Your browser doesn't support javascript.
loading
Leishmania amazonensis exhibits phosphatidylserine-dependent procoagulant activity, a process that is counteracted by sandfly saliva
Memorias do Instituto Oswaldo Cruz; Rochael, Natalia Cadaxo; Lima, Luize Goncalves; Oliveira, Sandra Maria Pereira de; Barcinski, Marcello Andre; Saraiva, Elvira Maria; Monteiro, Robson Queiroz; Pinto-da-Silva, Lucia Helena.
Afiliação
  • Rochael, Natalia Cadaxo; s.af
  • Lima, Luize Goncalves; s.af
  • Oliveira, Sandra Maria Pereira de; s.af
  • Barcinski, Marcello Andre; s.af
  • Saraiva, Elvira Maria; s.af
  • Monteiro, Robson Queiroz; s.af
  • Pinto-da-Silva, Lucia Helena; s.af
Mem. Inst. Oswaldo Cruz ; 108(6): 679-685, set. 2013. graf
Artigo em Inglês | LILACS | ID: lil-685490
Biblioteca responsável: BR1.1
ABSTRACT
Leishmania parasites expose phosphatidylserine (PS) on their surface, a process that has been associated with regulation of host's immune responses. In this study we demonstrate that PS exposure by metacyclic promastigotes of Leishmania amazonensis favours blood coagulation. L. amazonensis accelerates in vitro coagulation of human plasma. In addition, L. amazonensis supports the assembly of the prothrombinase complex, thus promoting thrombin formation. This process was reversed by annexin V which blocks PS binding sites. During blood meal, Lutzomyia longipalpis sandfly inject saliva in the bite site, which has a series of pharmacologically active compounds that inhibit blood coagulation. Since saliva and parasites are co-injected in the host during natural transmission, we evaluated the anticoagulant properties of sandfly saliva in counteracting the procoagulant activity of L. amazonensis . Lu. longipalpis saliva reverses plasma clotting promoted by promastigotes. It also inhibits thrombin formation by the prothrombinase complex assembled either in phosphatidylcholine (PC)/PS vesicles or in L. amazonensis . Sandfly saliva inhibits factor X activation by the intrinsic tenase complex assembled on PC/PS vesicles and blocks factor Xa catalytic activity. Altogether our results show that metacyclic promastigotes of L. amazonensis are procoagulant due to PS exposure. Notably, this effect is efficiently counteracted by sandfly saliva.
Assuntos


Texto completo: Disponível Coleções: Bases de dados internacionais Base de dados: LILACS Assunto principal: Fosfatidilserinas / Psychodidae / Saliva / Coagulação Sanguínea / Leishmania Limite: Animais / Humanos Idioma: Inglês Revista: Mem. Inst. Oswaldo Cruz Assunto da revista: Medicina Tropical / Parasitologia Ano de publicação: 2013 Tipo de documento: Artigo

Texto completo: Disponível Coleções: Bases de dados internacionais Base de dados: LILACS Assunto principal: Fosfatidilserinas / Psychodidae / Saliva / Coagulação Sanguínea / Leishmania Limite: Animais / Humanos Idioma: Inglês Revista: Mem. Inst. Oswaldo Cruz Assunto da revista: Medicina Tropical / Parasitologia Ano de publicação: 2013 Tipo de documento: Artigo
...