Korean Journal of Veterinary Research (대한수의학회지)

The Korean Society of Veterinary Science (대한수의학회)
권호 표지

Pathogenesis and pathogenicity for the porcine circovirus 2 Korean isolates in weaned pigs

국내 분리 porcine circovirus 2의 이유자돈에 대한 병원성 시험연구

  • Roh, In-Soon (National Veterinary Reseach and Quarantine Service) ;
  • Lee, Kyung-Woo (National Veterinary Reseach and Quarantine Service) ;
  • Kim, Jae-Hoon (College of Veterinary Medicine, Cheju National University) ;
  • Han, Jeong-Hee (College of Veterinary Medicine, Kangwon National University) ;
  • Jean, Young-Hwa (National Veterinary Reseach and Quarantine Service)
  • Accepted : 2007.03.23
  • Published : 2007.06.30
Download PDF
⟨ Previous Next ⟩

Abstract

This study was carried out to investigate the pathogenesis and pathogenicity of the porcine circovirus type 2 (PCV2) Korean isolate from weaned pigs. Twenty four weaned pigs, PCV2, porcine reproductive and respiratory syndrome virus (PRRSV) and porcine parvovirus (PPV) antibodies free, were allocated to 4 groups (n = 6). Six pigs were inoculated intranasally with PCV2 alone, 6 with PCV2 and PRRSV, 6 with the combined PCV2/PRRSV/PPV inoculum, and 6 were remained as a uninoculated negative control. Pigs were killed 3 and 6 weeks after inoculation and tissue samples examined for gross and microscopic lesions and for the presence of PCV2 antigens and nucleic acids. Experimentally inoculated pigs were evaluated for 3 considerations: 1. development of postweaning multisystemic wasting syndrome (PMWS), 2. distribution of viral antigens by immunohistochemistry and polymerase chain reaction (PCR), and 3. cytokine mRNA levels in lymph nodes. Pigs inoculated with PCV2/PRRSV/PPV showed typical clinical signs, gross findings, and histopathologic characteristics of PMWS. In the PCV2/PRRSV/PPV inoculated group, the PCV2 antigen was widely distributed in various parenchymal organs such as brain, spinal cord, tonsil, lymph nodes, lung, heart, liver, kidney, spleen, and peyer's patch. Lymph node mRNA expression of IL-$1{\alpha}$, IL-2R and IL-8 was determined by real-time PCR. The pigs of PCV2/PRRSV and PCV2/PRRSV/PPV inoculation group, the mRNA expression was characterized by a decrease of IL-$1{\alpha}$, IL-2R and IL-8. The decrease of cytokine mRNA represent the state of T cell immuno-suppression in pig, and nicely support the evidence for the impairment of immune system in pigs with PMWS. In conclusion, PCV2 infection and some additional infectious causes such as PRRSV and/or PPV are warranted for the presence of PMWS in weaned pigs in Korea.

