title: Differences in virus receptor for type I and type II feline infectious peritonitis virus.
abstract: Feline infectious peritonitis viruses (FIPVs) are classified into type I and type II serogroups. Here, we report that feline aminopeptidase N (APN), a cell-surface metalloprotease on the intestinal, lung and kidney epithelial cells, is a receptor for type II FIPV but not for type I FIPV. A monoclonal antibody (MAb) R-G-4, which blocks infection of Felis catus whole fetus (fcwf-4) cells by type II FIPV, was obtained by immunizing mice with fcwf-4 cells which are highly susceptible to FIPV. This MAb also blocked infection of fcwf-4 cells by type II feline enteric coronavirus (FECV), canine coronavirus (CCV), and transmissible gastroenteritis virus (TGEV). On the other hand, it did not block infection by type I FIPVs. MAb R-G-4 recognized a polypeptide of relative molecular mass 120-130 kDa in feline intestinal brush-border membrane (BBM) proteins. The polypeptide possessed aminopeptidase activity, and the first 15 N-terminal amino acid sequence was identical to that of the feline APN. Feline intestinal BBM proteins and the polypeptide reacted with MAb R-G-4 (feline APN) inhibited the infectivity of type II FIPV, type II FECV, CCV and TGEV to fcwf-4 cells, but did not inhibit the infectivity of type I FIPVs.
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: Y
authors.initials: Y
authors.lastname: Izumiya
authors.forename: Y
authors.initials: Y
authors.lastname: Yokoyama
authors.forename: K
authors.initials: K
authors.lastname: Kida
authors.forename: H
authors.initials: H
authors.lastname: Koyama
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D018826:CD13 Antigens / Q000235:genetics / Q000276:immunology / Q000502:physiology; D002415:Cats; D002478:Cells, Cultured; D017934:Coronavirus / Q000145:classification / Q000472:pathogenicity; D017939:Coronavirus, Canine / Q000472:pathogenicity; D016765:Coronavirus, Feline / Q000145:classification / Q000472:pathogenicity*; D004285:Dogs; D028301:Feline Panleukopenia Virus / Q000472:pathogenicity; D006801:Humans; D007422:Intestines / Q000201:enzymology / Q000821:virology; D008565:Membrane Proteins / Q000235:genetics / Q000276:immunology / Q000502:physiology; D051379:Mice; D008871:Microvilli / Q000201:enzymology / Q000821:virology; D008969:Molecular Sequence Data; D011991:Receptors, Virus / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D013552:Swine; D005760:Transmissible gastroenteritis virus / Q000472:pathogenicity
chemical_list: D000911:Antibodies, Monoclonal; D008565:Membrane Proteins; D011991:Receptors, Virus; D018826:CD13 Antigens