Bone marrow derived (B)3 lymphocytes in lymphoid organs represent the precursors of antibody-producing cells and are known to bear immunoglobulin molecules on their cell surface representative of the antibody ultimately to be produced. It has been suggested that B-cells in bone marrow, although at least partially sensitive (1), are more resistant than splenic B-cells to inactivation by incubation with highly radioactive antigen (2). Similarly, induction of tolerance by injection of ultracentrifuged human γ globulin (HGG) occurs much more rapidly in B-cells of the spleen than of the bone marrow (3). In light of these observations and in view of the fact that Ig receptors on the surface of B-cells most probably mediate their interaction with antigen, it seemed interesting to compare the relative sensitivities of mouse bone marrow and spleen precursors of antibody-forming cells to inactivation by anti-Ig antisera.
Supported by Grant AI-3076 from the United States Public Health Service.
Abbreviations used in this paper: B, bone marrow derived; HGG, human γ globulin; BA, Brucella abortus; T, thymus derived; NRS, normal rabbit sera.