title: Immunoglobulin C-gene expression. I. The commitment to IgG subclass of secretory cells is determined by the quality of the nonspecific stimuli.
abstract: Polyclonal stimulation of normal splenic B lymphocytes with either lipopolysaccharide (LPS) or helper T lymphocytes specific for B cell surface antigens results in the selective expression of IgG subclasses by the secretory cells: in addition to IgM-secreting plaque-forming cells (PFC), thymus-independent stimulation leads to the development of IgG2 and IgG3 PFC, while helper cell-dependent activation leads to IgG1 and IgG2 PFC. This cannot be solely explained by selective stimulation of distinct B cell subpopulations, because purified LPS-reactive blasts if restimulated by helper cells switch to IgG1 while if maintained with LPS switch to IgG3. The simultaneous stimulation of splenic B cells with LPS and helper cells results in additive IgM and IgG2 responses, but in the selective suppression of IgG3 PFC with a concomitant synergic enhancement of IgG1 responses. These results are interpreted to indicate that the expression of IgG C genes in proliferating B lymphocytes is directed by the quality of nonspecific stimuli.
mesh_terms: D000818:Animals; D000921:Antibody-Producing Cells / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology; D002478:Cells, Cultured; D007074:Immunoglobulin G / Q000145:classification*; D007136:Immunoglobulins / Q000235:genetics*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation; D051379:Mice; D008809:Mice, Inbred C3H; D008808:Mice, Inbred CBA; D008811:Mice, Inbred DBA; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D007074:Immunoglobulin G; D007136:Immunoglobulins; D008070:Lipopolysaccharides