title: Recruitment and selection of marginal zone B cells is independent of exogenous antigens.
abstract: Marginal zone B (MZ-B) cells of the spleen contribute significantly to the immunity against invasive infections with polysaccharide-encapsulated bacteria. Recent evidence indicates that recruitment and selection of MZ-B cells occurs on the basis of positive selection constraints that likely operate via B cell receptor (BCR) signaling. Previous studies have shown that MZ-B cells carry relatively shorter immunoglobulin (Ig) heavy (H) chain complementarity-determining region 3 (H-CDR3) sequences and express BCR which are thought to be polyreactive. In this scenario, MZ-B cell selection proceeds via engagement of the BCR with exogenous (i.e. microbial gut flora-derived) and/or endogenous (self) antigens. Here, we studied the influence of exogenous antigens on the selection process of MZ-B cells using non-genetically manipulated adult germ-free and conventionally reared infant rats. This study was carried out by H-CDR3 spectratype analysis of V(H)(PC7183)-encoded Ig V(H)DJ(H)-mu transcripts expressed by purified splenic MZ-B cells and other B cell subsets. We show that MZ-B cells in both adult germ-free and conventionally reared infant (14-day-old) rats are H-CDR3-selected cells, providing strong evidence that recruitment and selection of MZ-B cells is driven by self antigens.
authors.affiliation: Department of Cell Biology, Histology and Immunology Section, University Medical Center Groningen (UMCG), University of Groningen, Groningen, The Netherlands. p.m.dammers@med.umcg.nl
authors.forename: Peter M
authors.initials: PM
authors.lastname: Dammers
authors.forename: Frans G M
authors.initials: FG
authors.lastname: Kroese
mesh_terms: D000367:Age Factors; D000818:Animals; D000941:Antigens / Q000502:physiology*; D001402:B-Lymphocytes / Q000276:immunology*; D002454:Cell Differentiation / Q000276:immunology*; D002465:Cell Movement / Q000276:immunology*; D022801:Complementarity Determining Regions / Q000235:genetics / Q000276:immunology; D005260:Female; D005434:Flow Cytometry; D019084:Fluorescent Antibody Technique, Indirect; D005856:Germ-Free Life; D018858:Germinal Center / Q000166:cytology* / Q000276:immunology*; D007143:Immunoglobulin Heavy Chains / Q000235:genetics / Q000276:immunology; D016130:Immunophenotyping; D051381:Rats; D017208:Rats, Wistar; D013154:Spleen / Q000166:cytology / Q000276:immunology
chemical_list: D000941:Antigens; D022801:Complementarity Determining Regions; D007143:Immunoglobulin Heavy Chains