title: Chinese highly pathogenic porcine reproductive and respiratory syndrome virus exhibits more extensive tissue tropism for pigs.
abstract: BACKGROUND
  The highly pathogenic porcine reproductive and respiratory syndrome virus (PRRSV) emerging in China exhibits high fatality to pigs. However, the mechanism related to the increased pathogenicity of the virus remains unclear. In the present study, the differences in tissue tropism between the highly pathogenic PRRSV strain (JXwn06) and the low pathogenic PRRSV strain (HB-1/3.9) were investigated using PRRSV-specific immunohistochemistry (IHC) staining to provide evidence for elucidating possible mechanism of the pathogenicity of Chinese highly pathogenic PRRSV.
  
  
  RESULTS
  IHC examination showed that PRRSV antigen in the tissues including spleen, tonsil, thymus, kidney, cerebellum, stomach, small intestine, large intestine, turbinal bone and laryngeal cartilage was positive in more pigs inoculated with JXwn06 than HB-1/3.9, and the tissues including trachea, esophagus, liver, mandibular gland and thyroid gland were positive for viral antigen in the pigs inoculated with JXwn06, but not in the pigs inoculated with HB-1/3.9. Meanwhile, we observed that epithelium in tissues including interlobular bile duct in liver, distal renal tubule of kidney, esophageal gland and tracheal gland were positive for viral antigen only in JXwn06-inoculated pigs, and epithelium of gastric mucosa and fundic gland, and intestinal gland were positive for viral antigen in both JXwn06- and HB-1/3.9-inoculated pigs, using monoclonal antibodies to N and Nsp2 proteins.
  
  
  CONCLUSIONS
  Taken together, these findings indicate that the highly pathogenic PRRSV JXwn06 displays an expanded tissue tropism in vivo, suggesting this may contribute to its high pathogenicity to pigs.
authors.affiliation: Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, No, 2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, China.
authors.forename: Limin
authors.initials: L
authors.lastname: Li
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhao
authors.forename: Xinna
authors.initials: X
authors.lastname: Ge
authors.forename: Kedao
authors.initials: K
authors.lastname: Teng
authors.forename: Yu
authors.initials: Y
authors.lastname: Kuang
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Chen
authors.forename: Xin
authors.initials: X
authors.lastname: Guo
authors.forename: Hanchun
authors.initials: H
authors.lastname: Yang
mesh_terms: D000818:Animals; D000956:Antigens, Viral / Q000378:metabolism; D002681:China; D004848:Epithelium / Q000378:metabolism / Q000473:pathology; D008168:Lung / Q000378:metabolism / Q000473:pathology; D008198:Lymph Nodes / Q000378:metabolism / Q000473:pathology; D019318:Porcine Reproductive and Respiratory Syndrome / Q000401:mortality / Q000821:virology*; D019316:Porcine respiratory and reproductive syndrome virus / Q000502:physiology*; D013552:Swine; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism; D056189:Viral Tropism
chemical_list: D000956:Antigens, Viral; D014764:Viral Proteins