Systematic editing of synthetic RIG-I ligands to produce effective antiviral and anti-tumor RNA immunotherapies.

Retinoic acid-inducible gene I (RIG-I) recognizes double-stranded viral RNAs (dsRNAs) containing two or three 5' phosphates. A few reports of 5'-PPP-independent RIG-I agonists have emerged, but little is known about the molecular principles underlying their recognition. We recently found that the bent duplex RNA from the influenza A panhandle promoter activates RIG-I even in the absence of a 5'-triphosphate moiety. Here, we report that non-canonical synthetic RNA oligonucleotides containing G-U wobble base pairs that form a bent helix can exert RIG-I-mediated antiviral and anti-tumor effects in a sequence- and site-dependent manner. We present synthetic RNAs that have been systematically modified to enhance their efficacy and we outline the basic principles for engineering RIG-I agonists applicable to immunotherapy.

This article has been retracted, please see retraction notice 10.1093/nar/gky819 for further details.

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