Molecular Determinants of GS-9620-Dependent TLR7 Activation

PLoS One. 2016 Jan 19;11(1):e0146835. doi: 10.1371/journal.pone.0146835. eCollection 2016.

Abstract

GS-9620 is an orally administered agonist of Toll-like receptor (TLR)7 currently being evaluated in clinical studies for the treatment of chronic HBV and HIV patients. GS-9620 has shown antiviral efficacy in preclinical models of chronic hepadnavirus infection in woodchuck as well as chimpanzee. However, the molecular determinants of GS-9620-dependent activation of TLR7 are not well defined. The studies presented here elucidate GS-9620 subcellular distribution and characterize its molecular interactions with human TLR7 using structure-guided mutational analysis. Based on our results we present a molecular model of TLR7 bound to GS-9620. We also determine that several coding SNPs had no effect on GS-9620-dependent TLR7 activation. In addition, our studies provide evidence that TLR7 exists in a ligand-independent oligomeric state and that, TLR7 activation by GS-9620 is likely associated with compound-induced conformational changes. Finally, we demonstrate that activation of NF-κB and Akt pathways in primary plasmacytoid dendritic cells occur as immediate downstream cellular responses to GS-9620 stimulation. The data presented here further our understanding of the molecular parameters governing TLR7 activation by GS-9620, and more generally by nucleos/tide-related ligands.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Binding Sites
  • Cells, Cultured
  • HEK293 Cells
  • Humans
  • Molecular Sequence Data
  • Mutation
  • Polymorphism, Single Nucleotide
  • Protein Binding
  • Pteridines / pharmacology*
  • Toll-Like Receptor 7 / agonists
  • Toll-Like Receptor 7 / chemistry*
  • Toll-Like Receptor 7 / genetics
  • Toll-Like Receptor 7 / metabolism

Substances

  • Pteridines
  • TLR7 protein, human
  • Toll-Like Receptor 7
  • vesatolimod

Grants and funding

The funder of this study, Gilead Sciences Inc, provided support in the form of salaries, employee benefits, and company stock for authors IR, GB, JP, WX, HK, and SP, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.