Bacterial RNA sensing by TLR8 requires RNase 6 processing and is inhibited by RNA 2’O-methylation
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ABSTRACT: Mechanistic studies have revealed that TLR8 senses single-stranded RNA (ssRNA) fragments, processed via synergistic cleavage by ribonucleases (RNase) T2 and RNase A family members. Processing by these RNases releases uridines and purine-terminated residues resulting in TLR8 activation. Monocytes show high expression of RNase 6, yet this RNase has not been analyzed for its physiological contribution to recognition of bacterial RNA by TLR8. Herein, we characterized molecular RNase 6 cleavage mechanisms. BLaER1 RNASE6-/- cells showed a dampened TLR8-dependent response upon stimulation with isolated bacterial RNA (bRNA) but also upon infection with live whole bacteria. Pretreatment of bacterial RNA with recombinant RNase 6 generated fragments that induced stimulation in RNASE6 knockout cells. 2’O-RNA methyl modification, when introduced at the first uridine in the UA dinucleotide, impaired upstream processing by RNase 6 and dampened TLR8 stimulation. In summary, this data shows that RNase 6 plays a critical role in the processing of bacterial RNA by generating uridine-terminated breakdown products that ultimately activate TLR8.
INSTRUMENT(S): timsTOF HT, Orbitrap Exploris 480
ORGANISM(S): Homo Sapiens (human)
SUBMITTER: F Butter
LAB HEAD: Falk Butter
PROVIDER: PXD053881 | Pride | 2024-09-12
REPOSITORIES: Pride
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