BIOLOGICAL CHARACTERIZATION OF VESICLES FROM EXCRETION-SECRETION PRODUCTS OF TRICHINELLA SPIRALIS

SARACINO, MP; FALDUTO, GH; VILA, C; MALCHIODI, E; DÍAZ, M; PAPADEMETRIO, DL

Daegu

Congreso; 14th International Congress of Parasitology (ICOPA).; 2018

ICOPA

Parasites have developed, through millions of years of co-evolution with their hosts, different strategies to evade or modulate the host immune system. One of them is extracellular vesicle secretion that has been characterized in terms of proteins, lipids and nucleic acids contents. Trichinella spiralis is a nematode parasite distributed worldwide.Recently, we have described the presence of vesicles in excretion-secretion products from muscle larvae (ESP-ML). The aim of this work was to study the biological effect of these vesicles and to characterize them with a proteomic approach. Vesicles were purified from ESP-ML by ultra-centrifugation of a four days ML culture and their presence was confirmed by transmission electron microscope. For immunization protocol, intranasal administration of exosomes (5, 10 and 15µg) in PBS with choleric toxin (CT), PBS alone or with CT was performed in mice once a week during four weeks before infection with 200 ML. Mice were sacrificed a month post-infection and artificial digestion was carried out. Proteome analyse was done as a preliminary approach to characterize vesicles composition. Peritoneal macrophages were co-culture with LPS and/or different doses of exosomes in order to evaluate their activation profile through the secretion of nitrites. Pre-treatment with exosomes did not provide an effective protection against T. spiralis infection. Surprisingly, 10μg dose showed a tendency to increase parasite burden. Proteome characterization showed a huge diversity of components varying from proteases to proteins involved in synthesis and docking. Peritoneal macrophages showed a decreased in nitrites secretion when they were first co-cultured with LPS and then with exosomes but not the other way around. In this work we could characterized exosomes derived from ESP-ML. They seemed to facilitate T. spiralis infection. In this sense, proteomic characterization of vesicles would be an interesting tool to predict the host immune system modulation.