[PDF][PDF] Selective export into extracellular vesicles and function of tRNA fragments during T cell activation

NT Chiou, R Kageyama, KM Ansel - Cell reports, 2018 - cell.com
NT Chiou, R Kageyama, KM Ansel
Cell reports, 2018cell.com
The discovery of microRNA (miRNA) sorting into extracellular vesicles (EVs) revealed a
novel mode of intercellular communication and uncovered a link between cellular
endomembrane compartments and small RNAs in EV-secreting cells. Using a two-step
ultracentrifugation procedure to isolate EVs released by T cells, we found that 45% of tRNA
fragments (tRFs), but fewer than 1% of miRNAs, were significantly enriched in EVs
compared with the corresponding cellular RNA. T cell activation induced the EV-mediated …
Summary
The discovery of microRNA (miRNA) sorting into extracellular vesicles (EVs) revealed a novel mode of intercellular communication and uncovered a link between cellular endomembrane compartments and small RNAs in EV-secreting cells. Using a two-step ultracentrifugation procedure to isolate EVs released by T cells, we found that 45% of tRNA fragments (tRFs), but fewer than 1% of miRNAs, were significantly enriched in EVs compared with the corresponding cellular RNA. T cell activation induced the EV-mediated release of a specific set of tRFs derived from the 5′ end and 3′-internal region of tRNAs without variable loops. Inhibition of EV biogenesis pathways specifically led to the accumulation of these activation-induced EV-enriched tRFs within multivesicular bodies (MVBs). Introducing antisense oligonucleotides to inhibit these tRFs enhanced T cell activation. Taken together, these results demonstrate that T cells selectively release tRFs into EVs via MVBs and suggest that this process may remove tRFs that repress immune activation.
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