Leishmania amazonensis exhibits phosphatidylserine-dependent procoagulant activity, a process that is counteracted by sandfly saliva
| Autor: | Robson Q. Monteiro, Natalia C. Rochael, Luize G. Lima, Lucia H. Pinto-da-Silva, Marcello André Barcinski, Sandra Maria Pereira de Oliveira, Elvira M. Saraiva |
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| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: |
Microbiology (medical)
Saliva phosphatidylserine lcsh:Arctic medicine. Tropical medicine lcsh:RC955-962 lcsh:QR1-502 Phosphatidylserines lcsh:Microbiology blood coagulation chemistry.chemical_compound Thrombin Lutzomyia longipalpis Annexin Prothrombinase medicine Animals Humans Leishmania biology Tissue Extracts Factor X Anticoagulants Factor V Articles Phosphatidylserine biology.organism_classification Molecular biology Insect Vectors Neoplasm Proteins Cysteine Endopeptidases sandfly saliva Coagulation Biochemistry chemistry Factor Xa Phosphatidylcholines Partial Thromboplastin Time Psychodidae Factor Xa Inhibitors medicine.drug Leishmania amazonensis |
| Zdroj: | Memórias do Instituto Oswaldo Cruz., Vol 108, Iss 6, Pp 679-685 (2013) Memórias do Instituto Oswaldo Cruz Memórias do Instituto Oswaldo Cruz, Volume: 108, Issue: 6, Pages: 679-685, Published: SEP 2013 |
| ISSN: | 1678-8060 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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