title: trans-Sialidase from Trypanosoma cruzi binds host T-lymphocytes in a lectin manner.
abstract: Trypanosoma cruzi, the protozoan parasite responsible for Chagas' disease, expresses on its surface an uncommon membrane-bound sialidase, known as trans-sialidase. trans-Sialidase is the product of a multigene family encoding both active and inactive proteins. We report here that an inactive mutant of trans-sialidase physically interacts with CD4(+) T cells. Using a combination of flow cytometry and immunoprecipitation techniques, we identified the sialomucin CD43 as a counterreceptor for trans-sialidase on CD4(+) T cells. Using biochemical, immunological, and spectroscopic approaches, we demonstrated that the inactive trans-sialidase is a sialic acid-binding protein displaying the same specificity required by active trans-sialidase. Taken together, these results suggest that inactive members of the trans-sialidase family can physically interact with sialic acid-containing molecules on host cells and could play a role in host cell/T. cruzi interaction.
authors.affiliation: Departamento de Bioquimica, Instituto de Biologia, 20551-013 Universidade do Estado do Rio de Janeiro, Brasil.
authors.forename: Adriane R
authors.initials: AR
authors.lastname: Todeschini
authors.forename: Murielle F
authors.initials: MF
authors.lastname: Girard
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Wieruszeski
authors.forename: Marise P
authors.initials: MP
authors.lastname: Nunes
authors.forename: George A
authors.initials: GA
authors.lastname: DosReis
authors.forename: Lucia
authors.initials: L
authors.lastname: Mendonca-Previato
authors.forename: Jose O
authors.initials: JO
authors.lastname: Previato
mesh_terms: D000818:Animals; D015703:Antigens, CD; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D006023:Glycoproteins; D037102:Lectins / Q000378:metabolism*; D051917:Leukosialin; D009439:Neuraminidase / Q000378:metabolism*; D019906:Nuclear Magnetic Resonance, Biomolecular; D011485:Protein Binding; D012795:Sialoglycoproteins / Q000378:metabolism; D014349:Trypanosoma cruzi / Q000201:enzymology*
chemical_list: D015703:Antigens, CD; D006023:Glycoproteins; D037102:Lectins; D051917:Leukosialin; D012795:Sialoglycoproteins; C069715:trans-sialidase; D009439:Neuraminidase