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de Mello JL, Lorencena D, Delai RR, Kunz AF, Possatti F, Alfieri AA, Takiuchi E. A comprehensive molecular analysis of bovine coronavirus strains isolated from Brazil and comparison of a wild-type and cell culture-adapted strain associated with respiratory disease. Braz J Microbiol 2024:10.1007/s42770-024-01287-0. [PMID: 38381350 DOI: 10.1007/s42770-024-01287-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Accepted: 02/10/2024] [Indexed: 02/22/2024] Open
Abstract
Bovine coronavirus (BCoV) has dual tropisms that can trigger enteric and respiratory diseases in cattle. Despite its global distribution, BCoV field strains from Brazil remain underexplored in studies investigating the virus's worldwide circulation. Another research gap involves the comparative analysis of S protein sequences in BCoV isolates from passages in cell lines versus direct sequencing from clinical samples. Therefore, one of the objectives of our study was to conduct a comprehensive phylogenetic analysis of BCoV strains identified from Brazil, including a respiratory strain obtained during this study, comparing them with global and ancestral BCoV strains. Additionally, we performed a comparative analysis between wild-type BCoV directly sequenced from the clinical sample (nasal secretion) and the cell culture-adapted strain, utilizing the Sanger method. The field strain and multiple cell passage in cell culture (HRT-18) adapted BCoV strain (BOV19 NS) detected in this study were characterized through molecular and phylogenetic analyses based on partial fragments of 1,448 nt covering the hypervariable region of the S gene. The analyses have demonstrated that different BCoV strains circulating in Brazil, and possibly Brazilian variants, constitute a new genotype (putative G15 genotype). Compared with the ancestral prototype (Mebus strain) of BCoV, 33 nt substitutions were identified of which 15 resulted in non-synonymous mutations (nine transitions and six transversions). Now, compared with the wild-type strain was identified only one nt substitution in nt 2,428 from the seventh passage onwards, which resulted in transversion, neutral-neutral charge, and one substitution of asparagine for tyrosine at aa residue 810 (N810Y).
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Affiliation(s)
- Janaina Lustosa de Mello
- Departament of Veterinary Sciences, Universidade Federal do Paraná-UFPR, Rua Pioneiro, 2153, Palotina, Paraná, 85950-000, Brazil
| | - Daniela Lorencena
- Departament of Veterinary Sciences, Universidade Federal do Paraná-UFPR, Rua Pioneiro, 2153, Palotina, Paraná, 85950-000, Brazil
| | - Ruana Renostro Delai
- Departament of Veterinary Sciences, Universidade Federal do Paraná-UFPR, Rua Pioneiro, 2153, Palotina, Paraná, 85950-000, Brazil
| | - Andressa Fernanda Kunz
- Departament of Veterinary Sciences, Universidade Federal do Paraná-UFPR, Rua Pioneiro, 2153, Palotina, Paraná, 85950-000, Brazil
| | - Flávia Possatti
- Department of Preventive Veterinary Medicine, Universidade Estadual de Londrina-UEL, PO Box 6001, Londrina, Paraná, 86051-990, Brazil
| | - Amauri Alcindo Alfieri
- Department of Preventive Veterinary Medicine, Universidade Estadual de Londrina-UEL, PO Box 6001, Londrina, Paraná, 86051-990, Brazil
- Multi-User Animal Health Laboratory, Molecular Biology Unit, Department of Veterinary Preventive Medicine, Universidade Estadual de Londrina, Londrina, Paraná, 86057-970, Brazil
| | - Elisabete Takiuchi
- Departament of Veterinary Sciences, Universidade Federal do Paraná-UFPR, Rua Pioneiro, 2153, Palotina, Paraná, 85950-000, Brazil.
