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The porcine microRNA transcriptome response to transmissible gastroenteritis virus infection. PLoS One 2015; 10:e0120377. [PMID: 25781021 PMCID: PMC4363316 DOI: 10.1371/journal.pone.0120377] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 01/20/2015] [Indexed: 11/26/2022] Open
Abstract
Transmissible gastroenteritis virus (TGEV; Coronaviridae family) causes huge economic losses to the swine industry. MicroRNAs (miRNAs) play a regulatory role in viral infection and may be involved in the mammalian immune response. Here, we report a comprehensive analysis of host miRNA expression in TGEV-infected swine testis (ST) cells. Deep sequencing generated 3,704,353 and 2,763,665 reads from uninfected ST cells and infected ST cells, respectively. The reads were aligned to known Sus scrofa pre-miRNAs in miRBase 19, identifying 284 annotated miRNAs. Certain miRNAs were differentially regulated during TGEV infection. 59 unique miRNAs displayed significant differentially expression between the normal and TGEV-infected ST cell samples: 15 miRNAs were significantly up-regulated and 44 were significantly down-regulated. Stem-loop RT-PCR was carried out to determine the expression levels of specific miRNAs in the two samples, and the results were consistent with those of sequencing. Gene ontology enrichment analysis of host target genes demonstrated that the differentially expressed miRNAs are involved in regulatory networks, including cellular process, metabolic process, immune system process. This is the first report of the identification of ST cell miRNAs and the comprehensive analysis of the miRNA regulatory mechanism during TGEV infection, which revealed the miRNA molecular regulatory mechanisms for the viral infection, expression of viral genes and the expression of immune-related genes. The results presented here will aid research on the prevention and treatment of viral diseases.
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Lőrincz M, Biksi I, Andersson S, Cságola A, Tuboly T. Sporadic re-emergence of enzootic porcine transmissible gastroenteritis in Hungary. Acta Vet Hung 2014; 62:125-33. [PMID: 23974941 DOI: 10.1556/avet.2013.043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Transmissible gastroenteritis (TGE) is a coronavirus-induced disease of pigs, characterised by diarrhoea and vomiting. The incidence of the disease had been decreasing since the late 1980s when deletion mutant variants (porcine respiratory coronavirus, PRCoV) of the virus emerged, repressing TGE gradually. Although disease manifestations are infrequent, the virus is still present in pig herds, causing sporadic outbreaks in a milder form. Identification and characterisation of the spike genes from TGEV and PRCoV, detected in such outbreaks, were performed in Hungary. Analysis of the amplified partial gene sequences showed that TGEV was present in herds with TGE clinical signs together with PRCoV. The sequences, apart from the deletions in PRCoV, were identical and at least two types of PRCoV spike proteins could be identified based on the length of the deleted sequence.
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Affiliation(s)
- Márta Lőrincz
- 1 Szent István University Department of Microbiology and Infectious Diseases, Faculty of Veterinary Science Hungária krt. 23-25 H-1143 Budapest Hungary
| | - Imre Biksi
- 2 Szent István University Large Animal Clinic, Faculty of Veterinary Science Dóra major Üllő Hungary
| | - Simon Andersson
- 1 Szent István University Department of Microbiology and Infectious Diseases, Faculty of Veterinary Science Hungária krt. 23-25 H-1143 Budapest Hungary
| | - Attila Cságola
- 1 Szent István University Department of Microbiology and Infectious Diseases, Faculty of Veterinary Science Hungária krt. 23-25 H-1143 Budapest Hungary
| | - Tamás Tuboly
- 1 Szent István University Department of Microbiology and Infectious Diseases, Faculty of Veterinary Science Hungária krt. 23-25 H-1143 Budapest Hungary
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3
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An Oral Vaccine for TGEV Immunization of Pigs. COMMERCIAL PLANT-PRODUCED RECOMBINANT PROTEIN PRODUCTS 2014. [PMCID: PMC7120389 DOI: 10.1007/978-3-662-43836-7_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Transmissible gastroenteritis virus (TGEV) is a commercially important pathogen of hog farms and causes contagious, lethal diarrhea in piglets. While orally and parenterally administered vaccines made from inactivated or attenuated TGEV are commercially available, they require individual administration to piglets, which is time and labor intensive, and run the risk of reversion to pathogenicity. Also, parenteral vaccines produce neutralizing serum antibodies which may be less effective against an orally transmitted pathogen, compared to an oral vaccine that would induce the production of mucosal antibodies. There has been an effort to produce subunit vaccines in an edible form in plants for convenient administration through feed. These efforts towards the expression of the S-antigen of TGEV in maize seed, its effectiveness at inducing neutralizing antibody production in the colostrum of gilts, and its efficacy in protecting piglets against challenge by virulent TGEV are summarized here.
