Protective Response in Experimental Paracoccidioidomycosis Elicited by Extracellular Vesicles Containing Antigens of <i>Paracoccidioides brasiliensis</i>

• Published in: Cells
• Main Authors: Ludmila Matos Baltazar, Gabriela Fior Ribeiro, Gustavo J. Freitas, Celso Martins Queiroz-Junior, Caio Tavares Fagundes, Carlos Chaves-Olórtegui, Mauro Martins Teixeira, Daniele G. Souza
• Format: Article
• Language: English
• Published: MDPI AG 2021-07-01
• Subjects: extracellular vesicles; <i>Paracoccidioides brasiliensis</i>; immunization; host response
• Online Access: https://www.mdpi.com/2073-4409/10/7/1813

Paracoccidioidomycosis (PCM) is a systemic disease caused by <i>Paracoccidioides</i> spp. PCM is endemic in Latin America and most cases are registered in Brazil. This mycosis affects mainly the lungs, but can also spread to other tissues and organs, including the liver. Several approaches have been investigated to improve treatment effectiveness and protection against the disease. Extracellular vesicles (EVs) are good antigen delivery vehicles. The present work aims to investigate the use of EVs derived from <i>Paracoccidioides brasiliensis</i> as an immunization tool in a murine model of PCM. For this, male C57BL/6 were immunized with two doses of EVs plus adjuvant and then infected with <i>P. brasiliensis</i>. EV immunization induced IgM and IgG in vivo and cytokine production by splenocytes ex vivo. Further, immunization with EVs had a positive effect on mice infected with <i>P. brasiliensis</i>, as it induced activated T lymphocytes and NKT cell mobilization to the infected lungs, improved production of proinflammatory cytokines and the histopathological profile, and reduced fungal burden. Therefore, the present study shows a new role for <i>P. brasiliensis</i> EVs in the presence of adjuvant as modulators of the host immune system, suggesting their utility as immunizing agents.