Description of the effect of polyclonal mitogens on a population of splenic lymphocytes in the presence of serum against isologous aggregated mouse immunoglobulins

Antiserum against isologous aggregated mouse immunoglobulins was shown to be mitogenic for spleen cells during the first 48 hours of culture. The mitogenic effect of the serum factor is mediated through T lymphocytes and may be macrophage-dependent. Whe incubated with spleen cells the serum was demonstrated to inhibit the DNA synthesis in B cells in response to sulfate dextran and lipopolysaccharide. Experiments with B cells and the thymidine "suicide" test suggest that the target cells for the serum factor may reside in the population of radiosensitive and highly proliferating B lymphocytes. The degree of suppressing by the antiserum factor depends on the differentiation stage and the presence of antigen-binding receptors on the membrane of B cells.