GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR MODULATES IMMUNE FUNCTION AND IMPROVES SURVIVAL AFTER EXPERIMENTAL THERMAL-INJURY

Thermal injury is associated with reduced colony-stimulating activity, which correlates with increased susceptibility to infection. To asses s the effect of susceptibility to infection. To assess the effect of t herapeutic administration of granulocyte-macrophage colony-stimulating factor (GM-CSF), 8-week old anaesthetized mice were subjected to eith er a 20 per cent body surface burn or a sham burn. Animals were subseq uently treated with either vehicle or a range of doses of GM-CSF (10-1 000 ng) with or without indomethacin (5 mu g). Sepsis was induced by c aecal ligation and puncture on day 10 after injury. Survival was signi ficantly better in animals treated with 200 ng GM-CSF on days 5-9 afte r the burn. Concanavalin A-stimulated T cell proliferation and interle ukin (IL)2 production were significantly depressed after burn injury. In vivo therapy with 200 ng GM-CSF, however, led to a significant impr ovement in both of these parameters of T cell function. These data sug gest that GM-CSF has a potential therapeutic role in the prevention of death from burn sepsis and appears to act, at least in part, by resto ring defective T cell proliferation and IL-2 production.