Ji
- Key Laboratory of Ruminant Biological Products, Ministry of Agriculture and Rural Affair, Hohhot 010011, China
- The Spirit JinYu Biological Pharmaceutical Co., Ltd., Hohhot 010030, China
| | - Jianguo Chen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (S.Z.)
- Hubei International Scientific and Technological Cooperation Base of Veterinary Epidemiology, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
| | - Changmin Hu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (S.Z.)
- Hubei International Scientific and Technological Cooperation Base of Veterinary Epidemiology, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
| | - Xi Chen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (S.Z.)
- Hubei International Scientific and Technological Cooperation Base of Veterinary Epidemiology, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
| | - Aizhen Guo
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (S.Z.)
- Hubei International Scientific and Technological Cooperation Base of Veterinary Epidemiology, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
- Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture and Rural Affair, Wuhan 430070, China
| | - Yingyu Chen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (S.Z.)
- Hubei International Scientific and Technological Cooperation Base of Veterinary Epidemiology, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
- Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture and Rural Affair, Wuhan 430070, China
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Rosales J, Nieto Farías M, Burucúa M, Marin M, Pérez S. Infection by bovine alphaherpesvirus types 1 and 5 induces IFN-λ3 expression in neuronal-type cells and bovine neural tissues. Vet Immunol Immunopathol 2022; 245:110391. [DOI: 10.1016/j.vetimm.2022.110391] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 01/22/2022] [Accepted: 01/25/2022] [Indexed: 12/01/2022]
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Characterisation of the Whole Blood mRNA Transcriptome in Holstein-Friesian and Jersey Calves in Response to Gradual Weaning. PLoS One 2016; 11:e0159707. [PMID: 27479136 PMCID: PMC4968839 DOI: 10.1371/journal.pone.0159707] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 07/07/2016] [Indexed: 12/11/2022] Open
Abstract
Weaning of dairy calves is an early life husbandry management practice which involves the changeover from a liquid to a solid feed based diet. The objectives of the study were to use RNA-seq technology to examine the effect of (i) breed and (ii) gradual weaning, on the whole blood mRNA transcriptome of artificially reared Holstein-Friesian and Jersey calves. The calves were gradually weaned over 14 days (day (d) -13 to d 0) and mRNA transcription was examined one day before gradual weaning was initiated (d -14), one day after weaning (d 1), and 8 days after weaning (d 8). On d -14, 550 genes were differentially expressed between Holstein-Friesian and Jersey calves, while there were 490 differentially expressed genes (DEG) identified on d 1, and 411 DEG detected eight days after weaning (P < 0.05; FDR < 0.1). No genes were differentially expressed within breed, in response to gradual weaning (P > 0.05). The pathways, gene ontology terms, and biological functions consistently over-represented among the DEG between Holstein-Friesian and Jersey were associated with the immune response and immune cell signalling, specifically chemotaxis. Decreased transcription of several cytokines, chemokines, immunoglobulin-like genes, phagocytosis-promoting receptors and g-protein coupled receptors suggests decreased monocyte, natural killer cell, and T lymphocyte, chemotaxis and activation in Jersey compared to Holstein-Friesian calves. Knowledge of breed-specific immune responses could facilitate health management practices better tailored towards specific disease sensitivities of Holstein-Friesian and Jersey calves. Gradual weaning did not compromise the welfare of artificially-reared dairy calves, evidenced by the lack of alterations in the expression of any genes in response to gradual weaning.
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Wang J, Alexander J, Wiebe M, Jones C. Bovine herpesvirus 1 productive infection stimulates inflammasome formation and caspase 1 activity. Virus Res 2014; 185:72-6. [PMID: 24657787 PMCID: PMC6240421 DOI: 10.1016/j.virusres.2014.03.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Revised: 03/05/2014] [Accepted: 03/05/2014] [Indexed: 10/25/2022]
Abstract
Bovine herpesvirus 1 (BoHV-1), a significant viral pathogen of cattle, causes inflammation in affected tissue during acute infection. Consequently, we tested whether productively infected bovine cells stimulate inflammasome formation. Expression of two components required for inflammasome formation, the DNA sensor IFI16 (gamma-interferon-inducible protein 16) and NLRP3 (NOD-like receptor family, pyrin domain containing 3), were induced in bovine kidney cells by eight hours after infection. IFI16 was detected in punctate granules localized to the cytoplasm and nucleus. During productive infection, more than ten times more cells were caspase 1 positive, which is activated following inflammasome formation. Two caspase 1 inhibitors had no effect on productive infection. Conversely, another caspase 1 inhibitor, glyburide, significantly inhibited virus infection suggesting it had off-target effects on related enzymes or interfered with infection via non-enzymatic mechanisms. Collectively, these studies demonstrated that BoHV-1 infection stimulated inflammasome formation, which we predict is important for clinical symptoms in cattle.
