title: Mapping of amino acid residues responsible for adhesion of cell culture-adapted foot-and-mouth disease SAT type viruses.
abstract: Foot-and-mouth disease virus (FMDV) infects host cells by adhering to the alpha(V) subgroup of the integrin family of cellular receptors in a Arg-Gly-Asp (RGD) dependent manner. FMD viruses, propagated in non-host cell cultures are reported to acquire the ability to enter cells via alternative cell surface molecules. Sequencing analysis of SAT1 and SAT2 cell culture-adapted variants showed acquisition of positively charged amino acid residues within surface-exposed loops of the outer capsid structural proteins. The fixation of positively charged residues at position 110-112 in the beta F-beta G loop of VP1 of SAT1 isolates is thought to correlate with the acquisition of the ability to utilise alternative glycosaminoglycan (GAG) molecules for cell entry. Similarly, two SAT2 viruses that adapted readily to BHK-21 cells accumulated positively charged residues at positions 83 and 85 of the beta D-beta E loop of VP1. Both regions surround the fivefold axis of the virion. Recombinant viruses containing positively charged residues at position 110 and 112 of VP1 were able to infect CHO-K1 cells (that expresses GAG) and demonstrated increased infectivity in BHK-21 cells. Therefore, recombinant SAT viruses engineered to express substitutions that induce GAG-binding could be exploited in the rational design of vaccine seed stocks with improved growth properties in cell cultures.
authors.affiliation: Transboundary Animal Diseases Programme, Onderstepoort Veterinary Institute, Agricultural Research Council, Onderstepoort 0110, South Africa. Mareef@arc.agric.za
authors.forename: Francois F
authors.initials: FF
authors.lastname: Maree
authors.forename: Belinda
authors.initials: B
authors.lastname: Blignaut
authors.forename: Tjaart A P
authors.initials: TA
authors.lastname: de Beer
authors.forename: Nico
authors.initials: N
authors.lastname: Visser
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Rieder
mesh_terms: D000220:Adaptation, Biological; D019943:Amino Acid Substitution / Q000235:genetics; D000818:Animals; D036022:Capsid Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D002460:Cell Line; D006224:Cricetinae; D029544:Foot-and-Mouth Disease Virus / Q000235:genetics / Q000502:physiology*; D008958:Models, Molecular; D020125:Mutation, Missense; D017434:Protein Structure, Tertiary; D012692:Serial Passage; D010948:Viral Plaque Assay; D053585:Virus Attachment; D014776:Virus Cultivation
chemical_list: D036022:Capsid Proteins; C442501:VP1 protein, Foot-and-mouth disease virus