title: Intravenous immunoglobulin up-regulates the expression of the inhibitory FcgammaIIB receptor on B cells.
abstract: Intravenous immunoglobulin (IVIg) preparations are known to modulate autoimmune/inflammatory diseases through several F(ab')(2)- and Fc-dependent mechanisms. In this study, we show that the in vitro and the in vivo exposure of B lymphocytes from lupus-prone and from healthy mice to IVIg results in an increased expression of their surface inhibitory FcgammaIIB receptors. Further, this exposure enhanced the ability of a chimeric antibody, cross-linking FcgammaRIIB and immunoglobulin receptors on DNA-specific B lymphocytes, to suppress IgG anti-DNA antibody production. F(ab')(2) fragments of IVIg had a similar activity as the intact preparation, whereas Fc fragments had no effect. This study describes a novel approach with clinical relevance for modulating B lymphocyte activity.
authors.affiliation: Department of Immunology, Stefan Angelov Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, Bulgaria.
authors.forename: Kalina A
authors.initials: KA
authors.lastname: Nikolova
authors.forename: Andrey I
authors.initials: AI
authors.lastname: Tchorbanov
authors.forename: Iglika K
authors.initials: IK
authors.lastname: Djoumerska-Alexieva
authors.forename: Maria
authors.initials: M
authors.lastname: Nikolova
authors.forename: Tchavdar L
authors.initials: TL
authors.lastname: Vassilev
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D002478:Cells, Cultured; D004353:Drug Evaluation, Preclinical; D005260:Female; D016756:Immunoglobulins, Intravenous / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000187:drug effects; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D017452:Receptors, IgG / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects
chemical_list: C499172:Fcgr2b protein, mouse; D016756:Immunoglobulins, Intravenous; D017452:Receptors, IgG