Prediction of Conserved Peptides of <i>Paracoccidioides</i> for Interferon-γ Release Assay: The First Step in the Development of a Lab-Based Approach for Immunological Assessment during Antifungal Therapy

• Main Authors: Sarah Brena Aparecida Rosa, Bárbara Guimarães Csordas, Sandra Maria do Valle Leone de Oliveira, Amanda Ribeiro dos Santos, Anamaria Mello Miranda Paniago, James Venturini
• Format: Article
• Language: English
• Published: MDPI AG 2020-12-01
• Series: Journal of Fungi
• Subjects: cellular immunity; paracoccidioidomycosis; in silico prediction; MHC II; IFN-γ; <i>Paracoccidioides brasiliensis</i>
• Online Access: https://www.mdpi.com/2309-608X/6/4/379

Impaired antigen-specific cell-mediated immunity (CMI) is a primary immunological disturbance observed in individuals that develop paracoccidioidomycosis (PCM) after exposure to <i>Paracoccidioides</i> spp. Restoration of <i>Paracoccidioides</i>-specific CMI is crucial to stop the antifungal treatment and avoid relapses. A convenient and specific laboratory tool to assess antigen specific CMI is required for the appropriate clinical treatment of fungal infections, in order to decrease the time of antifungal therapy. We used an interferon-γ release assay strategy, used in the diagnosis of latent tuberculosis infection, to address our aims in this study. Information on proteins secreted by two well-studied representative strains—<i>Paracoccidioides brasiliensis</i> (Pb18) and <i>P. lutzii</i> (Pb-01)—were explored using PubMed or MEDLINE. From 26 publications, 252 proteins were identified, of which 203 were similar according to the Basic Local Alignment Search Tool. This enabled a selection of conserved peptides using the MEGA software. The SignalP-5.0, TMHMM, IEDB, NetMHC II, and IFNepitope algorithms were used to identify appropriate epitopes. In our study, we predicted antigenic epitopes of <i>Paracoccidioides</i> that could bind to MHC class II and induce IFN-γ secretion. These T cell epitopes can be used in the development of a laboratory tool to monitor the CMI of patients with PCM.