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Bidokhti MRM, Tråvén M, Krishna NK, Munir M, Belák S, Alenius S, Cortey M. Evolutionary dynamics of bovine coronaviruses: natural selection pattern of the spike gene implies adaptive evolution of the strains. J Gen Virol 2013; 94:2036-2049. [PMID: 23804565 DOI: 10.1099/vir.0.054940-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Coronaviruses demonstrate great potential for interspecies transmission, including zoonotic outbreaks. Although bovine coronavirus (BCoV) strains are frequently circulating in cattle farms worldwide, causing both enteric and respiratory disease, little is known about their genomic evolution. We sequenced and analysed the full-length spike (S) protein gene of 33 BCoV strains from dairy and feedlot farms collected during outbreaks that occurred from 2002 to 2010 in Sweden and Denmark. Amino acid identities were >97 % for the BCoV strains analysed in this work. These strains formed a clade together with Italian BCoV strains and were highly similar to human enteric coronavirus HECV-4408/US/94. A high similarity was observed between BCoV, canine respiratory coronavirus (CRCoV) and human coronavirus OC43 (HCoV-OC43). Molecular clock analysis of the S gene sequences estimated BCoV and CRCoV diverged from a common ancestor in 1951, while the time of divergence from a common ancestor of BCoV and HCoV-OC43 was estimated to be 1899. BCoV strains showed the lowest similarity to equine coronavirus, placing the date of divergence at the end of the eighteenth century. Two strongly positive selection sites were detected along the receptor-binding subunit of the S protein gene: spanning amino acid residues 109-131 and 495-527. By contrast, the fusion subunit was observed to be under negative selection. The selection pattern along the S glycoprotein implies adaptive evolution of BCoVs, suggesting a successful mechanism for BCoV to continuously circulate among cattle and other ruminants without disappearance.
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Affiliation(s)
- Mehdi R M Bidokhti
- Division of Ruminant Medicine and Veterinary Epidemiology, Department of Clinical Sciences, Swedish University of Agricultural Sciences, Box 7054, SE-750 07 Uppsala, Sweden
| | - Madeleine Tråvén
- Division of Ruminant Medicine and Veterinary Epidemiology, Department of Clinical Sciences, Swedish University of Agricultural Sciences, Box 7054, SE-750 07 Uppsala, Sweden
| | - Neel K Krishna
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, 700 West Olney Road, Norfolk, VA 23507-1696, USA
| | - Muhammad Munir
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden.,Department of Virology, Immunobiology and Parasitology, National Veterinary Institute, Box 7028, SE-751 89 Uppsala, Sweden
| | - Sándor Belák
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden.,Department of Virology, Immunobiology and Parasitology, National Veterinary Institute, Box 7028, SE-751 89 Uppsala, Sweden
| | - Stefan Alenius
- Division of Ruminant Medicine and Veterinary Epidemiology, Department of Clinical Sciences, Swedish University of Agricultural Sciences, Box 7054, SE-750 07 Uppsala, Sweden
| | - Martí Cortey
- Department of Immunology, The Pirbright Institute, Ash Road, Pirbright GU24 0NF, UK
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Zhang J, Guy JS, Snijder EJ, Denniston DA, Timoney PJ, Balasuriya UBR. Genomic characterization of equine coronavirus. Virology 2007; 369:92-104. [PMID: 17706262 PMCID: PMC7103287 DOI: 10.1016/j.virol.2007.06.035] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2007] [Revised: 05/08/2007] [Accepted: 06/30/2007] [Indexed: 11/03/2022]
Abstract
The complete genome sequence of the first equine coronavirus (ECoV) isolate, NC99 strain was accomplished by directly sequencing 11 overlapping fragments which were RT–PCR amplified from viral RNA. The ECoV genome is 30,992 nucleotides in length, excluding the polyA tail. Analysis of the sequence identified 11 open reading frames which encode two replicase polyproteins, five structural proteins (hemagglutinin esterase, spike, envelope, membrane, and nucleocapsid) and four accessory proteins (NS2, p4.7, p12.7, and I). The two replicase polyproteins are predicted to be proteolytically processed by three virus-encoded proteases into 16 non-structural proteins (nsp1–16). The ECoV nsp3 protein had considerable amino acid deletions and insertions compared to the nsp3 proteins of bovine coronavirus, human coronavirus OC43, and porcine hemagglutinating encephalomyelitis virus, three group 2 coronaviruses phylogenetically most closely related to ECoV. The structure of subgenomic mRNAs was analyzed by Northern blot analysis and sequencing of the leader–body junction in each sg mRNA.
