T. cruzi-Dendritic Cells interaction: Extracellular vesicles as mediators for immune modulation

BRENDA CELESTE GUTIÉRREZ; ANCAROLA ME; ROSSI, IZADORA; MARCILLA A; MARCEL RAMIREZ; MARA ROSENZVIT; CUCHER MARCELA; CAROLINA PONCINI

Congreso; REUNIÓN CONJUNTA SAIC SAI&FAIC SAFIS 2022; 2022

Extracellular vesicles (EVs) include a heterogeneous group of particles. Microvesicles, exosomes and apoptotic bodies are the most characterised vesicles. They can be distinguished by their size, morphology, origin and molecular composition. To date, increasing studies demonstrate that EVs mediates intercellular communication. EVs reach considerable interest in the scientific community due to their role in diverse processes including antigen-presentation, stimulation of anti-tumoral immune responses, tolerogenic or inflammatory effects. An important breakthrough was the discovery of nucleic acids in EVs such as mRNA and miRNA. Several studies have shown that EV-associated mRNAs and miRNAs can be functionally transferred to recipient cells. In pathogens,EVs shedding is well described in fungus, bacteria, protozoan parasites and helminths. In Trypanosoma cruzi, not only EVs liberation but also their protein composition was described.Dendritic cells (DCs) are important antigen presenting cells, key players promoting the immune response against pathogens and also maintaining self-tolerance. In previous reports we have demonstrated thatT. cruzidown regulates DCs immunogenicity in vitro and in vivo.Here we analyze EVs from the in vitro interaction between blood circulating tripomastigotes (Tp) and bone marrow (BM)DCs.EVs from culture supernatants were enriched after ultracentrifugation and characterized by TEM. By nanoparticle tracking analysis and flow cytometry we found that Tp incremented the number but not the size of EVs in BMDC culture supernatants. EVs displayed some exosome markers and intracellular RNA. By proteomics we found that, to some extent, the parasite changes the protein secretion profile of BMDCs. In addition, EVs from Tp-BMDCs (EVs DCs-Tp)interaction were easily captured by unstimulated BMDCs in comparison to EVs from BMDCs cultured without the parasite and also that EVs DCs-Tp modified the activation status of LPS-stimulated BMDCs.Our goal is to go deep into the molecular characterization of EVs DCs-Tp,in order to identify mediators with therapeutic proposes.