title: Effects of platelet-activating factor on the interaction of Trypanosoma cruzi with Rhodnius prolixus.
abstract: We investigated the effects of platelet-activating factor (PAF) on the interaction of Trypanosoma cruzi with Rhodnius prolixus. The parasites (epimastigotes) were treated with PAF and/or WEB 2086 (PAF antagonist) for 1 h prior to the interaction experiments. PAF stimulated both in vivo and ex vivo interactions between T. cruzi and R. prolixus while WEB 2086 abrogated these effects. PAF-treated epimastigotes also showed an increase in surface negativity and in the amount of surface sialic acid. Neither of these effects was observed when the epimastigotes were treated with neuraminidase following PAF treatment. In the ex vivo interaction experiments, the number of epimastigotes bound to the midguts of the insects was reduced when the epimastigotes had been treated with neuraminidase. We conclude that PAF modulates the interaction of T. cruzi with R. prolixus by altering the amount of sialyl residues at the surface of the parasite.
authors.affiliation: Instituto de Microbiologia Prof. Paulo de Góes, Universidade Federal do Rio de Janeiro, Cidade Universitária, Ilha do Fundão, 21941-590, Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Luciana T
authors.initials: LT
authors.lastname: Zimmermann
authors.forename: Evelize
authors.initials: E
authors.lastname: Folly
authors.forename: Marta T
authors.initials: MT
authors.lastname: Gomes
authors.forename: Daniela S
authors.initials: DS
authors.lastname: Alviano
authors.forename: Celuta S
authors.initials: CS
authors.lastname: Alviano
authors.forename: Fernando C
authors.initials: FC
authors.lastname: Silva-Filho
authors.forename: Geórgia C
authors.initials: GC
authors.lastname: Atella
authors.forename: Angela H
authors.initials: AH
authors.lastname: Lopes
mesh_terms: D000818:Animals; D001381:Azepines / Q000494:pharmacology*; D014355:Chagas Disease; D006790:Host-Parasite Interactions / Q000187:drug effects; D019158:N-Acetylneuraminic Acid / Q000032:analysis; D009439:Neuraminidase / Q000494:pharmacology*; D010972:Platelet Activating Factor / Q000037:antagonists & inhibitors* / Q000378:metabolism; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D012239:Rhodnius / Q000187:drug effects* / Q000469:parasitology; D014230:Triazoles / Q000494:pharmacology*; D014349:Trypanosoma cruzi / Q000187:drug effects*
chemical_list: D001381:Azepines; D010972:Platelet Activating Factor; D010975:Platelet Aggregation Inhibitors; D014230:Triazoles; C052518:WEB 2086; D009439:Neuraminidase; D019158:N-Acetylneuraminic Acid