Lambertz, U, Oviedo Ovando, ME, Vasconcelos, E orcid.org/0000-0001-5130-6622 et al. (3 more authors) (2015) Small RNAs derived from tRNAs and rRNAs are highly enriched in exosomes from both old and new world Leishmania providing evidence for conserved exosomal RNA Packaging. BMC Genomics, 16 (1). 151. ISSN 1471-2164
Abstract
Background
Leishmania use exosomes to communicate with their mammalian hosts and these secreted vesicles appear to contribute to pathogenesis by delivering protein virulence factors to macrophages. In other eukaryotes, exosomes were found to carry RNA cargo, such as mRNAs and small non-coding RNAs, capable of altering recipient cell phenotype. Whether leishmania exosomes also contain RNAs which they are able to deliver to bystander cells is not known. Here, we show that leishmania exosomes indeed contain RNAs and compare and contrast the RNA content of exosomes released by Leishmania donovani and Leishmania braziliensis.
Results
We purified RNA from exosomes collected from axenic amastigote culture supernatant and found that when compared with total leishmania RNA, exosomes mainly contained short RNA sequences. Exosomes with intact membranes were capable of protecting their RNA cargo from degradation by RNase. Moreover, exosome RNA cargo was delivered to host cell cytoplasm in vitro. Sequencing of exosomal RNA indicated that the majority of cargo sequences were derived from non-coding RNA species such as rRNA and tRNA. In depth analysis revealed the presence of tRNA-derived small RNAs, a novel RNA type with suspected regulatory functions. Northern blotting confirmed the specific and selective enrichment of tRNA-derived small RNAs in exosomes. We also identified a number of novel transcripts, which appeared to be specifically enriched in exosomes compared to total cell RNA. In addition, we observed the presence of sequences mapping to siRNA-coding regions in L. braziliensis , but not in L. donovani exosomes.
Conclusions
These results show that leishmania exosomes are selectively and specifically enriched in small RNAs derived almost exclusively from non-coding RNAs. These exosomes are competent to deliver their cargo of novel, potential small regulatory RNAs to macrophages where they may influence parasite-host cell interactions. The remarkably high degree of congruence in exosomal RNA content between L. donovani and L. braziliensis, argues for the presence of a conserved mechanism for exosomal RNA packaging in leishmania. These findings open up a new avenue of research on non-canonical, small RNA pathways in this trypanosomatid, which may elucidate pathogenesis and identify novel therapeutic approaches.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2015 Lambertz et al.; licensee BioMed Central. This is an Open Access article distributed under the terms of the CreativeCommons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, andreproduction in any medium, provided the original work is properly credited. The Creative Commons Public DomainDedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article,unless otherwise stated. |
Keywords: | Leishmania; Exosomes; Shuttle RNA; Small non-coding RNA; tRNA-derived small RNA |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Biological Sciences (Leeds) > School of Molecular and Cellular Biology (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 20 May 2021 08:25 |
Last Modified: | 20 May 2021 08:25 |
Status: | Published |
Publisher: | BMC |
Identification Number: | 10.1186/s12864-015-1260-7 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:174323 |