Parasite-derived trans-sialidase binds to heart tissue in Trypanosoma cruzi-infected animals.
Trypanosoma cruzi is an obligate intracellular protozoan parasite that actively penetrates into non-phagocytic mammalian cells. To accomplish this, the parasite relies on the binding of cell surface ligands. It is reported herein that the T. cruzi trans-sialidase (TS), which is exposed on the parasite surface, binds to mouse heart cells, and should therefore be further studied as a possible cell penetration-related ligand. In addition, as has been proposed elsewhere, the binding of T. cruzi to tissues may turn them into targets for parasite-specific immune reactions. Washed heart sections from T. cruzi-infected mice were subjected to immunoenzymatic staining with antisera against whole T. cruzi and with polyclonal or monoclonal antibodies against TS. The anti-TS antibodies stained both parasites and uninfected heart cells in the vicinity of T. cruzi nest remains/trypomastigotes. On the other hand, an anti-T. cruzi serum, which did not recognize TS, only stained the parasites. In addition, normal heart sections from uninfected nude mice were shown to react with both enzymatically active and inactive recombinant TS molecules, probably through their amino-terminal region, since a recombinant TS lacking this region failed to bind.
Alcântara-Neves
Neuza M
NM
Instituto de Ciências da Saúde, Universidade Federal da Bahia, Avenida Reitor Miguel Calmon, sem no, Canela, CEP, 40110-100 Salvador, Bahia, Brazil. neuza@ufba.br
Ribeiro-dos-Santos
Ricardo
R
Amor
Ana Lúcia Moreno
AL
Uemura
Haruki
H
Silva-Neto
Samuel J
SJ
Eichinger
Daniel
D
Pontes-de-Carvalho
Lain
L
D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D006023:Glycoproteins; D066298:In Vitro Techniques; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009206:Myocardium / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000166:cytology / Q000378:metabolism* / Q000469:parasitology; D009439:Neuraminidase / Q000378:metabolism*; D014349:Trypanosoma cruzi / Q000201:enzymology* / Q000276:immunology; D014774:Virulence
D000913:Antibodies, Protozoan; D006023:Glycoproteins; C069715:trans-sialidase; D009439:Neuraminidase