3wn4

Publication Abstract from PubMed

Toll-like receptor (TLR)-8 agonists activate adaptive immune responses by inducing robust production of T helper 1-polarizing cytokines, suggesting that TLR8-active compounds might be promising candidate vaccine adjuvants. Recently, a C2-butyl furo[2,3-c]quinoline was reported with purely TLR8 agonistic activity. This compound was successfully co-crystallized with the human TLR8 ectodomain, and the co-crystal structure revealed ligand-induced reorganization of the binding pocket of TLR8. The loss of a key hydrogen bond between the oxygen atom of the furanyl ring of the agonist and Thr 574 in TLR8 suggested that the furan ring is dispensable. Employing a disconnection strategy, 3- and 4-substituted aminoquinolines were investigated. Focused structure-based ligand design studies led to the identification of 3-pentyl-quinoline-2-amine as a novel, structurally simple, and highly potent human TLR8-specific agonist (EC50 =0.2 muM). Preliminary evaluation of this compound in ex vivo human blood assay systems revealed that it retains prominent cytokine-inducing activity. Together, these results indicate the suitability of this compound as a novel vaccine adjuvant, warranting further investigation.

Structure-Based Design of Novel Human Toll-like Receptor 8 Agonists.,Kokatla HP, Sil D, Tanji H, Ohto U, Malladi SS, Fox LM, Shimizu T, David SA ChemMedChem. 2014 Jan 28. doi: 10.1002/cmdc.201300573. PMID:24474703^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.