title: B-cell activation in cats with feline infectious peritonitis (FIP) by FIP-virus-induced B-cell differentiation/survival factors.
abstract: It has been suggested that antibody overproduction plays a role in the pathogenesis of feline infectious peritonitis (FIP). However, only a few studies on the B-cell activation mechanism after FIP virus (FIPV) infection have been reported. The present study shows that: (1) the ratio of peripheral blood sIg(+) CD21(-) B-cells was higher in cats with FIP than in SPF cats, (2) the albumin-to-globulin ratio has negative correlation with the ratio of peripheral blood sIg(+) CD21(-) B-cell, (3) cells strongly expressing mRNA of the plasma cell master gene, B-lymphocyte-induced maturation protein 1 (Blimp-1), were increased in peripheral blood in cats with FIP, (4) mRNA expression of B-cell differentiation/survival factors, IL-6, CD40 ligand, and B-cell-activating factor belonging to the tumor necrosis factor family (BAFF), was enhanced in macrophages in cats with FIP, and (5) mRNAs of these B-cell differentiation/survival factors were overexpressed in antibody-dependent enhancement (ADE)-induced macrophages. These data suggest that virus-infected macrophages overproduce B-cell differentiation/survival factors, and these factors act on B-cells and promote B-cell differentiation into plasma cells in FIPV-infected cats.
authors.affiliation: Laboratory of Veterinary Infectious Disease, School of Veterinary Medicine, Kitasato University, Towada, Aomori, Japan.
authors.forename: Tomomi
authors.initials: T
authors.lastname: Takano
authors.forename: Natsuko
authors.initials: N
authors.lastname: Azuma
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
mesh_terms: D000818:Animals; D053265:B-Cell Activation Factor Receptor / Q000235:genetics; D001402:B-Lymphocytes / Q000276:immunology*; D023201:CD40 Ligand / Q000235:genetics; D002415:Cats; D002454:Cell Differentiation / Q000235:genetics*; D018352:Coronavirus Infections / Q000276:immunology / Q000662:veterinary*; D016765:Coronavirus, Feline / Q000276:immunology*; D018076:DNA, Complementary / Q000032:analysis; D016766:Feline Infectious Peritonitis / Q000276:immunology* / Q000821:virology; D005786:Gene Expression Regulation; D015850:Interleukin-6 / Q000235:genetics; D008213:Lymphocyte Activation / Q000276:immunology*; D008264:Macrophages / Q000276:immunology; D012097:Repressor Proteins / Q000235:genetics; D017421:Sequence Analysis; D014779:Virus Replication
chemical_list: D053265:B-Cell Activation Factor Receptor; D018076:DNA, Complementary; D015850:Interleukin-6; D012097:Repressor Proteins; D023201:CD40 Ligand