POKEWEED MITOGEN INDUCED-DIFFERENTIATION OF HUMAN B-CELLS - EVALUATION BY A PROTEIN-A HEMOLYTIC PLAQUE-ASSAY

  • 1 January 1979
    • journal article
    • research article
    • Vol. 38  (1) , 181-189
Abstract
Using the protein A plaque assay, number of human cells secreting immunoglobulin (Ig) of various classes after pokeweed mitogen [PWM] stimulation was determined. At optimal response (on day 5-7) a mean of 58,354 IgM PFC [plaque-forming cells]/106, 34,207 IgG PFC/106 and 10,525 IgA PFC/106 cells was found when using peripheral blood lymphocytes. In spleen cells, peak values slightly higher than in blood were obtained at day 4-6. Proportions of cells secreting L chains of either type were comparable to those of unstimulated cells supporting the notion of the polyclonality of the response. PWM stimulation of peripheral blood lymphocytes was totally T [thymus-derived] cell dependent whereas response of spleen cells was not. When assayed for antigen-specific precursor cells in cultures stimulated by mitogen, frequency of SRBC [sheep red blood cell]-specific IgM producing cells was 1:3/1000 cells. This frequency was regularly independent of medium supplement.