MACROPHAGE ACTIVATION IN RESPONSE TO S-FORM LIPOPOLYSACCHARIDES (LPS)SEPARATED BY CENTRIFUGAL PARTITION CHROMATOGRAPHY FROM WILD-TYPE LPS - EFFECTS OF THE O-POLYSACCHARIDE PORTION OF LPS

The S-form lipopolysaccharide (LPS) was effectively separated from a n ative preparation of smooth-type Salmonella abortus equi LPS by means of the centrifugal partition chromatography (CPC). To clarify the mech anisms by which LPS activates macrophages, CPC-separated S-form LPS wa s assessed for its ability to induce the secretion of tumor necrosis f actor-alpha (TNF-alpha) by murine macrophage-like J774.1 cells in comp arison with other fractions of LPS which lacks most of O-polysaccharid es, LPS dose-response and time-kinetics studies showed that serum fact or(s) regulated especially the onset of TNF-alpha secretion in stimula tion with S-form LPS. These results strongly suggest that the native ( unfractionated) LPS activates macrophages in both O-polysaccharide/ser um-dependent and -independent pathways. (C) 1995 Academic Press, Inc.