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Dawe WH, Kapczynski DR, Linnemann EG, Gauthiersloan VR, Sellers HS. Analysis of the Immune Response and Identification of Antibody Epitopes Against the Sigma C Protein of Avian Orthoreovirus Following Immunization with Live or Inactivated Vaccines. Avian Dis 2022; 66:465-478. [PMID: 36715481 DOI: 10.1637/aviandiseases-d-22-99992] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 09/01/2022] [Indexed: 01/24/2023]
Abstract
Avian orthoreoviruses are causative agents of tenosynovitis and viral arthritis in both chickens and turkeys. Current commercial reovirus vaccines do not protect against disease caused by emerging variants. Custom-made inactivated reovirus vaccines are commonly utilized to help protect commercial poultry against disease. Antibody epitopes located on the viral attachment protein, σC, involved in virus neutralization, have not been clearly identified. In this study, the S1133 vaccine strain (Genetic Cluster 1 [GC1], a GC1 field isolate (117816), and a GC5 field isolate (94826) were determined to be genetically and serologically unrelated. In addition, chickens were vaccinated with either a commercial S1133 vaccine, 117816 GC1, or 94826 GC5, and sera were used in peptide microarrays to identify linear B-cell epitopes within the σC protein. Specific-pathogen-free (SPF) chickens were vaccinated twice with either: 1) live and live, 2) inactivated and inactivated, or 3) a combination of live and inactivated vaccines. Epitope mapping was performed on individual serum samples from birds in each group using S1133, 117816, and 94826 σC sequences translated into an overlapping peptides and spotted onto microarray chips. Vaccination with a combination of live and inactivated viruses resulted in a greater number of B-cell binding sites on the outer-capsid domains of σC for 117816 and 94826, but not for S1133. In contrast, the S1133-vaccinated birds demonstrated fewer epitopes, and those epitopes were located in the stalk region of the protein. However, within each of the vaccinated groups, the highest virus-neutralization titers were observed in the live/inactivated groups. This study demonstrates differences in antibody binding sites within σC between genetically and antigenically distinct reoviruses and provides initial antigenic characterization of avian orthoreoviruses and insight into the inability of vaccine-induced antibodies to provide adequate protection against variant reovirus-induced disease.
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Affiliation(s)
- W H Dawe
- Poultry Diagnostic and Research Center, Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA 30602
| | - D R Kapczynski
- U.S. National Poultry Research Center, Agricultural Research Services, U.S. Department of Agriculture, Athens, GA 30605
| | - E G Linnemann
- Poultry Diagnostic and Research Center, Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA 30602
| | - V R Gauthiersloan
- Poultry Diagnostic and Research Center, Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA 30602
| | - H S Sellers
- Poultry Diagnostic and Research Center, Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA 30602,
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2
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Efficacy and Immunogenicity of Recombinant Pichinde Virus-Vectored Turkey Arthritis Reovirus Subunit Vaccine. Vaccines (Basel) 2022; 10:vaccines10040486. [PMID: 35455235 PMCID: PMC9030058 DOI: 10.3390/vaccines10040486] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/18/2022] [Accepted: 03/18/2022] [Indexed: 02/04/2023] Open
Abstract
We created a recombinant live pichinde virus-vectored bivalent codon optimized subunit vaccine that expresses immunogenic Sigma C and Sigma B proteins of turkey arthritis reovirus. The vaccine virus could be transmitted horizontally immunizing the non-vaccinated pen mates. The vaccine was tested for efficacy against homologous (TARV SKM121) and heterologous (TARV O’Neil) virus challenge. Immunized poults produced serum neutralizing antibodies capable of neutralizing both viruses. The vaccinated and control birds showed similar body weights indicating no adverse effect on feed efficiency. Comparison of virus gene copy numbers in intestine and histologic lesion scores in tendons of vaccinated and non-vaccinated birds showed a decrease in the replication of challenge viruses in the intestine and tendons of vaccinated birds. These results indicate the potential usefulness of this vaccine.
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3
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Xie L, Wang S, Xie Z, Wang X, Wan L, Deng X, Xie Z, Luo S, Zeng T, Zhang M, Fan Q, Huang J, Zhang Y, Li M. Gallus NME/NM23 nucleoside diphosphate kinase 2 interacts with viral σA and affects the replication of avian reovirus. Vet Microbiol 2020; 252:108926. [PMID: 33223234 DOI: 10.1016/j.vetmic.2020.108926] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 11/06/2020] [Indexed: 11/19/2022]
Abstract
Our present study aimed to identify host cell proteins that may interact with avian reovirus (ARV) σA protein and their potential effect on ARV replication. The ARV structural protein σA has been demonstrated to suppress interferon production and confirmed to activate the PI3K/Akt pathway. However, host cell factors interacting with σA to affect ARV replication remain unknown. In current study, a cDNA library of chicken embryo fibroblasts (CEFs) was constructed, and host cell proteins interacting with σA were screened by a yeast two-hybrid system. We identified four candidate cellular proteins that interact with ARV σA protein. Among them, Gallus NME/NM23 nucleoside diphosphate kinase 2 (NME2) was further validated as a σA-binding protein through co-immunoprecipitation. The key interaction domain was identified at amino acids (aa) 121-416 in NME2 and at aa 71-139 in σA, respectively. We demonstrated that overexpression of NME2 substantially inhibited ARV replication. In addition silencing NME2 by small interfering RNAs (siRNAs) resulted in marked enhancement of ARV replication. Our work has demonstrated that NME2 is a σA-binding protein that may affect ARV replication in CEF cells.
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Affiliation(s)
- Liji Xie
- Department of Biotechnology, Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Veterinary Research Institute, Nanning, 530001, China.
| | - Sheng Wang
- Department of Biotechnology, Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Veterinary Research Institute, Nanning, 530001, China.
| | - Zhixun Xie
- Department of Biotechnology, Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Veterinary Research Institute, Nanning, 530001, China.
| | - Xiaohu Wang
- Department of Biotechnology, Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Veterinary Research Institute, Nanning, 530001, China.
| | - Lijun Wan
- Department of Biotechnology, Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Veterinary Research Institute, Nanning, 530001, China.
| | - Xianwen Deng
- Department of Biotechnology, Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Veterinary Research Institute, Nanning, 530001, China.
| | - Zhiqin Xie
- Department of Biotechnology, Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Veterinary Research Institute, Nanning, 530001, China.
| | - Sisi Luo
- Department of Biotechnology, Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Veterinary Research Institute, Nanning, 530001, China.
| | - Tingting Zeng
- Department of Biotechnology, Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Veterinary Research Institute, Nanning, 530001, China.
| | - Minxiu Zhang
- Department of Biotechnology, Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Veterinary Research Institute, Nanning, 530001, China.
| | - Qing Fan
- Department of Biotechnology, Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Veterinary Research Institute, Nanning, 530001, China.
| | - Jiaoling Huang
- Department of Biotechnology, Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Veterinary Research Institute, Nanning, 530001, China.
| | - Yanfang Zhang
- Department of Biotechnology, Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Veterinary Research Institute, Nanning, 530001, China.
| | - Meng Li
- Department of Biotechnology, Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Veterinary Research Institute, Nanning, 530001, China.
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4
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Niu X, Zhang B, Yu X, Zhang X, Dou Y, Tang Y, Diao Y. Preparation and evaluation of goose reovirus inactivated vaccine. BMC Vet Res 2017; 13:214. [PMID: 28683792 PMCID: PMC5501479 DOI: 10.1186/s12917-017-1134-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 06/26/2017] [Indexed: 12/22/2022] Open
Abstract
Background Infection with Goose Reovirus (GRV) can cause serious economic losses in the goose breeding industry. In this study, the GRV allantoic fluid was concentrated and used as an antigen in a formalin-inactivated oil-emulsion vaccine. Results When 6 day-old geese were inoculated, antibodies against GRV became detectable at 6 days post-vaccination, their concentration peaked at 3 weeks. These antibodies were maintained for longer than 2 weeks. As the most susceptible age for GRV infection is birds under 2 weeks of age this vaccine should provide adequate cover for the most at risk birds. When geese were exposed to reovirus at different time intervals after immunization, the data revealed that the vaccine can provide a protection rate of 80%. The developed vaccine has good stability and could be stored at 4 °C for at least 12 months. Conclusion These results indicate that the developed GRV vaccine is safe, effectively absorbed, efficacious in inducing a rapid immune response, and effective in controlling GRV infection. Our results should be useful for the application of vaccines for controlling GRV in different goose flocks. Electronic supplementary material The online version of this article (doi:10.1186/s12917-017-1134-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xiaoyu Niu
- College of Animal Science and Technology, Shandong Agricultural University, Daizong Road 61, Tai'an, Shandong, 271018, China
| | - Bingqian Zhang
- College of Animal Science and Technology, Shandong Agricultural University, Daizong Road 61, Tai'an, Shandong, 271018, China
| | - Xianglong Yu
- College of Animal Science and Technology, Shandong Agricultural University, Daizong Road 61, Tai'an, Shandong, 271018, China
| | - Xin Zhang
- College of Animal Science and Technology, Shandong Agricultural University, Daizong Road 61, Tai'an, Shandong, 271018, China
| | - Yanguo Dou
- College of Animal Science and Technology, Shandong Agricultural University, Daizong Road 61, Tai'an, Shandong, 271018, China
| | - Yi Tang
- College of Animal Science and Technology, Shandong Agricultural University, Daizong Road 61, Tai'an, Shandong, 271018, China.
| | - Youxiang Diao
- College of Animal Science and Technology, Shandong Agricultural University, Daizong Road 61, Tai'an, Shandong, 271018, China.
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Ayalew LE, Gupta A, Fricke J, Ahmed KA, Popowich S, Lockerbie B, Tikoo SK, Ojkic D, Gomis S. Phenotypic, genotypic and antigenic characterization of emerging avian reoviruses isolated from clinical cases of arthritis in broilers in Saskatchewan, Canada. Sci Rep 2017; 7:3565. [PMID: 28620186 PMCID: PMC5472580 DOI: 10.1038/s41598-017-02743-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 04/19/2017] [Indexed: 11/08/2022] Open
Abstract
In recent years, emerging strains of pathogenic arthrogenic avian reovirus (ARV) have become a challenge to the chicken industry across USA and Canada causing significant economic impact. In this study, we characterized emerging variant ARV strains and examined their genetic and antigenic relationship with reference strains. We isolated 37 emerging variant ARV strains from tendons of broiler chickens with clinical cases of arthritis/tenosynovitis at commercial farms in Saskatchewan, Canada. Viral characterization using immunocytochemistry, gold-immunolabeling and electron microscopy revealed distinct features characteristic of ARV. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analyses of the viral Sigma C gene revealed genetic heterogeneity between the field isolates. On phylogenetic analyses, the Sigma C amino acid sequences of the isolates were clustered into four distinct genotypic groups. These ARV field strains were genetically diverse and quite distant from the vaccine and vaccine related field strains. Antibodies produced against a commercial Reo 2177 ® vaccine did not neutralize these variants. Moreover, structure based analysis of the Sigma C protein revealed significant antigenic variability between the cluster groups and the vaccine strains. To the best of our knowledge, this is the first report on the genetic, phenotypic and antigenic characterization of emerging ARVs in Canada.
