Immune response modulation after burn injury: T cells and antibodies.

Studies have been conducted to characterize phenotypic and functional characteristics of murine and human cells after burn injury. The detailed analysis of T-cell distribution in the burned mouse, and the analysis of activation markers L3T4/Lyt-2 and Ia, reveals characteristic changes including the presence of "activated" suppressor cells during post-injury suppression. Studies of humoral markers suggest an increased production of IgG in burned animals upon sheep red blood cells (SRBC) challenge, accompanied by increased clearance or catabolism of serum antibody, which results in depressed serum levels. Finally, in vitro phagocytosis studies using fluorescein isothiocyanate (FITC)-labeled killed bacteria reveal that burn patient sera are clearly defective in their ability to promote opsonization of one or more specific organisms by neutrophils. The addition of exogenous IgG to the incubation medium improves this response, suggesting that postburn phagocytic depression is an opsonic defect, rather than an inhibitory effect of burn serum on neutrophils.