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Affiliation(s)
- Jianqiang Zhang
- Department of Veterinary Science, 108 Maxwell H. Gluck Equine Research Center, University of Kentucky, Lexington, KY 40546, USA
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Axel Schmidt, Olaf Weber, Manfred H. Wolff. Coronaviridae: a review of coronaviruses and toroviruses. Coronaviruses with Special Emphasis on First Insights Concerning SARS 2005. [ DOI: 10.1007/3-7643-7339-3_1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/22/2023]
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Sasseville AMJ, Boutin M, Gélinas AM, Dea S. Sequence of the 3'-terminal end (8.1 kb) of the genome of porcine haemagglutinating encephalomyelitis virus: comparison with other haemagglutinating coronaviruses. J Gen Virol 2002; 83:2411-2416. [PMID: 12237422 DOI: 10.1099/0022-1317-83-10-2411] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A cytopathogenic coronavirus, serologically identified as porcine haemagglutinating encephalomyelitis virus (HEV), has recently been associated with acute outbreaks of wasting and encephalitis in nursing piglets from pig farms in southern Québec and Ontario, Canada. The 3'-terminal end of the genome of the prototype HEV-67N strain and that of the recent Québec IAF-404 field isolate, both propagated in HRT-18 cells, were sequenced. Overall, sequencing data indicated that HEV has remained antigenically and genetically stable since its first isolation in North America in 1962. Compared with the prototype strain of bovine enteropathogenic coronavirus (BCoV), HEV, as well as the human respiratory coronavirus (HCoV-OC43) showed a major deletion in their ORF4 gene. Deduced amino acid sequences for both HEV strains revealed 89/88, 80, 93/92 and 95/94% identities with the structural proteins HE, S, M and N of BCoV and HCoV-OC43, respectively. Major variations were observed in the S1 portion of the S gene of both HEV strains, with only 73/71% amino acid identities compared with those of the two other haemagglutinating coronaviruses.
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Affiliation(s)
- A Marie-Josée Sasseville
- INRS-Institut Armand-Frappier, Centre de Microbiologie et Biotechnologie, Université du Québec, 531 boul. des Prairies, Laval, Québec, Canada H7V 1B71
| | - Martine Boutin
- INRS-Institut Armand-Frappier, Centre de Microbiologie et Biotechnologie, Université du Québec, 531 boul. des Prairies, Laval, Québec, Canada H7V 1B71
| | - Anne-Marie Gélinas
- INRS-Institut Armand-Frappier, Centre de Microbiologie et Biotechnologie, Université du Québec, 531 boul. des Prairies, Laval, Québec, Canada H7V 1B71
| | - Serge Dea
- INRS-Institut Armand-Frappier, Centre de Microbiologie et Biotechnologie, Université du Québec, 531 boul. des Prairies, Laval, Québec, Canada H7V 1B71
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Hasoksuz M, Sreevatsan S, Cho KO, Hoet AE, Saif LJ. Molecular analysis of the S1 subunit of the spike glycoprotein of respiratory and enteric bovine coronavirus isolates. Virus Res 2002; 84:101-9. [PMID: 11900843 PMCID: PMC7127276 DOI: 10.1016/s0168-1702(02)00004-7] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2001] [Revised: 12/12/2001] [Accepted: 12/12/2001] [Indexed: 11/23/2022]
Abstract
It is unclear whether respiratory and enteric bovine coronavirus (BoCV) strains are distinctive in biological, antigenic and genetic characteristics. In the present study, we analyzed the nucleotide and amino acid sequence of the S1 subunit of the S glycoprotein, including the cleavage site, of both respiratory (n=5) and enteric (n=3) BoCV isolates including two paired isolates from the same feedlot animals and compared them with the prototype Mebus and two enteric and one respiratory BoCV strains from Quebec. A total of 75 polymorphic nucleotides were identified in the S1 subunit of the spike glycoprotein of BoCV isolates compared with the Mebus strain. These polymorphisms led to 42 amino acid changes at 38 distinct sites. The amino acid changes were distributed throughout the S1 subunit with clustering around residues 40-118, 146-179, and 458-531. Among these variations, only 19 amino acid substitutions altered the charge, hydrophobicity and surface probability of the protein. Based on phylogenetic analysis, our respiratory and enteric isolates clustered into two major groups with two subgroups. Although, there were only a few amino acid changes between the respiratory and enteric paired isolates, the other two respiratory isolates, one isolated from the same farm as a paired strain and the other from a different farm, showed more sequence diversity. Amino acid alterations in residues 113, 115, 118, 146, 148, 501, 510 and 531 of respiratory isolates conferred significant changes in the predicted secondary structure compared with the prototype winter dysentery (WD) and the calf diarrhea (CD) strains of BoCV. In conclusion, the data suggests that respiratory strains of BoCV may differ genetically from the classical calf enteric and adult WD strains.