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Di-qiu L, Xin-yuan Q, Jun-wei G, Li-jie T, Yan-ping J, Yi-jing L. Construction and characterization of Lactobacillus pentosus expressing the D antigenic site of the spike protein of Transmissible gastroenteritis virus. Can J Microbiol 2011; 57:392-7. [DOI: 10.1139/w11-027] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
This study explored the feasibility of Lactobacillus pentosus as a live vehicle to deliver and express antigen. First of all, L. pentosus transformed by electroporation with the plasmids pg611-6D (anchored) and pg612-6D (secretory) based on the xylose operon generated the recombinant strains rLppg611-6D and rLppg612-6D, respectively, expressing the D antigenic site of the spike (S) protein of Transmissible gastroenteritis virus (TGEV), for intragastric administration in mice. Secondly, we collected serum, fecal, nasal, ophthalmic, and vaginal samples from pre-immune mice and after the first immunization (on days 7, 14, 21, 28, 35, and 42) that were used to analyze the levels of immunoglobulins G and A against TGEV by using ELISA. In addition, a plaque reduction assay was performed using sera from groups pg611, pg612-6D, pg11-6D, and phosphate-buffered saline (blank control) to analyze TGEV-neutralizing antibody activity in vitro. A statistically significant difference in serum tests between groups demonstrated that rLppg612-6D induced better immunogenicity than rLppg611-6D, making rLppg612-6D the better candidate for oral vaccine. Taken together, L. pentosus possessed the potential to become a novel vector for mucosal vaccine in the future.
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Affiliation(s)
- Liu Di-qiu
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northeast Agricultural University, 59 Mucai Street, Harbin 150030, the People’s Republic of China
- Key Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, the People’s Republic of China
| | - Qiao Xin-yuan
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northeast Agricultural University, 59 Mucai Street, Harbin 150030, the People’s Republic of China
| | - Ge Jun-wei
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northeast Agricultural University, 59 Mucai Street, Harbin 150030, the People’s Republic of China
| | - Tang Li-jie
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northeast Agricultural University, 59 Mucai Street, Harbin 150030, the People’s Republic of China
| | - Jiang Yan-ping
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northeast Agricultural University, 59 Mucai Street, Harbin 150030, the People’s Republic of China
| | - Li Yi-jing
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northeast Agricultural University, 59 Mucai Street, Harbin 150030, the People’s Republic of China
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5
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Yin J, Glende J, Schwegmann-Wessels C, Enjuanes L, Herrler G, Ren X. Cholesterol is important for a post-adsorption step in the entry process of transmissible gastroenteritis virus. Antiviral Res 2010; 88:311-6. [PMID: 20951168 PMCID: PMC7114218 DOI: 10.1016/j.antiviral.2010.10.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2010] [Revised: 10/05/2010] [Accepted: 10/05/2010] [Indexed: 12/13/2022]
Abstract
Cholesterol is a major constituent of detergent-resistant membrane microdomains (DRMs). We localized transmissible gastroenteritis virus (TGEV) spike (S) protein in DRMs in the viral envelope. Though S protein was not solubilized by cold non-ionic detergents, this behavior was unchanged when cholesterol was depleted from viral membrane by methyl-β-cyclodextrin (MβCD) and the protein did not comigrate with cellular DRM marker proteins in flotation analyses. Therefore, the S protein is not anchored in the viral membrane DRMs as they are known to occur in the plasma membrane. Cholesterol depletion from viral membrane may not affect the adsorption process as neither the sialic acid binding activity nor the binding to aminopeptidase N was reduced post-MβCD treatment. Reduced infectivity of cholesterol-depleted TGEV was observed only when the adsorption process occurred at 37 °C but not when the virus was applied at 4 °C. Cholesterol is important for a post-adsorption step, allowing membrane rearrangements that facilitate virus entry.
