FORMATION OF EXTRACELLULAR VESICLES AND THEIR POSSIBLE ROLE IN THE PATHOGENICITY AND DRUG RESISTANCE OF THE PARASITE Giardia lamblia

MOYANO S; MUSSO, JULIANA; LANFREDI-RANGEL, A; TOUZ, MC

Congreso; Reunión Conjunta de Sociedades de Biología de la República Argentina; 2021

A defining characteristic of cells is the ability to communicate with each other through different mechanisms including direct cell-cell contact or thetransfer of secreted molecules. Recently, a third intercellular communication mechanism was found that involves the release of extracellular vesiclesor EVs, carriers of biologically active molecules with defined biological functions that are a conserved mechanism present in Bacteria, Archaea, andEukarya. In our laboratory, we discovered that G. lamblia trophozoites are capable of producing small VEs similar to exosomes of other cell types interms of size, shape, density, and presence of typical proteins. The results obtained also showed that, despite the lack of typical multivesicular bodiesin this parasite, exosome-like vesicles (tExo) are form in the endo-lysosomal peripheral vacuoles (PVs) of G. lamblia. We also found that theESCRT-associated protein Vps4a, the small GTPase Rab1, and ceramide are essential for the formation of intraluminal vesicles in PVs and forobtaining tExo in the extracellular medium. Furthermore, we carried out the first proteomic analysis of the extracellular vesicles of twopathogenically different assemblages and found that both microvesicle-type and exosome-type vesicles could be selecting the content of conservedand specific G. lamblia proteins. Differences in the composition, origin, and release of EVs from the protozoan parasite may reveal functional andstructural properties of EVs and thus may provide information on cell-to-cell communication and survival mechanisms.