ANCAROLA MarÍa eugenia
congresos y reuniones científicas
Cestode extracellular vesicles carry small RNAs
MARIA EUGENIA ANCAROLA; ANTONIO MARCILLA; MICHAELA HERZ; NATALIA MACCHIAROLI; GABRIEL LICHTENSTEIN; LUCAS MALDONADO; MATIAS PEREZ; KLAUS BREHM; CAROLINA PONCINI; LAURA KAMENETZKY; MARA ROSENZVIT; MARCELA CUCHER
Congreso; II Reunión Argentina de Biología de ARNs no codificantes; 2018
Cestode parasites are flatworms with complex life cycles that can affect almost all vertebrate species. The larval (metacestode) stage of many cestodes cause severe diseases in humans such as cysticercosis and echinococcosis, whose etiologic agents are Taenia solium and parasites of the genus Echinococcus, respectively. Cross-species communication is crucial for parasites to regulate host immune response and thus generate the proper environment for establishment, development and reproduction. In this respect, many studies have recently reported the secretion of extracellular vesicles (EV) as a means of interaction between parasite and host. EV are membrane-bound structures that can carry different kinds of molecules such as nucleic acids, proteins and lipids. Several types of host cells were shown to internalize parasitic EV which induce transcriptional and/or phenotypical changes in recipient cells. Among the molecules responsible of these alterations are small non-coding RNAs, such as microRNAs (miRNAs) which are ~22-nt long RNAs that can down-regulate the expression of target genes. Here we aimed to determine if the metacestode stages of Taenia crassiceps, Mesocestoides corti and Echinococcus multilocularis secrete EV containing small RNAs, particularly miRNAs, and to analyse their putative target genes in host cells. For this, EV-enriched samples from metacestode conditioned media from each parasite were isolated by differential centrifugation. Also, EV-enriched samples from E. multilocularis hydatid fluid were obtained. By transmission electron microscopy we found that T. crassiceps and M. corti secrete EV to the extra-parasite milieu whereas EV secreted from the apical surface of the tegument of E. multilocularis metacestodes are mostly retained by the laminated layer. However, EV secreted by the basal surface can be detected in the hydatid fluid. According to capillary electrophoresis analysis, the EV secreted by the three parasites contain mostly small RNAs (< 200 nt) and the presence of miRNAs was confirmed by RT-PCR or RNA-seq. Finally, the putative role of EV miRNAs on host genes was predicted using the miRanda algorithm, showing that cestode let-7-5p may regulate mRNAs related to organ tropism within each host of the life cycle.In summary, we show that cestodes produce EV carrying regulatory small RNAs, whose interaction with host recipient cells depends on/is hindered by the particular morphological traits of each parasite species. Also, our predictions suggest that cestode EV miRNAs may have a significant role during parasite establishment by regulating host genes related to the generation of a proper environment for parasite development.