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Affiliation(s)
- Lisanework E Ayalew
- Veterinary Pathology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Ashish Gupta
- Veterinary Pathology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Jenny Fricke
- Veterinary Pathology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Khawaja Ashfaque Ahmed
- Veterinary Pathology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Shelly Popowich
- Veterinary Pathology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Betty Lockerbie
- Veterinary Pathology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Suresh K Tikoo
- Vaccinology & Immunotherapeutic Program, School of Public Health, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Davor Ojkic
- Animal Health Laboratory, Laboratory Services Division, University of Guelph, Guelph, Ontario, Canada
| | - Susantha Gomis
- Veterinary Pathology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
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6
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Replication and Oncolytic Activity of an Avian Orthoreovirus in Human Hepatocellular Carcinoma Cells. Viruses 2017; 9:v9040090. [PMID: 28441762 PMCID: PMC5408696 DOI: 10.3390/v9040090] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2017] [Revised: 04/19/2017] [Accepted: 04/19/2017] [Indexed: 12/13/2022] Open
Abstract
Oncolytic viruses are cancer therapeutics with promising outcomes in pre-clinical and clinical settings. Animal viruses have the possibility to avoid pre-existing immunity in humans, while being safe and immunostimulatory. We isolated an avian orthoreovirus (ARV-PB1), and tested it against a panel of hepatocellular carcinoma cells. We found that ARV-PB1 replicated well and induced strong cytopathic effects. It was determined that one mechanism of cell death was through syncytia formation, resulting in apoptosis and induction of interferon stimulated genes (ISGs). As hepatitis C virus (HCV) is a major cause of hepatocellular carcinoma worldwide, we investigated the effect of ARV-PB1 against cells already infected with this virus. Both HCV replicon-containing and infected cells supported ARV-PB1 replication and underwent cytolysis. Finally, we generated in silico models to compare the structures of human reovirus- and ARV-PB1-derived S1 proteins, which are the primary targets of neutralizing antibodies. Tertiary alignments confirmed that ARV-PB1 differs from its human homolog, suggesting that immunity to human reoviruses would not be a barrier to its use. Therefore, ARV-PB1 can potentially expand the repertoire of oncolytic viruses for treatment of human hepatocellular carcinoma and other malignancies.
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7
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Sellers HS. Current limitations in control of viral arthritis and tenosynovitis caused by avian reoviruses in commercial poultry. Vet Microbiol 2016; 206:152-156. [PMID: 28024855 DOI: 10.1016/j.vetmic.2016.12.014] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 12/02/2016] [Accepted: 12/12/2016] [Indexed: 10/20/2022]
Abstract
Avian reoviruses are the causative agent of viral arthritis/tenosynovitis in chickens and turkeys. Clinical signs of disease include swelling of the hock joints accompanied by lesions in the gastrocnemius and digital flexor tendons causing lameness in addition to hydropericardium. The economic impact is significant as it results in poor weight gain, increased feed conversion ratios and condemnations at the processing plant. Vaccination with both live attenuated and inactivated oil emulsion vaccines have been used successfully for decades to control the disease. Current commercial vaccine strains belong to the same serotype and are antigenically and serologically distinct from circulating variant field viruses isolated from clinical cases of tenosynovitis. Since 2012, there has been a dramatic increase in the number of clinical cases of tenosynovitis in commercial poultry and commercial vaccines are unable to provide adequate levels of protection against disease. Producers have elected to use custom inactivated vaccines in the absence of any commercially available homologous vaccines. Identification and selection of field isolates for use in autogenous vaccines can be difficult especially when multiple reoviruses are co-circulating among flocks. In addition, field data suggests that in some cases the custom vaccines are providing adequate protection against disease but as new genetic variants emerge, new vaccines are needed.
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Affiliation(s)
- Holly S Sellers
- Poultry Diagnostic and Research Center, Department of Population Health, College of Veterinary Medicine, University of Georgia, 953 College Station Road, Athens, GA, 30602, USA.
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8
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A critical role of LAMP-1 in avian reovirus P10 degradation associated with inhibition of apoptosis and virus release. Arch Virol 2016; 161:899-911. [PMID: 26744063 DOI: 10.1007/s00705-015-2731-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Accepted: 12/17/2015] [Indexed: 10/22/2022]
Abstract
Avian reovirus (ARV) causes viral arthritis, chronic respiratory diseases, retarded growth and malabsorption syndrome. The ARV p10 protein, a viroporin responsible for the induction of cell syncytium formation and apoptosis, is rapidly degraded in host cells. However, the mechanism of p10 degradation and its relevance are still unclear. We report here the identification of cellular lysosome-associated membrane protein 1 (LAMP-1) as an interaction partner of p10 by yeast two-hybrid screening, immunoprecipitation and confocal microscopy assays. We found that rapid degradation of p10 was associated with ubiquitination. Importantly, ARV p10 degradation in host cells could be completely abolished by knockdown of LAMP-1 by siRNA, indicating that LAMP-1 is required for ARV p10 degradation in host cells. In contrast, overexpression of LAMP-1 facilitated p10 degradation. Furthermore, knockdown of LAMP-1 allowed p10 accumulation, enhancing p10-induced apoptosis and viral release. Thus, LAMP-1 plays a critical role in ARV p10 degradation associated with inhibition of apoptosis and viral release.
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9
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Critical role of eukaryotic elongation factor 1 alpha 1 (EEF1A1) in avian reovirus sigma-C-induced apoptosis and inhibition of viral growth. Arch Virol 2015; 160:1449-61. [PMID: 25854689 DOI: 10.1007/s00705-015-2403-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 03/16/2015] [Indexed: 10/23/2022]
Abstract
Avian reovirus (ARV) causes viral arthritis, chronic respiratory diseases, retarded growth and malabsorption syndrome. It is well established that the ARV sigma-C protein induces apoptosis in host cells. However, the underlying molecular mechanism of this induction is still unclear. We report here the identification of eukaryotic elongation factor 1 alpha 1 (EEF1A1) as the interacting partner of σC. We found that σC-induced apoptosis in DF-1 cells could be completely abolished by knockdown of EEF1A1 by siRNA. Furthermore, knockdown of EEF1A1 markedly reduced ARV-induced apoptosis associated with decreased caspase-9 and -3 activation and cytochrome C release, leading to increased ARV growth in host cells. Thus, EEF1A1 plays a critical role in σC-induced apoptosis and inhibition of viral growth.
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10
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Wessel Ø, Nyman IB, Markussen T, Dahle MK, Rimstad E. Piscine orthoreovirus (PRV) ơ3 protein binds dsRNA. Virus Res 2015; 198:22-9. [PMID: 25596495 DOI: 10.1016/j.virusres.2015.01.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 01/05/2015] [Accepted: 01/05/2015] [Indexed: 12/27/2022]
Abstract
Piscine orthoreovirus (PRV) has a double-stranded, segmented RNA genome and belongs to the family Reoviridae. PRV is associated with heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon (Salmo salar L.) and cause intraerythrocytic inclusions. The virus is widespread in both wild and farmed salmonid fish in Europe, North- and South America. In mammalian orthoreovirus (MRV), the outer capsid protein ơ3 has dsRNA binding properties, which serve to inhibit the early innate immune response of the host. Important structural motifs and key amino acid residues are conserved between MRV ơ3 and the homologous PRV protein, and we hypothesized that PRV ơ3 binds dsRNA. Gene regions and amino acid residues predicted to be important for dsRNA binding were determined through bioinformatic analysis and investigated functionally following site-directed mutagenesis and the generation of truncated ơ3 variants. Our results provide evidence that the PRV protein ơ3 binds dsRNA in a sequence independent manner, thus sharing this function with MRV ơ3. Although no specific domain solely responsible for dsRNA binding was determined, the results point to residues within a predominantly basic region to be important for this functional property. We conclude that multiple sites are involved in the dsRNA binding activity of PRV ơ3.
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Affiliation(s)
- Øystein Wessel
- Department of Food Safety & Infection Biology, Norwegian University of Life Sciences, Oslo, Norway.
| | - Ingvild Berg Nyman
- Department of Food Safety & Infection Biology, Norwegian University of Life Sciences, Oslo, Norway.
| | | | | | - Espen Rimstad
- Department of Food Safety & Infection Biology, Norwegian University of Life Sciences, Oslo, Norway.
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11
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Yin CH, Qin LT, Sun MY, Gao YL, Qi XL, Gao HL, Wang YQ, Wang XM. Antigenic analysis of monoclonal antibodies against different epitopes of σB protein of avian reovirus. PLoS One 2013; 8:e81533. [PMID: 24312314 PMCID: PMC3842295 DOI: 10.1371/journal.pone.0081533] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Accepted: 10/14/2013] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Avian reovirus (ARV) causes arthritis, tenosynovitis, runting-stunting syndrome (RSS), malabsorption syndrome (MAS) and immunosuppression in chickens. σB is one of the major structural proteins of ARV, which is able to induce group-specific antibodies against the virus. METHODS AND RESULTS The present study described the identification of two linear B-cell epitopes in ARV σB through expressing a set of partially overlapping and consecutive truncated peptides spanning σB screened with two monoclonal antibodies (mAbs) 1F4 and 1H3-1.The data indicated that (21)KTPACW(26) (epitope A) and (32)WDTVTFH(38) (epitope B) were minimal determinants of the linear B cell epitopes. Antibodies present in the serum of ARV-positive chickens recognized the minimal linear epitopes in Western blot analyses. By sequence alignment analysis, we determined that the epitopes A and B were not conserved among ARV, duck reovirus (DRV) and turkey reovirus (TRV) strains. Western blot assays, confirmed that epitopes A and B were ARV-specific epitopes, and they could not react with the corresponding peptides of DRV and TRV. CONCLUSIONS AND SIGNIFICANCE We identified (21)KTPACW(26) and (32)WDTVTFH(38) as σB -specific epitopes recognized by mAbs 1F4 and 1H3-1, respectively. The results in this study may have potential applications in development of diagnostic techniques and epitope-based marker vaccines against ARV groups.
