title: Development of monoclonal antibodies (MAbs) to feline interferon (fIFN)-γ as tools to evaluate cellular immune responses to feline infectious peritonitis virus (FIPV).
abstract: Feline infectious peritonitis virus (FIPV) can cause a lethal disease in cats, feline infectious peritonitis (FIP). The antibody-dependent enhancement (ADE) of FIPV infection has been recognised in experimentally infected cats, and cellular immunity is considered to play an important role in preventing the onset of FIP. To evaluate the importance of cellular immunity for FIPV infection, monoclonal antibodies (MAbs) against feline interferon (fIFN)-γ were first created to establish fIFN-γ detection systems using the MAbs. Six anti-fIFN-γ MAbs were created. Then, the difference in epitope which those MAbs recognise was demonstrated by competitive enzyme-linked immunosorbent assay (ELISA) and IFN-γ neutralisation tests. Detection systems for fIFN-γ (sandwich ELISA, ELISpot assay, and two-colour flow cytometry) were established using anti-fIFN-γ MAbs that recognise different epitopes. In all tests, fIFN-γ production from peripheral blood mononuclear cells (PBMCs) obtained from cats experimentally infected with an FIPV isolate that did not develop the disease was significantly increased by heat-inactivated FIPV stimulation in comparison with medium alone. Especially, CD8(+)fIFN-γ(+) cells, but not CD4(+)fIFN-γ(+) cells, were increased. In contrast, fIFN-γ production from PBMCs isolated from cats that had developed FIP and specific pathogen-free (SPF) cats was not increased by heat-inactivated FIPV stimulation. These results suggest that cellular immunity plays an important role in preventing the development of FIP. Measurement of fIFN-γ production with the anti-fIFN-γ MAbs created in this study appeared to be useful in evaluating cellular immunity in cats.
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.forename: Ayumi
authors.initials: A
authors.lastname: Kaku
authors.forename: Megumi
authors.initials: M
authors.lastname: Satomura
authors.forename: Michiyo
authors.initials: M
authors.lastname: Kohori
authors.forename: Kanako
authors.initials: K
authors.lastname: Noura
authors.forename: Tomoko
authors.initials: T
authors.lastname: Furukawa
authors.forename: Masako
authors.initials: M
authors.lastname: Kotake
authors.forename: Tomomi
authors.initials: T
authors.lastname: Takano
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Hohdatsu
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D002415:Cats; D016765:Coronavirus, Feline / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D058501:Enzyme-Linked Immunospot Assay / Q000379:methods / Q000662:veterinary; D016766:Feline Infectious Peritonitis / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D007111:Immunity, Cellular / Q000276:immunology; D007371:Interferon-gamma / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C
chemical_list: D000911:Antibodies, Monoclonal; D007371:Interferon-gamma