The roles of macrophage (M phi) and PGE-2 in postburn immunosuppression

Postburn immunosuppression in mice with full skin thickness burns was assessed after Con A stimulation of splenic lymphocytes. The immunosuppression was detected within 24 h of injury and was maximal 3-7 days later. Such lymphocyte proliferation was enhanced by depletion of adherent cells (M phi) in burned mice and could be depressed in normal mice by injection of these adherent cells from burned mice. These results suggest the presence of M phi s with a suppressor function. No difference in spontaneous blastogenic transformation (SBT) of spleen cells between the burned and normal mice was found, but after removal of the M phi s the SBT of spleen cells of burned mice became significantly elevated. Hence both M phi and lymphocytes in mouse spleen cells were activated after severe thermal injury.