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Affiliation(s)
| | | | | | | | - Linda J Saif
- Food Animal Health Research Program, Department of Veterinary Preventive Medicine, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH 44691-4096, USA
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Yoo D, Deregt D. A single amino acid change within antigenic domain II of the spike protein of bovine coronavirus confers resistance to virus neutralization. Clin Diagn Lab Immunol 2001; 8:297-302. [PMID: 11238212 PMCID: PMC96053 DOI: 10.1128/cdli.8.2.297-302.2001] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The spike glycoprotein is a major neutralizing antigen of bovine coronavirus (BCV). Conformational neutralizing epitopes of group A and group B monoclonal antibodies (MAbs) have previously been mapped to two domains at amino acids 351 to 403 (domain I) and amino acids 517 to 621 (domain II). To further map antigenic sites, neutralization escape mutants of BCV were selected with a group A MAb which has both in vitro and in vivo virus-neutralizing ability. The escape mutants were demonstrated to be neutralization resistant to the selecting group A MAb and remained sensitive to neutralization by a group B MAb. In radioimmunoprecipitation assays, the spike proteins of neutralization escape mutants were shown to have lost their reactivities with the selecting group A MAb. Sequence analysis of the spike protein genes of the escape mutants identified a single nucleotide substitution of C to T at position 1583, resulting in the change of alanine to valine at amino acid position 528 (A528V). The mutation occurs in domain II and in a location which corresponds to the hypervariable region of the spike protein of the coronavirus mouse hepatitis virus. Experimental introduction of the A528V mutation into the wild-type spike protein resulted in the loss of MAb binding of the mutant protein, confirming that the single point mutation was responsible for the escape of BCV from immunological selective pressure.
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Affiliation(s)
- D Yoo
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, Ontario N1G 2W1.
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Wootton SK, Nelson EA, Yoo D. Antigenic structure of the nucleocapsid protein of porcine reproductive and respiratory syndrome virus. Clin Diagn Lab Immunol 1998; 5:773-9. [PMID: 9801333 PMCID: PMC96200 DOI: 10.1128/cdli.5.6.773-779.1998] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A collection of 12 monoclonal antibodies (MAbs) raised against porcine reproductive and respiratory syndrome (PRRS) virus was used to study the antigenic structure of the virus nucleocapsid protein (N). The full-length N gene, encoded by open reading frame 7, was cloned from the Canadian PRRS virus, PA-8. Deletions were introduced into the N gene to produce a series of nine overlapping protein fragments ranging in length from 25 to 112 amino acids. The individual truncated genes were cloned as glutathione S-transferase fusions into a eukaryotic expression vector downstream of the T7 RNA polymerase promoter. HeLa cells infected with recombinant vaccinia virus expressing T7 RNA polymerase were transfected with plasmid DNA encoding the N protein fragments, and the antigenicity of the synthesized proteins was analyzed by immunoprecipitation. Based on the immunoreactivities of the N protein deletion mutants with the panel of N-specific MAbs, five domains of antigenic importance were identified. MAbs SDOW17, SR30, and 5H2.3B12.1C9 each identified independent domains defined by amino acids 30 to 52, 69 to 123, and 37 to 52, respectively. Seven of the MAbs tested specifically recognized the local protein conformation formed in part by the amino acid residues 52 to 69. Furthermore, deletion of 11 amino acids from the carboxy terminus of the nucleocapsid protein disrupted the epitope configuration recognized by all of the conformation-dependent MAbs, suggesting that the carboxy-terminal region plays an important role in maintaining local protein conformation.
