Occurrence of fibronectin antigenic determinants onSchistosoma mansonilung schistosomula and adult worms

Abstract
SUMMARY: Fibronectin determinants were revealed in a soluble extract ofSchistosoma mansoniadult worms by standard immunodiffusion and immunoelectrophoresis techniques. The same target molecules were demonstrated on the parasite's surface using a binding assay with [125I] anti-fibronectin. The use of fluorescein- and peroxidase-conjugated antibodies confirmed the above observations and provided a fairly precise means for locating the cross-reacting antigen on the worm surface. Anin vitrocytotoxic assay using inactivated (56°C, 2 h) anti-fibronectin rabbit immune serum and guinea-pig serum as a source of complement was developed. In these conditions, anti-fibronectin exerted cytotoxic activity against lung schistosomula and adult worms but not skin schistosomula. The ultrastructural damage induced by anti-fibronectin in the presence of complement was studied using transmission electron microscopy. The results suggest a close association between fibronectin determinants andS. mansonimembrane.