J Vet Sci.  2017 Jun;18(2):201-207. 10.4142/jvs.2017.18.2.201.

Antigenic characterization of classical swine fever virus YC11WB isolates from wild boar

• Lim SI
• Kim YK
• Lim JA
• Han SH
• Hyun HS
• Kim KS
• Hyun BH
• Kim JJ
• Cho IS
• Song JY
• Choi SH
• Kim SH
• An DJ

• KMID: 2412573
• DOI: http://doi.org/10.4142/jvs.2017.18.2.201

Abstract

Classical swine fever (CSF), a highly contagious disease that affects domestic pigs and wild boar, has serious economic implications. The present study examined the virulence and transmission of CSF virus strain YC11WB (isolated from a wild boar in 2011) in breeding wild boar. Virulence of strain YC11WB in domestic pigs was also examined. Based on the severe clinical signs and high mortality observed among breeding wild boar, the pathogenicity of strain YC11WB resembled that of typical acute CSF. Surprisingly, in contrast to strain SW03 (isolated from breeding pigs in 2003), strain YC11WB showed both acute and strong virulence in breeding pigs. None of three specific monoclonal antibodies (7F2, 7F83, and 6F65) raised against the B/C domain of the SW03 E2 protein bound to the B/C domain of strain YC11WB due to amino acid mutations (⁷²â°K→R and ⁷²³N→S) in the YC11WB E2 protein. Although strains YC11WB and SW03 belong to subgroup 2.1b, they had different mortality rates in breeding pigs. Thus, if breeding pigs have not developed protective immunity against CSF virus, they may be susceptible to strain YC11WB transmitted by wild boar, resulting in severe economic losses for the pig industry.

Keyword

B/C domain; Classical swine fever virus; Sus scrofa; virulence

MeSH Terms

Animals
Animals, Wild/immunology/virology
Antibodies, Monoclonal/immunology
Antigens, Viral/*immunology
Classical Swine Fever/*immunology/transmission/virology
Classical swine fever virus/*immunology/isolation & purification/pathogenicity
Cloning, Molecular
Real-Time Polymerase Chain Reaction/veterinary
Sus scrofa/*virology
Swine
Antibodies, Monoclonal
Antigens, Viral

Figure

• 

  Fig. 1 Predicted structure of glycoprotein E2, and amino acid sequence similarities between the B/C and D/A domains of classical swine fever virus (CSFV) strains SW03 and YC11WB. (A) The best RCSB Protein Data Bank template for strains SW03 and YC11WB was 2YQ2 (BVDV1 envelope glycoprotein E2). (B) Amino acid sequence similarity between the B/C and D/A domains of strains SW03 and YC11WB. The B/C and D/A domains are marked with a green bar and a pink bar, respectively. Three linear epitope determinants identified by using antibody epitope prediction programs are shown in gray. The epitope region binding the WH303 mAb is shown as a black box.

Reference

1. Bautista MJ, Ruiz-Villamor E, Salguero FJ, Sánchez-Cordón PJ, Carrasco L, Gómez-Villamandos JC. Early platelet aggregation as a cause of thrombocytopenia in classical swine fever. Vet Pathol. 2002; 39:84–91.

2. Berman HM, Westbrook J, Feng Z, Gilliland G, Bhat TN, Weissig H, Shindyalov IN, Bourne PE. The Protein Data Bank. Nucleic Acids Res. 2000; 28:235–242.

3. Blacksell SD, Khounsy S, Van Aken D, Gleeson LJ, Westbury HA. Comparative susceptibility of indigenous and improved pig breeds to Classical swine fever virus infection: practical and epidemiological implications in a subsistence-based, developing country setting. Trop Anim Health Prod. 2006; 38:467–474.

4. Chang CY, Huang CC, Lin YJ, Deng MC, Chen HC, Tsai CH, Chang WM, Wang FI. Antigenic domains analysis of classical swine fever virus E2 glycoprotein by mutagenesis and conformation-dependent monoclonal antibodies. Virus Res. 2010; 149:183–189.

5. Chang CY, Huang CC, Lin YJ, Deng MC, Tsai CH, Chang WM, Wang FI. Identification of antigen-specific residues on E2 glycoprotein of classical swine fever virus. Virus Res. 2010; 152:65–72.

6. Das A, Beckham TR, McIntosh MT. Comparison of methods for improved RNA extraction from blood for early detection of Classical swine fever virus by real-time reverse transcription polymerase chain reaction. J Vet Diagn Invest. 2011; 23:727–735.

7. Depner KR, Hinrichs U, Bickhardt K, Greiser-Wilke I, Pohlenz J, Moennig V, Liess B. Influence of breed-related factors on the course of classical swine fever virus infection. Vet Rec. 1997; 140:506–507.

8. Dong XN, Qi Y, Ying J, Chen X, Chen YH. Candidate peptide-vaccine induced potent protection against CSFV and identified a principal sequential neutralizing determinant on E2. Vaccine. 2006; 24:426–434.

9. Emini EA, Hughes JV, Perlow DS, Boger J. Induction of hepatitis A virus-neutralizing antibody by a virus-specific synthetic peptide. J Virol. 1985; 55:836–839.

10. Everett H, Salguero FJ, Graham SP, Haines F, Johns H, Clifford D, Nunez A, La Rocca SA, Parchariyanon S, Steinbach F, Drew T, Crooke H. Characterisation of experimental infections in domestic pigs with genotype 2.1 and 3.3 isolates of classical swine fever virus. Vet Microbiol. 2010; 142:26–33.