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Affiliation(s)
- Chun-hong Yin
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, P. R. China
| | - Li-ting Qin
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, P. R. China
| | - Mei-yu Sun
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, P. R. China
| | - Yu-long Gao
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, P. R. China
| | - Xiao-le Qi
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, P. R. China
| | - Hong-lei Gao
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, P. R. China
| | - Yong-qiang Wang
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, P. R. China
| | - Xiao-mei Wang
- Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, P. R. China
- * E-mail:
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12
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Markussen T, Dahle MK, Tengs T, Løvoll M, Finstad ØW, Wiik-Nielsen CR, Grove S, Lauksund S, Robertsen B, Rimstad E. Sequence analysis of the genome of piscine orthoreovirus (PRV) associated with heart and skeletal muscle inflammation (HSMI) in Atlantic salmon (Salmo salar). PLoS One 2013; 8:e70075. [PMID: 23922911 PMCID: PMC3726481 DOI: 10.1371/journal.pone.0070075] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Accepted: 06/16/2013] [Indexed: 12/20/2022] Open
Abstract
Piscine orthoreovirus (PRV) is associated with heart- and skeletal muscle inflammation (HSMI) of farmed Atlantic salmon (Salmo salar). We have performed detailed sequence analysis of the PRV genome with focus on putative encoded proteins, compared with prototype strains from mammalian (MRV T3D)- and avian orthoreoviruses (ARV-138), and aquareovirus (GCRV-873). Amino acid identities were low for most gene segments but detailed sequence analysis showed that many protein motifs or key amino acid residues known to be central to protein function are conserved for most PRV proteins. For M-class proteins this included a proline residue in μ2 which, for MRV, has been shown to play a key role in both the formation and structural organization of virus inclusion bodies, and affect interferon-β signaling and induction of myocarditis. Predicted structural similarities in the inner core-forming proteins λ1 and σ2 suggest a conserved core structure. In contrast, low amino acid identities in the predicted PRV surface proteins μ1, σ1 and σ3 suggested differences regarding cellular interactions between the reovirus genera. However, for σ1, amino acid residues central for MRV binding to sialic acids, and cleavage- and myristoylation sites in μ1 required for endosomal membrane penetration during infection are partially or wholly conserved in the homologous PRV proteins. In PRV σ3 the only conserved element found was a zinc finger motif. We provide evidence that the S1 segment encoding σ3 also encodes a 124 aa (p13) protein, which appears to be localized to intracellular Golgi-like structures. The S2 and L2 gene segments are also potentially polycistronic, predicted to encode a 71 aa- (p8) and a 98 aa (p11) protein, respectively. It is concluded that PRV has more properties in common with orthoreoviruses than with aquareoviruses.
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Affiliation(s)
- Turhan Markussen
- Department of Laboratory Services, National Veterinary Institute, Oslo, Norway
| | - Maria K. Dahle
- Department of Laboratory Services, National Veterinary Institute, Oslo, Norway
| | - Torstein Tengs
- Department of Laboratory Services, National Veterinary Institute, Oslo, Norway
| | - Marie Løvoll
- Department of Laboratory Services, National Veterinary Institute, Oslo, Norway
| | - Øystein W. Finstad
- Department of Food Safety and Infection Biology, Norwegian School of Veterinary Science, Oslo, Norway
| | | | - Søren Grove
- Department of Laboratory Services, National Veterinary Institute, Oslo, Norway
| | - Silje Lauksund
- Norwegian College of Fishery Science, University of Tromsø, Tromsø, Norway
| | - Børre Robertsen
- Norwegian College of Fishery Science, University of Tromsø, Tromsø, Norway
| | - Espen Rimstad
- Department of Food Safety and Infection Biology, Norwegian School of Veterinary Science, Oslo, Norway
- * E-mail:
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13
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Xie Z, Peng Y, Luo S, Wang Y, Liu J, Pang Y, Deng X, Xie Z, Xie L, Fan Q, Teng L, Wang X. Development of a reverse transcription loop-mediated isothermal amplification assay for visual detection of avian reovirus. Avian Pathol 2012; 41:311-6. [PMID: 22702459 DOI: 10.1080/03079457.2012.686104] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Avian reovirus (ARV) is an important pathogen of poultry and causes significant economic losses to the poultry industry. To develop a rapid and sensitive method for the surveillance of ARV, a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was established using a set of six primers specific to the S1 gene segment of ARV. The established assay was performed at 62°C for 60 min in a thermal block, and the result was visualized directly under daylight or ultraviolet light. The detection limit of the RT-LAMP assay was 10 fg total RNA, which was 100-fold higher than that of reverse transcriptase polymerase chain reactions. The specificity of the assay was supported by the lack of cross-reaction with other avian pathogens. Furthermore, viral RNAs of field isolates were successfully detected by the assay. Overall, the newly established RT-LAMP assay is simple, rapid, sensitive, specific, and can visually detect ARV without the use of any specialized equipment.
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Affiliation(s)
- Zhixun Xie
- Department of Biotechnology, Guangxi Key Laboratory of Animal Vaccines and New Technology, Guangxi Veterinary Research Institute, Nanning Guangxi, PR China.
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Wan J, Wen X, Huang X, Tang Y, Huang Y, Yan Q, Zhao Q, Cao S. Immunogenic analysis of two DNA vaccines of avian reovirus mediated by attenuated Salmonella typhimurium in chickens. Vet Immunol Immunopathol 2012; 147:154-60. [PMID: 22575372 DOI: 10.1016/j.vetimm.2012.04.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Revised: 03/30/2012] [Accepted: 04/08/2012] [Indexed: 10/28/2022]
Abstract
Avian reovirus (ARV) is an important pathogen in poultry industry and causes great economic losses. As attenuated Salmonella typhimurium is already being used as an effective vehicle for the transfer of DNA vaccines, so in this study we evaluated two DNA vaccines mediated by S. typhimurium on their ability of eliciting antibody production. SPF chickens were respectively immunized with SL7207 (pVAX-σB), SL7207 (pVAX-σC) and SL7027 (pVAX-σB-σC) three times. The results showed that the antibody production was highly dependent on the immunizing times, detectable antibodies of serum antibody IgG and small intestinal mucosal antibody IgA were generated at week 4 and were further improved at week 6 and antibody titers in group SL7207 (pVAX-σC) were higher than that in group SL7207 (pVAX-σB), demonstrating that SL7207 (pVAX-σC) was more powerful than SL7207 (pVAX-σB) in antibody production. The higher antibody titer in SL7027 (pVAX-σB-σC) than that in SL7207 (pVAX-σC) group showed that co-expressing σB and σC could improve antibody production. IFN-γ detection showed that significant higher IFN-γ was generated both in groups SL7027 (pVAX-σB-σC) and SL7207 (pVAX-σC). Subsequent challenge showed that SL7207 (pVAX-σB), SL7207 (pVAX-σC) and SL7027 (pVAX-σB-σC) conferred 50%, 75% and 87.5% respectively.
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Affiliation(s)
- Junjie Wan
- Laboratory of Animal Infectious Disease and Microarray, Key Laboratory of Animal Disease and Human Health of Sichuan Province, College of Veterinary Medicine, Sichuan Agricultural University, Ya'an 625014, China
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15
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Goldenberg D, Lublin A, Rosenbluth E, Heller ED, Pitcovski J. Differentiating infected from vaccinated animals, and among virulent prototypes of reovirus. J Virol Methods 2011; 177:80-6. [PMID: 21762731 DOI: 10.1016/j.jviromet.2011.06.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Revised: 06/27/2011] [Accepted: 06/29/2011] [Indexed: 11/17/2022]
Abstract
Birds are most susceptible to infection by avian reovirus, genus Orthoreovirus family Reoviridae, at a young age. Although chicks are protected by antibodies transferred from vaccinated maternal flocks, due to the many variants in the field, the efficiency of the vaccines is limited. The level of antibodies against viruses is generally determined by enzyme-linked immunosorbent assay (ELISA), using the whole virus as the antigen. This has some disadvantages: first, the test measures antibodies against all capsid proteins, most of which are irrelevant for neutralizing the virus, and as such does not reflect the real protection status; second, it is impossible to distinguish between vaccine- and infection-derived antibodies. In the case of a virus that changes frequently, a third disadvantage is the inability to distinguish among serotypes. The aim of this study was to develop a test that would address these concerns. Four prototypes of the avian reovirus protein sigma C were used as antigens on the ELISA plate. Sigma C is the main protein inducing neutralizing antibodies and the most variable among strains and isolates, and it is used for reovirus classification. This differentiating ELISA enabled distinguishing between vaccine and field strains of the virus, identifying the infection source, and in the case of vaccination, exclusively determining the level of protective antibodies. Whereas the whole virus detected antibodies against all strains, differentiating ELISA enabled differentiating between infected and vaccinated animals (DIVA) and in most cases, identifying the sigma C genotype. In a field study, a correlation was found between disease symptoms and antibodies identified against virulent strains in the flock. Thus virulent strains can be identified in the field, enabling adjustment of the relevant vaccines.
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16
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Liu HJ, Lee LH, Shih WL, Li YJ, Su HY. Rapid characterization of avian reoviruses using phylogenetic analysis, reverse transcription-polymerase chain reaction and restriction enzyme fragment length polymorphism. Avian Pathol 2010; 33:171-80. [PMID: 15276984 DOI: 10.1080/03079450310001652130] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
A reverse transcription-polymerase chain reaction is described, which amplified the full-length sigmaC-encoding and sigmaNS-encoding genes of avian reovirus (ARV). DNA fragments of 1022 and 1152 base pairs were amplified among ARV isolates, respectively, indicating that there were no apparent deletions or insertions in these regions. Fragments amplified from vaccine strains and field isolates were digested with five different restriction enzymes Bcn I, Hae III, Taq I, Dde I, and Hinc II, respectively. Restriction fragment profiles observed on polyacrylamide gels showed heterogeneity between vaccine and Taiwanese isolates. All ARV isolates tested showed different restriction enzyme cleavage patterns and could be clearly distinguished. The strain-typing based on the cleavage sites in the sigmaC-encoding gene of ARV showed that viruses could be classified into four distinct groups. A phylogenetic tree based on the nucleotide sequences of the sigmaC-encoding gene revealed that Taiwanese ARV isolates were classified into four distinct groups, indicating that the genotyping is consistent with typing based on restriction enzyme fragment length polymorphism of the sigmaC-encoding gene of ARV. The results suggested that polymerase chain reaction followed by restriction enzyme analysis provided a simple and rapid approach for characterization of ARV isolates. Also, it is possible to determine whether a new variant strain has been introduced into a flock or a given virus strain has spread from one flock to another.
