Characterization of alpha-galactopyranosyl epitopes in Paracoccidioides and other pathogenic fungal species

• Grant number: 14/23617-6
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: March 01, 2015
• End date: September 30, 2017
• Field of knowledge: Biological Sciences - Microbiology - Biology and Physiology of Microorganisms
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Rosana Puccia
• Grantee: Gregory Gegembauer
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil

Abstract

We have previously shown in Paracoccidioides brasiliensis extracellular vesicles carrying immunogenic epitopes containing alfa-linked galactopyranosyl residues (alfa-Gal), which were also localized on the cell-wall and intracellular vacuoles of the fungal yeast cell. alfa-Gal epitopes produced intense reaction in ELISA with anti-alfa-Gal antibodies from chagasic and paracoccidioidomycosis patients, and with the MOA lectin that mainly recognizes the disaccharide alfa-Galp1,3Galp. The general goal of this project is to improve our knowledge about alfa-Gal epitopes in Paracoccidioides and other pathogenic fungi. The specific goals are: 1. evaluation of differential gene expression of alpha-galactosyl tranferase in Paracoccidioides and other pathogenic fungi such as Aspergillus fumigatus, Cryptococcus neoformans and Histoplasma capsulatum grown in selected growth contitions; attempt to express alpha-galactosyltranferase genes in its active form to perform enzimatic activity assays; 2. microscopic localization (confocal/TEM) of alfa-Gal epitopes in mycelium and transitional forms of Paraccodioides and other pathogenic fungal species; 3. macrophage stimulation with yeasts from Paracoccidioides strains and its related extracellular vesicles previously treated with alfa-galactosidase; 4. identification of reactive components with anti-alfa-Gal/MOA by Western blot. Isolation of components containing alfa-Gal epitopes from Paracoccidioides cell extracts. (AU)