title: Distribution of Ig classes and IgG subclasses among human B cells activated by Nocardia opaca-delipidated cell mitogen or by pokeweed mitogen.
abstract: The relative proportions of cells synthesizing the three major Ig classes or one of the four IgG subclasses in cultures stimulated with pokeweed mitogen (PWM) or Nocardia-delipidated cell mitogen (NDCM) were investigated. In cultures of human peripheral blood mononuclear cells (PB MNC) stimulated with PWM, the number of IgG-containing cells (CC) was higher than the number of IgM-CC, and a substantial number of IgA-CC was found. Conversely, in NDCM-stimulated PB MNC cultures IgM-CC outnumbered IgG-CC and only few IgA-CC were detected. In those cultures, the removal of T cells resulted in an increase in the number of IgM-CC concomitant with a decrease in the number of IgG-CC. A substantial number of cells containing simultaneously IgG or IgA in addition to IgM could be found in PWM-stimulated cultures. These cells were virtually absent in NDCM-stimulated cultures. The relative proportions of IgG subclass-CC were IgG1-CC greater than IgG2-CC greater than IgG3-CC greater than or equal to IgG4-CC in PWM-stimulated and IgG2-CC greater than IgG1-CC greater than IgG3-CC greater than or equal to IgG4-CC in NDCM-stimulated cultures. The removal of T cells from NDCM-stimulated cultures did not result in major alteration of this distribution. The role of T cells and of the genomic order of the Igh-C genes in their phenotypic expression triggered in vitro by PBA is discussed.
mesh_terms: D001402:B-Lymphocytes / Q000145:classification / Q000378:metabolism*; D006801:Humans; D007070:Immunoglobulin A / Q000096:biosynthesis; D007126:Immunoglobulin Allotypes / Q000096:biosynthesis / Q000145:classification*; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000145:classification*; D007075:Immunoglobulin M / Q000096:biosynthesis; D007700:Kinetics; D008213:Lymphocyte Activation; D008212:Lymphocyte Depletion; D009615:Nocardia / Q000276:immunology; D011043:Pokeweed Mitogens / Q000494:pharmacology; D013601:T-Lymphocytes
chemical_list: D007070:Immunoglobulin A; D007126:Immunoglobulin Allotypes; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D011043:Pokeweed Mitogens