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Affiliation(s)
- Hung J Liu
- Department of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan.
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17
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Immunogenicity of a DNA vaccine of Avian Reovirus orally delivered by attenuated Salmonella typhimurium. Res Vet Sci 2010; 91:382-3. [PMID: 20947110 DOI: 10.1016/j.rvsc.2010.09.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2010] [Revised: 09/13/2010] [Accepted: 09/16/2010] [Indexed: 11/23/2022]
Abstract
This study aimed to assess the ability of a Salmonella typhimurium-mediated Avain Reovirus DNA vaccine in eliciting antibody production. Six-day-old SPF chickens were orally immunized with SL7207 (pVAX-σC) twice at 2-week interval, detectable antibody was generated 2 weeks after immunization and was significantly higher than the control groups (P<0.01) and ten chickens (66.7%) were considered safe in the subsequent challenge. These results show that SL7207 (pVAX-σC) can induce protective antibody in chickens and the newly-constructed vaccine is also effective in protection chickens against ARV infection.
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18
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Liu M, Chen X, Wang Y, Zhang Y, Li Y, Wang Y, Shen N, Chen H. Characterization of monoclonal antibodies against Muscovy duck reovirus sigmaB protein. Virol J 2010; 7:133. [PMID: 20569474 PMCID: PMC2907335 DOI: 10.1186/1743-422x-7-133] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Accepted: 06/23/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The sigmaB protein of Muscovy duck reovirus (DRV), one of the major structural proteins, is able to induce neutralizing antibody in ducks, but the monoclonal antibody (MAb) against sigmaB protein has never been characterized. RESULTS Four hybridoma cell lines secreting anti-DRV sigmaB MAbs were obtained, designated 1E5, 2F7, 4E3 and 5D8. Immunoglobulin subclass tests differentiated them as IgG2b (1E5 and 4E3) and IgM (2F7 and 5D8). Dot blot and western blotting assays showed that MAbs reacted with His-sigmaB protein in a conformation-independent manner. Competitive binding assay indicated that the MAbs delineated two epitopes, A and B of sigmaB. Immunofluorescence assay indicated that the four MAbs could specifically bind to Vero cells infected with DRV and sigmaB was distributed diffusely in the cytoplasma of infected cells. MAbs had universal reactivity to all DRVs tested in an antigen-capture enzyme-linked immunosorbent assay. CONCLUSION Results of this research provide important information about the four monoclonal antibodies and therefore the MAbs may be useful candidate for the development of a MAb capture ELISA for rapid detection of DRVs. In addition, it showed that the sigmaB protein was located in the cytoplasma of infected cells by immunofluorescence assay with MAbs. Virus isolation and RT-PCR are reliable way for detection of DRV infection, but these procedures are laborious, time consuming, and requiring instruments. These obvious diagnosis problems highlight the ongoing demand of rapid, reproducible, and automatic methods for the sensitive detection of DRV.
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Affiliation(s)
- Ming Liu
- National Avian Influenza Reference Laboratory, Animal Influenza Laboratory of the Ministry of Agriculture, Harbin Veterinary Research Institute, CAAS, Harbin 150001, China
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Pu J, Liu X, Guo Y, Cao Y, Zhao J, Zhang G. Seroprevalence of avian reovirus in egg-laying chicken flocks in China. Avian Dis 2009; 52:675-9. [PMID: 19166062 DOI: 10.1637/8300-040108-reg.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
In the present study, the epidemiologic status of avian reovirus (ARV) infections was investigated from egg-laying chicken flocks in China with an enzyme-linked immunosorbent assay (ELISA) kit. Because the chickens were not vaccinated against ARV, antibodies were attributed to the infection. Antibodies specific to ARV were found in more than 92% (542/587) of the average positivity and ranged from 30% to 100% in different chicken population. A virus, designated HB06, was isolated from flocks with suspicious ARV infections. Sequence analysis of the S1 gene revealed that strain HB06 was closely related with the most ARVs with less than 2% nucleotide divergence, and the homology was highest with the vaccine strain S1133, with a 98.97% nucleotide identity. The potential significance of vaccination against ARV in egg-laying chicken flocks in China is also discussed.
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Affiliation(s)
- Juan Pu
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, China Agricultural University, Beijing 100193, P.R. China
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20
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Wu YF, Liu HJ, Shien JH, Chiou SH, Lee LH. Characterization of interleukin-1beta mRNA expression in chicken macrophages in response to avian reovirus. J Gen Virol 2008; 89:1059-1068. [PMID: 18343850 DOI: 10.1099/vir.0.82957-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Inhibitors of viral disassembly or RNA and protein synthesis, viral disassembly intermediates (infectious subviral particles, ISVP), binary ethylenimine-inactivated virions, and viral particles lacking genomic double-stranded (ds) RNA (empty particles) were used to assess the expression of interleukin-1beta (IL-1beta) mRNA in chicken (chIL-1beta) macrophages in response to avian reovirus. The results demonstrate that two distinct expression patterns of chIL-1beta mRNA mediated by different steps in viral replication were found. Viral disassembly was required for the induction of a rapid, transient expression pattern of chIL-1beta mRNA that was rapidly induced at 30 min, with maximal levels reached by 2 h, and fell to a low level within 6 h post-inoculation, while viral RNA synthesis rather than protein translation, which was subsequent to membrane penetration, was required to induce a stable, sustained expression pattern of chIL-1beta mRNA that occurred at and after 6 h post-inoculation. In addition, the induction of chIL-1beta mRNA expression by the empty particles and ISVP was extremely weak, compared with the active dsRNA(+) virions or binary ethylenimine-inactivated virions, suggesting that the presence of dsRNA, even if transcriptionally inactive, may be an important factor in this response.
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Affiliation(s)
- Yung Fu Wu
- Graduate Institute of Veterinary Microbiology, College of Veterinary Medicine, National Chung Hsing University, Taichung 402, Taiwan ROC
| | - Hung Jen Liu
- Department of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 912, Taiwan ROC
| | - Jui Huang Shien
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University, Taichung 402, Taiwan ROC
| | - Shiow Her Chiou
- Graduate Institute of Veterinary Microbiology, College of Veterinary Medicine, National Chung Hsing University, Taichung 402, Taiwan ROC
| | - Long Huw Lee
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University, Taichung 402, Taiwan ROC
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21
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Shapouri MRS, Frenette D, Larochelle R, Arella M, Silim A. Characterization of monoclonal antibodies against avian reovirus strain S1133. Avian Pathol 2007; 25:57-67. [DOI: 10.1080/03079459608419120] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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22
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Meanger J, Wickramasinghe R, Enriquez CE, Robertson MD, Wilcox GE. Type‐specific antigenicity of avian reoviruses. Avian Pathol 2007; 24:121-34. [DOI: 10.1080/03079459508419053] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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23
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Su YP, Shien JH, Liu HJ, Yin HS, Lee LH. Avian reovirus core protein μA expressed in Escherichia coli possesses both NTPase and RTPase activities. J Gen Virol 2007; 88:1797-1805. [PMID: 17485541 DOI: 10.1099/vir.0.82592-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Analysis of the amino acid sequence of core protein μA of avian reovirus has indicated that it may share similar functions to protein μ2 of mammalian reovirus. Since μ2 displayed both nucleotide triphosphatase (NTPase) and RNA triphosphatase (RTPase) activities, the purified recombinant μA ( μA) was designed and used to test these activities. μA was thus expressed in bacteria with a 4.5 kDa fusion peptide and six His tags at its N terminus. Results indicated that μA possessed NTPase activity that enabled the protein to hydrolyse theβ–γphosphoanhydride bond of all four NTPs, since NDPs were the only radiolabelled products observed. The substrate preference was ATP>CTP>GTP>UTP, based on the estimatedkcatvalues. Alanine substitutions for lysines 408 and 412 (K408A/K412A) in a putative nucleotide-binding site of μA abolished NTPase activity, further suggesting that NTPase activity is attributable to protein μA. The activity of μA is dependent on the divalent cations Mg2+or Mn2+, but not Ca2+or Zn2+. Optimal NTPase activity of μA was achieved between pH 5.5 and 6.0. In addition, μA enzymic activity increased with temperature up to 40 °C and was almost totally inhibited at temperatures higher than 55 °C. Tests of phosphate release from RNA substrates with μA or K408A/K412A μA indicated that μA, but not K408A/K412A μA, displayed RTPase activity. The results suggested that both NTPase and RTPase activities of μA might be carried out at the same active site, and that protein μA could play important roles during viral RNA synthesis.
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Affiliation(s)
- Yu Pin Su
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University, Taichung 402, Taiwan
| | - Jui Huang Shien
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University, Taichung 402, Taiwan
| | - Hung Jen Liu
- Department of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 912, Taiwan
| | - Hsien Sheng Yin
- Institute of Bioinformatics and Structural Biology, College of Life Sciences, National Tsing Hua University, Hsinchu 300, Taiwan
| | - Long Huw Lee
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University, Taichung 402, Taiwan
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24
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Benavente J, Martínez-Costas J. Avian reovirus: Structure and biology. Virus Res 2007; 123:105-19. [PMID: 17018239 DOI: 10.1016/j.virusres.2006.09.005] [Citation(s) in RCA: 168] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2006] [Revised: 09/06/2006] [Accepted: 09/07/2006] [Indexed: 11/28/2022]
Abstract
Avian reoviruses are important pathogens that cause considerable losses to the poultry industry, but they have been poorly characterized at the molecular level in the past, mostly because they have been considered to be very similar to the well-studied mammalian reoviruses. Studies performed over the last 20 years have revealed that avian reoviruses have unique properties and activities, different to those displayed by their mammalian counterparts, and of considerable interest to molecular virologists. Notably, the avian reovirus S1 gene is unique, in that it is a functional tricistronic gene that possesses three out-of-phase and partially overlapping open reading frames; the identification of the mechanisms that govern the initiation of translation of the three S1 cistrons, and the study of the properties and activities displayed by their encoded proteins, are particularly interesting areas of research. For instance, avian reoviruses are one of the few nonenveloped viruses that cause cell-cell fusion, and their fusogenic phenotype has been associated with a nonstructural 10 kDa transmembrane protein, which is expressed by the second cistron of the S1 gene; the small size of this atypical fusion protein offers an interesting model for studying the mechanisms of cell-cell fusion and for identifying fusogenic domains. Finally, avian reoviruses are highly resistant to interferon, and therefore they may be useful for investigating the mechanisms and strategies that viruses utilize to counteract the antiviral actions of interferons.
