HUMAN BONE-MARROW LYMPHOCYTES .3. POLYCLONAL ACTIVATION OF B LYMPHOCYTES IN HUMAN BONE-MARROW MEASURED BY A DIRECT PLAQUE-FORMING CELL ASSAY

  • 1 January 1977
    • journal article
    • research article
    • Vol. 118  (4) , 1150-1153
Abstract
Lymphocytes from the bone marrow and peripheral blood of the same normal individuals were assayed simultaneously for blast transformation and polyclonal activation with differentiation to antibody-forming cells after stimulation with pokeweed mitogen. Blastogenic responses were measured by 3H-thymidine incorporation and antibody-forming cells were enumerated by a newly described hemolysis-in-gel plaque-forming cell assay. There was no significant difference between the blastogenic responses of lymphocytes in the peripheral blood compared to the bone marrow of the same individuals. However, differentiation to antibody-forming cells measured by the plaque-forming cells response was significantly greater in lymphocytes in the bone marrow as compared to peripheral blood of the same individuals. The lymphocytes in human bone marrow are at a stage of differentiation whereby they can be readily induced to differentiation toward antibody production by polyclonal activation, even more so than peripheral blood lymphocytes. The bone marrow is apparently a major source of Ig production in man.