Seleção de antígenos de Leishmania infantum por imunoproteômica para emprego no diagnóstico da leishmaniose visceral humana

• Ano de defesa: 2020
• Autor(a) principal: Daniela Pagliara Lage
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais
• Palavras-chave em Português: Leishmania infantum; Leishmaniose Visceral; Diagnóstico; Proteínas Recombinantes
• Link de acesso: https://hdl.handle.net/1843/60081

The control of visceral leishmaniasis (VL) requires an adequate diagnosis and treatment, since an accurate diagnosis is essential for an effective medication regimen for patients. In this context, biotechnological tools must be improved for the clinical management and epidemiological assessment of the disease. However, there are limitations related to the sensitivity and / or specificity of the antigens currently used, showing the necessity to identify new molecules to be tested in a more sensitive and specific serological diagnosis. In this sense, in the present study, an immunoproteomics approach was used to identify antigenic proteins of the Leishmania infantum promastigote and amastigote forms, which causes VL in our country, through its recognition by antibodies in sera of patients with the disease. Samples from healthy individuals living in an endemic region of the disease and from patients with Chagas disease were used to obtain more specific proteins for the Leishmania parasite, aiming their future application in the VL diagnosis. As results obtained, a total of 29 and 21 proteins were identified in the extracts of parasitic promastigotes and amastigotes, respectively. For validation of the diagnostic capacity, two proteins, endonuclease III and GTP-binding protein, were selected, cloned, expressed and purified to be tested in ELISA experiments. The test results showed sensitivity and specificity values greater than 99.0% for the identification of VL. The antigens also exhibited a differential when presenting low serological reactivity in cured and treated patients, suggesting the possibility that they can be applied as prognostic markers of the disease. In conclusion, the immunoproteomic study proved to be effective in the selection of L. infantum antigenic proteins and two of them, endonuclease III and GTP-binding protein, were well evaluated for the diagnosis of VL against a serological panel, in addition, demonstrating a potential for monitoring patients with VL after treatment.