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Affiliation(s)
- S K Wootton
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, Ontario N1G 2W1, Canada
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Milane G, Kourtesis AB, Dea S. Characterization of monoclonal antibodies to the hemagglutinin-esterase glycoprotein of a bovine coronavirus associated with winter dysentery and cross-reactivity to field isolates. J Clin Microbiol 1997; 35:33-40. [PMID: 8968877 PMCID: PMC229508 DOI: 10.1128/jcm.35.1.33-40.1997] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Seven hybridoma cell lines producing monoclonal antibodies (MAbs) to the hemagglutinin-esterase (HE) glycoprotein of bovine coronavirus (BCV) were obtained from BALB/c mice that were immunized with an enriched peplomeric fraction of the winter dysentery (WD)-associated strain BCQ.2590. The specificities of these MAbs to either the dimeric (140-kDa) or the monomeric (65-kDa) form of the HE glycoprotein were determined by Western immunoblotting experiments with purified virus and immunoprecipitation tests with [35S]methionine-labelled infected cell extracts. Four of these anti-HE MAbs inhibited the hemagglutinating activity of the virus and three weakly neutralized its infectivity in vitro. In addition, competition binding assays allowed for the definition of two independent antigenic domains (domains A and D) and two overlapping antigenic domains (domains B and C) for the HE glycoprotein of the WD-associated strain; epitopes located within antigenic domain A were not associated with hemagglutination inhibition (HAI) and virus neutralization activities. In HAI tests, the four anti-HA MAbs defined two distinct antigenic subgroups among 24 BCV field isolates that have been associated with either typical outbreaks of WD or neonatal calf diarrhea (NCD) in Quebec dairy herds from 1986 to 1996. The Quebec WD-associated strains of BCV, as well as some of the NCD-associated strains isolated since 1991, fell within a subgroup distinct from that of the prototype Mebus strain.
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Affiliation(s)
- G Milane
- Centre de Recherche en Virologie, Institut Armand-Frappier, Université du Québec, Canada
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Künkel F, Herrler G. Structural and functional analysis of the S proteins of two human coronavirus OC43 strains adapted to growth in different cells. Arch Virol 1996; 141:1123-31. [PMID: 8712929 PMCID: PMC7086633 DOI: 10.1007/bf01718615] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/1995] [Accepted: 02/06/1996] [Indexed: 02/01/2023]
Abstract
The receptor-binding activity of strain CU (grown in MDCK I cells) and of strain VA (adapted to Vero cells) of human coronavirus OC43 was analyzed and compared with the binding activity of bovine coronavirus (BCV) and of the OC43 strain provided by the American Type Culture Collection (AT). Results obtained with resialylated erythrocytes indicated that the ability of the viruses to recognize 9-O-acetylated sialic acid in an alpha 2,6-linkage decreased in the following order: AT > CU > BCV > VA. Only minor differences were observed with respect to the alpha 2,3-linkage. The amino acid sequence of the S protein of strain CU and VA was derived from the nucleotide sequence of the cloned gene. Strain VA differed from strain CU in 34 positions, 18 in the S1 and 16 in the S2 subunit.
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Affiliation(s)
- F Künkel
- Institut für Virologie, Philipps-Universität Marburg, Federal Republic of Germany
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Enjuanes L, Smerdou C, Castilla J, Antón IM, Torres JM, Sola I, Golvano J, Sánchez JM, Pintado B. Development of protection against coronavirus induced diseases. A review. Adv Exp Med Biol 1995; 380:197-211. [PMID: 8830481 DOI: 10.1007/978-1-4615-1899-0_34] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- L Enjuanes
- Department of Molecular and Cellular Biology, Centro Nacional de Biotecnologia, CSIC, Madrid, Spain
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Abstract
Complementary oligonucleotide primers which flank a 1146-nucleotide gene fragment (S1B: nt 1185 to 2333) encompassing a polymorphic region (nt 1368 to 1776) of the S1 subunit of bovine coronavirus spike glycoprotein were used for enzymatic amplification by PCR. We chose four clinical isolates, recovered from cases of epidemic diarrhea in neonatal calves in Québec dairy herds between 1987-1990, to specifically amplify and analyze their sequences in the selected genomic area. Nucleotide sequence analysis of the four clinical isolates indicated that their S1B gene fragments were highly conserved. We also compared the S1B gene sequences of the Québec BCV isolates to the published corresponding sequences from BCV-L9 [37], BCV-MEB [1], and BCV-F15 [3] reference strains. A high degree of similarity was demonstrated for all viruses, no deletions or insertions were observed, and the only variations that were identified consisted of nucleotide substitutions. The differing nucleotides and amino acids (aa) were not distributed randomly over the entire sequence but rather were clustered in the polymorphic region. Of these, four sporadic aa changes were located in antigenic domain II (aa residues 517 to 720) of S1. This correlates with varied antigenicity observed among the BCV Québec isolates when reacting with MAbs directed against the S glycoprotein of the Mebus strain. The other mutations seem to be fixed in all Québec isolates.
