PRODUCTION OF CYTOKINES AND PGE2 AND CYTOTOXICITY OF STIMULATED BONE-MARROW MACROPHAGES AFTER THERMAL-INJURY AND CYTOTOXICITY OF STIMULATEDU-937 MACROPHAGES

Bone marrow-derived macrophages from normal and burned rats were cultu red for one and four days in the presence of LPS, PHA, or opsonized zy mosan as activators, and the supernatants were assayed for the inflamm atory mediators TNF, IL-6, and PGE2 and the cells assayed for cytotoxi city. The macrophages responded differently to the various stimuli reg arding cytotoxicity and the production of mediators, perhaps implicati ng the complement receptor CR1 in TNF production and the LPS receptor CD14 or the PHA lectin receptor in IL-6 and PGE2 production and for cy totoxicity. The response of die cells also depended on culture time an d postburn time; in addition, macrophages from burned and unburned ani mals responded differently, depending on postburn day and the type of stimulus. TNF production was generally higher for one-day compared to four-day cultures (i.e., TNF was disappearing in the cultures), but IL -6 and PGE2 production was greater in four-day cultures. The results o f this study suggest that thermal injury can contribute to the develop ment of inflammatory and cytotoxic macrophages from bone marrow progen itor cells.