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Affiliation(s)
- Jiechao Yin
- Northeast Agricultural University, Harbin, China
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6
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López L, Venteo A, García M, Camuñas A, Ranz A, García J, Sarraseca J, Anaya C, Rueda P. Antigen-Capture Blocking Enzyme-Linked Immunosorbent Assay Based on a Baculovirus Recombinant Antigen to Differentiate Transmissible Gastroenteritis Virus from Porcine Respiratory Coronavirus Antibodies. J Vet Diagn Invest 2009; 21:598-608. [DOI: 10.1177/104063870902100503] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
A new commercially available antigen-capture, blocking enzyme-linked immunosorbent assay (antigen-capture b-ELISA), based on baculovirus truncated-S recombinant protein of Transmissible gastroenteritis virus (TGEV) and 3 specific monoclonal antibodies, was developed and evaluated by examining a panel of 453 positive Porcine respiratory coronavirus (PRCoV), 31 positive TGEV, and 126 negative field sera by using another commercially available differential coronavirus b-ELISA as the reference technique to differentiate TGEV- from PRCoV-induced antibodies. The recombinant S protein-based ELISA appeared to be 100% sensitive for TGEV and PRCoV detection and highly specific for TGEV and PRCoV detection (100% and 92.06%, respectively), when qualitative results (positive or negative) were compared with those of the reference technique. In variability experiments, the ELISA gave consistent results when the same serum was evaluated on different wells and different plates. These results indicated that truncated recombinant S protein is a suitable alternative to the complete virus as antigen in ELISA assays. The use of recombinant S protein as antigen offers great advantages because it is an easy-to-produce, easy-to-standardize, noninfectious antigen that does not require further purification or concentration. Those advantages represent an important improvement for antigen preparation, in comparison with other assays in which an inactivated virus from mammalian cell cultures is used.
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Affiliation(s)
| | - Angel Venteo
- Inmunología y Genética Aplicada S.A., Madrid, Spain
| | - Marga García
- Inmunología y Genética Aplicada S.A., Madrid, Spain
| | - Ana Camuñas
- Inmunología y Genética Aplicada S.A., Madrid, Spain
| | - Ana Ranz
- Inmunología y Genética Aplicada S.A., Madrid, Spain
| | - Julia García
- Inmunología y Genética Aplicada S.A., Madrid, Spain
| | | | - Carmen Anaya
- Inmunología y Genética Aplicada S.A., Madrid, Spain
| | - Paloma Rueda
- Inmunología y Genética Aplicada S.A., Madrid, Spain
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Yang H, Cao S, Huang X, Liu J, Tang Y, Wen X. Intragastric administration of attenuated Salmonella typhimurium harbouring transmissible gastroenteritis virus (TGEV) DNA vaccine induced specific antibody production. Vaccine 2009; 27:5035-40. [PMID: 19573642 PMCID: PMC7126841 DOI: 10.1016/j.vaccine.2009.06.050] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2009] [Revised: 05/03/2009] [Accepted: 06/10/2009] [Indexed: 11/17/2022]
Abstract
Attenuated Salmonella typhimurium was selected as a transgenic vehicle for the development of live mucosal vaccines against transmissible gastroenteritis virus (TGEV). A 2.2kb DNA fragment, encoding for N-terminal domain glycoprotein S of TGEV, was amplified by RT-PCR and cloned into eukaryotic expression vector pVAX1. The recombinant plasmid pVAX-S was transformed by electroporation into attenuated S. typhimurium SL7207, the expression and translation of the pVAX-S delivered by recombinant S. typhimurium SL7207 (pVAX-S) was detected in vitro and in vivo respectively. BALB/c mice were inoculated orally with SL7207 (pVAX-S) at different dosages, the bacterium was safe to mice at dosage of 2x10(9)CFU and eventually eliminated from the spleen and liver at week 4 post-immunization. Mice immunized with different dosages of SL7207 (pVAX-S) elicited specific anti-TGEV local mucosal and humoral responses as measured by indirect ELISA assay. Moreover, the immunogenicity of the DNA vaccine was highly dependent on the dosage of the attenuated bacteria used for oral administration, 10(9)CFU dosage group showed higher antibody response than 10(8)CFU and 10(7)CFU dosages groups during week 4-8 post-immunization. The results indicated that attenuated S. typhimurium could be used as a delivery vector for oral immunization of TGEV DNA vaccine.