11. Floegel-Niesmann G, Blome S, Gerss-Dülmer H, Bunzenthal C, Moennig V. Virulence of classical swine fever virus isolates from Europe and other areas during 1996 until 2007. Vet Microbiol. 2009; 139:165–169.

12. Floegel-Niesmann G, Bunzenthal C, Fischer S, Moennig V. Virulence of recent and former classical swine fever isolates evaluated by their clinical and pathological signs. J Vet Med B Infect Dis Vet Public Health. 2003; 50:214–220.

13. Fritzemeier J, Teuffert J, Greiser-Wilke I, Staubach C, Schlüter H, Moennig V. Epidemiology of classical swine fever in Germany in the 1990s. Vet Microbiol. 2000; 77:29–41.

14. Gomez-Villamandos JC, Salguero FJ, Ruiz-Villamor E, Sánchez-Cordón PJ, Bautista MJ, Sierra MA. Classical swine fever: pathology of bone marrow. Vet Pathol. 2003; 40:157–163.

15. Jeoung HY, Lim JA, Lim SI, Kim JJ, Song JY, Hyun BH, Kim YK, An DJ. Complete genome sequence of classical swine fever virus isolated from wild boar in South Korea. Genome Announc. 2013; 1:e0014713.

16. Jespersen MC, Peters B, Nielsen M, Marcatili P. BepiPred-2.0: improving sequence-based B-cell epitope prediction using conformational epitopes. Nucleic Acids Res. 2017; Epub ahead of print. DOI: 10.1093/nar/gkx346.

17. Kaden V, Lange E, Polster U, Klopfleisch R, Teifke JP. Studies on the virulence of two field isolates of the classical swine fever virus genotype 2.3 Rostock in wild boars of different age groups. J Vet Med B Infect Dis Vet Public Health. 2004; 51:202–208.

18. Laddomada A. Incidence and control of CSF in wild boar in Europe. Vet Microbiol. 2000; 73:121–130.

19. Lindenbach BD, Rice CM. Flaviviridae: the viruses and their replication. In : Knipe DM, Howley PM, Griffin DE, editors. Fundamental Virology. 4th ed. Philadelphia: Lippincott Williams & Wilkins;2001. p. 589–639.

20. Meyers G, Rümenapf T, Thiel HJ. Molecular cloning and nucleotide sequence of the genome of hog cholera virus. Virology. 1989; 171:555–567.

21. Mintiens K, Verloo D, Venot E, Laevens H, Dufey J, Dewulf J, Boelaert F, Kerkhofs P, Koenen F. Estimating the probability of freedom of classical swine fever virus of the East-Belgium wild-boar population. Prev Vet Med. 2005; 70:211–222.

22. Mittelholzer C, Moser C, Tratschin JD, Hofmann MA. Analysis of classical swine fever virus replication kinetics allows differentiation of highly virulent from avirulent strains. Vet Microbiol. 2000; 74:293–308.

23. Morten Källberg, Haipeng Wang, Sheng Wang, Jian Peng, Zhiyong Wang, Hui Lu, Jinbo Xu. Template-based protein structure modeling using the RaptorX web server. Nat Protoc. 2012; 7:1511–1522.

24. Nielsen J, Lohse L, Rasmussen TB, Uttenthal A. Classical swine fever in 6- and 11-week-old pigs: haematological and immunological parameters are modulated in pigs with mild clinical disease. Vet Immunol Immunopathol. 2010; 138:159–173.

25. Pérez LJ, Díaz de Arce H, Perera CL, Rosell R, Frías MT, Percedo MI, Tarradas J, Dominguez P, Núñez JI, Ganges L. Positive selection pressure on the B/C domains of the E2-gene of classical swine fever virus in endemic areas under C-strain vaccination. Infect Genet Evol. 2012; 12:1405–1412.

26. Summerfield A, Knötig SM, McCullough KC. Lymphocyte apoptosis during classical swine fever: implication of activation-induced cell death. J Virol. 1998; 72:1853–1861.

27. Summerfield A, McNeilly F, Walker I, Allan G, Knoetig SM, McCullough KC. Depletion of CD4⁺ and CD8^high+ T-cells before the onset of viraemia during classical swine fever. Vet Immunol Immunopathol. 2001; 78:3–19.

28. Wee SH, Park CK, Jeong JM, Kim CH, Hwang IJ, Kim SJ, Yoon H, Lee ES, Nam HM, Park JY, Moon OK. Outbreaks of classical swine fever in the Republic of Korea in 2003. Vet Rec. 2005; 157:113–115.

29. Weiland E, Stark R, Haas B, Rümenapf T, Meyers G, Thiel HJ. Pestivirus glycoprotein which induces neutralizing antibodies forms part of a disulfide-linked heterodimer. J Virol. 1990; 64:3563–3569.

30. Wensvoort G. Topographical and functional mapping of epitopes on hog cholera virus with monoclonal antibodies. J Gen Virol. 1989; 70:2865–2876.

31. Wensvoort G, Boonstra J, Bodzinga BG. Immunoaffinity purification and characterization of the envelope protein E1 of hog cholera virus. J Gen Virol. 1990; 71:531–540.

32. Wensvoort G, Terpstra C, Boonstra J, Bloemraad M, van Zaane D. Production of monoclonal antibodies against swine fever virus and their use in laboratory diagnosis. Vet Microbiol. 1986; 12:101–108.