Altered schistosome granuloma formation in nude mice
Byram, J.E.; von Lichtenberg, F.
American Journal of Tropical Medicine and Hygiene 26(5 Pt 1): 944-956
1977
ISSN/ISBN: 0002-9637 PMID: 303056 Document Number: 113090
Lesions induced by Schistosoma mansoni eggs were different in congenitally athymic mice from those in normal heterozygous controls. Hepatic lesions in nude mice were much smaller and lacked epithelioid macrophages, with lesions about mature eggs typically consisting of monocytes and macrophages filled with pigment, occasional neutrophils, and rarely one or more eosinophils or giant cells. While heterozygote granulomata damaged liver cells mainly by encroachment or by their vascular effects, in the nudes hepatocytes bordering the lesions showed microvesicular cytoplasmic damage and either hydropic degeneration or focal acidophilic necrosis of individual liver cells. In heterozygotes, immunofluorescent-stainable schistosome egg antigen (SEA) was concentrated in the granuloma centre. In nude mice, SEA, was distributed throughout the infiltrates and in and around hepatocytes adjacent to egg lesions corresponding to the observed pattern of hepatocyte necrosis. Nude mice may lack hypersensitivity granulomata and fail to sequester toxic egg products. [AS].