title: Trypanosoma cruzi-secreted vesicles have acid and alkaline phosphatase activities capable of increasing parasite adhesion and infection.
abstract: Trypanosoma cruzi virulence factors include molecules expressed on the cell surface as well as those secreted or shed into the extracellular medium. Phosphatase activities modulate different aspects of T. cruzi infection, although no studies to date addressed the presence and activity of phosphatases in vesicles secreted by this parasite. Here, we characterized acidic and alkaline secreted phosphatase activities of human-infective trypomastigote forms of T. cruzi from the Y strain and the CL-Brener clone. These are widely studied T. cruzi strains that represent "opposite ends of the spectrum" regarding both in vitro and in vivo behavior. Ecto-phosphatase activities were determined in live parasites, and secreted phosphatase activities were analyzed in soluble protein (SP) and vesicular membrane fractions (VFs) of parasite-conditioned medium. Our analysis using different phosphatase inhibitors strongly suggests that vesicles secreted by Y strain (VF(Y)) and CL-Brener (VF(CLB)) trypomastigotes are derived mostly from the cell surface and from exosome secretion, respectively. Importantly, our results show that the acid phosphatase activities in vesicles secreted by trypomastigotes are largely responsible for the VF-induced increase in adhesion of Y strain parasites to host cells and also for the VF-induced increase in host cell infection by CL-Brener trypomastigotes.
authors.affiliation: Instituto de Microbiologia Paulo de Góes, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors.forename: Roberta F C
authors.initials: RF
authors.lastname: Neves
authors.forename: Anne C S
authors.initials: AC
authors.lastname: Fernandes
authors.forename: José R
authors.initials: JR
authors.lastname: Meyer-Fernandes
authors.forename: Thais
authors.initials: T
authors.lastname: Souto-Padrón
mesh_terms: D000135:Acid Phosphatase / Q000378:metabolism*; D000469:Alkaline Phosphatase / Q000378:metabolism*; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D008264:Macrophages / Q000469:parasitology; D051379:Mice; D022142:Secretory Vesicles / Q000201:enzymology* / Q000648:ultrastructure; D014349:Trypanosoma cruzi / Q000201:enzymology / Q000472:pathogenicity*; D037521:Virulence Factors / Q000378:metabolism*
chemical_list: D037521:Virulence Factors; D000469:Alkaline Phosphatase; D000135:Acid Phosphatase