Viral DNA Binding to NLRC3, an Inhibitory Nucleic Acid Sensor, Unleashes STING, a Cyclic Dinucleotide Receptor that Activates Type I Interferon

Immunity. 2019 Mar 19;50(3):591-599.e6. doi: 10.1016/j.immuni.2019.02.009.

Abstract

Immune suppression is a crucial component of immunoregulation and a subgroup of nucleotide-binding domain (NBD), leucine-rich repeat (LRR)-containing proteins (NLRs) attenuate innate immunity. How this inhibitory function is controlled is unknown. A key question is whether microbial ligands can regulate this inhibition. NLRC3 is a negative regulator that attenuates type I interferon (IFN-I) response by sequestering and attenuating stimulator of interferon genes (STING) activation. Here, we report that NLRC3 binds viral DNA and other nucleic acids through its LRR domain. DNA binding to NLRC3 increases its ATPase activity, and ATP-binding by NLRC3 diminishes its interaction with STING, thus licensing an IFN-I response. This work uncovers a mechanism wherein viral nucleic acid binding releases an inhibitory innate receptor from its target.

Keywords: DNA-binding receptor; NOD-like receptor; STING; TBK1; interferon.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Cell Line
  • Cell Line, Tumor
  • DNA, Viral / metabolism*
  • HEK293 Cells
  • HeLa Cells
  • Humans
  • Immunity, Innate / immunology
  • Intercellular Signaling Peptides and Proteins / metabolism*
  • Interferon Type I / metabolism*
  • Membrane Proteins / metabolism*
  • Mice
  • Mice, Inbred C57BL
  • Nucleic Acids / metabolism
  • Protein Binding / immunology

Substances

  • DNA, Viral
  • Intercellular Signaling Peptides and Proteins
  • Interferon Type I
  • Membrane Proteins
  • NLRC3 protein, mouse
  • Nucleic Acids
  • Sting1 protein, mouse