Trypanosoma cruzi enters cells by a unique mechanism, distinct from phagocytosis. Invasion is facilitated by disruption of host cell actin microfilaments, and involves recruitment and fusion of host lysosomes at the site of parasite entry. These findings implied the existence of transmembrane signaling mechanisms triggered by the parasites in the host cells before invasion. Here we show that infective trypomastigotes or their isolated membranes, but not the noninfective epimastigotes, induce repetitive cytosolic-free Ca2+ transients in individual normal rat kidney fibroblasts, in a pertussis toxin-sensitive manner. Parasite entry is inhibited by buffering or depleting host cell cytosolic-free Ca2+, or by pretreatment with Ca2+ channel blockers or pertussis toxin. In contrast, invasion is enhanced by brief exposure of the host cells to cytochalasin D. These results indicate that a trypomastigote membrane factor triggers cytosolic-free Ca2+ transients in host cells through a G-protein-coupled pathway. This signaling event may promote invasion through modulation of the host cell actin cytoskeleton.
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1 March 1994
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March 01 1994
Role in host cell invasion of Trypanosoma cruzi-induced cytosolic-free Ca2+ transients.
I Tardieux,
I Tardieux
Infectious Diseases Section, Yale University School of Medicine, New Haven, Connecticut 06510.
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M H Nathanson,
M H Nathanson
Infectious Diseases Section, Yale University School of Medicine, New Haven, Connecticut 06510.
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N W Andrews
N W Andrews
Infectious Diseases Section, Yale University School of Medicine, New Haven, Connecticut 06510.
Search for other works by this author on:
I Tardieux
Infectious Diseases Section, Yale University School of Medicine, New Haven, Connecticut 06510.
M H Nathanson
Infectious Diseases Section, Yale University School of Medicine, New Haven, Connecticut 06510.
N W Andrews
Infectious Diseases Section, Yale University School of Medicine, New Haven, Connecticut 06510.
Online ISSN: 1540-9538
Print ISSN: 0022-1007
J Exp Med (1994) 179 (3): 1017–1022.
Citation
I Tardieux, M H Nathanson, N W Andrews; Role in host cell invasion of Trypanosoma cruzi-induced cytosolic-free Ca2+ transients.. J Exp Med 1 March 1994; 179 (3): 1017–1022. doi: https://doi.org/10.1084/jem.179.3.1017
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