Keywords

References

  1. Allan GM, McNeilly F, Cassidy JP, Reilly GA, Adair B, Ellis WA, McNulty MS. Pathogenesis of porcine circovirus; experimental infections of colostrum deprived piglets and examination of pig foetal material. Vet Microbiol 1995, 44, 49-64 https://doi.org/10.1016/0378-1135(94)00136-K
  2. Allan GM, McNeilly F, Meehan BM, Kennedy S, Mackie DP, Ellis JA, Clark EG, Espuna E, Saubi N, Riera P, Botner A, Charreyre CE. Isolation and characterisation of circoviruses from pigs with wasting syndromes in Spain, Denmark and Northern Ireland. Vet Microbiol 1999, 66, 115-123 https://doi.org/10.1016/S0378-1135(99)00004-8
  3. Darwich L, Balasch M, Plana-Duran J, Segales J, Domingo M, Mateu E. Cytokine profiles of peripheral blood mononuclear cells from pigs with postweaning multisystemic wasting syndrome in response to mitogen, superantigen or recall viral antigens. J Gen Virol 2003, 84, 3453-3457 https://doi.org/10.1099/vir.0.19364-0
  4. Darwich L, Pie S, Rovira A, Segales J, Domingo M, Oswald IP, Mateu E. Cytokine mRNA expression profiles in lymphoid tissues of pigs naturally affected by postweaning multisystemic wasting syndrome. J Gen Virol 2003, 84, 2117-2125 https://doi.org/10.1099/vir.0.19124-0
  5. Darwich L, Segales J, Domingo M, Mateu E. Change in the $CD4^+$, $CD8^+$, $CD4^+$ $CD8^+$, and immunoglobulin M-positive peripheral blood mononuclear cells from postweaning multisystemic wasting syndrome-affected pigs and age-matched uninfected wasted and healthy pigs correlate with lesions and porcine circovirus type 2 load in lymphoid tissues. Clin Diagn Lab Immunol 2002, 9, 236-242
  6. Darwich L, Segales J, Mateu E. Pathogenesis of postweaning multisystemic wasting syndrome caused by Porcine circovirus 2: An immune riddle. Arch Virol 2004, 149, 857-874 https://doi.org/10.1007/s00705-003-0280-9
  7. Harding JC. Post-weaning multisystemic wasting syndrome (PMWS): preliminary epidemiology and clinical presentation. Proc Am Assoc Swine Pract 1997, 28, 503
  8. Harding MJ, Molitor TW. Porcine parvovirus replication and inhibition of swine alveolar macrophages and peripheral blood lymphocytes. Arch Virol 1988, 101, 105-117 https://doi.org/10.1007/BF01314655
  9. Harms PA, Sorden SD, Halbur PG, Bolin SR, Lager KM, Morozov I, Paul PS. Experimental reproduction of severe disease in CD/CD pigs concurrently infected with type 2 porcine circovirus and porcine reproductive and respiratory syndrome virus. Vet Pathol 2001, 38, 528-539 https://doi.org/10.1354/vp.38-5-528
  10. Goldsby RA, Kindt TJ, Osborne BA. Cytokine. In: Goldsby RA, Kindt TJ, Osborne BA (eds.). Immunology. 4th ed. pp. 303-327, W.H. Freeman & Co., 2000
  11. Kennedy S, Moffett D, McNeilly F, Meehan B, Ellis J, Krakowka S, Allan GM. Reproduction of lesions of postweaning multisystemic wasting syndrome by infection of conventional pigs with porcine circovirus type 2 alone or in combination with porcine parvovirus. J Comp Pathol 2000, 122, 9-24 https://doi.org/10.1053/jcpa.1999.0337
  12. Krakowka S, Ellis JA, McNeilly F, Ringler S, Rings DM, Allan G. Activation of the immune system is the pivotal event in the production of wasting disease in pigs infected with porcine circovirus-2. Vet Pathol 2001, 38, 31-42 https://doi.org/10.1354/vp.38-1-31
  13. Krakowka S, Ellis JA, Meehan B, Kennedy S, McNeilly F, Allan G. Viral wasting syndrome of swine: experimental reproduction of postweaning multisystemic wasting syndrome in gnotobiotic swine by coinfection with porcine circovirus 2 and porcine parvovirus. Vet Pathol 2000, 37, 254-263 https://doi.org/10.1354/vp.37-3-254
  14. Okuda Y, Ono M, Yazawa S, Shibata I. Experimental reproduction of postweaning multisystemic wasting syndrome in cesarean-derived, colostrum-deprived piglets inoculated with porcine circovirus type 2(PCV2) investigation of quantitative PCV2 distribution and antibody responses. J Vet Diagn Invest 2003, 15, 107-114 https://doi.org/10.1177/104063870301500204
  15. Pogranichnyy RM, Yoon KJ, Harms PA, Swenson SL, Zimmerman JJ, Sorden SD. Characterization of immune response of young pigs to porcine circovirus type 2 infection. Viral Immunol 2000, 13, 43-153
  16. Quintana J, Segales J, Rosell C, Calsamiglia M, Rodriguez-Arrioja GM, Chianini F, Folch JM, Maldonado J, Canal M, Plana-Duran J, Domingo M. Clinical and pathological observations on pigs with postweaning multisystemic wasting syndrome. Vet Rec 2001, 149, 357-361 https://doi.org/10.1136/vr.149.12.357
  17. Rosell C, Segales J, Plana-Duran J, Balasch M, Rodriguez-Arrioja GM, Kennedy S, Allan GM, McNeilly F, Latimer KS, Domingo M. Pathological, immunohistochemical, and in-situ hybridization studies of natural cases of postweaning multisystemic wasting syndrome in pigs. J Comp Pathol 1999, 120, 59-78 https://doi.org/10.1053/jcpa.1998.0258
  18. Rovira A, Balasch M, Segales J, Garcia L, Plana-Duran J, Rosell C, Ellerbrok H, Mankertz A, Domingo M. Experimental inoculation of conventional pigs with porcine reproductive and respiratory syndrome virus and porcine circovirus type 2 in conventional pigs. J Virol 2002, 76, 3232-3239 https://doi.org/10.1128/JVI.76.7.3232-3239.2002
  19. Segales J, Alonso F, Rosell C, Pastor J, Chianini F, Campos E, Lopez-Fuertes L, Quintana J, Rodriguez-Arrioja G, Calsamiglia M, Pujols J, Dominguez J, Domingo M. Changes in peripheral blood leukocyte populations in pigs with natural postweaning multisystemic wasting syndrome. Vet Immunol Immunopathol 2001, 81, 37-44 https://doi.org/10.1016/S0165-2427(01)00326-9
  20. Tischer I, Mields W, Wolff D, Vagt M, Griem W. Studies on epidemiology and pathogenicity of porcine circovirus. Arch Virol 1986, 91, 271-276 https://doi.org/10.1007/BF01314286