Dissociation between the Adjuvant vs Mitogenic Activity of a Synthetic Muramyl Dipeptide for Murine Splenocytes

Abstract

A relatively low MW synthetic muramyl dipeptide stimulated antibody formation by normal mouse splenocytes immunized with sheep red blood cells in vitro. This material also resulted in a marked stimulation of background antibody-forming cells to the erythrocytes in cultures incubated without antigen. The muramyl dipeptide, regardless of concentration, did not induce a marked blastogenic response in vitro, as occurs with adjuvants such as bacterial lipopolysaccharides. The nonspecific immunostimulatory properties of a low MW substance such as the muramyl dipeptide tested, which is commonly found in bacterial cell walls, may not be dependent upon mitogenicity.