Pharmacology and Toxicology, Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195 Berlin, Germany.
Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195 Berlin, Germany.
Biochem Pharmacol. 2020 Jul;177:113957. doi: 10.1016/j.bcp.2020.113957. Epub 2020 Apr 5.
Toll-like receptor 2 (TLR2) and TLR8 are involved in the recognition of bacterial and viral components and are linked not only to protective antimicrobial immunity but also to inflammatory diseases. Recently, increasing attention has been paid to the receptor crosstalk between TLR2 and TLR8 to fine-tune innate immune responses. In this study, we report a novel dual TLR2/TLR8 antagonist, compound 24 that was developed by a modeling-guided synthesis approach. The modulator was optimized from the previously reported 1,3-benzothiazole derivative, compound 8. Compound 24 was pharmacologically characterized for the ability to inhibit TLR2- and TLR8-mediated responses in TLR-overexpressing reporter cells and THP-1 macrophages. The modulator showed high efficacy with IC values in the low micromolar range for both TLRs, selectivity towards other TLRs and low cytotoxicity. At TLR2, a slight predominance for the TLR2/1 heterodimer was found in reporter cells selectively expressing TLR2/1 or TLR2/6 heterodimers. Concentration ratio analysis in the presence of PamCSK or PamCSK indicated non-competitive antagonist behavior at hTLR2. In computational docking studies, a plausible alternative binding mode of compound 24 was predicted for both TLR2 and TLR8. Our results provide evidence that it is feasible to simultaneously and selectively target endosomal- and surface-located TLRs. We identified a small-molecule dual TLR2/8 antagonist that may serve as a valuable pharmacological tool to decipher the role of TLR2/8 co-signaling in inflammation.
Toll 样受体 2（TLR2）和 TLR8 参与识别细菌和病毒成分，不仅与保护性抗菌免疫有关，还与炎症性疾病有关。最近，人们越来越关注 TLR2 和 TLR8 受体的串扰，以微调先天免疫反应。在这项研究中，我们报告了一种新型双 TLR2/TLR8 拮抗剂化合物 24，它是通过建模指导的合成方法开发的。该调节剂是从之前报道的 1,3-苯并噻唑衍生物化合物 8 优化而来的。该调节剂在 TLR 过表达报告细胞和 THP-1 巨噬细胞中抑制 TLR2 和 TLR8 介导的反应的能力进行了药理学表征。调节剂对两种 TLR 的 IC 值均在低微摩尔范围内表现出高效，对其他 TLR 具有选择性，细胞毒性低。在 TLR2 上，在选择性表达 TLR2/1 或 TLR2/6 异二聚体的报告细胞中，发现 TLR2/1 异二聚体略占优势。在存在 PamCSK 或 PamCSK 的情况下进行浓度比分析表明，化合物 24 在 hTLR2 上表现出非竞争性拮抗剂行为。在计算 docking 研究中，预测了化合物 24 在 TLR2 和 TLR8 中的两种可行的替代结合模式。我们的结果表明，同时和选择性地靶向内体和表面定位的 TLR 是可行的。我们确定了一种小分子双 TLR2/8 拮抗剂，它可以作为一种有价值的药理学工具，用于破译 TLR2/8 共信号在炎症中的作用。
