title: [Establishment and application of a Vero cell line stably expressing raccoon dog SLAM, the cellular receptor of canine distemper virus].
abstract: OBJECTIVE
  The signaling lymphocyte activation molecule (SLAM, also known as CD150), is used as a cellular receptor by canine distemper virus (CDV). Wild-type strains of CDVs can be isolated and propagated efficiently in non-lymphoid cells expressing this protein. Our aim is to establish a Vero cells expressing raccoon dog SLAM (rSLAM) to efficiently isolate CDV from pathological samples.
  
  
  METHODS
  A eukaryotic expression plasmid, pIRES2-EGFP-rSLAMhis, containing rSLAM gene fused with six histidine-coding sequence, EGFP gene, and neomycin resistance gene was constructed. After transfection with the plasmid, a stable cell line, Vero-rSLAM, was screened from Vero cells with the identification of EGFP reporter and G418 resistance. Three CD positive specimens from infected foxes and raccoon dogs were inoculated to Vero-rSLAM cells for CDV isolation. Foxes and raccoon dogs were inoculated subcutaneously LN (10)fl strain with 4 x 10(2.39)TCID50 dose to evaluate pathogenicity of CDV isolations.
  
  
  RESULTS
  The rSLAMh fused gene was shown to transcript and express stably in Vero-rSLAM cells by RT-PCR and Immunohistochemistry assay. Three CDV strains were isolated successfully in Vero-rSLAM cells 36 -48 hours after inoculation with spleen or lung specimens from foxes and raccoon dogs with distemper. By contrast, no CDV was recovered from those CD positive specimens when Vero cells were used for virus isolation. Infected foxes and raccoon dogs with LN(10)f1 strain all showed typical CD symptoms and high mortality (2/3 for foxes and 3/3 for raccoon dogs) in 22 days post challenge.
  
  
  CONCLUSIONS
  Our results indicate that Vero-rSLAM cells stably expressing raccoon dog SLAM are highly sensitive to CDV in clinical specimens and the CDV isolation can maintain high virulence to its host animals.
authors: Division of Preventive Veterinary Medicine, Institute of Special Economic Animal and Plant Sciences, Chinese Academy of Agricultural Sciences, Changchun 130112, China. jianjunzhao2004@yahoo.com.cn
authors: Jianjun
authors: J
authors: Zhao
authors: Ruxun
authors: R
authors: Yan
authors: Hailing
authors: H
authors: Zhang
authors: Lei
authors: L
authors: Zhang
authors: Bo
authors: B
authors: Hu
authors: Xue
authors: X
authors: Bai
authors: Xiqun
authors: X
authors: Shao
authors: Xiuli
authors: X
authors: Chai
authors: Xijun
authors: X
authors: Yan
authors: Wei
authors: W
authors: Wu
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000235:genetics* / Q000378:metabolism; D002522:Chlorocebus aethiops; D004216:Distemper / Q000235:genetics* / Q000378:metabolism / Q000821:virology; D004217:Distemper Virus, Canine / Q000235:genetics / Q000254:growth & development* / Q000302:isolation & purification; D005589:Foxes / Q000821:virology; D015870:Gene Expression; D046031:Raccoon Dogs / Q000235:genetics* / Q000378:metabolism / Q000821:virology; D011956:Receptors, Cell Surface / Q000235:genetics* / Q000378:metabolism; D011991:Receptors, Virus / Q000235:genetics* / Q000378:metabolism; D000071177:Signaling Lymphocytic Activation Molecule Family Member 1; D014709:Vero Cells
chemical_list: D015703:Antigens, CD; D011956:Receptors, Cell Surface; D011991:Receptors, Virus; D000071177:Signaling Lymphocytic Activation Molecule Family Member 1