Widespread antigenic cross-reactivity between plasma proteins of a gastropod, and its trematode parasite.

Evidence obtained earlier with immunofluorescence and immunoelectron microscopy was interpreted to imply molecular mimicry of the host Biomphalaria glabrata by the parasite Schistosoma mansoni. Using Western Blotting, we find that "mimicry" is due to widespread shared epitopes. Furthermore, at least one individual plasma protein of B. glabrata shares epitopes with the majority of plasma proteins in the mollusc. The widespread antigenic determinants may be carbohydrates. Caution is warranted when antisera, raised in mammals against heterogeneous invertebrate extracts, are used to screen for related antigenic determinants.