Schistosoma mansoni antigens. II. A comparative immunoelectro-phoretic study on various larval stages and of adults of both sexes. Immunological aspects of the host-parasite relationships of S. Mansoni cercaria and adults
Capron, A.; Biguet, J.; Rose, F.; Vernes, A.
Ann Inst Pasteur 109(5): 798-810
Twenty-one fractions of S. mansoni using hamster antisera were immunoelectrophoretically analyzed. Male and female schistosomas do not seem to differ as to their major constituents. The fact that 20 days old schistosomules possess the main part of sexually mature adult antigenic structure suggests that the genital proteins do not play any important part. A comparative study of various larval stages to adults demonstrates the existence of 11 antigenic fractions common to adults and eggs, of 14 fractions in cercaria, and 12 fractions in incubation products. The structural identity of various larval stages and somatic or incubation extracts is proved by the existence of a fraction which induces the early appearance of the corresponding antibody during immunization. This fraction is a major constituent of the various extracts used. A comparative analysis of cercarian extracts and of Australorbis glabratus cells (an intermediary host for S. mansoni) shows the existence of an antigenic community between 5 fractions, 4 of these fractions being identified in the adult schistosoma. These facts demonstrate for the 1st time in helminths that the parasite synthesizes proteins possessing the same antigenic behavior as that of the intermediary host. These relationships between the parasite and its host seem to be due to a parasitic adaptation. The existence of 4 antigenic fractions common to the adult schistosoma and to its final host may be due to the same adaptation; however, it would not be impossible that these fractions be determined by the schistosoma caecal content.