title: Analysis of the mechanism of antibody-dependent enhancement of feline infectious peritonitis virus infection: aminopeptidase N is not important and a process of acidification of the endosome is necessary.
abstract: Infection of the monocyte/macrophage lineage with feline infectious peritonitis virus (FIPV) is enhanced in the presence of anti-FIPV antibodies (antibody-dependent enhancement or ADE). We investigated the following unclear points concerning ADE of FIPV infection: (i) involvement of the virus receptor, feline aminopeptidase N (fAPN), in ADE activity in FIPV infection; (ii) necessity of acidification of the endosome in cellular invasion of FIPV. Virus receptor-blocking experiments using anti-fAPN antibodies at 4 or 37 degrees C and experiments using fAPN-negative U937 cells revealed that fAPN is not involved in ADE of FIPV infection. Experiments using lysosomotropic agents clarified that acidification of the endosome is necessary for cellular invasion by FIPV, regardless of the presence or absence of antibodies. These findings may be very important for understanding the mechanism of ADE of FIPV infection.
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.affiliation: Laboratory of Veterinary Infectious Disease, School of Veterinary Medicine, Kitasato University, Towada, Aomori 034-8628, Japan.
authors.forename: Yukari
authors.initials: Y
authors.lastname: Katada
authors.affiliation: Laboratory of Veterinary Infectious Disease, School of Veterinary Medicine, Kitasato University, Towada, Aomori 034-8628, Japan.
authors.forename: Saiko
authors.initials: S
authors.lastname: Moritoh
authors.affiliation: Laboratory of Veterinary Infectious Disease, School of Veterinary Medicine, Kitasato University, Towada, Aomori 034-8628, Japan.
authors.forename: Mika
authors.initials: M
authors.lastname: Ogasawara
authors.affiliation: Laboratory of Veterinary Infectious Disease, School of Veterinary Medicine, Kitasato University, Towada, Aomori 034-8628, Japan.
authors.forename: Kumi
authors.initials: K
authors.lastname: Satoh
authors.affiliation: Laboratory of Veterinary Infectious Disease, School of Veterinary Medicine, Kitasato University, Towada, Aomori 034-8628, Japan.
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Satoh
authors.affiliation: Laboratory of Veterinary Infectious Disease, School of Veterinary Medicine, Kitasato University, Towada, Aomori 034-8628, Japan.
authors.forename: Maki
authors.initials: M
authors.lastname: Tanabe
authors.affiliation: Laboratory of Veterinary Infectious Disease, School of Veterinary Medicine, Kitasato University, Towada, Aomori 034-8628, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Hohdatsu
mesh_terms: D000643:Ammonium Chloride / Q000494:pharmacology; D000818:Animals; D000914:Antibodies, Viral / Q000494:pharmacology*; D019067:Antibody-Dependent Enhancement; D018826:CD13 Antigens / Q000502:physiology*; D002415:Cats; D016765:Coronavirus, Feline / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D011992:Endosomes / Q000187:drug effects / Q000378:metabolism*; D016766:Feline Infectious Peritonitis / Q000276:immunology* / Q000821:virology*; D018942:Macrolides / Q000494:pharmacology; D016676:Macrophages, Alveolar / Q000166:cytology / Q000821:virology; D011991:Receptors, Virus / Q000502:physiology*; D014779:Virus Replication / Q000187:drug effects
chemical_list: D000914:Antibodies, Viral; D018942:Macrolides; D011991:Receptors, Virus; D000643:Ammonium Chloride; C040929:bafilomycin A1; D018826:CD13 Antigens