title: Memory B-cell persistence is independent of persisting immunizing antigen.
abstract: Immunological memory in the antibody system is generated in T-cell-dependent responses and carried by long-lived memory B cells that recognize antigen by high-affinity antibodies. But it remains controversial whether these B cells represent true 'memory' cells (that is, their maintenance is independent of the immunizing antigen), or whether they are a product of a chronic immune response driven by the immunizing antigen, which can be retained in the organism for extended time periods on the surface of specialized antigen-presenting cells (follicular dendritic cells). Cell transfer experiments provided evidence in favour of a role of the immunizing antigen; however, analysis of memory cells in intact animals, which showed that these cells are mostly resting and can persist in the absence of detectable T-cell help or follicular dendritic cells, argued against it. Here we show, by using a genetic switch mediated by Cre recombinase, that memory B cells switching their antibody specificity away from the immunizing antigen are indeed maintained in the animal over long periods of time, similar to cells retaining their original antigen-binding specificity.
authors.affiliation: Institute for Genetics, University of Cologne, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Maruyama
authors.forename: K P
authors.initials: KP
authors.lastname: Lam
authors.forename: K
authors.initials: K
authors.lastname: Rajewsky
mesh_terms: D000483:Alleles; D000818:Animals; D000918:Antibody Specificity; D000941:Antigens / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D003001:Cloning, Molecular; D005812:Genes, Switch; D005838:Genotype; D006241:Haptens / Q000276:immunology; D007074:Immunoglobulin G / Q000235:genetics / Q000276:immunology; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D007156:Immunologic Memory; D019426:Integrases / Q000378:metabolism; D007370:Interferon Type I / Q000502:physiology; D008969:Molecular Sequence Data; D009596:Nitrophenols / Q000276:immunology; D010648:Phenylacetates; D010799:Phycoerythrin / Q000276:immunology; D011995:Recombination, Genetic; D014764:Viral Proteins
chemical_list: D000941:Antigens; D006241:Haptens; D007074:Immunoglobulin G; D007143:Immunoglobulin Heavy Chains; D007370:Interferon Type I; D009596:Nitrophenols; D010648:Phenylacetates; D014764:Viral Proteins; C026242:4-hydroxy-5-nitrophenyl acetic acid; D010799:Phycoerythrin; C045073:Cre recombinase; D019426:Integrases