title: Mutation of neutralizing/antibody-dependent enhancing epitope on spike protein and 7b gene of feline infectious peritonitis virus: influences of viral replication in monocytes/macrophages and virulence in cats.
abstract: We previously prepared neutralizing monoclonal antibody (MAb)-resistant (mar) mutant viruses using a laboratory strain feline infectious peritonitis virus (FIPV) 79-1146 (Kida et al., 1999). Mar mutant viruses are mutated several amino acids of the neutralizing epitope of Spike protein, compared with the parent strain, FIPV 79-1146. We clarified that MAb used to prepare mar mutant viruses also lost its activity to enhance homologous mar mutant viruses, strongly suggesting that neutralizing and antibody-dependent enhancing epitopes are present in the same region in the strain FIPV 79-1146. We also discovered that amino acid mutation in the neutralizing epitope reduced viral replication in monocytes/macrophages. We also demonstrated that the mutation or deletion of two nucleotides in 7b gene abrogate the virulence of strain FIPV 79-1146.
authors.affiliation: Laboratory of Veterinary Infectious Disease, School of Veterinary Medicine, Kitasato University, Towada, Aomori 034-8628, Japan.
authors.forename: Tomomi
authors.initials: T
authors.lastname: Takano
authors.forename: Yoshika
authors.initials: Y
authors.lastname: Tomiyama
authors.forename: Yasuichiroh
authors.initials: Y
authors.lastname: Katoh
authors.forename: Michiyo
authors.initials: M
authors.lastname: Nakamura
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Satoh
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Hohdatsu
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D057134:Antibodies, Neutralizing / Q000235:genetics / Q000276:immunology*; D002415:Cats; D002478:Cells, Cultured; D016765:Coronavirus, Feline / Q000235:genetics / Q000276:immunology / Q000472:pathogenicity; D000939:Epitopes / Q000235:genetics / Q000276:immunology; D016766:Feline Infectious Peritonitis / Q000276:immunology / Q000821:virology; D016679:Genome, Viral; D008264:Macrophages / Q000821:virology*; D009000:Monocytes / Q000821:virology*; D009154:Mutation; D016019:Survival Analysis; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology; D014774:Virulence / Q000235:genetics; D014779:Virus Replication / Q000502:physiology*
chemical_list: D057134:Antibodies, Neutralizing; D000939:Epitopes; D014759:Viral Envelope Proteins