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Affiliation(s)
- Heng Yang
- Sichuan Agricultural University, Ya'an, China
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Yin J, Ren X, Tian Z, Li Y. Assembly of pseudorabies virus genome-based transfer vehicle carrying major antigen sites of S gene of transmissible gastroenteritis virus: potential perspective for developing live vector vaccines. Biologicals 2006; 35:55-61. [PMID: 16731004 PMCID: PMC7128284 DOI: 10.1016/j.biologicals.2006.02.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2005] [Revised: 12/20/2005] [Accepted: 02/01/2006] [Indexed: 01/08/2023] Open
Abstract
Two severe porcine infectious diseases, pseudorabies (PR) and transmissible gastroenteritis (TGE) caused by pseudorabies virus (PRV) and transmissible gastroenteritis virus (TGEV) respectively often result in serious economic loss in animal husbandry worldwide. Vaccination is the important prevention means against both infections. To achieve a PRV genome-based virus live vector, aiming at further TGEV/PRV bivalent vaccine development, a recombinant plasmid pUG was constructed via inserting partial PK and full-length gG genes of PRV strain Bartha K-61 amplified into pUC119 vector. In parallel, another recombinant pHS was generated by introducing a fragment designated S1 encoding the major antigen sites of S gene from TGEV strain TH-98 into a prokaryotic expression vector pPROEX HTc. The SV40 polyA sequence was then inserted into the downstream of S1 fragment of pHS. The continuous region containing S1fragment, SV40 polyA and four single restriction enzyme sites digested from pHS was subcloned into the downstream of gG promoter of pUG. In addition, a LacZ reporter gene was introduced into the universal transfer vector named pUGS-LacZ. Subsequently, a PRV genome-based virus live vector was generated via homologous recombination. The functionally effective vector was purified and partially characterized. Moreover, the potential advantages of this system are discussed.
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Affiliation(s)
- Jiechao Yin
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northeast Agricultural University, 59 Mucai Street, 150030 Harbin, PR China
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Mason HS, Chikwamba R, Santi L, Mahoney RT, Arntzen CJ. Transgenic Plants for Mucosal Vaccines. Mucosal Immunol 2005. [PMCID: PMC7150293 DOI: 10.1016/b978-012491543-5/50062-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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10
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Bukreyev A, Lamirande EW, Buchholz UJ, Vogel LN, Elkins WR, St Claire M, Murphy BR, Subbarao K, Collins PL. Mucosal immunisation of African green monkeys (Cercopithecus aethiops) with an attenuated parainfluenza virus expressing the SARS coronavirus spike protein for the prevention of SARS. Lancet 2004; 363:2122-7. [PMID: 15220033 PMCID: PMC7112367 DOI: 10.1016/s0140-6736(04)16501-x] [Citation(s) in RCA: 213] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND The outbreak of severe acute respiratory syndrome (SARS) in 2002 was caused by a previously unknown coronavirus-SARS coronavirus (SARS-CoV). We have developed an experimental SARS vaccine for direct immunisation of the respiratory tract, the major site of SARS- coronavirus transmission and disease. METHODS We expressed the complete SARS coronavirus envelope spike (S) protein from a recombinant attenuated parainfluenza virus (BHPIV3) that is being developed as a live attenuated, intranasal paediatric vaccine against human parainfluenza virus type 3 (HPIV3). We immunised eight African green monkeys, four with a single dose of BHPIV3/ SARS-S and four with a control, BHPIV3/Ctrl, administered via the respiratory tract. A SARS-coronavirus challenge was given to all monkeys 28 days after immunisation. FINDINGS Immunisation of animals with BHPIV3/SARS-S induced the production of SARS-coronavirus-neutralising serum antibodies, indicating that a systemic immune response resulted from mucosal immunisation. After challenge with SARS coronavirus, all monkeys in the control group shed SARS coronavirus, with shedding lasting 5-8 days. No viral shedding occurred in the group immunised with BHPIV3/SARS-S. INTERPRETATION A vectored mucosal vaccine expressing the SARS-coronavirus S protein alone may be highly effective in a single-dose format for the prevention of SARS.
