Infection-induced 5'-half molecules of tRNAHisGUG activate Toll-like receptor 7.
PLoS Biol
; 18(12): e3000982, 2020 12.
Article
en En
| MEDLINE
| ID: mdl-33332353
ABSTRACT
Toll-like receptors (TLRs) play a crucial role in the innate immune response. Although endosomal TLR7 recognizes single-stranded RNAs, their endogenous RNA ligands have not been fully explored. Here, we report 5'-tRNA half molecules as abundant activators of TLR7. Mycobacterial infection and accompanying surface TLR activation up-regulate the expression of 5'-tRNA half molecules in human monocyte-derived macrophages (HMDMs). The abundant accumulation of 5'-tRNA halves also occur in HMDM-secreted extracellular vehicles (EVs); the abundance of EV-5'-tRNAHisGUG half molecules is >200-fold higher than that of the most abundant EV-microRNA (miRNA). Sequence identification of the 5'-tRNA halves using cP-RNA-seq revealed abundant and selective packaging of specific 5'-tRNA half species into EVs. The EV-5'-tRNAHisGUG half was experimentally demonstrated to be delivered into endosomes in recipient cells and to activate endosomal TLR7. Up-regulation of the 5'-tRNA half molecules was also observed in the plasma of patients infected with Mycobacterium tuberculosis. These results unveil a novel tRNA-engaged pathway in the innate immune response and assign the role of "immune activators" to 5'-tRNA half molecules.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
ARN de Transferencia de Histidina
/
Receptor Toll-Like 7
/
Vesículas Extracelulares
Límite:
Humans
Idioma:
En
Revista:
PLoS Biol
Asunto de la revista:
BIOLOGIA
Año:
2020
Tipo del documento:
Article
País de afiliación:
Estados Unidos