The feeding of A type red blood cells in vitro and the ability of Schistosoma mansoni schistosomules to acquire A epitopes on their surfaces.

In vitro-raised Schistosoma mansoni schistosomules fed human A type red blood cells at day 7 postpenetration displayed A epitopes on their surfaces but not B epitopes when tested by the mixed agglutination procedure. Schistosomules treated with colchicine prior to exposure to red blood cells, exposed to plasma derived from human A type blood, or not exposed to host red blood cells did not display A epitopes on their surfaces. Under the conditions used in these experiments, it is likely that feeding of host red blood cells may be necessary for the tegument to become responsive to adsorption of host red blood cell epitopes.