Purificação e caracterização de proteína ligante de heparina de promastigotas de Leishmania chagasi: implicações na infecciosidade do parasito

• Ano de defesa: 2013
• Autor(a) principal: Martins, Thaís Viana Fialho
• Orientador(a): Silva, Eduardo de Almeida Marques da
• Banca de defesa: Cardoso, Silvia Almeida , Gomes, Daniel Cláudio de Oliveira
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Biologia Celular e Estrutural
• Departamento: Análises quantitativas e moleculares do Genoma; Biologia das células e dos tecidos
• País: BR
• Palavras-chave em Português: Leishmania; Lectina; Proteína Ligante de Heparina
• Palavras-chave em Inglês: Leishmania; Lectin; Heparin Binding Protein
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::BIOLOGIA GERAL
• Link de acesso: http://locus.ufv.br/handle/123456789/2364

Visceral leishmaniasis is a fatal human disease caused by the intracellular protozoan parasite Leishmania infantum/chagasi. The uptake of Leishmania promastigotes by host cells is a process mediated by classics receptors that initiate phagocytosis. The search for molecules that are involved in the infection process of the parasite to the host cell is important to design strategies to disease control. Among these molecules is the Heparin Binding Protein (HBP), a lectin of the group of ubiquitous proteins, whose main characteristic is to bind to carbohydrates present in glycoproteins or glycolipids. The presence of these molecules in Leishmania species is poorly studied. Therefore, in this work, the presence of HBP in L. chagasi promastigotes was assessed, as well its role in the parasite infection process. L. chagasi HBP was purified by affinity chromatography on a heparin-agarose column in FPLC automated system and the production of polyclonal antibody antiHBPLc was performed. We checked the affinity of the antibody for the protein and found the location of this in the parasite performing Western blotting and immunolabeling tests. Once detected, the antibody antiHBPLc and heparin were used as blocking agents of HBP and the effect caused by the blockage was investigated in the infection of J774 macrophages in vitro. We were able to verify that this protein is an important receptor that mediates the process of parasitic infection. Its blocking has generated a partial reduction in the accession and internalization of Leishmania by phagocytic cells. According to the results, it is believed that this protein may become, in in vivo future studies, a therapeutic alternative for resolution of visceral leishmaniasis.