Rejection of mouse-derived Schistosoma japonicum and serum lethality of host immunized with mouse globulin or mouse erythrocytes.

Fourteen-day-old, mouse-derived Schistosoma japonicum schistosomula survived, matured, and deposited viable eggs following surgical transfer to the hepatic portal system of rabbits. The survival of such schistosomula is essentially eliminated in rabbits immunized with either mouse erythrocytes or mouse gamma globulin. Sera from rabbits immunized with either mouse erthrocytes or mouse gamma globulin in the presence of normal leukocytes is lethal for mouse-derived schistosomula 14 days of age or older. These sera have no significant effect on newly transformed schistosomula or those derived from rabbits. It is suggested that these results give additional evidence that immunological enhancement is one of the mechanisms involved in parasite survival.