title: Differential expression of Trypanosoma cruzi neuraminidase in intra- and extracellular trypomastigotes.
abstract: The developmentally regulated expression of Trypanosoma cruzi neuraminidase in culture cells was monitored by immunofluorescence with a monoclonal antibody (TCN-2) against the enzyme. The results showed that TCN-2 reacted with all intracellular trypomastigote forms (NA+) but not with amastigotes. Immunoprecipitation of radiolabeled neuraminidase confirmed TCN-2 reactivity with trypomastigotes and the specificity of the antibody binding. During exiting from the host cells, all trypomastigotes were still NA+. However, when free in the extracellular environment, the relative proportion of NA+ parasites declined from 100% to about 20%, thereby establishing a subpopulation of trypomastigotes which did not express enzyme (NA-). The expression of neuraminidase in all intracellular trypomastigotes and in only a subpopulation of the extracellular counterpart suggests that the enzyme may play a role in parasite exiting from infected cells.
authors.affiliation: New England Medical Center Hospitals, Department of Geographic Medicine and Infectious Diseases, Boston, Massachusetts 02111.
authors.forename: I A
authors.initials: IA
authors.lastname: Rosenberg
authors.forename: R P
authors.initials: RP
authors.lastname: Prioli
authors.forename: J S
authors.initials: JS
authors.lastname: Mejia
authors.forename: M E
authors.initials: ME
authors.lastname: Pereira
mesh_terms: D000818:Animals; D005455:Fluorescent Antibody Technique; D009439:Neuraminidase / Q000032:analysis* / Q000276:immunology / Q000502:physiology; D014349:Trypanosoma cruzi / Q000201:enzymology*
chemical_list: D009439:Neuraminidase