Immunoproteomic and Immunopeptidomic Analyses of Histoplasma capsulatum Reveal Promiscuous and Conserved Epitopes Among Fungi With Vaccine Potential

Author(s)

Kischkel, Brenda ^[1] ; Boniche-Alfaro, Camila ^[1] ; Menezes, Isabela de Godoy ^[2] ; Rossi, Suelen Andreia ^{[1, 3]} ; Angeli, Claudia Blanes ^[4] ; de Almeida, Sandro Rogerio ^[2] ; Palmisano, Giuseppe ^[4] ; Lopes-Bezerra, Leila ^[1] ; Nosanchuk, Joshua D. ^{[5, 6]} ; Taborda, Carlos Pelleschi ^{[1, 3]}

Affiliation

^[1] Univ Sao Paulo, Biomed Sci Inst, Dept Microbiol, Sao Paulo - Brazil

^[2] Univ Sao Paulo, Fac Pharmaceut Sci, Dept Clin & Toxicol Anal, Sao Paulo - Brazil

^[3] Univ Sao Paulo, Fac Med, Trop Med Inst, Dept Dermatol, Sao Paulo - Brazil

^[4] Univ Sao Paulo, Biomed Sci Inst, Dept Parasitol, Sao Paulo - Brazil

^[5] Albert Einstein Coll Med, Dept Microbiol & Immunol, New York, NY - USA

^[6] Albert Einstein Coll Med, Dept Med, Div Infect Dis, New York, NY - USA

• Document type: Journal article
• Source: FRONTIERS IN IMMUNOLOGY; v. 12, NOV 22 2021.
• Web of Science Citations: 0

Abstract

As there are more than 6 million human deaths due to mycoses each year, there is an urgent need to develop fungal vaccines. Moreover, given the similarities among pathogenic fungi, it may be possible to create a multi-fungi vaccine. In this study, we combined immunoproteomic and immunopeptidomic methods, for which we have adapted a technique based on co-immunoprecipitation (Co-IP) that made it possible to map Histoplasma capsulatum epitopes for the first time in a natural context using murine dendritic cells (DCs) and macrophages (M phi). Although polysaccharide epitopes exist, this research focused on mapping protein epitopes as these are more immunogenic. We used different algorithms to screen proteins and peptides identified by two-dimensional electrophoresis (2-D) and Co-IP. Seventeen proteins were revealed by 2-D gels, and 45 and 24 peptides from distinct proteins were presented by DCs and M phi, respectively. We then determined which epitopes were restricted to MHC-I and II from humans and mice and showed high promiscuity, but lacked identity with human proteins. The 4 most promising peptides were synthesized, and the peptides with and without incorporation into glucan particles induced CD4+ and CD8+ T cell proliferation and produced a Th1 and Th17 response marked by the secretion of high levels of IFN-gamma, IL-17 and IL-2. These epitopes were from heat shock protein 60, enolase, and the ATP-dependent molecular chaperone HSC82, and they each have a high degree of identity with proteins expressed by other medically important pathogenic fungi. Thus, the epitopes described in this study have the potential for use in the development of vaccines that could result in cross-protection among fungal species. (AU)

• FAPESP's process: 18/18257-1 - Multi-user equipment approved in grant 14/06863-3: HPLC system configured for analysis of carbohydrates, amino acidis, peptides and glycoproteins
• Grantee: Giuseppe Palmisano
• Support Opportunities: Multi-user Equipment Program
• FAPESP's process: 16/08730-6 - Fungal pathogenicity: environmental effects, immune response and vaccine modulation in the Brazilian endemic mycoses paracoccidioidomycosis and histoplasmosis
• Grantee: Carlos Pelleschi Taborda
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 14/06863-3 - Post-translational modifications in cancer and parasite infection diagnosis: methodological approaches and biological implications
• Grantee: Giuseppe Palmisano
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 17/25780-0 - Presentation by human dendritic cells of peptides with vaccine capacity and prospection of pan-fungal antigens in paracoccidioidomycosis
• Grantee: Suélen Andreia Rossi
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 18/26402-1 - Prospection of new epitopes with vaccine potential in the control of experimental infection by Histoplasma capsulatum
• Grantee: Brenda Kischkel
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 18/15549-1 - Post-translational modifications in Chagas Disease biological processes and diagnostics: novel methodological approaches and biological applications
• Grantee: Giuseppe Palmisano
• Support Opportunities: Research Grants - Young Investigators Grants - Phase 2