Ultrastructural detection in vitro of WGA-, RCA I-, and Con A-binding sites involved in the invasion of heart muscle cells by Trypanosoma cruzi.
The presence of carbohydrate residues in the plasma membrane of normal and Trypanosoma cruzi-infected heart muscle cells was investigated cytochemically using ruthenium red, lanthanum nitrate, periodic acid-Schiff/thiocarbohydrazide/silver, and gold- and ferritin-lectin complexes. The study combined conventional electron microscopy with the new analytical technique of electron spectroscopic imaging (ESI). Galactosyl, mannosyl, and sialyl residues were detected in regions of host-cell plasma membrane that undergo interiorization together with the parasite. Lectin-binding sites were sometimes found to show a punctate or patchy distribution in the endocytic vacuole membrane. These findings suggest the that glycoconjugates cytochemically detected in the host-cell plasma membrane participate in the invasion of heart muscle cells by T. cruzi.
Barbosa
H S
HS
Departamento de Ultra-estrutura e Biologia Celular, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brasil.
de Meirelles
M de N
Mde N
D000818:Animals; D001665:Binding Sites; D002478:Cells, Cultured; D006321:Heart / Q000469:parasitology*; D037102:Lectins / Q000378:metabolism*; D051379:Mice; D008854:Microscopy, Electron; D009206:Myocardium / Q000166:cytology* / Q000648:ultrastructure; D011975:Receptors, Mitogen / Q000032:analysis* / Q000648:ultrastructure; D014349:Trypanosoma cruzi / Q000502:physiology*
D037102:Lectins; D011975:Receptors, Mitogen