LIPOPOLYSACCHARIDE-INDUCED CHANGE OF ADP-RIBOSYLATION OF A CYTOSOLIC PROTEIN IN BONE-MARROW-DERIVED MACROPHAGES

Treatment of bone-marrow-derived macrophages with nanogram quantities of bacterial lipopolysaccharide (LPS) or with the synthetic bacterial lipopeptide analogue palmitoyl-(S)-[2,3-bis(palmitoyloxy)-(2RS)-propyl ] (Pam(3))Cys-Ala-Gly results in a change of ADP-ribosylation of a cyt osolic 33 kDa protein. The immunostimulant-induced change is both dose - and time-dependent. It is not observed in macrophages from an LPS-un responsive C3H/HeJ mouse strain upon treatment with LPS. Non-endotoxic LPS from Rhodopseudomonas pallustris, the inactive lipopeptide analog ue Pam(3)CysOH, and LPS in the presence of polymyxin B fail to induce the change of ADP-ribosylation of the protein. These observations indi cate that reversible protein modification by ADP-ribosylation might pl ay a role in macrophage activation.