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Affiliation(s)
- Jianlin Wang
- College of Animal Science and Veterinary Medicine, Qingdao Agricultural University, Changcheng Road 700, Chengyang District, Qingdao 266109, PR China
| | - Jeff Alexander
- School of Veterinary Medicine and Biomedical Sciences, Nebraska Center for Virology, University of Nebraska, Lincoln Morisson Life Science Center, RM234, Lincoln, NE 68583-0900, United States
| | - Matthew Wiebe
- School of Veterinary Medicine and Biomedical Sciences, Nebraska Center for Virology, University of Nebraska, Lincoln Morisson Life Science Center, RM234, Lincoln, NE 68583-0900, United States
| | - Clinton Jones
- School of Veterinary Medicine and Biomedical Sciences, Nebraska Center for Virology, University of Nebraska, Lincoln Morisson Life Science Center, RM234, Lincoln, NE 68583-0900, United States.
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da Silva LF, Jones C. Small non-coding RNAs encoded within the herpes simplex virus type 1 latency associated transcript (LAT) cooperate with the retinoic acid inducible gene I (RIG-I) to induce beta-interferon promoter activity and promote cell survival. Virus Res 2013; 175:101-9. [PMID: 23648811 PMCID: PMC4074922 DOI: 10.1016/j.virusres.2013.04.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 04/04/2013] [Accepted: 04/08/2013] [Indexed: 12/23/2022]
Abstract
The herpes simplex virus type 1 (HSV-1) latency-associated transcript (LAT) is abundantly expressed in latently infected trigeminal ganglionic sensory neurons. Expression of the first 1.5 kb of LAT coding sequences restores wild type reactivation to a LAT null HSV-1 mutant. The anti-apoptosis functions of the first 1.5 kb of LAT coding sequences are important for wild type levels of reactivation from latency. Two small non-coding RNAs (sncRNAs) contained within the first 1.5 kb of LAT coding sequences are expressed in trigeminal ganglia of latently infected mice, they cooperate to inhibit apoptosis, and reduce the efficiency of productive infection. In this study, we demonstrated that LAT sncRNA1 cooperates with the RNA sensor, retinoic acid inducible gene I (RIG-I), to stimulate IFN-β promoter activity and NF-κB dependent transcription in human or mouse cells. LAT sncRNA2 stimulated RIG-I induction of NF-κB dependent transcription in mouse neuroblastoma cells (Neuro-2A) but not human 293 cells. Since it is well established that NF-κB interferes with apoptosis, we tested whether the sncRNAs cooperated with RIG-I to inhibit apoptosis. In Neuro-2A cells, both sncRNAs cooperated with RIG-I to inhibit cold-shock induced apoptosis. Double stranded RNA (PolyI:C) stimulates RIG-I dependent signaling; but enhanced cold-shock induced apoptosis. PolyI:C, but not LAT sncRNAs, interfered with protein synthesis when cotransfected with RIG-I, which correlated with increased levels of cold-shock induced apoptosis. LAT sncRNA1 appeared to interact with RIG-I in transiently transfected cells suggesting this interaction stimulates RIG-I.
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Affiliation(s)
- Leticia Frizzo da Silva
- School of Veterinary Medicine and Biomedical Sciences, Nebraska Center for Virology, University of Nebraska, Lincoln, NE 68583-0900, United States
- Morisson Life Science Center, RM234 Lincoln, NE 68583-0900, United States
| | - Clinton Jones
- School of Veterinary Medicine and Biomedical Sciences, Nebraska Center for Virology, University of Nebraska, Lincoln, NE 68583-0900, United States
- Morisson Life Science Center, RM234 Lincoln, NE 68583-0900, United States
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da Silva LF, Sinani D, Jones C. ICP27 protein encoded by bovine herpesvirus type 1 (bICP27) interferes with promoter activity of the bovine genes encoding beta interferon 1 (IFN-β1) and IFN-β3. Virus Res 2012; 169:162-8. [PMID: 22902481 PMCID: PMC3472000 DOI: 10.1016/j.virusres.2012.07.023] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Revised: 07/25/2012] [Accepted: 07/25/2012] [Indexed: 12/29/2022]
Abstract
Bovine herpes virus 1 (BHV-1) infection leads to upper respiratory tract infections, conjunctivitis, and the infection predisposes cattle to secondary bacterial infections. The infected cell protein 0 (bICP0) encoded by BHV-1 suppresses antiviral innate immune signaling by interfering with expression of interferon beta (IFN-β). In contrast to humans or mice, cattle contain three IFN-β genes that have distinct transcriptional promoters. We previously cloned and characterized all three bovine IFN-β promoters. In this study, we provide evidence that bICP27; a viral early protein that shuttles between the nucleus and cytoplasm inhibits transcriptional activity of two bovine IFN-β gene promoters (IFN-β1 and IFN-β3). Conversely, the BHV-1 infected cell protein 0 (bICP0) early promoter was not inhibited by bICP27. C-terminal mutants lacking the bICP27 zinc RING finger-like motif did not efficiently inhibit IFN-β3 promoter activity but inhibited IFN-β1 promoter activity as efficiently as wild type bICP27. An N-terminal mutant lacking the nuclear localization signal (NLS) and nucleolar localization signal (NoLS) was localized to the cytoplasm and this mutant had no effect on IFN-β promoter activity. In summary, these studies provided evidence that bICP27 inhibited IFN-β1 and IFN-β3 promoter activity in transiently transfected cells.
