Discovery of small molecule inhibitors of MyD88-dependent signaling pathways using a computational screen

Sci Rep. 2015 Sep 18:5:14246. doi: 10.1038/srep14246.

Abstract

In this study, we used high-throughput computational screening to discover drug-like inhibitors of the host MyD88 protein-protein signaling interaction implicated in the potentially lethal immune response associated with Staphylococcal enterotoxins. We built a protein-protein dimeric docking model of the Toll-interleukin receptor (TIR)-domain of MyD88 and identified a binding site for docking small molecules. Computational screening of 5 million drug-like compounds led to testing of 30 small molecules; one of these molecules inhibits the TIR-TIR domain interaction and attenuates pro-inflammatory cytokine production in human primary cell cultures. Compounds chemically similar to this hit from the PubChem database were observed to be more potent with improved drug-like properties. Most of these 2(nd) generation compounds inhibit Staphylococcal enterotoxin B (SEB)-induced TNF-α, IFN-γ, IL-6, and IL-1β production at 2-10 μM in human primary cells. Biochemical analysis and a cell-based reporter assay revealed that the most promising compound, T6167923, disrupts MyD88 homodimeric formation, which is critical for its signaling function. Furthermore, we observed that administration of a single dose of T6167923 completely protects mice from lethal SEB-induced toxic shock. In summary, our in silico approach has identified anti-inflammatory inhibitors against in vitro and in vivo toxin exposure with promise to treat other MyD88-related pro-inflammatory diseases.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Computational Biology / methods*
  • Computer Simulation*
  • Cytokines / metabolism
  • Dose-Response Relationship, Drug
  • Drug Discovery / methods*
  • Enterotoxins / immunology
  • Enterotoxins / metabolism
  • Humans
  • Inflammation Mediators / metabolism
  • Inhibitory Concentration 50
  • Leukocytes, Mononuclear / drug effects
  • Leukocytes, Mononuclear / immunology
  • Leukocytes, Mononuclear / metabolism
  • Mice
  • Models, Molecular
  • Myeloid Differentiation Factor 88 / chemistry*
  • Myeloid Differentiation Factor 88 / metabolism*
  • Protein Binding
  • Protein Conformation
  • Protein Interaction Domains and Motifs
  • Protein Multimerization / drug effects
  • Signal Transduction* / drug effects

Substances

  • Cytokines
  • Enterotoxins
  • Inflammation Mediators
  • Myeloid Differentiation Factor 88
  • enterotoxin B, staphylococcal