title: Down regulation of Fc and complement receptors on B cells in rheumatoid arthritis.
abstract: B cell tolerance is regulated by receptors that modulate B cell receptor signaling, such as Fc gamma receptor IIb (FcγRIIb; CD32b) and complement receptors (CR) 1 and 2. Deficiency in these receptors may contribute to autoimmunity. To address this we have investigated the receptor expression in healthy individuals in comparison with rheumatoid arthritis (RA) patients. In healthy subjects we found that women had overall lower FcγRIIb expression on B cells than men that significantly decreased with age. RA patients had fewer FcγRIIb, CR1 and CR2 positive B cells and decreased receptor expressions compared to healthy subjects. Further, the RA B cells displayed a significantly increased proliferative response when cultured with interleukin-2 in vitro. In summary, the dysregulated B cells in RA are associated with lower FcγRIIb, CR1 and CR2 levels. The reduced FcγRIIb expression on B cells in women may influence the increased frequency of autoimmunity in women.
authors.affiliation: Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden.
authors.forename: Kajsa E
authors.initials: KE
authors.lastname: Prokopec
authors.forename: Mia
authors.initials: M
authors.lastname: Rhodiner
authors.forename: Peter
authors.initials: P
authors.lastname: Matt
authors.forename: Ulla
authors.initials: U
authors.lastname: Lindqvist
authors.forename: Sandra
authors.initials: S
authors.lastname: Kleinau
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000276:immunology*; D015551:Autoimmunity; D001402:B-Lymphocytes / Q000276:immunology*; D049109:Cell Proliferation; D004198:Disease Susceptibility; D015536:Down-Regulation / Q000276:immunology; D005260:Female; D006801:Humans; D007376:Interleukin-2 / Q000276:immunology; D008297:Male; D008875:Middle Aged; D017463:Receptors, Complement 3b / Q000172:deficiency / Q000276:immunology*; D017464:Receptors, Complement 3d / Q000172:deficiency / Q000276:immunology*; D017452:Receptors, IgG / Q000276:immunology* / Q000378:metabolism*; D012737:Sex Factors
chemical_list: C080571:Fc gamma receptor IIB; D007376:Interleukin-2; D017463:Receptors, Complement 3b; D017464:Receptors, Complement 3d; D017452:Receptors, IgG