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Affiliation(s)
- M R Rekik
- Centre de recherche en virologie, Institut Armand-Frappier, Université du Québec Laval, Canada
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Abstract
Seven fragments of the spike (S) gene cDNA of transmissible gastroenteritis virus (TGEV), as well as the full length cDNA, were cloned and expressed in baculovirus vectors. Piglets were immunized with cells infected with the recombinant viruses. Each of the recombinants induced TGEV-specific antibodies detected in a fixed cell enzyme immunoassay. The amino terminal half of the S protein, containing all four major antigenic sites (A, B, C and D), and encoded by a 2.2 kb fragment of the S gene, induced virus neutralizing (VN) antibody titers comparable with those induced by the complete S protein. Recombinant proteins lacking the A antigenic site, or with a deletion including the putative receptor binding sites and the D antigenic site, were not capable of inducing levels of VN antibodies similar to those induced by the whole S protein.
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Affiliation(s)
- T Tuboly
- Department of Veterinary Microbiology and Immunology, University of Guelph, Ontario, Canada
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Abstract
Feline infectious peritonitis (FIP) has been an elusive and frustrating problem for veterinary practitioners and cat breeders for many years. Over the last several years, reports have begun to elucidate aspects of the molecular biology of the causal virus (FIPV). These papers complement a rapidly growing base of knowledge concerning the molecular organization and replication of coronaviruses in general. The fascinating immunopathogenesis of FIPV infection and the virus' interaction with macrophages has also been the subject of several recent papers. It is now clear that FIPV may be of interest to scientists other than veterinary virologists since its pathogenesis may provide a useful model system for other viruses whose infectivity is enhanced in the presence of virus-specific antibody. With these advances and the recent release of the first commercially-available FIPV vaccine, it is appropriate to review what is known about the organization and replication of coronaviruses and the pathogenesis of FIPV infection.
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Affiliation(s)
- C W Olsen
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison
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Abstract
This review aims to summarize current data describing the characteristics of bovine coronavirus (BCV) and the three clinical syndromes with which this virus is associated. The first half of this paper consists of a general description of the virus, commencing with a brief outline of the methods used for in vitro growth. The structure of the virus is then described in more detail, with particular reference to the structure and functions of the four major viral proteins. This is followed by an outline of the unique replication strategy adopted by coronaviruses. The second half of this review discusses the clinical significance of the virus, beginning with a detailed account of BCV-induced neonatal calf diarrhoea, the clinical syndrome with which this virus is most commonly associated. The clinical and epidemiological importance of BCV respiratory tract infection is then discussed, and finally the evidence supporting the aetiological role of BCV in outbreaks of winter dysentery in adult cattle is examined.
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Affiliation(s)
- M A Clark
- Department of Physiological Sciences, Medical School, University of Newcastle upon Tyne
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Abstract
Twenty monoclonal antibodies (MAbs) were prepared against the Mebus strain of bovine enteric coronavirus, 14 of them reacting with the peplomeric S (gp 100) glycoprotein. Competition binding assays allowed the definition of at least 4 distinct antigenic domains for the S glycoprotein, designated as A, B, C, and D; epitopes associated to neutralizing activity being located in sites A, B, and C. One MAb directed to the hemagglutinin HE (gp 140/gp 65) glycoprotein inhibited the hemagglutinating activity of the virus, but had no neutralizing activity. Comparison of Quebec enteropathogenic BCV isolates using polyclonal antiserum and MAbs directed to the S glycoprotein confirmed their close antigenic relationship, but also revealed the occurrence of at least three distinct antigenic subgroups. Antigenic domain D was highly conserved among BCV isolates, as well as non-neutralizing epitopes assigned to antigenic domains A and C. The Minnesota strain of turkey enteric coronavirus could be distinguished from BCV isolates by MAbs directed to epitopes of antigenic domain C, whereas human coronavirus HCV-OC 43 could be distinguished by MAbs directed to epitopes of antigenic domain A. The porcine hemagglutinating encephalomyelitis virus could be distinguished from the other hemagglutinating coronaviruses by neutralizing epitopes located on antigenic domains A, B, and C.
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Affiliation(s)
- L Michaud
- Centre de Recherche en Virologie, Institut Armand-Frappier, Université du Québec, Laval-des-Rapides, Canada
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