title: Neutrophil survival factors (TNF-alpha, GM-CSF, and G-CSF) produced by macrophages in cats infected with feline infectious peritonitis virus contribute to the pathogenesis of granulomatous lesions.
abstract: Feline infectious peritonitis (FIP) is a feline coronavirus (FCoV)-induced fatal disease of domestic and wild cats. The infiltration of neutrophils into granulomatous lesions is unusual for a viral disease, but it is a typical finding of FIP. This study aimed to investigate the reason for the lesions containing neutrophils in cats with FIP. Neutrophils of cats with FIP were cultured, and changes in the cell survival rate were assessed. In addition, the presence or absence of neutrophil survival factors was investigated in specimens collected from cats with FIP. Furthermore, it was investigated whether macrophages, one of the target cells of FIPV infection, produce neutrophil survival factors (TNF-alpha, GM-CSF, and G-CSF). We showed that virus-infected macrophages overproduce neutrophil survival factors, and these factors act on neutrophils and up-regulate their survival. These observations suggest that sustained production of neutrophil survival factors by macrophages during FCoV infection is sufficient for neutrophil survival and contributes to development of granulomatous lesions.
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.forename: Natsuko
authors.initials: N
authors.lastname: Azuma
authors.forename: Miyuki
authors.initials: M
authors.lastname: Satoh
authors.forename: Ayako
authors.initials: A
authors.lastname: Toda
authors.forename: Yoshikiyo
authors.initials: Y
authors.lastname: Hashida
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Satoh
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Hohdatsu