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Affiliation(s)
- Alexander Bukreyev
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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Tuboly T, Nagy É. Construction and characterization of recombinant porcine adenovirus serotype 5 expressing the transmissible gastroenteritis virus spike gene. J Gen Virol 2001; 82:183-190. [PMID: 11125171 DOI: 10.1099/0022-1317-82-1-183] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Five recombinant porcine adenoviruses of serotype 5 (PAdV-5) carrying the full-length or the 5' 2.2 kb half of the transmissible gastroenteritis virus (TGEV) spike (S) gene were generated by homologous recombination in E. coli strain BJ5183 cells and subsequent transfection of swine testicle cells. The foreign genes were inserted into the E3 region of PAdV-5. One recombinant virus had no deletion in the E3 region, whereas a 1.2 kb fragment was removed from the E3 region in the remainder of the recombinant viruses. One stable construct with a 4.4 kb insertion had a genome size of 109.6% of the wild-type genome, the largest reported for any recombinant adenovirus. Only those viruses that carried the S gene in the left to right orientation expressed the S gene. Three recombinant viruses were tested by oral immunization of pigs and both antibody response and virus shedding were monitored. None of the pigs showed clinical signs and the virus was recovered from rectal swabs until 6-7 days post-infection. Viruses expressing the S gene induced TGEV- and PAdV-5-specific virus-neutralizing antibodies. Moreover, TGEV-specific secretory IgA was detected in the small intestine and in the lungs of the immunized animals.
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Affiliation(s)
- Tamás Tuboly
- Veterinary Medical Research Institute of the Hungarian Academy of Sciences, Budapest, Hungary1
| | - Éva Nagy
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, Ontario, CanadaN1G 2W12
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12
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Tuboly T, Yu W, Bailey A, Degrandis S, Du S, Erickson L, Nagy E. Immunogenicity of porcine transmissible gastroenteritis virus spike protein expressed in plants. Vaccine 2000; 18:2023-8. [PMID: 10706964 DOI: 10.1016/s0264-410x(99)00525-3] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Transgenic plants expressing recombinant proteins from pathogenic microorganisms provide an inexpensive edible vaccine for induction of local immunity. Three transgenic plant lines were generated expressing the spike (S) protein of transmissible gastroenteritis virus (TGEV), a protein crucial for establishing mucosal immunity. All three of them were driven by a strong plant promoter. One construct contained the 3.7 kb 5' end of the native S gene sequence. In the second construct part of the S gene, from nucleotide 49 to 1785, was modified for optimal plant recognition and was fused to a plant signal peptide coding sequence. The third construct contained the D epitope-coding region of the S gene, from nucleotide 1201 to 1591, which was fused to the alfalfa beta-amylase gene. The S gene products were detected by enzyme-linked immunosorbent assay (ELISA) and Western blotting. Antigens from all three transgenic plant lines induced TGEV-specific immune responses in pigs as determined by virus neutralization and ELISA, and the resultant antibody titers for all three constructs were similar.
