title: Impairment of T-cell-dependent B-cell responses and B-1 cell development in CD19-deficient mice.
abstract: CD19 is the hallmark differentiation antigen of the B lineage. Its early expression has implicated a role for CD19 during the antigen-independent phases of B-cell development, whereas in mature B cells CD19 can act synergistically with surface immunoglobulin to induce activation. We have generated CD19-deficient mice and found that development of conventional B cells is unperturbed. However, mature CD19-/- B cells show a profound deficiency in responding to protein antigens that require T-cell help. This is accompanied by a lack of germinal centre formation and affinity maturation of serum antibodies. Thus CD19 is crucial for both initial B-cell activation by T-cell-dependent antigens and the maturation and/or selection of the activated cells into the memory compartment. An impairment in ligand-driven selection may also be responsible for the observation of a striking reduction in the B-1 (formerly Ly-1) B-cell subset, thought to develop under the control of self-antigens and bacterial antigens (reviewed in ref. 2).
authors.affiliation: Institute for Genetics, University of Cologne, Germany.
authors.forename: R C
authors.initials: RC
authors.lastname: Rickert
authors.forename: K
authors.initials: K
authors.lastname: Rajewsky
authors.forename: J
authors.initials: J
authors.lastname: Roes
mesh_terms: D000818:Animals; D000941:Antigens / Q000276:immunology; D015703:Antigens, CD / Q000276:immunology*; D018941:Antigens, CD19; D000944:Antigens, Differentiation, B-Lymphocyte / Q000276:immunology*; D016175:B-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology*; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D001483:Base Sequence; D001854:Bone Marrow Cells; D002454:Cell Differentiation; D002478:Cells, Cultured; D017931:DNA Primers; D005434:Flow Cytometry; D006412:Hematopoietic Stem Cells; D008213:Lymphocyte Activation / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D016296:Mutagenesis; D010529:Peritoneal Cavity / Q000166:cytology; D013154:Spleen / Q000166:cytology; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000941:Antigens; D015703:Antigens, CD; D018941:Antigens, CD19; D000944:Antigens, Differentiation, B-Lymphocyte; D017931:DNA Primers