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Affiliation(s)
- Javier Benavente
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
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25
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Abstract
Avian reoviruses are important pathogens that may cause considerable economic losses in poultry farming. Their genome expresses at least eight structural and four nonstructural proteins, three of them encoded by the S1 gene. These viruses enter cells by receptor-mediated endocytosis, and acidification of virus-containing endosomes is necessary for the virus to uncoat and release transcriptionally active cores into the cytosol. Avian reoviruses replicate within cytoplasmic inclusions of globular morphology, termed viral factories, which are not microtubule-associated, and which are formed by the nonstructural protein muNS. This protein also mediates the association of some viral proteins (but not of others) with inclusions, suggesting that the recruitment of viral proteins into avian reovirus factories has specificity. Avian reovirus morphogenesis is a complex and temporally controlled process that takes place exclusively within viral factories of infected cells. Core assembly takes place within the first 30 min after the synthesis of their protein components, and fully formed cores are then coated by outer-capsid polypeptides over the next 30 min to generate mature infectious reovirions. Based on data from avian reovirus studies and on results reported for other members of the Reoviridae family, we present a model for avian reovirus gene expression and morphogenesis.
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Affiliation(s)
- J Benavente
- Departamento de Bioquímica y Biología Molecular, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
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26
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Zhang Y, Liu M, Shuidong O, Hu QL, Guo DC, Chen HY, Han Z. Detection and identification of avian, duck, and goose reoviruses by RT-PCR: goose and duck reoviruses are part of the same genogroup in the genus Orthoreovirus. Arch Virol 2006; 151:1525-38. [PMID: 16502280 DOI: 10.1007/s00705-006-0731-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2005] [Accepted: 01/19/2006] [Indexed: 11/26/2022]
Abstract
A reverse transcription-polymerase chain reaction (RT-PCR) procedure for the detection of avian, duck, and goose reovirus (ARV, DRV, and GRV) RNA from cell culture supernatant and clinical samples was established. Based on multiple sequence alignment, a pair of degenerate primers was selected and synthesized. The amplified, cloned, and sequenced 598-base-pair products from the sigmaA-encoding gene fragment from 16 isolates (ranging over 30 years) indicated that the primer regions were well conserved. The sensitivity of this method was determined to be 10(-2) PFU. The specificity of the RT-PCR method was determined by testing specimens containing avian influenza A viruses, Newcastle disease virus, and infectious bronchitis virus, all of which yielded negative results with no discernible background. The efficiency of the system for detection of ARV, DRV, and GRV directly in 71/83 clinical samples was confirmed. The nucleotide sequence analysis indicated that DRV and GRV isolated from China in different locales and years were closely related, showing 97.4-100% homology to each other, but with only 86.7-88.5% identity to DRV 89026. The nucleotide and amino acid sequence identities in the amplified sigmaA-encoding gene were 74.2-78.4% and 86.9-92.0%, respectively, between duck/goose and chicken species. Phylogenetic analysis indicated that GRV and DRV aggregated into the same specified genogroup within subgroup II of the genus Orthoreovirus and are more closely related to ARV than to Nelson Bay virus. Overall, this study developed a sensitive and specific technique for the identification ARV, DRV, and GRV, and sequencing analysis has enhanced our understanding of the evolutionary relationship between ARV, DRV, and GRV.
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Affiliation(s)
- Y Zhang
- National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, P.R. China.
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27
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Zhang X, Tang J, Walker SB, O’Hara D, Nibert ML, Duncan R, Baker TS. Structure of avian orthoreovirus virion by electron cryomicroscopy and image reconstruction. Virology 2005; 343:25-35. [PMID: 16153672 PMCID: PMC4152769 DOI: 10.1016/j.virol.2005.08.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2005] [Revised: 06/06/2005] [Accepted: 08/04/2005] [Indexed: 12/30/2022]
Abstract
Among members of the genus Orthoreovirus, family Reoviridae, a group of non-enveloped viruses with genomes comprising ten segments of double-stranded RNA, only the "non-fusogenic" mammalian orthoreoviruses (MRVs) have been studied to date by electron cryomicroscopy and three-dimensional image reconstruction. In addition to MRVs, this genus comprises other species that induce syncytium formation in cultured cells, a property shared with members of the related genus Aquareovirus. To augment studies of these "fusogenic" orthoreoviruses, we used electron cryomicroscopy and image reconstruction to analyze the virions of a fusogenic avian orthoreovirus (ARV). The structure of the ARV virion, determined from data at an effective resolution of 14.6 A, showed strong similarities to that of MRVs. Of particular note, the ARV virion has its pentameric lambda-class core turret protein in a closed conformation as in MRVs, not in a more open conformation as reported for aquareovirus. Similarly, the ARV virion contains 150 copies of its monomeric sigma-class core-nodule protein as in MRVs, not 120 copies as reported for aquareovirus. On the other hand, unlike that of MRVs, the ARV virion lacks "hub-and-spokes" complexes within the solvent channels at sites of local sixfold symmetry in the incomplete T=13l outer capsid. In MRVs, these complexes are formed by C-terminal sequences in the trimeric mu-class outer-capsid protein, sequences that are genetically missing from the homologous protein of ARVs. The channel structures and C-terminal sequences of the homologous outer-capsid protein are also genetically missing from aquareoviruses. Overall, the results place ARVs between MRVs and aquareoviruses with respect to the highlighted features.
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Affiliation(s)
- Xing Zhang
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Jinghua Tang
- Department of Chemistry and Biochemistry and Department of Molecular Biology, University of California-San Diego, La Jolla, CA 92093, USA
| | - Stephen B. Walker
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - David O’Hara
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada B3H4H7
| | - Max L. Nibert
- Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Roy Duncan
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada B3H4H7
| | - Timothy S. Baker
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
- Department of Chemistry and Biochemistry and Department of Molecular Biology, University of California-San Diego, La Jolla, CA 92093, USA
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28
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Wu H, Williams Y, Gunn KS, Singh NK, Locy RD, Giambrone JJ. Yeast-derived sigma C protein-induced immunity against avian reovirus. Avian Dis 2005; 49:281-4. [PMID: 16094835 DOI: 10.1637/7284-092904r1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Avian reoviruses (ARVs) can result in disease and economic losses in the poultry industry. Vaccines against ARV may not provide full protection and can cause adverse reactions. The coding sequence of the sigma C protein from strain S1133 of avian reovirus was expressed in Schizasaccharomyces pombe. Sigma C protein expression was demonstrated by Western blotting, and the protein was evaluated for its ability to protect specific-pathogen-free (SPF) chickens against challenge with the virulent S1133 strain. Serologic and challenge-infection data showed the efficacy of the recombinant vaccine administered orally each week for 3 consecutive wk. Sigma C protein induced antibody, as determined by enzyme-linked immunosorbent assay. Percentage (%) protection induced by the low dose (125 microg purified yeast-expressed sigma C protein/chicken) or the high dose (250 microg purified yeast-expressed sigma C protein/chicken) was 64 and 91, respectively. The commercial vaccine administered once or twice provided 82% protection. Results supported the feasibility of a plant-derived vaccine for use in poultry immunization schemes.
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Affiliation(s)
- H Wu
- Department of Biological Sciences, Alabama State University, Auburn, AL 36104, USA
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29
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Xu W, Patrick MK, Hazelton PR, Coombs KM. Avian reovirus temperature-sensitive mutant tsA12 has a lesion in major core protein sigmaA and is defective in assembly. J Virol 2004; 78:11142-51. [PMID: 15452234 PMCID: PMC521821 DOI: 10.1128/jvi.78.20.11142-11151.2004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2004] [Accepted: 05/18/2004] [Indexed: 11/20/2022] Open
Abstract
Members of our laboratory previously generated and described a set of avian reovirus (ARV) temperature-sensitive (ts) mutants and assigned 11 of them to 7 of the 10 expected recombination groups, named A through G (M. Patrick, R. Duncan, and K. M. Coombs, Virology 284:113-122, 2001). This report presents a more detailed analysis of two of these mutants (tsA12 and tsA146), which were previously assigned to recombination group A. The capacities of tsA12 and tsA146 to replicate at a variety of temperatures were determined. Morphological analyses indicated that cells infected with tsA12 at a nonpermissive temperature produced approximately 100-fold fewer particles than cells infected at a permissive temperature and accumulated core particles. Cells infected with tsA146 at a nonpermissive temperature also produced approximately 100-fold fewer particles, a larger proportion of which were intact virions. We crossed tsA12 with ARV strain 176 to generate reassortant clones and used them to map the temperature-sensitive lesion in tsA12 to the S2 gene. S2 encodes the major core protein sigmaA. Sequence analysis of the tsA12 S2 gene showed a single alteration, a cytosine-to-uracil transition, at nucleotide position 488. This alteration leads to a predicted amino acid change from proline to leucine at amino acid position 158 in the sigmaA protein. An analysis of the core crystal structure of the closely related mammalian reovirus suggested that the Leu(158) substitution in ARV sigmaA lies directly under the outer face of the sigmaA protein. This may cause a perturbation in sigmaA such that outer capsid proteins are incapable of condensing onto nascent cores. Thus, the ARV tsA12 mutant represents a novel assembly-defective orthoreovirus clone that may prove useful for delineating virus assembly.
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Affiliation(s)
- Wanhong Xu
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Manitoba, Canada R3E 0W3
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30
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Sellers HS, Linnemann EG, Pereira L, Kapczynski DR. Phylogenetic Analysis of the Sigma 2 Protein Gene of Turkey Reoviruses. Avian Dis 2004; 48:651-7. [PMID: 15529990 DOI: 10.1637/7181-032304r] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The open reading frame of the S3 segment encoding the sigma2 protein of four turkey reovirus field isolates was analyzed for sequence heterogeneity. The turkey reoviruses we present here have a 97% amino acid identity to turkey NC 98. The S3 nucleotide and amino acid sequence similarity was < or =61% and 78%-80%, respectively, when compared to the chicken reovirus isolates. Comparison of amino acid sequences from chickens and turkeys with that of a duck isolate revealed a 53% and 55% similarity, respectively. Phylogenetic analyses, based on both nucleotide and amino acid sequence, resulted in three major groups among the avian reoviruses; these groups were clearly separated by species. The results of this study provide further evidence, based on the deduced sigma2 sequence, that turkey reoviruses form a distinct, separate group relative to chicken and duck isolates. In addition, as a result of the limited sequence identity with their avian counterparts, turkey reoviruses could potentially be considered a separate virus species within subgroup 2 of the Orthoreovirus genus.