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MESH Headings
- Animals
- Antibodies, Viral/biosynthesis
- Antibodies, Viral/blood
- Antigens, Viral/genetics
- Enzyme-Linked Immunosorbent Assay
- Gastroenteritis, Transmissible, of Swine/immunology
- Gastroenteritis, Transmissible, of Swine/prevention & control
- Gene Expression
- Genes, Viral
- Genetic Vectors
- Neutralization Tests
- Plants, Genetically Modified
- Plants, Toxic
- Recombinant Proteins/genetics
- Recombinant Proteins/immunology
- Swine
- Nicotiana/genetics
- Transmissible gastroenteritis virus/genetics
- Transmissible gastroenteritis virus/immunology
- Transmissible gastroenteritis virus/pathogenicity
- Vaccines, Synthetic/genetics
- Vaccines, Synthetic/immunology
- Viral Proteins/genetics
- Viral Proteins/immunology
- Viral Vaccines/genetics
- Viral Vaccines/immunology
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Affiliation(s)
- T Tuboly
- Department of Pathobiology, University of Guelph, Guelph, Canada
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13
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Sestak K, Zhou Z, Shoup DI, Saif LJ. Evaluation of the baculovirus-expressed S glycoprotein of transmissible gastroenteritis virus (TGEV) as antigen in a competition ELISA to differentiate porcine respiratory coronavirus from TGEV antibodies in pigs. J Vet Diagn Invest 1999; 11:205-14. [PMID: 10353350 DOI: 10.1177/104063879901100301] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The spike (S) glycoprotein of the Miller strain of transmissible gastroenteritis virus (TGEV) was recently cloned and expressed in baculovirus. The recombinant S protein was used as the coating antigen in a competition (blocking) enzyme-linked immunosorbent assay (ELISA) in combination with monoclonal antibodies to the S protein epitope A (conserved on TGEV and porcine respiratory coronavirus [PRCV]) or epitope D (present on TGEV only) to differentiate PRCV- from TGEV-induced antibodies. One set (set A) of 125 serum samples were collected at different times after inoculation of caesarean-derived, colostrum-deprived (n = 52) and conventional young pigs (n = 73) with 1 of the 2 porcine coronaviruses or uninoculated negative controls (TGEV/PRCV/negative = 75/30/20). A second set (set B) of 63 serum samples originated from adult sows inoculated with PRCV and the recombinant TGEV S protein or with mock-protein control and then exposed to virulent TGEV after challenge of their litters. Sera from set A were used to assess the accuracy indicators (sensitivity, specificity, accuracy) of the fixed-cell blocking ELISA, which uses swine testicular cells infected with the M6 strain of TGEV as the antigen source (ELISA 1) and the newly developed ELISA based on the recombinant S protein as antigen (ELISA 2). The sera from set B (adults) were tested for comparison. The plaque reduction virus neutralization test was used as a confirmatory test for the presence of antibodies to TGEV/PRCV in the test sera. The accuracy indicators for both ELISAs suggest that differential diagnosis can be of practical use at least 3 weeks after inoculation by testing the dual (acute/convalescent) samples from each individual in conjunction with another confirmatory (virus neutralization) antibody assay to provide valid and complete differentiation information. Moreover, whereas ELISA 1 had 10-20% false positive results to epitope D for PRCV-infected pigs (set A samples), no false-positive results to epitope D occurred using ELISA 2, indicating its greater specificity. The progression of seroresponses to the TGEV S protein epitopes A or D, as measured by the 2 ELISAs, was similar for both sets (A and B) of samples. Differentiation between TGEV and PRCV antibodies (based on seroresponses to epitope D) was consistently measured after the third week of inoculation.
