SOLUBLE PEPTIDOGLYCAN-INDUCED MONOKINE PRODUCTION CAN BE BLOCKED BY ANTI-CD14 MONOCLONAL-ANTIBODIES AND BY LIPID-A PARTIAL STRUCTURES

We have investigated the interaction of soluble peptidoglycan (sPG), i n comparison with lipopolysaccharide (LPS), with human mononuclear cel ls (MNC) by determining the capacity of sPG to induce interleukin-6 (I L-6) and IL-1 release. In addition, we investigated the modulation of their interaction by anti-CD14 monoclonal antibody and by partial stru ctures of LPS. We found that sPG, like LPS, was able to induce IL-6 an d IL-1 production by MNC. However, dose-response experiments revealed that at least 3,000 ng of sPG per mt was necessary for induction, wher eas the optimal LPS concentration was 1 ng/ml. Anti-CD14 monoclonal an tibody reduced sPG- and LPS-induced IL-6 and IL-1 production. Moreover , partial structures of LPS mere able to reduce monokine production in duced by sPG and LPS. We conclude that sPG constitutes, like LPS, an i nflammatory cytokine inducer and that CD14 is involved in the activati on of human monocytes not only by LPS but also by sPG.