title: Enhancement and neutralization of feline infectious peritonitis virus infection in feline macrophages by neutralizing monoclonal antibodies recognizing different epitopes.
abstract: The interaction between the enhancing and neutralizing activities of three monoclonal antibodies (MAbs) (5-6-2, 6-4-2 and 7-4-1) to the spike protein of feline infectious peritonitis virus (FIPV) strain 79-1146 was determined using feline macrophages. At a high MAb concentration, all of the three MAbs completely inhibited the FIPV infection at 37 C. However, two of them (6-4-2 and 7-4-1) enhanced FIPV infection when either the MAb concentration or reaction temperature was lowered. These MAbs also exerted an immediate infectivity-enhancing activity for up to 10 min of reaction and by 20 min, neutralizing activities were observed. Only MAb 5-6-2 consistently showed neutralizing activity regardless of the reaction conditions. Competition with sera from cats experimentally infected with FIPV strain 79-1146 or feline enteric coronavirus strain 79-1683 showed that the two epitopes recognized by MAb 5-6-2 and MAb 6-4-2, respectively, are also recognized by the natural host.
authors.affiliation: Department of Veterinary Infectious Diseases, School of Veterinary Medicine and Animal Sciences, Kitasato University, Aomori, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Hohdatsu
authors.forename: H
authors.initials: H
authors.lastname: Yamada
authors.forename: Y
authors.initials: Y
authors.lastname: Ishizuka
authors.forename: H
authors.initials: H
authors.lastname: Koyama
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000914:Antibodies, Viral / Q000276:immunology; D000956:Antigens, Viral / Q000276:immunology; D002415:Cats; D016765:Coronavirus, Feline / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000276:immunology*; D016766:Feline Infectious Peritonitis / Q000276:immunology*; D028301:Feline Panleukopenia Virus / Q000276:immunology; D008264:Macrophages / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D000956:Antigens, Viral; D000939:Epitopes