title: Effect of 3-bromopyruvate and atovaquone on infection during in vitro interaction of Toxoplasma gondii and LLC-MK2 cells.
abstract: Toxoplasma gondii infection can be severe during pregnancy and in immunocompromised patients. Current therapies for toxoplasmosis are restricted to tachyzoites and have little or no effect on bradyzoites, which are maintained in tissue cysts. Consequently, new therapeutic alternatives have been proposed as the use of atovaquone has demonstrated partial efficacy against tachyzoites and bradyzoites. This work studies the effect of 3-bromopyruvate (3-BrPA), a compound that is being tested against cancer cells, on the infection of LLC-MK2 cells with T. gondii tachyzoites, RH strain. No effect of 3-BrPA on host cell proliferation or viability was observed, but it inhibited the proliferation of T. gondii. The incubation of cultures with lectin Dolichos biflorus agglutinin (DBA) showed the development of cystogenesis, and an ultrastructural analysis of parasite intracellular development confirmed morphological characteristics commonly found in tissue cysts. Moreover, the presence of degraded parasites and the influence of 3-BrPA on endodyogeny were observed. Infected cultures were alternatively treated with a combination of this compound plus atovaquone. This resulted in a 73% reduction in intracellular parasites after 24 h of treatment and a 71% reduction after 48 h; cyst wall formation did not occur in these cultures. Therefore, we conclude that the use of 3-BrPA may serve as an important tool for the study of (i) in vitro cystogenesis; (ii) parasite metabolism, requiring a deeper understanding of the target of action of this compound on T. gondii; (iii) the alternative parasite metabolic pathways; and (iv) the molecular/cellular mechanisms that trigger parasite death.
authors.affiliation: Laboratório de Biologia Estrutural, Instituto Oswaldo Cruz, Fiocruz, Manguinhos, Rio de Janeiro, Brazil Laboratório de Tecnologia em Bioquímica e Microscopia, Centro Universitário Estadual da Zona Oeste (UEZO), Campo Grande, Rio de Janeiro, Brazil.
authors.forename: Loyze Paola O
authors.initials: LP
authors.lastname: de Lima
authors.affiliation: Laboratório de Tecnologia em Bioquímica e Microscopia, Centro Universitário Estadual da Zona Oeste (UEZO), Campo Grande, Rio de Janeiro, Brazil.
authors.forename: Sergio H
authors.initials: SH
authors.lastname: Seabra
authors.affiliation: Laboratório de Biologia Estrutural, Instituto Oswaldo Cruz, Fiocruz, Manguinhos, Rio de Janeiro, Brazil.
authors.forename: Henrique
authors.initials: H
authors.lastname: Carneiro
authors.affiliation: Laboratório de Biologia Estrutural, Instituto Oswaldo Cruz, Fiocruz, Manguinhos, Rio de Janeiro, Brazil helene@ioc.fiocruz.br.
authors.forename: Helene S
authors.identifier: http://orcid.org/0000-0002-5672-5444
authors.initials: HS
authors.lastname: Barbosa
mesh_terms: D000818:Animals; D053626:Atovaquone / Q000627:therapeutic use*; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D008253:Macaca mulatta; D051379:Mice; D011773:Pyruvates / Q000627:therapeutic use*; D014122:Toxoplasma / Q000187:drug effects / Q000472:pathogenicity*; D014124:Toxoplasmosis, Animal / Q000188:drug therapy*
chemical_list: D011773:Pyruvates; C017092:bromopyruvate; D053626:Atovaquone