Studies of the thymus in Chagas' disease: III. Colonization of the thymus and other lymphoid organs of adult and newborn mice by Trypanosoma cruzi.
Among newborn and adult euthymic and athymic mice infected intraperitoneally with 10(2) or 10(4) trypomastigotes, neonates and adult athymic animals exhibited greater susceptibility with heavier colonization of central and peripheral lymphoid organs. Contiguity was also found to be a significant factor in colonization: after similar inocula, the parasitic load in the thymus was comparable in adults and neonates when the former were infected by subcutaneous injection in the anterior neck. In the nude athymic mice, the Y (reticulotropic) strain and the CL (myotropic) strain exhibited similar invasiveness, suggesting that the host immune response modulated the tissular tropism of these strains seen in the heterozygous littermates (Nu/+). The bone marrow was heavily infected; parasites were found in chondrocytes and cells of the mononucleate phagocytic system. Ultrastructural studies of infected thymus specimens showed that the corticomedullary architecture was unaltered and that both macrophages and epithelial cells were infected: both these cell types were infected in vitro.
Da Costa
S C
SC
Department of Protozoology, Institute Oswaldo Cruz, Rio-de-Janeiro, Brazil.
Calabrese
K S
KS
Bauer
P G
PG
Savino
W
W
Lagrange
P H
PH
D000328:Adult; D000818:Animals; D001853:Bone Marrow / Q000469:parasitology*; D014355:Chagas Disease / Q000401:mortality / Q000469:parasitology; D006801:Humans; D007231:Infant, Newborn; D008198:Lymph Nodes / Q000469:parasitology*; D051379:Mice; D008819:Mice, Nude; D008854:Microscopy, Electron; D013154:Spleen / Q000469:parasitology*; D013950:Thymus Gland / Q000469:parasitology / Q000473:pathology / Q000648:ultrastructure