EFFECTS OF SINEFUNGIN AND 5'-DEOXY-5'-S-ISOBUTYL-ADENOSINE ON LIPOPOLYSACCHARIDE-INDUCED PROLIFERATION AND PROTEIN N-METHYLATION OF ARGINYL RESIDUES IN MURINE SPLENIC LYMPHOCYTES

Abstract

The effects of sinefungin (SF) and 5'-deoxy-5'-S-isobutyl-adenosine (SIBA) on lymphoproliferation and protein N-methylation of arginyl residues were investigated in splenic lymphocyte culture in vitro. Both SF and SIBA produced a dose-related inhibition of the lymphoproliferative response to lipopolysaccharide (LPS). The time-course of the inhibition indicated that SIBA had a more inhibitory effect than that of SF at short incubation periods, but SF showed more inhibition when the incubation was prolonged. The effects of SF and SIBA on the lymphoproliferative response corresponded with their effects on the protein N-methylation of arginyl residues by protein methylase I.