Análise imunoproteômica das proteínas de superfície do Aspergillus fumigatus utilizando soro de pacientes com aspergilose invasiva

• Autor(a) principal: Virginio, Emylli Dias
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/16311
• topic: Aspergillus fumigatus; European Organisation for Research on Treatment of Cancer; Mycosis Study Group; Immunoproteomics; Diagnostic; Biomarker.; Aspergillus fumigatus; Organização Européia para Pesquisa no Tratamento do Câncer; Grupo de Estudo de Micoses; Imunoproteômica; Diagnóstico; Biomarcador; Aspergilose pulmonar Diagnóstico; Aspergillus fumigatus; Proteômica; Marcadores biológicos; European Organisation for Research on Treatment of Cancer; CNPQ::CIENCIAS BIOLOGICAS::MICROBIOLOGIA::BIOLOGIA E FISIOLOGIA DOS MICROORGANISMOS::MICOLOGIA

Aspergillus fumigatus is known as a worldwide saprophyte mould and it is the main etiological agent responsible for a wide range of diseases denominated aspergillosis. Invasive aspergillosis is a life-threatening lung or systemic infection that affects mainly immunocompromised hosts such as patients with hematological malignances or submitted to stem cell transplants. Symptoms of invasive aspergillosis are often non-specific or even masked by the empirical antifungal treatment administered, making the disease difficult to diagnose. The goal of this study was to investigate and identify antigenic proteins seeking for putative candidates to biomarkers for the diagnosis of invasive aspergillosis. To this purpose we have used extract of A. fumigatus germlings (TG6h) and an immunoproteomic approach. The 2-D western immunoblots were performed using sera of patients classified as probable and proven according to the European Organisation for Research on Treatment of Cancer (EORTC) and the Mycosis Study Group (MSG) criteria. Also, sera from healthy individuals were used as negative control and sera from patients with other mycosis were used to verify possible cross-reactivity to the identified antigens. Sera from hematological patients of the National Cancer Institute (INCA) were collected twice a week and tested for the presence of galactomanana (GM) by the Platelia® Aspergillus (Bio-Rad). Patients with at least two consecutive positive tests for GM and with enough information to fulfill the EORTC/MSG classification criteria were selected to this study. Sixteen patients were included: thirteen were classified as probable and three as proven for invasive aspergillosis. The sera of patients classified as probable were also separated according to the neutropenic state of the patients. Twenty five antigenic proteins were identified by MS/MS analysis, including proteins involved in ion transport, cell signaling, protein assembly, hydrolysis and others. Fourteen antigenic proteins were exclusively recognized by the pool of sera from patients classified as probable and proven for invasive aspergillosis. Three of these antigens were pointed as putative candidates to biomarkers for the diagnostic of fungal infections, in general: beta-glucosidase, Sqt1 and the Phosphatase 2C. Another antigens, the cytochrome P450, is being described for the first time as an A. fumigatus antigen, being the main candidate to biomarker for the diagnostic of invasive aspergillosis, leading to a patent application (in progress).