title: In-vitro and in-vivo phenotype of type Asia 1 foot-and-mouth disease viruses utilizing two non-RGD receptor recognition sites.
abstract: BACKGROUND
  Foot-and-mouth disease virus (FMDV) uses a highly conserved Arg-Gly-Asp (RGD) triplet for attachment to host cells and this motif is believed to be essential for virus viability. Previous sequence analyses of the 1D-encoding region of an FMDV field isolate (Asia1/JS/CHA/05) and its two derivatives indicated that two viruses, which contained an Arg-Asp-Asp (RDD) or an Arg-Ser-Asp (RSD) triplet instead of the RGD integrin recognition motif, were generated serendipitously upon short-term evolution of field isolate in different biological environments. To examine the influence of single amino acid substitutions in the receptor binding site of the RDD-containing FMD viral genome on virus viability and the ability of non-RGD FMDVs to cause disease in susceptible animals, we constructed an RDD-containing FMDV full-length cDNA clone and derived mutant molecules with RGD or RSD receptor recognition motifs. Following transfection of BSR cells with the full-length genome plasmids, the genetically engineered viruses were examined for their infectious potential in cell culture and susceptible animals.
  
  
  RESULTS
  Amino acid sequence analysis of the 1D-coding region of different derivatives derived from the Asia1/JS/CHA/05 field isolate revealed that the RDD mutants became dominant or achieved population equilibrium with coexistence of the RGD and RSD subpopulations at an early phase of type Asia1 FMDV quasispecies evolution. Furthermore, the RDD and RSD sequences remained genetically stable for at least 20 passages. Using reverse genetics, the RDD-, RSD-, and RGD-containing FMD viruses were rescued from full-length cDNA clones, and single amino acid substitution in RDD-containing FMD viral genome did not affect virus viability. The genetically engineered viruses replicated stably in BHK-21 cells and had similar growth properties to the parental virus. The RDD parental virus and two non-RGD recombinant viruses were virulent to pigs and bovines that developed typical clinical disease and viremia.
  
  
  CONCLUSIONS
  FMDV quasispecies evolving in a different biological environment gained the capability of selecting different receptor recognition site. The RDD-containing FMD viral genome can accommodate substitutions in the receptor binding site without additional changes in the capsid. The viruses expressing non-RGD receptor binding sites can replicate stably in vitro and produce typical FMD clinical disease in susceptible animals.
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 1 Xujiaping, Yanchangbao, Lanzhou, Gansu 730046, PR China.
authors.forename: Pinghua
authors.initials: P
authors.lastname: Li
authors.forename: Zengjun
authors.initials: Z
authors.lastname: Lu
authors.forename: Huifang
authors.initials: H
authors.lastname: Bao
authors.forename: Dong
authors.initials: D
authors.lastname: Li
authors.forename: Donald P
authors.initials: DP
authors.lastname: King
authors.forename: Pu
authors.initials: P
authors.lastname: Sun
authors.forename: Xingwen
authors.initials: X
authors.lastname: Bai
authors.forename: Weijun
authors.initials: W
authors.lastname: Cao
authors.forename: Simon
authors.initials: S
authors.lastname: Gubbins
authors.forename: Yingli
authors.initials: Y
authors.lastname: Chen
authors.forename: Baoxia
authors.initials: B
authors.lastname: Xie
authors.forename: Jianhong
authors.initials: J
authors.lastname: Guo
authors.forename: Hong
authors.initials: H
authors.lastname: Yin
authors.forename: Zaixin
authors.initials: Z
authors.lastname: Liu
mesh_terms: D019943:Amino Acid Substitution / Q000235:genetics; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000473:pathology / Q000821:virology; D002460:Cell Line; D006224:Cricetinae; D005536:Foot-and-Mouth Disease / Q000473:pathology / Q000821:virology; D029544:Foot-and-Mouth Disease Virus / Q000254:growth & development / Q000472:pathogenicity / Q000502:physiology*; D050296:Microbial Viability; D016297:Mutagenesis, Site-Directed; D011991:Receptors, Virus / Q000378:metabolism*; D013552:Swine; D013553:Swine Diseases / Q000473:pathology / Q000821:virology; D014764:Viral Proteins / Q000235:genetics* / Q000378:metabolism*; D053585:Virus Attachment
chemical_list: D011991:Receptors, Virus; D014764:Viral Proteins