Differential expression of Trypanosoma cruzi neuraminidase in intra- and extracellular trypomastigotes.
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.
Rosenberg
I A
IA
New England Medical Center Hospitals, Department of Geographic Medicine and Infectious Diseases, Boston, Massachusetts 02111.
Prioli
R P
RP
Mejia
J S
JS
Pereira
M E
ME
D000818:Animals; D005455:Fluorescent Antibody Technique; D009439:Neuraminidase / Q000032:analysis* / Q000276:immunology / Q000502:physiology; D014349:Trypanosoma cruzi / Q000201:enzymology*
D009439:Neuraminidase