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Affiliation(s)
- Holly S Sellers
- Department of Avian Medicine, Poultry Diagnostic and Research Center, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
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31
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Vasserman Y, Eliahoo D, Hemsani E, Kass N, Ayali G, Pokamunski S, Pitcovskiad J. The Influence of Reovirus Sigma C Protein Diversity on Vaccination Efficiency. Avian Dis 2004; 48:271-8. [PMID: 15283414 DOI: 10.1637/7091] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Avian reovirus (ARV) is a disease agent that causes economic losses in the poultry industry. The available vaccines do not confer full protection. One possible reason is the existence in the field of many virulent serotypes with no cross protection. Several ARV strains have been isolated in Israel in the last few years. In this study, we investigated the diversity of the sigma C protein of ARV because this is the most variable protein in the virus and it induces the production of neutralizing antibodies. Sigma C from two virulent isolates was sequenced, cloned, and expressed. The protein sequence differed from the attenuated vaccine strain (strain 1133) but was similar to a U.S. virulent strain (strain 1733). Those differences led to a change in the antigenic index of the protein, mainly at three sites. Sera of infected birds in a field trial and of birds in a controlled experiment vaccinated with the recombinant sigma C protein showed high titers in enzyme-linked immunosorbent assay to the recombinant protein and lower titers to the attenuated vaccine strain. This means that sigma C can be used as a diagnostic tool for the detection of antibodies relevant for protection and in the future as a subunit vaccine. The results of this study highlight the need to reconsider vaccinations against ARV in terms of the strains to be used and of the method of identifying protective antibodies transferred to progeny.
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Affiliation(s)
- Y Vasserman
- MIGAL, South Industrial Area, Kiryat Shmona 10200, Israel
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32
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Hsiao J, Martínez-Costas J, Benavente J, Vakharia VN. Cloning, expression, and characterization of avian reovirus guanylyltransferase. Virology 2002; 296:288-99. [PMID: 12069527 DOI: 10.1006/viro.2002.1427] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have cloned and sequenced the L3 genome segment of avian reovirus strain 1733, which specifies the viral guanylyltransferase protein, lambdaC. The L3 gene is 3907 nucleotides long and encodes, in a single large open-reading frame, a polypeptide of 1285 amino acid residues, with a calculated M(r) of 142.2 kDa. Expression of this gene in a baculovirus/insect cell system produced a recombinant protein that comigrated with reovirion lambdaC and reacted with anti-reovirus polyclonal serum in a Western blot assay. Incubation of recombinant lambdaC with GTP led to the formation GMP-lambdaC complex via a phosphoamide linkage. Interestingly, a 42-kDa amino-terminal proteolytic fragment of recombinant lambdaC protein also exhibited autoguanylylation activity, demonstrating both that this fragment is necessary and sufficient for autoguanylylation activity and that the 100-kDa complementary fragment is expendable for that activity. Comparison of the deduced amino acid sequence of protein lambdaC with those of the mammalian and grass carp reovirus guanylyltransferases revealed that only two of eight lysine residues within the amino-terminal 42-kDa region are conserved. Interestingly, these two lysines match with the lysine residues in the mammalian reovirus capping enzyme proposed to be essential for autoguanylylation activity. Our alignment analysis also showed that the S-adenosyl-l-methionine-binding pocket previously detected in the mammalian reovirus capping enzyme is fully conserved in its avian and grass carp reovirus counterparts, suggesting that all three enzymes have methylase activity.
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Affiliation(s)
- Joseph Hsiao
- Center for Agricultural Biotechnology, University of Maryland Biotechnology Institute and VA-MD Regional College of Veterinary Medicine, College Park, Maryland 20742, USA
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33
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Liu HJ, Kuo LC, Hu YC, Liao MH, Lien YY. Development of an ELISA for detection of antibodies to avian reovirus in chickens. J Virol Methods 2002; 102:129-38. [PMID: 11879701 DOI: 10.1016/s0166-0934(02)00010-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
An enzyme-linked immunosorbent assay (ELISA) using the expressed sigmaC and sigmaB proteins which induce neutralizing antibodies as the coating antigen (sigmaC-sigmaB-ELISA) for the detection of antibodies to avian reovirus in chickens was developed and compared with serum neutralization and conventional ELISA tests. These assays were used to examine the sera from chickens vaccinated experimentally and farm chickens. The correlation rate between serum neutralization and a sigmaC-sigmaB-ELISA was 100% (156/156), and that between serum neutralization and conventional ELISA was 89.1% (139/156). The results revealed that preparation of an ELISA by using sigmaC and sigmaB of ARV as the coating antigen in detecting the field chicken sera in comparison with the conventional ELISA gave a titer more correlated to the serum neutralization test. The sigmaC-sigmaB-ELISA showed a higher correlation with the serum neutralization-positive and -negative sera than that obtained with conventional ELISA. This combination antigen may thus be the best suited for preparing an ELISA for improving the determination of the immune status of chicken flocks or for detection of chicken infections with avian reovirus.
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Affiliation(s)
- Hung J Liu
- Department of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan.
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34
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Shmulevitz M, Yameen Z, Dawe S, Shou J, O'Hara D, Holmes I, Duncan R. Sequential partially overlapping gene arrangement in the tricistronic S1 genome segments of avian reovirus and Nelson Bay reovirus: implications for translation initiation. J Virol 2002; 76:609-18. [PMID: 11752152 PMCID: PMC136829 DOI: 10.1128/jvi.76.2.609-618.2002] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2001] [Accepted: 10/04/2001] [Indexed: 01/03/2023] Open
Abstract
Previous studies of the avian reovirus strain S1133 (ARV-S1133) S1 genome segment revealed that the open reading frame (ORF) encoding the final sigmaC viral cell attachment protein initiates over 600 nucleotides distal from the 5' end of the S1 mRNA and is preceded by two predicted small nonoverlapping ORFs. To more clearly define the translational properties of this unusual polycistronic RNA, we pursued a comparative analysis of the S1 genome segment of the related Nelson Bay reovirus (NBV). Sequence analysis indicated that the 3'-proximal ORF present on the NBV S1 genome segment also encodes a final sigmaC homolog, as evidenced by the presence of an extended N-terminal heptad repeat characteristic of the coiled-coil region common to the cell attachment proteins of reoviruses. Most importantly, the NBV S1 genome segment contains two conserved ORFs upstream of the final sigmaC coding region that are extended relative to the predicted ORFs of ARV-S1133 and are arranged in a sequential, partially overlapping fashion. Sequence analysis of the S1 genome segments of two additional strains of ARV indicated a similar overlapping tricistronic gene arrangement as predicted for the NBV S1 genome segment. Expression analysis of the ARV S1 genome segment indicated that all three ORFs are functional in vitro and in virus-infected cells. In addition to the previously described p10 and final sigmaC gene products, the S1 genome segment encodes from the central ORF a 17-kDa basic protein (p17) of no known function. Optimizing the translation start site of the ARV p10 ORF lead to an approximately 15-fold increase in p10 expression with little or no effect on translation of the downstream final sigmaC ORF. These results suggest that translation initiation complexes can bypass over 600 nucleotides and two functional overlapping upstream ORFs in order to access the distal final sigmaC start site.
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Affiliation(s)
- Maya Shmulevitz
- Department of Microbiology and Immunology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia B3H 4H7, Canada
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35
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Abstract
The deduced sigma-2 protein sequence from the S3 gene segment of a novel turkey reovirus, designated NC98, isolated from the bursa of birds exhibiting poult enteritis and mortality syndrome was determined. The isolate, serologically distinct from other avian reoviruses, was isolated in turkey embryo kidney cells and RNA was purified for cDNA synthesis. Oligonucleotide primers were designed based on conserved avian S3 nucleotide sequence data. The NC98 S3 open reading frame comprised 1,101 base pairs and encoded 366 amino acids with a predicated molecular mass of 40.5 kDa. Although the S3 nucleotide sequence from several chicken isolates share at least 86% identity, they share only 64% with the NC98 turkey isolate. Interestingly, the S3 nucleotide sequence from a muscovy duck reovirus shares 55% identity with NC98 and 53% identity with chicken isolates. As observed in other avian reovirus sigma2 protein sequences, a zinc-binding motif and double-stranded RNA binding domain were found within the predicted amino acid sequence of NC98. Phylogenetic analysis of the deduced sigma2 sequence demonstrated that NC98 separated as a distinct virus relative to other avian strains. The results of this study indicate that NC98 is a novel turkey reovirus that shares limited genomic sequence identity to isolates of chicken and duck origin and should be considered a separate virus species within subgroup 2 of the Orthoreovirus genus.
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Affiliation(s)
- Darrell R Kapczynski
- Agricultural Research Service, United States Department of Agriculture, Athens, Georgia 30605, USA.
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36
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Swanson GJ, Meyers J, Huang DD. Restricted growth of avirulent avian reovirus strain 2177 in macrophage derived HD11 cells. Virus Res 2001; 81:103-11. [PMID: 11682129 DOI: 10.1016/s0168-1702(01)00370-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The replication of two pathotypes of avian reovirus, 1733 and 2177 in transformed chicken lymphoid and myeloid cell lines was examined, showing that only the macrophage cell line, HD11, supports replication. The virulent strain 1733 causes a lytic infection producing 100-1000 fold more virus than the avirulent strain 2177. Cells infected with strain 2177 display delayed viral RNA and protein synthesis as well as a suppressed expression of the major capsid protein muB. These features may contribute to the lower virulence of the strain 2177 in their natural host in vivo.
