Schistosoma mansoni: Immediate hypersensitivity to adult antigens in the rat

Abstract

Antigen fractions from adult S. mansoni, obtained from infected mice, were isolated by a variety of methods. A readily soluble fraction was obtained in good yield by freezing and thawing the schistosomes, while the less soluble residue was fractionated by the use of a number of the methods currently used for the extraction of tissue and cell surface antigens. The dialyzed, centrifuged products were characterized by acrylamide gel disc electrophoresis methods, agar gel precipitin reactions with antisera from rabbits immunized with whole schistosome homogenate, and by Prausnitz-Kustner (P-K) assay with sera from schistosome infected rats. The pattern of P-K reactivity suggested that there were a number of different antigen specificities involved in the reaginic antibody response to schistosome infection in rats. With repeated infection and increased duration of infection, more different antigens seemed to be involved in the reagin response. The schistosome antigen fraction obtained by freezing and thawing was especially reactive with both early infection rat sera and sera from multiply infected rats. Both the soluble fraction isolated by freezing and thawing and residue solubilized materials were found to be able to induce the formation of reagin antibodies on immunization with alum and B. pertussis vaccine.