Macrophages Are Required for the Dextran-Sulfate Induced Activation of B Lymphocytes

Abstract

The proliferative response induced by the B cell activating ligand dextran-sulfate (D×S) requires the presence of macrophage-produced factors or the macrophage-substituting compound 2-mercaptoethanol. Thus, the mechanism for activation of mouse B splenic lymphocytes is different for D×S than for other polyclonal B cell activators such as lipopolysaccharides, which can trigger B cells directly in the absence of helper factors. It is suggested that the disappearance of the D×S-induced response could be studied in a simple functional test for the efficiency of macrophage depletion obtained by different techniques.