Suppressor Cell Activity after Major Injury

Abstract

In vitro responses to streptokinase-streptodornase (SKSD), mumps and mixed lymphocyte culture (MLC) in 19 burned and 13 multitrauma patients were studied sequentially by lymphocyte 3H-thymidine incorporation and compared to responses of 28 normals. Mean responses to SKSD remained significantly depressed from normal for up to 14-28 days following injury; MLC responses, significantly depressed at 48 h, recovered promptly to normal levels. Because of evidence that the proliferative capacity of the T-cell population to soluble antigens is contained within the inducer subpopulation while both inducer and suppressor subpopulations respond in MLC, the observed increase in MLC responses, coupled with a sustained depression of SKSD and mumps responses, suggests activation of a population of suppressor cells. In a direct assay of suppressor cell function, lymphocytes from 3 of 4 multitrauma patients incubated in a 2-way MLC with normal lymphocytes significantly suppressed PHA [phytohemagglutinin] responsiveness, confirming the findings of the direct assay.