Antibody potential of human peripheral blood lymphocytes differentially expressing surface membrane IgM.
The appearance of circulating pokeweed mitogen-reactive B lymphocyte subpopulations responsible for the synthesis of IgM and IgG anti-tetanus toxoid antibody after in vivo booster immunization has been analyzed for differential expression of surface membrane IgM. B cells were rosetted with human mu-chain specific antiglobulin-coupled ox red blood cells and separated by density centrifugation into mu+ and mu- populations. After 8 days in vitro culture with irradiated T cells and pokeweed mitogen, antibody synthesis was assessed by quantitative radioimmunoassay. Mu+ cells synthesized both IgG and IgM anti-tetanus toxoid antibodies, whereas mu- cells predominantly synthesized IgG anti-tetanus toxoid antibodies. Limiting dilution analysis revealed a greater number of IgG anti-tetanus toxoid precursors in the mu+ population at all times after immunization compared with mu- cells. However, the activity, as measured by the amount of antibody produced per IgG anti-tetanus toxoid antibody precursor, was 2 to 4 times greater in the mu- population than that in the mu+ population. These results indicate that functionally distinct human circulating B lymphocytes can be identified by their differential expression of surface membrane IgM.
D000818:Animals; D000917:Antibody Formation; D000921:Antibody-Producing Cells / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology; D002417:Cattle; D006801:Humans; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007148:Immunoglobulin mu-Chains; D008214:Lymphocytes / Q000276:immunology*; D011817:Rabbits; D011947:Receptors, Antigen, B-Cell; D012397:Rosette Formation; D013745:Tetanus Toxoid / Q000276:immunology
D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007148:Immunoglobulin mu-Chains; D011947:Receptors, Antigen, B-Cell; D013745:Tetanus Toxoid