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Affiliation(s)
- G J Swanson
- Department of Otolaryngology, Wayne State University, 540 E. Canfield, Detroit, MI, USA
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37
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Bodelón G, Labrada L, Martínez-Costas J, Benavente J. The avian reovirus genome segment S1 is a functionally tricistronic gene that expresses one structural and two nonstructural proteins in infected cells. Virology 2001; 290:181-91. [PMID: 11883183 DOI: 10.1006/viro.2001.1159] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The avian reovirus S1 gene contains three partially overlapping, out-of-phase open reading frames (ORFs) that the highly conserved in all avian reovirus strains examined to date. The three S1 ORFs of the avian reovirus strain S1133 were individually expressed in bacterial cells, and their purified translation products used as antigens to raise specific polyclonal antibodies. With these antibodies we were able to demonstrate that all three S1 ORFs from different avian reovirus strains are translatable in infected cells. Proteins p10 and p17, which are specified by ORF1 and ORF2, respectively, are nonstructural proteins which associate with cell membranes, whereas ORF3 directs the synthesis of protein sigma C, a structural oligomeric protein responsible for cell attachment. While intracellular synthesis of protein sigma C was demonstrated a long time ago and that of protein p10 was reported recently, this is the first time that expression of the S1 ORF2 has been demonstrated experimentally. Thus, the previously reported coding capacity of the avian reovirus genome is now expanded to 14 proteins, of which ten are structural (lambda A, lambda B, lambda C, microA, microB, microBC, microBN, sigma A, sigma B, and sigma C) and four are nonstructural (microNS, sigma NS, p17, and p10). Finally, protein p10, but not p17 or sigma C, induces cell-cell fusion when transiently expressed in mammalian cells, supporting a previously published observation that the polypeptide encoded by the S1 ORF1 plays an important role in the syncytial phenotype displayed by avian reoviruses.
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Affiliation(s)
- G Bodelón
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
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38
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Marcus PI, Sekellick MJ. Combined sequential treatment with interferon and dsRNA abrogates virus resistance to interferon action. J Interferon Cytokine Res 2001; 21:423-9. [PMID: 11440640 DOI: 10.1089/107999001750277907] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Many viruses have evolved mechanisms to resist the action of interferon (IFN). These include production of viral gene products that sequester double-stranded RNA (dsRNA) and of small helical RNA. These potentially prevent activation of dsRNA-dependent pathways of IFN action or block expression of cellular genes activated exclusively by dsRNA that may contribute to the antiviral state. Thus, dsRNA might be rate limiting in the development of an IFN-mediated antiviral state. In support of this hypothesis, dsRNA added exogenously to IFN-treated cells in the form of poly(rI):poly(rC) is shown to establish in a dose-dependent manner an antiviral state against two viruses otherwise highly refractory to IFN action, avian reovirus (ARV) and Newcaste disease virus (NDV). Cells exposed singly to high doses of IFN or dsRNA reduced the plaque-forming capacity of these viruses on chicken embryo cells 2-fold. When used in combination, there was up to a 100-fold reduction. In order to abrogate IFN resistance, dsRNA must be added after, not before, an IFN-mediated latent antiviral state is established. dsRNA added exogenously is thought to achieve the threshold required for activation of dsRNA-dependent pathways of IFN action or to induce some dsRNA-stimulated gene whose product acts synergistically with that of some IFN-stimulated gene. The combined sequential treatment with IFN and dsRNA may be useful in overcoming the anti-IFN activity of viruses of clinical interest or in other clinical conditions.
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Affiliation(s)
- P I Marcus
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269-3044, USA.
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39
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Shien JH, Yin HS, Lee LH. An enzyme-linked immunosorbent assay for the detection of antibody to avian reovirus by using protein sigma B as the coating antigen. Res Vet Sci 2000; 69:107-12. [PMID: 11020359 DOI: 10.1053/rvsc.2000.0414] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
An enzyme-linked immunosorbent assay using the expressed protein sigma B as the coating antigen (sigma B-ELISA) for detecting antibody to avian reovirus (ARV) in chickens was developed and compared with a conventional ELISA. Both ELISA s and a serum neutralisation (SN) test were used to test the sera from experimentally vaccinated and farm chickens. The sigma B-ELISA could clearly distinguish the SN-positive and -negative sera in 38-week-old chickens. The correlation rate between SN and a sigma B-ELISA was 100 per cent (65/65), and that between SN and conventional ELISA was 84 per cent (55/65). With the sigma B-ELISA, all SN-negative sera had low absorbance values (below 0.06), and the absorbance values correlated closely with the SN titres. However, the sera which were antibody-negative by SN had various absorbance values, ranging from 0.07 to 0.39 in the conventional ELISA. Hence, the sigma B-ELISA had lower non-specific binding reactions than the conventional ELISA against sera from ARV -negative birds. Antibody against ARV could be detected by sigma B-ELISA after vaccination. Absorbance values peaked 4 weeks after vaccination at 2 weeks of age and were maintained until the birds were 27 weeks old. The results suggest that the presence of antibody against viral protein sigma B in birds may be used as a good indicator by the sigma B - ELISA for detecting immune status of a chicken flock or to detect chickens infected with ARV.
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Affiliation(s)
- J H Shien
- Department of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan 403, Republic of China
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40
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Grande A, Rodriguez E, Costas C, Everitt E, Benavente J. Oligomerization and cell-binding properties of the avian reovirus cell-attachment protein sigmaC. Virology 2000; 274:367-77. [PMID: 10964779 DOI: 10.1006/viro.2000.0473] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Avian reovirus protein sigmaC, the viral cell-attachment protein, is a minor component of the outer-capsid shell of the viral particle that is synthesized in small amounts in infected cells. We cloned the sigmaC-encoding ORF in vector pIL-2f, expressed it in Escherichia coli, and partially purified the resulting recombinant protein from inclusion bodies. Rabbit polyclonal antibodies raised against the recombinant protein specifically recognized the viral polypeptide in ELISA, immunoprecipitation, and Western blotting. To study the oligomerization capacity and cell-binding affinity of protein sigmaC, the sigmaC-encoding ORF was also expressed in chicken embryo fibroblasts (CEFs) and in reticulocyte lysates. In all three systems protein sigmaC is expressed as a multimer with identical electrophoretic mobility to the naturally occurring protein. Cell-binding experiments show that both in vitro and in vivo expressed protein sigmaC display affinity for CEF receptors, and this property is exclusively associated with the oligomeric form of the protein. The fact that incubation of CEF cells with the recombinant protein expressed in bacterial cells completely blocks the binding of purified reovirions indicates both that binding of this protein to cells is specific and saturable, and that reovirions and protein sigmaC bind to the same class of cell receptor. Saturation binding experiments, performed with the recombinant protein expressed in E. coli and with purified reovirions, showed that the number of cellular receptor sites (CRSs) for avian reovirus S1133 is 1.8 x 10(4) per CEF cell, whereas the number of cellular receptor units (CRUs) for sigmaC is 2.2 x 10(5) per CEF cell. These results are consistent with previous reports on the binding of mammalian reoviruses.
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Affiliation(s)
- A Grande
- Departamento de Bioquímica y Biología Molecular, Universidad de Santiago de Compostela, Santiago de Compostela, 15706, Spain
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41
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Liu HJ, Giambrone JJ, Wu YH, Liao MH, Lu CF. The use of monoclonal antibody probes for the detection of avian reovirus antigens. J Virol Methods 2000; 86:115-9. [PMID: 10785286 DOI: 10.1016/s0166-0934(00)00137-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Two monoclonal antibodies (MAb), E9 and H3, prepared against avian reovirus (ARV) S1133, were used in an immuno-dot assay to detect ARV antigens from cell culture and from tendon tissue samples of chickens. The limit of viral antigens detected was 8 ng using both MAb probes. The probes detected 10 ARV isolates representing at least two serotypes or pathotypes. The results indicated that these probes had broad specificity. The probes, however, did not cross-react with viral antigens prepared from six unrelated avian viruses. The ARV antigens in tendon tissue samples were detected by both probes, and it is possible, therefore, to use either of the two MAb probes for detection of ARV infections.
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Affiliation(s)
- H J Liu
- Department of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan, ROC.
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42
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Grande A, Benavente J. Optimal conditions for the growth, purification and storage of the avian reovirus S1133. J Virol Methods 2000; 85:43-54. [PMID: 10716337 DOI: 10.1016/s0166-0934(99)00155-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
In spite of their importance as avian pathogens causing important losses in poultry farming, the biochemistry of avian reoviruses has been little investigated. In order to facilitate the handling of these agents in the laboratory, a study was carried out to establish the best conditions both for growing the avian reovirus S1133 in primary cultures of chicken embryo fibroblasts and for purification and storage of viral suspensions. The results indicate that the conditions used currently for the manipulation of mammalian reoviruses are not always the best for handling their avian counterparts. In particular, avian reoviruses are much less stable than mammalian reoviruses, and specific conditions for the purification and storage of avian reoviruses therefore should be used. Furthermore, the instability of avian reovirions may have important implications for the life cycle and pathogenesis of the virus within the animal host.
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Affiliation(s)
- A Grande
- Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, University of Santiago de Compostela, Spain
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43
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Martínez-Costas J, González-López C, Vakharia VN, Benavente J. Possible involvement of the double-stranded RNA-binding core protein sigmaA in the resistance of avian reovirus to interferon. J Virol 2000; 74:1124-31. [PMID: 10627522 PMCID: PMC111446 DOI: 10.1128/jvi.74.3.1124-1131.2000] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/1999] [Accepted: 11/08/1999] [Indexed: 01/12/2023] Open
Abstract
Treatment of primary cultures of chicken embryo fibroblasts with a recombinant chicken alpha/beta interferon (rcIFN) induces an antiviral state that causes a strong inhibition of vaccinia virus and vesicular stomatitis virus replication but has no effect on avian reovirus S1133 replication. The fact that avian reovirus polypeptides are synthesized normally in rcIFN-treated cells prompted us to investigate whether this virus expresses factors that interfere with the activation and/or the activity of the IFN-induced, double-stranded RNA (dsRNA)-dependent enzymes. Our results demonstrate that extracts of avian-reovirus-infected cells, but not those of uninfected cells, are able to relieve the translation-inhibitory activity of dsRNA in reticulocyte lysates, by blocking the activation of the dsRNA-dependent enzymes. In addition, our results show that protein sigmaA, an S1133 core polypeptide, binds to dsRNA in an irreversible manner and that clearing this protein from extracts of infected cells abolishes their protranslational capacity. Taken together, our results raise the interesting possibility that protein sigmaA antagonizes the IFN-induced cellular response against avian reovirus by blocking the intracellular activation of enzyme pathways dependent on dsRNA, as has been suggested for several other viral dsRNA-binding proteins.
