title: Effect of TH-lines and clones on the growth and differentiation of B cell clones in microculture.
abstract: Antibody isotype expression by B cell clones was analyzed using in vitro microcultures containing low numbers of hapten-gelatin-enriched B cells and higher numbers of hemocyanin-specific helper T cell lines or clones. Twenty-eight to sixty-three percent of clones grown in microculture with haptenated hemocyanin and T cells from established lines expressed IgG and/or IgA isotypes in random mixtures, almost always accompanied by IgM. Helper T cells from hemocyanin-specific clones also supported the expression of non-IgM isotypes by the B cell clones, suggesting that a single specificity of T cell can provide sufficient growth and differentiation factors for the display of isotype switching. A positive correlation between the antibody output of clones and the expression of non-IgM isotypes indicated that the switching process may be associated with cell division. Although memory B cells that give clones expressing IgG and/or IgA in the absence of IgM are also enriched on haptenated gelatin, they are not stimulable under conditions of this microculture assay.
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D002460:Cell Line; D002999:Clone Cells / Q000276:immunology; D000939:Epitopes / Q000276:immunology; D006241:Haptens / Q000276:immunology; D007070:Immunoglobulin A / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis; D007132:Immunoglobulin Isotypes / Q000032:analysis; D008213:Lymphocyte Activation; D008211:Lymphocyte Cooperation; D051379:Mice; D008807:Mice, Inbred BALB C; D008808:Mice, Inbred CBA; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
chemical_list: D000939:Epitopes; D006241:Haptens; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007132:Immunoglobulin Isotypes