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.
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.
Takano
Tomomi
T
Laboratory of Veterinary Infectious Disease, School of Veterinary Medicine, Kitasato University, Towada, Aomori 034-8628, Japan.
Katada
Yukari
Y
Laboratory of Veterinary Infectious Disease, School of Veterinary Medicine, Kitasato University, Towada, Aomori 034-8628, Japan.
Moritoh
Saiko
S
Laboratory of Veterinary Infectious Disease, School of Veterinary Medicine, Kitasato University, Towada, Aomori 034-8628, Japan.
Ogasawara
Mika
M
Laboratory of Veterinary Infectious Disease, School of Veterinary Medicine, Kitasato University, Towada, Aomori 034-8628, Japan.
Satoh
Kumi
K
Laboratory of Veterinary Infectious Disease, School of Veterinary Medicine, Kitasato University, Towada, Aomori 034-8628, Japan.
Satoh
Ryoichi
R
Laboratory of Veterinary Infectious Disease, School of Veterinary Medicine, Kitasato University, Towada, Aomori 034-8628, Japan.
Tanabe
Maki
M
Laboratory of Veterinary Infectious Disease, School of Veterinary Medicine, Kitasato University, Towada, Aomori 034-8628, Japan.
Hohdatsu
Tsutomu
T
Laboratory of Veterinary Infectious Disease, School of Veterinary Medicine, Kitasato University, Towada, Aomori 034-8628, Japan.
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
D000914:Antibodies, Viral; D018942:Macrolides; D011991:Receptors, Virus; D000643:Ammonium Chloride; C040929:bafilomycin A1; D018826:CD13 Antigens