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Affiliation(s)
- J Martínez-Costas
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Santiago de Compostela, 15706-Santiago de Compostela (A Coruña), Spain
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44
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Yin HS, Shien JH, Lee LH. Synthesis in Escherichia coli of avian reovirus core protein varsigmaA and its dsRNA-binding activity. Virology 2000; 266:33-41. [PMID: 10612658 DOI: 10.1006/viro.1999.0020] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The genome segment S2 of p6ian reovirus (ARV) S1133 was cloned and sequenced. The entire S2 nucleotide sequence is 1325 bp long with one long open reading frame that encodes a protein of 415 amino acids, corresponding to varsigmaA, a major core protein of ARV. S2 possesses a pentanucleotide, TCATC, at the 3'-terminus of its plus strand, common to other known genome segments of ARV and to 10 genome segments of mammalian reovirus. Amino acid sequence analysis revealed that varsigmaA contains a carboxy-terminal region (one-fourth of the protein) that is formed from alpha-helices and beta-turns, and the remainder (three-fourths of the protein) is formed predominantly from beta-strands and beta-turns. Analysis of binding activity to poly(rI)-poly(rC)-agarose suggested that ARV protein A present in total virus-infected chicken embryo fibroblasts (CEF) had dsRNA-binding activity. To further characterize the binding activity, protein varsigmaA was subsequently expressed in Escherichia coli BL21(DE3) cells as a fusion protein and isolated by metal chelate affinity chromatography. The expressed protein evarsigmaA was further purified through a Superdex 75 HR 10/30 column after digestion of the purified fusion peptide with enterokinase. The expressed protein evarsigmaA has the same molecular weight as virion protein varsigmaA purified from ARV-infected CEF and is indistinguishable from virion protein varsigmaA by immunoblot analysis. The evarsigmaA binds cooperatively alpha (32)P-labeled dsRNA probe produced by run-off transcription of clone pGEM-3Zf(+)S4. The binding reaction is blocked by homologous ARV dsRNA or heterologous infectious bursal disease virus dsRNA and poly(rI)-poly(rC), but not by salmon sperm DNA. The results indicate that the expressed protein evarsigmaA has dsRNA-binding activity similar to that of varsigmaA obtained from infected cells, and its binding is sequence-independent.
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Affiliation(s)
- H S Yin
- Department of Veterinary Medicine, National Chung Hsing University, Taichung, 403, Taiwan
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45
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Liu HJ, Chen JH, Liao MH, Lin MY, Chang GN. Identification of the sigma C-encoded gene of avian reovirus by nested PCR and restriction endonuclease analysis. J Virol Methods 1999; 81:83-90. [PMID: 10488765 DOI: 10.1016/s0166-0934(99)00063-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
A nested reverse transcription (RT)-polymerase chain reaction with subsequent restriction endonuclease analysis was developed for identification of the sigma C-encoded gene of avian reoviruses (ARV). PCR products derived from the sigma C-encoded gene of all tested ARVs resulted in a specific DNA band of 1023 bp, indicating that there were no apparent insertions or deletions in this region. Amplification with the nested primer pairs S1M-S1N and S1P-S1N generated 330 and 239 bp, respectively. PCR products amplified from the sigma C-encoded of all tested ARVs isolates were further confirmed by Southern blot hybridization and restriction endonuclease analysis. PCR amplified cDNA fragment (1023 bp) cleaved with Pst I generated two fragments of 565 and 458 bp. The amplified sigma C-encoded gene of ARV was subcloned into PQE 32 vector for further study of its antigenicity and immunogenicity. The sensitivity of RT-PCR was examined on nucleic acids from the ARV infected cell cultures. The detection limit was 10(0) to 10(-1) TCID50 of ARV in a ethidium bromide stained gel and could be increased further to 10(-1) to 10(-2) TCID50 of ARV by Southern blot hybridization using a digoxigenin-labeled cDNA probe. The sensitivity increased approximately 10(3) to 10(4) folds when the cDNA was reamplified with two sets of nested primers.
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Affiliation(s)
- H J Liu
- Department of Veterinary Medicine, National Pingtung University of Science and Technology, Taiwan, ROC.
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Liu HJ, Liao MH, Chang CD, Chen JH, Lin MY, Tung MC. Comparison of two molecular techniques for the detection of avian reoviruses in formalin-fixed, paraffin-embedded chicken tissues. J Virol Methods 1999; 80:197-201. [PMID: 10471029 DOI: 10.1016/s0166-0934(99)00047-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Reverse transcription (RT) in situ polymerase chain reaction (PCR) and in situ hybridization (ISH) techniques were used to detect the sigma c-encoded gene of avian reovirus (ARV) in chicken tissue sections. The advantage of using in situ methods is to make more rapid and accurate diagnosis of ARV infections. The sensitivity of these two techniques were compared. Of the two techniques, the RT in situ PCR test was found to be more sensitive than ISH and provided the rapid, sensitive, and specific detection of ARV infections.
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Affiliation(s)
- H J Liu
- Department of Veterinary Medicine, National Pingtung University of Science and Technology, Taiwan, ROC.
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Yin HS, Shieh HK, Lee LH. Characterization of the double-stranded RNA genome segment S3 of avian reovirus. J Virol Methods 1997; 67:93-101. [PMID: 9274822 DOI: 10.1016/s0166-0934(97)00080-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The double-stranded RNA genome segment S3 of avian reovirus (ARV) S1133 was cloned following polyadenylation of both strands and cDNA synthesis of S3 RNA. The complete segment S3 nucleotide sequence was determined. S3 is 1196 base pairs long with one long open reading frame (ORF). The ORF possesses the AUG initiation codon in an optimum context for translation and starts at the first initiation codon (residue 24) and extends for 367 codons, sufficient to encode a protein of the same size as the known S3 gene product, protein sigmaB, one of the major outer capsid proteins of avian reovirus (Mr 41471). Protein sigmaB was subsequently expressed in Escherichia coli. The expressed protein sigmaB was indistinguishable from virion protein sigmaB as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, immunoblot assay, and N-terminal amino acid sequencing of several peptides generated by Staphyloccus aureus V8 protease digestion. ARV S3 genome segment possesses a pentanucleotide UCAUC at the 3'-terminus of its plus strand. The pentanucleotide sequence is common to the other genome segment S1 of ARV and to ten genome segments of mammalian reovirus at the 3'-terminus of their plus strands. Amino acid sequence analysis revealed that ARV sigmaB does not contain a repeated basic amino acid motif as do the three serotypes of mammalian reovirus. The results of amino acid sequencing suggest that the most susceptible cleavage sites of sigmaB to V8 protease are located in a hydrophilic area between amino acids 95 and 140.
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Affiliation(s)
- H S Yin
- Department of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan
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Liu HJ, Giambrone JJ, Nielsen BL. Molecular characterization of avian reoviruses using nested PCR and nucleotide sequence analysis. J Virol Methods 1997; 65:159-67. [PMID: 9186939 DOI: 10.1016/s0166-0934(97)02199-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A nested polymerase chain reaction (PCR) with subsequent nucleotide sequence analysis identified and differentiated avian reoviruses (ARVs). PCR products amplified from the S1 gene segment of ARV of USA isolates were 738 and 342 bp, respectively. PCR products were conformed by Southern and dot blot hybridizations. The amplified cDNA fragments were cloned into the pUC18 vector and subjected to DNA sequencing. The nucleotide and deduced amino acid sequences of four USA (S1133, 1733, 2408, and CO8) and two Australian isolates (RAM-1 and SOM-4) were compared. Results of paired difference analysis and a predicted dendrogram revealed that USA isolates were closely related, but different from, Australian isolates. The deduced amino acid sequences of the N-terminal region of ARV sigma C showed a heptapeptide repeat of hydrophobic residues in all ARV isolates.
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Affiliation(s)
- H J Liu
- Department of Poultry Science, Auburn University, AL 36849-5416, USA
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Martínez-Costas J, Grande A, Varela R, García-Martínez C, Benavente J. Protein architecture of avian reovirus S1133 and identification of the cell attachment protein. J Virol 1997; 71:59-64. [PMID: 8985323 PMCID: PMC191024 DOI: 10.1128/jvi.71.1.59-64.1997] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
There are a number of discrepancies in the literature regarding the protein composition of the avian reoviruses. The present study demonstrates that avian reovirus S1133 contains at least 10 proteins (lambdaA, lambdaB, lambdaC, muA, muB, muBC, muBN, sigmaA, sigmaB, and sigmaC). Polypeptides muB, muBC, muBN, sigmaB, and sigmaC are components of the outer capsid layer of the virus, while lambdaA, lambdaB, muA, and sigmaA are core polypeptides. Protein lambdaC is a component of both layers, extending from the inner core to the outer capsid. The minor outer-capsid polypeptide sigmaC is shown to be the cell attachment protein, since it is the only viral polypeptide present in extracts of S1133-infected cells that binds specifically to chicken embryo fibroblasts; furthermore, its binding to avian cells was competitively inhibited by S1133 reovirions but not by mammalian reovirions. Our results also show that sigmaC is an oligomeric protein both in the virion and free in the cytoplasm, and preliminary results suggest that the multimer is made up of three monomeric units.
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Affiliation(s)
- J Martínez-Costas
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia,University of Santiago, Spain
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Liu HJ, Giambrone JJ. Amplification, cloning and sequencing of the sigmaC-encoded gene of avian reovirus. J Virol Methods 1997; 63:203-8. [PMID: 9015291 DOI: 10.1016/s0166-0934(96)02129-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The sigmaC-encoding cDNA of avian reovirus (ARV) 1733 strain was amplified, cloned and sequenced using double nested polymerase chain reaction (PCR). The ARV sigmaC protein is a minor component of the outer capsid that induces type-specific neutralization antibodies. Four overlapping sigmaC-encoding cDNA fragments were obtained. Together, the four fragments represented the whole coding sequence. The nucleotide and deduced amino acid sequences of sigmaC-encoded gene of U.S. (S1133 and 1733) and Australian isolates (RAM-1 and SOM-4) were compared. The U.S. isolates were closely related, but different from Australian isolates. The degree of differences between the U.S. and Australian isolates was over 44.89% at both the nucleotide and deduced amino acid levels and suggested that the virus is evolving separately in different continents. The deduced amino acid sequences of ARV sigmaC indicated a heptapeptide repeat in the N-terminal region of ARV sigmaC existed in all ARVs. The results suggested that ARV sigmaC is structurally related to mammalian reovirus (MRV) sigma1.
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Affiliation(s)
- H J Liu
- Department of Poultry Science, Alabama Agriculture Experiment Station, Auburn University, 36849-5416, USA
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