Evaluation of virulence reversion of an attenuated porcine epidemic diarrhea vaccine strain by serial passages in suckling piglets
2
조회
0
다운로드
0
인용
0
참고문헌
키워드
초록
Porcine epidemic diarrhea is an infectious intestinal disease caused by the porcine epidemic diarrhea virus (PEDV). Especially, when suckling piglets are infected, the mortality rate is close to 100%. PEDV is classified into G1 and G2 types based on genetic differences. The G2 type PEDV outbreak in the United States in 2013 was highly pathogenic and contagious, and it has spread worldwide and caused continuous economic losses. Most commercial vaccines used are G1 type vaccines, and existing vaccines do not fully protect piglets due to genetic differences. In this study, we evaluated the safety of the newly developed G2 type attenuated HSGP vaccine strain by inoculating it into piglets and testing whether the vaccine virus spreads to the non-vaccinated, negative pigs and whether the vaccine reverts to its virulence during serial passage experiments. Each experiment lasted for 7 days for each passage, and fecal viral titers, clinical symptoms, and weight gain were measured daily. After the experiment, necropsy was performed to measure intestinal virus titer and pathological evaluation. As a result of the first passage, no transmission of the vaccine virus to negative pigs co-housed with vaccinated pigs was observed. In addition, after four consecutive passage experiments, the clinical symptoms and small intestine lesions were gradually alleviated, and no virus was detected in the feces in the fourth passage experiment. Therefore, it was concluded that the vaccine was safe without virulence reversion in accordance with the guidelines of the current licensing authority. However, further studies are needed on the genetic changes and biological characteristics of the mutant virus that occur during successive passages of the attenuated vaccine since the replication and clinical symptoms of the virus increased until the third passage during successive passages of the vaccine virus. Based on this study, it was concluded that virulence reversion and safety evaluation of attenuated vaccines through serial passage in target animals can be useful to evaluate the safety of attenuated viruses.
Abstract
Porcine epidemic diarrhea is an infectious intestinal disease caused by the porcine epidemic diarrhea virus (PEDV). Especially, when suckling piglets are infected, the mortality rate is close to 100%. PEDV is classified into G1 and G2 types based on genetic differences. The G2 type PEDV outbreak in the United States in 2013 was highly pathogenic and contagious, and it has spread worldwide and caused continuous economic losses. Most commercial vaccines used are G1 type vaccines, and existing vaccines do not fully protect piglets due to genetic differences. In this study, we evaluated the safety of the newly developed G2 type attenuated HSGP vaccine strain by inoculating it into piglets and testing whether the vaccine virus spreads to the non-vaccinated, negative pigs and whether the vaccine reverts to its virulence during serial passage experiments. Each experiment lasted for 7 days for each passage, and fecal viral titers, clinical symptoms, and weight gain were measured daily. After the experiment, necropsy was performed to measure intestinal virus titer and pathological evaluation. As a result of the first passage, no transmission of the vaccine virus to negative pigs co-housed with vaccinated pigs was observed. In addition, after four consecutive passage experiments, the clinical symptoms and small intestine lesions were gradually alleviated, and no virus was detected in the feces in the fourth passage experiment. Therefore, it was concluded that the vaccine was safe without virulence reversion in accordance with the guidelines of the current licensing authority. However, further studies are needed on the genetic changes and biological characteristics of the mutant virus that occur during successive passages of the attenuated vaccine since the replication and clinical symptoms of the virus increased until the third passage during successive passages of the vaccine virus. Based on this study, it was concluded that virulence reversion and safety evaluation of attenuated vaccines through serial passage in target animals can be useful to evaluate the safety of attenuated viruses.
