Cestode parasites secrete extracelular vesicles carrying antigenic proteins and microRNAs

ANCAROLA, M.E.; MARCILLA, A; MACCHIAROLI, N.; PÉREZ, M.; ASURMENDI S; PONCINI, C; ROSENZVIT, M; CUCHER, M

Mar del Plata

Congreso; Reunión conjunta SAIC-SAI-SAFE; 2016

SAIC-SAI-SAFE

Cestode parasites are platyhelminths passively transmitted between the hosts involved in their life cycles and can infect almost all vertebrate species. Some of the zoonoses they cause are among the most severe neglected tropical diseases in humans prioritized by the World Health Organization.Lately, several studies described the secretion of extracellular vesicles (EV) as a path of intercellular communication in many organisms and also as a new mechanism of inter-species cross-talk1, e.g. host-parasite interplay. The term EV groups varying types of membranous structures which mainly differ in their biogenesis, morphology and protein content. EV can also carry lipids and nucleic acids, including DNA, mRNAs and small RNAs. It has been shown that nematode and trematode parasites secrete EV, which can be internalized by host cells. These EV contain proteins and small RNAs, among which microRNAs were identified. Here, we aimed to determine whether cestode parasites secrete EV and characterize their content.For this, we chose the larval stages of the model cestodes Taenia crassiceps and Mesocestoides corti. First, we demonstrated the presence of membranous structures compatible with EV in culture supernatants by transmission electron microscopy. We also detected EV with the same morphological characteristics in the parasites? tegument within multivesicular body-like structures and over the surface. Multivesicular bodies are involved in exosome biogenesis. Then, we characterized EV protein content by LC-MS/MS. As a result, we identified expected eukaryotic EV markers and other proteins such as clathrin, fatty acid binding proteins and proteins related to synaptic vesicles. We also identified proteins tested for immunodiagnosis of cestode infection as well as host immunoglobulins. Finally, we proved the presence of intravesicular small RNAs in cestode EV by capillary electrophoresis, and microRNAs were detected by RT-PCR in EV from both parasites.This is the first report of EV as well as microRNAs secretion in cestode parasites and could represent a new cross-species communication mechanism with the host. We also provide evidence on a new route used by cestode parasites for the secretion of formerly studied proteins. These results provide relevant information for the improvement or development of new diagnosis methods of cestodiases.