T-cell helper response to antigens of Schistosoma mansoni in CBA mice.

It is believed that a T-cell helper response against the schistosome surface is a necessary prerequisite for the development of protective immunity in schistosomiasis. Accordingly, the carrier effect has been used to assay eleven antigenic preparations of Schistosoma mansoni for their helper T-cell priming against surface components of the schistosomula. Three weeks after i.v. injection of the preparation, CBA mice were injected with schistosomula coated with trinitrophenol (TNP) and 4 days later, their spleens were assayed for plaque-forming cells (PFC) against TNP. Formalin-fixed schistosomula and crude adult worm tegumental membrane induced the highest response; only thirty schistosomula or 10mug of crude membrane protein were needed to generate a T-cell helper response equivalent to that induced by a living infection. All other antigenic preparations, including formalin-fixed cercariae, live miracidia, eggs and adult worm culture fluid, generated some response indicating the presence of shared carrier components.