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Affiliation(s)
- K Sestak
- Department of Veterinary Preventive Medicine, Ohio Agricultural Research and Development Center, Ohio State University, Wooster 44691, USA
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14
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Abstract
Several small and large viruses (e.g., adenovirus, poxvirus, and herpesviruses) have been investigated as vaccine vectors. Each viral system has its advantages and disadvantages. One major advantage for viral vector vaccines is their ability to elicit a protective cell-mediated immunity as well as a humoral response to the antigen delivered by the vector. One major problem to using recombinant viruses as vaccines is the pathogenic potential of the parent virus. Therefore, it is important that along with the optimal expression of the foreign genes and ability to provide protection, the pathogenicity of the vector virus must be reduced during genetic manipulation without affecting its multiplication. The requirements to develop a viral vector, for example, swinepox virus, are a cell culture system that will support the growth of the virus, a suitable nonessential region(s) in the virus genome for insertion of foreign DNA so that virus replication is not affected, a foreign gene(s) that encodes for an immunogenic protein of a swine pathogen, strong transcriptional regulatory elements (promoters) necessary for optimal expression of the foreign genes, a procedure for delivering the foreign gene(s) into the nonessential locus, and a convenient method of distinguishing the recombinant viruses from the parent wild-type virus. Using this methodology, recombinant swinepox virus vaccines expressing pseudorabies virus antigens have been developed and shown to provide protection against challenge. These studies and evidence of local infection of the oral tract by swinepox virus indicate its potential as a recombinant vector for providing immunity against various swine pathogens including those that infect the respiratory and gastrointestinal tracts.
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Affiliation(s)
- D N Tripathy
- Department of Veterinary Pathobiology, University of Illinois, Urbana 61802, USA
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15
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Abstract
Swine testis (ST) cell cultures were treated with various doses of recombinant human interferon-alpha 2a (IFN), and assayed for 2',5' oligoadenylate synthetase (2-5 A synthetase) activity. Treatment with 100 or 1000 units/ml of IFN resulted in increased 2-5 A synthetase activity, but there was no significant response to 1 unit/ml of IFN. Titres of porcine transmissible gastroenteritis virus (TGEV) were reduced between 6 and 15 hours post-infection in ST cells treated with 1000 or 2500 units/ml of IFN. Polyacrylamide gel electrophoresis of lysates of TGEV-infected ST cells, and of lysates immunoprecipitated with anti-TGEV antibodies, revealed that the synthesis of the N and S proteins of TGEV was reduced in cells treated with 100 or 1000 units/ml of IFN. Viral RNA production, as determined with a probe which hybridized to the S gene of TGEV, was found to be reduced in ST cells treated with 1000 units/ml of IFN, but not in cells treated with 100 units/ml. It was concluded that, in IFN-treated ST cells, TGEV protein production may be decreased in the absence of reduced viral RNA production, and that 2-5 A synthetase may not be a significant factor in the antiviral activity of IFN against TGEV.
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Affiliation(s)
- L T Jordan
- Department of Veterinary Microbiology and Immunology, University of Guelph, Canada
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16
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Tuboly T, Nagy E, Derbyshire JB. Passive protection of piglets by recombinant baculovirus induced transmissible gastroenteritis virus specific antibodies. CANADIAN JOURNAL OF VETERINARY RESEARCH = REVUE CANADIENNE DE RECHERCHE VETERINAIRE 1995; 59:70-2. [PMID: 7704846 PMCID: PMC1263737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Sera of pigs immunized with parts of the transmissible gastroenteritis virus (TGEV) spike (S) protein expressed by recombinant baculoviruses were tested, together with a TGEV hyperimmune antiserum, for their abilities to protect three-day-old piglets against TGEV infection. The piglets were infected with virulent TGEV and the sera were given orally 3 h before infection, together with the virus, and every 6 h postinfection during the 30 h of the experiment. Virus shedding was monitored by TGEV isolation from rectal swab samples. The sera containing antibodies induced by the complete S protein or the amino terminal half of the S protein showed protective properties, indicated by delayed onset of clinical signs and virus shedding, similar to the TGEV hyperimmune serum. Those immune sera containing antibodies induced by shorter recombinant proteins were not protective.
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Affiliation(s)
- T Tuboly
- Department of Veterinary Microbiology and Immunology, Ontario Veterinary College, University of Guelph, Ontario
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