Induction of Immunological Hyporesponsiveness to Granulomatous Hypersensitivity in Schistosoma mansoni Infection

Abstract

The induction in mice of immunological unresponsiveness to granulomatous hypersensitivity around Schistosoma mansoni eggs was attempted by exposure of mice to egg antigens in the prenatal, neonatal, and adult stages of life. Prenatal treatment was carried out by breeding of naturally infected females or by intravenous injection of intact living schistosome eggs or soluble schistosome egg antigens into pregnant females. Marked hyporesponsiveness was demonstrated only in offspring of massively infected mothers bred soon after the onset of egg-laying and in offspring of mothers injected with massive amounts of soluble egg antigens. The hyporesponsive state of progeny of mothers treated with large doses of soluble egg antigens was transient. Similar prenatal treatment caused no amelioration of hepatosplenic disease in offspring that were subsequently infected with S. mansoni. Hyporesponsiveness to granuloma formation was also induced neonatally with large doses of antigen. Lower doses of antigen (as low as 10⁻⁴ μg) induced sensitization. A moderate degree of hyporesponsiveness was also induced in adult mice by very large doses of antigen, but not in those treated with lower doses of antigen plus immunosuppressive drugs.