Cestode parasites secrete microRNAs packaged in extracellular vesicles

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

La Serena

Workshop; EMBO WORKSHOP on Actualizations in Membrane Trafficking in Health and Disease; 2016

EMBO

Cestode parasites are platyhelminths passively transmitted among the hosts involved in their life cycle that can affect almost all vertebrate species. Zoonoses caused by cestodes are among the most severe neglected tropical diseases in humans prioritized by the World Health Organization.Most parasites have different strategies that allow them to regulate the host immune response and thus create a proper environment for their proper development and differentiation. Lately, it has increased the number of studies about extracellular vesicles (EV) secretion as a path of intercellular communication in many organisms including parasite-host relationships. EVs are membrane-bound structures that can be classified by their size, biogenesis, morphology and composition, among which exosomes and microvesicles are the most studied. EVs can carry proteins, lipids, DNA, mRNAs and small RNAs, including miRNAs which are ~22 nt length non-coding RNAs that can down-regulate the expression of their target genes. In the case of helminth EVs, the presence of intravesicular miRNAs was confirmed as well as their internalization by host cells where they can modify the transcriptional profile.Since there are no reports on cestode EVs secretion, here we aimed to determine whether the larval stages of the model cestodes Taenia crassiceps and Mesocestoides corti secrete EVs and analyzed their RNA content. First, we demonstrated the secretion of membrane-bound structures compatible with EVs by transmission electron microscopy. Then, we proved that cestode EVs carry intravesicular small RNAs and particularly the presence of miRNAs was detected by RT-PCR. This is the first report of EV secretion as well as miRNAs secretion in cestode parasites and could represent a parasite-parasite or parasite-host path of communication. Also, these results could contribute with relevant information for the future development of new diagnosis methods of these diseases through the detection of circulating parasite miRNAs as non-invasive biomarkers.