Stimulation and suppression of response of mouse T cells to the schistosomules of Schistosoma mansoni during infection

Abstract

INFECTION of mice with cercariae of Schistosoma mansoni produces a disease with immunopathology similar to human bilharziasis¹, the chronic hepatosplenomegaly being probably secondary to granulomatous reactions to eggs deposited in the tissues². It has been shown that thymus-derived lymphocytes have a major role in the granulomatous reaction^3,4, but the reaction of the T cells to earlier stages of the parasite has not hitherto been studied. We have investigated one such reaction—the helper T-cell response to the schistosomule—by using schistosomules as carriers for a hapten and measuring the anti-hapten response in normal and infected mice. In analogous experiments using protein carriers, the anti-hapten response has been shown to be due to cooperation between T cells and B cells⁵. We have found evidence for a specific T-dependent helper response which is greatly increased during the first 2 weeks after infection and subsequently diminishes, and we suggest that the diminution may partly represent a specific suppression of helper T-cell function.