title: Discovery of small molecule inhibitors of MyD88-dependent signaling pathways using a computational screen.
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.
authors.affiliation: Department of Cell Biology and Biochemistry and.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Olson
authors.affiliation: Department of Cell Biology and Biochemistry and.|Computational Sciences Division, U.S. Army Research Laboratory, Aberdeen Proving Ground, MD 21005.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Lee
authors.affiliation: Department of Immunology, Molecular and Translational Sciences Division, U.S. Army Medical Research Institute of Infectious Diseases, Frederick, MD 21702.
authors.forename: Teri L
authors.initials: TL
authors.lastname: Kissner
authors.affiliation: Department of Immunology, Molecular and Translational Sciences Division, U.S. Army Medical Research Institute of Infectious Diseases, Frederick, MD 21702.
authors.forename: Shahabuddin
authors.initials: S
authors.lastname: Alam
authors.affiliation: Macromolecular Crystallography Laboratory, National Cancer Institute at Frederick, Frederick, MD 21702.
authors.forename: David S
authors.initials: DS
authors.lastname: Waugh
authors.affiliation: Department of Immunology, Molecular and Translational Sciences Division, U.S. Army Medical Research Institute of Infectious Diseases, Frederick, MD 21702.
authors.forename: Kamal U
authors.initials: KU
authors.lastname: Saikh
mesh_terms: D000818:Animals; D019295:Computational Biology / Q000379:methods*; D003198:Computer Simulation; D016207:Cytokines / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D055808:Drug Discovery / Q000379:methods*; D004768:Enterotoxins / Q000276:immunology / Q000378:metabolism; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D020128:Inhibitory Concentration 50; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008958:Models, Molecular; D053594:Myeloid Differentiation Factor 88 / Q000737:chemistry* / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation; D054730:Protein Interaction Domains and Motifs; D055503:Protein Multimerization / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D016207:Cytokines; D004768:Enterotoxins; D018836:Inflammation Mediators; D053594:Myeloid Differentiation Factor 88; C031818:enterotoxin B, staphylococcal