Time-Dependent Synergism of Rat Spleen and Bone Marrow Cells.

Normal rat spleen cells, when cultured with solubilized sheep erythrocyte stroma in vitro, did not produce antibody but did show an increased rate of thymidine uptake. Normal rat bone marrow cells did not show a similar increase in thymidine uptake when cultured with solubilized stroma. Culture of these two cell types together with antigen resulted in a synergistic increase in thymidine uptake which decreased in intensity as the animals aged. The bone marrow population is responsible for this diminished synergistic activity. [ABSTRACT FROM AUTHOR]