Extracellular vesicles released by Leishmania (Leishmania) amazonensis with distinct virulence profiles: characterization, role in immune response and disease progression

Abstract

Leishmaniasis are a group of diseases that are endemic in 98 countries including Brazil. Studies have shown that some species of the Leishmania genus are capable of releasing extracellular vesicles (EVs), which contain antigens, virulence factors, RNA, DNA, and parasite lipids. These EVs play an important role in the parasite-host relationship, pathogen survival at different levels, facilitation of infection in experimental models, immunomodulation and adaptation of the parasite to the host environment. Due to their ability to carry antigens and stimulate the immune response, the use of EVs in treatments and vaccine development has been studied. Our group has been studying the EVs released by Leishmania (Leishmania) amazonensis as well as cells infected with the parasite. We showed some evidence and mechanisms of the role of these EVs in the parasite-host relationship. This project aims to characterize and evaluate the role of EVs released by virulent L. amazonensis (newly recovered from animal lesions) and attenuated (obtained by long-term in vitro culture) will be evaluated in macrophage and B-1 cell responses as well as in immunity and disease development in previously immunized BALB/c mice. Changes in the content of EVs may impact on immune response and disease progression, so EVs derived from virulent and attenuated parasites may present relevant differences in immune response. Thus, this project may contribute to a better understanding of the parasite-host relationship and in the future provide support for the development of a vaccine with potential for Leishmaniasis prevention. (AU)