Abstract
Toll-like receptor (TLR) 7 has an important role in immune activation processes and represents an emerging drug discovery target for the development of immunomodulators. Three-dimensional similarity-based virtual screening was performed using the Rapid Overlay of Chemical Structures software (vROCS version 3.1.1. OpenEye Scientific Software, Santa Fe, NM. http://www.eyesopen.com) to search for potential ligands of TLR7. Six new compounds with three new chemical scaffolds were discovered as initial hit antagonists of TLR7, with IC50 values in the micromolar range, as determined by reporter assays. With only the imidazoquinolines described as small-molecule TLR7 antagonists to date, the new chemotypes described in this report represent an important starting point for the development of drug candidates for treatment of autoimmune diseases.
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References
Barrat FJ et al (2005) Nucleic acids of mammalian origin can act as endogenous ligands for Toll-like receptors and may promote systemic lupus erythematosus. J Exp Med 202:1131–1139. doi:10.1084/jem.20050914
Blasius AL, Beutler B (2010) Intracellular toll-like receptors immunity 32:305–315. doi:10.1016/j.immuni.2010.03.012
Bostrom J, Greenwood JR, Gottfries J (2003) Assessing the performance of OMEGA with respect to retrieving bioactive conformations. J Mol Graph Model 21:449–462
Grant JA, Gallardo MA, Pickup BT (1996) A fast method of molecular shape comparison: a simple application of a Gaussian description of molecular shape. J Comput Chem 17:1653–1666. doi:10.1002/(sici)1096-987x(19961115)17:14<1653:aid-jcc7>3.0.co;2-k
Hawkins PC, Skillman AG, Warren GL, Ellingson BA, Stahl MT (2010) Conformer generation with OMEGA: algorithm and validation using high quality structures from the Protein Databank and Cambridge Structural Database. J Chem Inf Model 50:572–584. doi:10.1021/ci100031x
Irwin JJ, Sterling T, Mysinger MM, Bolstad ES, Coleman RG (2012) ZINC: a free tool to discover chemistry for biology. J Chem Inf Model. doi:10.1021/ci3001277
Jurk M et al (2011) Immunostimulatory potential of silencing RNAs can be mediated by a non-uridine-rich toll-like receptor 7 motif. Nucleic Acid Ther 21:201–214. doi:10.1089/nat.2011.0298
Kanzler H, Barrat FJ, Hessel EM, Coffman RL (2007) Therapeutic targeting of innate immunity with toll-like receptor agonists and antagonists. Nat Med 13:552–559. doi:10.1038/nm1589
Matsuo T, Hayashi A, Abe M, Matsuda T, Hisaeda Y, Hayashi T (2009) Meso-unsubstituted iron corrole in hemoproteins: remarkable differences in effects on peroxidase activities between myoglobin and horseradish peroxidase. J Am Chem Soc 131:15124–15125. doi:10.1021/ja907428e
Meng T et al (2011) Simple and efficient Copper(I)-catalyzed access to three versatile aminocoumarin-based scaffolds using isocyanoacetate. Adv Synth Catal 353:918–924. doi:10.1002/adsc.201000895
Miller RL, Gerster JF, Owens ML, Slade HB, Tomai MA (1999) Imiquimod applied topically: a novel immune response modifier and new class of drug. Int J Immunopharmacol 21:1–14
Moresco EM, LaVine D, Beutler B (2011) Toll-like receptors. Curr Biol 21:R488–R493. doi:10.1016/j.cub.2011.05.039
Nicholls A et al (2010) Molecular shape and medicinal chemistry: a perspective. J Med Chem 53:3862–3886. doi:10.1021/jm900818s
Shukla NM, Kimbrell MR, Malladi SS, David SA (2009) Regioisomerism-dependent TLR7 agonism and antagonism in an imidazoquinoline. Bioorg Med Chem Lett 19:2211–2214. doi:10.1016/j.bmcl.2009.02.100
Shukla NM, Malladi SS, Mutz CA, Balakrishna R, David SA (2010) Structure-activity relationships in human toll-like receptor 7-active imidazoquinoline analogues. J Med Chem 53:4450–4465. doi:10.1021/jm100358c
Shukla NM, Malladi SS, Day V, David SA (2011) Preliminary evaluation of a 3H imidazoquinoline library as dual TLR7/TLR8 antagonists. Bioorg Med Chem 19:3801–3811. doi:10.1016/j.bmc.2011.04.052
Shukla NM, Salunke DB, Balakrishna R, Mutz CA, Malladi SS, David SA (2012) Potent adjuvanticity of a pure TLR7-agonistic imidazoquinoline dendrimer. PLoS One 7:e43612. doi:10.1371/journal.pone.0043612
Sun S, Rao NL, Venable J, Thurmond R, Karlsson L (2007) TLR7/9 antagonists as therapeutics for immune-mediated inflammatory disorders. Inflamm Allergy Drug Targets 6:223–235
Wang D, Bhagat L, Yu D, Zhu FG, Tang JX, Kandimalla ER, Agrawal S (2009) Oligodeoxyribonucleotide-based antagonists for toll-like receptors 7 and 9. J Med Chem 52:551–558. doi:10.1021/jm8014316
Acknowledgments
We thank OpenEye Scientific Software, Santa Fe, NM, USA, for free academic licenses for the use of their software, and Dr. Chris Berrie for critical reading of the manuscript. The financial support of the Slovenian Research Agency is gratefully acknowledged.
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Švajger, U., Horvat, Ž., Knez, D. et al. New antagonists of toll-like receptor 7 discovered through 3D ligand-based virtual screening. Med Chem Res 24, 362–371 (2015). https://doi.org/10.1007/s00044-014-1127-5
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DOI: https://doi.org/10.1007/s00044-014-1127-5