title: IgM memory B cells: a mouse/human paradox.
abstract: Humoral memory is maintained by two types of persistent cells, memory B cells and plasma cells, which have different phenotypes and functions. Long-lived plasma cells can survive for a lifespan within a complex niche in the bone marrow and provide continuous protective serum antibody levels. Memory B cells reside in secondary lymphoid organs, where they can be rapidly mobilized upon a new antigenic encounter. Surface IgG has long been taken as a surrogate marker for memory in the mouse. Recently, however, we have brought evidence for a long-lived IgM memory B cell population in the mouse, while we have also argued that, in humans, these same cells are not classical memory B cells but marginal zone (MZ) B cells which, as opposed to their mouse MZ counterpart, recirculate and carry a mutated B cell receptor. In this review, we will discuss these apparently paradoxical results.
authors.affiliation: Faculté de Médecine, Site Necker-Enfants Malades, INSERM U783 Développement du système immunitaire, Université Paris Descartes, 156 rue de Vaugirard, Paris Cedex 15, France. claude-agnes.reynaud@inserm.fr
authors.forename: Claude-Agnès
authors.initials: CA
authors.lastname: Reynaud
authors.forename: Marc
authors.initials: M
authors.lastname: Descatoire
authors.forename: Ismail
authors.initials: I
authors.lastname: Dogan
authors.forename: François
authors.initials: F
authors.lastname: Huetz
authors.forename: Sandra
authors.initials: S
authors.lastname: Weller
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Weill
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology* / Q000502:physiology; D006801:Humans; D007075:Immunoglobulin M / Q000737:chemistry*; D007156:Immunologic Memory; D051379:Mice; D011947:Receptors, Antigen, B-Cell / Q000235:genetics; D013045:Species Specificity
chemical_list: D007075:Immunoglobulin M; D011947:Receptors, Antigen, B-Cell