Cestode parasites secrete extracellular vesicles carrying antigenic proteins and microRNAs

ANCAROLA ME; MARCILLA A; MACCHIAROLI N; PEREZ M; ASURMENDI S; PONCINI C; ROSENZVIT M; CUCHER M

Congreso; LXI Reunión Anual de la Sociedad Argentina de Investigación Clínica (SAIC); 2016

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-talk in the 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 in vitro secretion of membranous structures compatible with EV by transmission electron microscopy. Then, we characterized their protein content by LC-MS/MS. As a result we identified expected eukaryotic EV markers and also, among others, proteins tested for immunodiagnosis of cestode infection as well as host immunoglobulins. Finally, we proved by capillaty electrophoresis that cestode EV carry small RNAs and then microRNAs were detected by RT-(q)PCR. 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.