Partial isolation of a membrane antigen which induces the formation of antibodies lethal to schistosomes cultured in vitro
Sher, A.; Kusel, J.R.; Perez, H.; Clegg, J.A.
Clinical and Experimental Immunology 18(3): 357-369
1974
ISSN/ISBN: 0009-9104 PMID: 4143304 Document Number: 74115
Fractions of adult Schistosoma mansoni were tested for absorption of IgG antibody, which appears in sera of infected rats and rhesus monkeys and is lethal to schistosomula, but not adult parasites in vitro. These fractions, given in Freunds' adjuvent, were tested for ability to raise lethal antibody in rats. The antigen, which absorbs and induces lethal antibody was present in the water-insoluble portion of adult schistosome homogenates and was tightly membrane-bound. Gel-filtration on Sephadex columns gave fractions which absorbed both rat and rhesus monkey lethal antibodies and induced the antibody in rats. Further purification and analysis suggested the antigen to be one of 4 proteins with molecular weights of between 21,000 and 33,000. Rats vaccinated with partially purified antigen developed similar lethal antibody levels to those in animals immune to challenge after previous infection, but were only marginally resistant to infection.