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Affiliation(s)
- Leticia Frizzo da Silva
- School of Veterinary Medicine and Biomedical Sciences, Nebraska Center for Virology, RM 234, Morisson Life Science Center, University of Nebraska, Lincoln, NE 68583
| | - Devis Sinani
- School of Veterinary Medicine and Biomedical Sciences, Nebraska Center for Virology, RM 234, Morisson Life Science Center, University of Nebraska, Lincoln, NE 68583
| | - Clinton Jones
- School of Veterinary Medicine and Biomedical Sciences, Nebraska Center for Virology, RM 234, Morisson Life Science Center, University of Nebraska, Lincoln, NE 68583
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Two microRNAs encoded within the bovine herpesvirus 1 latency-related gene promote cell survival by interacting with RIG-I and stimulating NF-κB-dependent transcription and beta interferon signaling pathways. J Virol 2011; 86:1670-82. [PMID: 22130548 DOI: 10.1128/jvi.06550-11] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Sensory neurons latently infected with bovine herpesvirus 1 (BHV-1) abundantly express latency-related (LR) RNA (LR-RNA). Genetic evidence indicates that LR protein expression plays a role in the latency-reactivation cycle, because an LR mutant virus that contains three stop codons downstream of the first open reading frame (ORF2) does not reactivate from latency. The LR mutant virus induces higher levels of apoptotic neurons in trigeminal ganglia, and ORF2 interferes with apoptosis. Although ORF2 is important for the latency-reactivation cycle, other factors encoded by the LR gene are believed to play a supportive role. For example, two microRNAs (miRNAs) encoded within the LR gene are expressed in trigeminal ganglia of latently infected calves. These miRNAs interfere with bICP0 protein expression and productive infection in transient-transfection assays. In this report, we provide evidence that the two LR miRNAs cooperate with poly(I·C), interferon (IFN) regulatory factor 3 (IRF3), or IRF7 to stimulate beta interferon (IFN-β) promoter activity. Both miRNAs also stimulated IFN-β promoter activity and nuclear factor-kappa B (NF-κB)-dependent transcription when cotransfected with a plasmid expressing retinoic acid-inducible gene I (RIG-I). In the presence of RIG-I, the LR miRNAs enhanced survival of mouse neuroblastoma cells, which correlated with activation of the antiapoptosis cellular transcription factor, NF-κB. Immunoprecipitation assays demonstrated that both miRNAs stably interact with RIG-I, suggesting that this interaction directly stimulates the RIG-I signaling pathway. In summary, the results of these studies suggest that interactions between LR miRNAs and RIG-I promote the establishment and maintenance of latency by enhancing survival of infected neurons.
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da Silva LF, Gaudreault N, Jones C. Cytoplasmic localized infected cell protein 0 (bICP0) encoded by bovine herpesvirus 1 inhibits β interferon promoter activity and reduces IRF3 (interferon response factor 3) protein levels. Virus Res 2011; 160:143-9. [PMID: 21689696 DOI: 10.1016/j.virusres.2011.06.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Revised: 06/02/2011] [Accepted: 06/03/2011] [Indexed: 11/29/2022]
Abstract
Bovine herpesvirus 1 (BHV-1), an alpha-herpesvirinae subfamily member, establishes a life-long latent infection in sensory neurons. Periodically, BHV-1 reactivates from latency, infectious virus is spread, and consequently virus transmission occurs. BHV-1 acute infection causes upper respiratory track infections and conjunctivitis in infected cattle. As a result of transient immune-suppression, BHV-1 infections can also lead to life-threatening secondary bacterial pneumonia that is referred to as bovine respiratory disease. The infected cell protein 0 (bICP0) encoded by BHV-1 reduces human β-interferon (IFN-β) promoter activity, in part, by inducing degradation of interferon response factor 3 (IRF3) and interacting with IRF7. In contrast to humans, cattle contain three IFN-β genes. All three bovine IFN-β proteins have anti-viral activity: but each IFN-β gene has a distinct transcriptional promoter. We have recently cloned and characterized the three bovine IFN-β promoters. Relative to the human IFN-β promoter, each of the three IFN-β promoters contain differences in the four positive regulatory domains that are required for virus-induced activity. In this study, we demonstrate that bICP0 effectively inhibits bovine IFN-β promoter activity following transfection of low passage bovine cells with interferon response factor 3 (IRF3) or IRF7. A bICP0 mutant that localizes to the cytoplasm inhibits bovine IFN-β promoter activity as efficiently as wt bICP0. The cytoplasmic localized bICP0 protein also induced IRF3 degradation with similar efficiency as wt bICP0. In summary, these studies suggested that cytoplasmic localized bICP0 plays a role in inhibiting the IFN-β response during productive infection.
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Affiliation(s)
- Leticia Frizzo da Silva
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska, Lincoln, NE 68503, United States
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