title: Expression of Ia antigens on hapten-specific B cells. I. Delineation of B-cell subpopulations.
abstract: The nonimmune adult spleen contains at least two B-cell subpopulations. The majority of primary B cells express cell surface Ia determinants and have the capacity to give rise to IgG antibody-producing clones after T-cell dependent antigenic stimulation. There is also a small subpopulation of primary B cells which are, by definition, Ia negative, since their activity is not eliminated by negative selection with anti-Ia serum and complement. The Ia-negative B cells give rise to clones that produce only IgM antibody. These B-cell subsets may form a continuum in B-cell maturation, or they may exist as discrete B-cell lineages. Since the cellular expression of Ia antigens appears to correlate with the ability of the B cell to generate IgG-producing clones, it is speculated that Ia molecules may have a role in the IgM to IgG B-cell switch mechanism.
mesh_terms: D000818:Animals; D000917:Antibody Formation; D001402:B-Lymphocytes / Q000276:immunology*; D002999:Clone Cells / Q000276:immunology; D007074:Immunoglobulin G / Q000096:biosynthesis; D007075:Immunoglobulin M / Q000096:biosynthesis; D007156:Immunologic Memory; D007519:Isoantigens; D051379:Mice; D008807:Mice, Inbred BALB C; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007519:Isoantigens