Evaluation of mimotopes with protective and/or diagnostic potential for Paracoccidioides brasiliensis selected by Phage Display in serum samples from patients with paracoccidioidomycosis

Abstract

Paracoccidioidomycosis (PCM) is a systemic granulomatous disease endemic in Latin America caused by Paracoccidioides brasiliensis. Although some fungal antigens have been characterized, identifying new molecules may contribute to the development and standardization of simple and rapid serological methods as to the development of therapies immunoprotective. Thus, the phage display methodology can be an important tool for the identification of new molecules. Phage display of peptides consists of a collection of 10 to 100 of billions of peptides displayed on the surface of bacteriophages that can be used to identify ligands from virtually any molecule of interest. Using this approach, it is possible to select peptide ligands for antibodies which can be used for the identification of antigens as well as epitope mapping. The peptides identified may be used to design vaccines or applied to serological diagnosis. In our laboratory, using the phage display methodology, peptide sequences were selected and identified from immunoglobulins of sera of patients with PCM. Binding assays showed that two clones (LP2 and LP15) bound with higher affinity to PCM patients' sera compared to sera from control subjects (normal). However, further studies are necessary to evaluate the protective and/or diagnostic potential of LP2 and LP15 in PCM. Therefore, in this work we propose to assess the diagnostic potential of the LP15 and LP2 peptides in serum samples of patients with PCM and to evaluate the protective potential of these peptides in animals infected with P. brasiliensis. This study may contribute to develop of new important tools for the study of paracoccidioidomycosis.