RIG-I Recognition of RNA Targets: The Influence of Terminal Base Pair Sequence and Overhangs on Affinity and Signaling

Cell Rep. 2019 Dec 17;29(12):3807-3815.e3. doi: 10.1016/j.celrep.2019.11.052.

Abstract

Within the complex environment of the human cell, the RIG-I innate immune receptor must detect the presence of double-stranded viral RNA molecules and differentiate them from a diversity of host RNA molecules. In an ongoing effort to understand the molecular basis for RIG-I target specificity, here, we evaluate the ability of this sensor to respond to triphosphorylated, double-stranded RNA molecules that contain all possible terminal base pairs and common mismatches. In addition, we test the response to duplexes with various types of 5' and 3' overhangs. We conducted quantitative measurements of RNA ligand affinity, then tested RNA variants for their ability to stimulate the RIG-I-dependent interferon response in cells and in whole animals. The resulting data provide insights into the design of RNA therapeutics that prevent RIG-I activation, and they provide valuable insights into the mechanisms of evasion by deadly pathogens such as the Ebola and Marburg viruses.

Keywords: RIG-I receptor; RLR; antiviral; innate immunity; oligonucleotide therapeutic.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Pairing
  • DEAD Box Protein 58 / chemistry
  • DEAD Box Protein 58 / genetics*
  • DEAD Box Protein 58 / immunology
  • DEAD Box Protein 58 / metabolism*
  • HEK293 Cells
  • Humans
  • Immunity, Innate / immunology*
  • Interferon-beta / metabolism*
  • Mice
  • Mice, Inbred C57BL
  • RNA, Double-Stranded / chemistry
  • RNA, Double-Stranded / genetics*
  • RNA, Double-Stranded / metabolism*
  • Signal Transduction

Substances

  • RNA, Double-Stranded
  • Interferon-beta
  • DDX58 protein, human
  • DEAD Box Protein 58