참고문헌 (37)
- Baudoux P, "Coronavirus pseudoparticles formed with recombinant M and E proteins induce alpha interferon synthesis by leukocytes", J Virol, 72, pp.8636~8643 (1998)
- Beall A, "Characterization of a pathogenic full-length cDNA clone and transmission model for porcine epidemic diarrhea virus strain PC22A", mBio, 7, pp.10~1128 (2016)
- Bosch BJ, "The coronavirus spike protein is a class I virus fusion protein : structural and functional characterization of the fusion core complex", J Virol, 77, pp.8801~8811 (2003)
- Cavanagh D, "Nidovirales : a new order comprising Coronaviridae and Arteriviridae", Arch Virol, 142, pp.629~633 (1997)
- Sun-Hwa Chang, "Identification of the Epitope Region Capable of Inducing Neutralizing Antibodies against the Porcine Epidemic Diarrhea Virus", Molecules and Cells, 14(2), pp.295~299 (2002), 한국분자세포생물학회
- de Haan CA, "Mapping of the coronavirus membrane protein domains involved in interaction with the spike protein", J Virol, 73, pp.7441~7452 (1999)
- de Haan CA, "Assembly of the coronavirus envelope : homotypic interactions between the M proteins", J Virol, 74, pp.4967~4978 (2000)
- Debouck P, "Experimental infection of pigs with a new porcine enteric coronavirus, CV777", Am J Vet Res, 41, pp.219~223 (1980)
- Duarte M, "Sequence analysis of the porcine epidemic diarrhea virus genome between the nucleocapsid and spike protein genes reveals a polymorphic ORF", Virology, 198, pp.466~476 (1994)
- Godet M, "Major receptor-binding and neutralization determinants are located within the same domain of the transmissible gastroenteritis virus(coronavirus)spike protein", J Virol, 68, pp.8008~8016 (1994)
- Horzinek MC, "Characterization of the structural proteins of porcine epizootoc diarrhea virus, strain CV777", Am J Vet Res, 49, pp.1320~1324 (1988)
- Huang YW, "Origin, evolution, and genotyping of emergent porcine epidemic diarrhea virus strains in the United States", mBio, 4, pp.10~1128 (2013)
- Jackwood MW, "Spike glycoprotein cleavage recognition site analysis of infectious bronchitis virus", Avian Dis, pp.366~372 (2001)
- Jang G, "Assessment of the safety and efficacy of an attenuated live vaccine based on highly virulent genotype 2b porcine epidemic diarrhea virus in nursing piglets", Vet Microbiol, 231, pp.120~128 (2019)
- Kim SH, "Genetic characterization of porcine epidemic diarrhea virus in Korea from 1998 to 2013", Arch Virol, 160, pp.1055~1064 (2015)
- Klumperman J, "Coronavirus M proteins accumulate in the Golgi complex beyond the site of virion budding", J Virol, 68, pp.6523~6534 (1994)
- Kocherhans R, "Completion of the porcine epidemic diarrhoea coronavirus(PEDV)genome sequence", Virus Genes, 23, pp.137~144 (2001)
- Kweon CH, "Isolation of porcine epidemic diarrhea virus(PEDV)in Korea", Korean J Vet Serv, 33, pp.249~254 (1993)
- Lee C, "Porcine epidemic diarrhea virus : an emerging and re-emerging epizootic swine virus", Virol J, 12, pp.1~16 (2015)
- Li W, "New variants of porcine epidemic diarrhea virus, China, 2011", Emerg Infect Dis, 18, pp.1350~ (2012)
- McBride R, "The coronavirus nucleocapsid is a multifunctional protein", Viruses, 6, pp.2991~3018 (2014)
- Nguyen VP, "Protein interactions during coronavirus assembly", J Virol, 71, pp.9278~9284 (1997)
- Opstelten DJ, "Envelope glycoprotein interactions in coronavirus assembly", J Cell Biol, 131, pp.339~349 (1995)
- Pensaert MB, "A new coronavirus-like particle associated with diarrhea in swine", Arch Virol, 58, pp.243~247 (1978)
- Pensaert MB, "Porcine epidemic diarrhea : a retrospect from Europe and matters of debate", Virus Res, 226, pp.1~6 (2016)
- Sato T, "Mutations in the spike gene of porcine epidemic diarrhea virus associated with growth adaptation in vitro and attenuation of virulence in vivo", Virus Genes, 43, pp.72~78 (2011)
- Song D, "Porcine epidemic diarrhea : a review of current epidemiology and available vaccines", Clin Exp Vaccine Res, 4, pp.166~176 (2015)
- Song D, "Porcine epidemic diarrhoea virus : a comprehensive review of molecular epidemiology, diagnosis, and vaccines", Virus Genes, 44, pp.167~175 (2012)
- Song DS, "Differentiation of a Vero cell adapted porcine epidemic diarrhea virus from Korean field strains by restriction fragment length polymorphism analysis of ORF 3", Vaccine, 21, pp.1833~1842 (2003)
- Stevenson GW, "Emergence of Porcine epidemic diarrhea virus in the United States : clinical signs, lesions, and viral genomic sequences", J Vet Diagn Invest, 25, pp.649~654 (2013)
- Sturman LS, "Proteolytic cleavage of peplomeric glycoprotein E2 of MHV yields two 90K subunits and activates cell fusion", Adv Exp Med Biol, pp.25~35 (1984)
- Su Y, "Detection and phylogenetic analysis of porcine epidemic diarrhea virus in central China based on the ORF3 gene and the S1 gene", Virol J, 13, pp.1~9 (2016)
- Sun RQ, "Outbreak of porcine epidemic diarrhea in suckling piglets, China", Emerg Infect Dis, 18, pp.161~ (2012)
- Vennema H, "Nucleocapsid-independent assembly of coronaviruslike particles by co-expression of viral envelope protein genes", EMBO J, 15, pp.2020~2028 (1996)
- Wang K, "PEDV ORF3 encodes an ion channel protein and regulates virus production", FEBS Lett, 586, pp.384~391 (2012)
- Wood EN, "An apparently new syndrome of porcine epidemic diarrhoea", Vet Rec, 100, pp.243~244 (1977)
- Zhang X, "Identification and pathogenicity of a variant porcine epidemic diarrhea virus field strain with reduced virulence", Virol J, 12, pp.1~5 (2015)