Tegument-associated antigen modulation by adult male Schistosoma mansoni

Adult Schistosoma mansoni from mice were incubated in rabbit anti-mouse immunoglobulin class or subclass-specific sera. The rabbit antibody binding was then visualized by incubation of the labeled worms in fluoresceinated Staphylococcus aureus, which associated with the Fc portion of the rabbit antibody molecule by means of bacterial cell wall Protein A. The assay system was found to be simple, inexpensive, specific, repeatable, and rapidly accomplished. By using this technique, previous work documenting the presence of mouse IgG1, IgG2a, IgG2b, IgG3, IgA, and IgM on the tegumental surface of adult worms of mouse origin was confirmed. It was further confirmed that the complexing of rabbit antibody to the mouse antigen led to the shedding of that antigen from the parasite's surface membrane within 20 min at 37 degrees C. This shedding phenomenon was specific for only those antigens interacting with the ligand and was inhibited by incubation with sodium fluoride, 2-deoxy-D-glucose, cytochalasin B, cytochalasin D, caffeine, or at 4 degrees C. These data indicate a sophisticated control mechanism exercised by the parasite over its interface with the host and may indicate a complexity of the host-parasite relationship not heretofore recognized.