Kalin Jay H, Yin Yanting, Tran Minh T, Piassek Madison, Fung Amy, Grosse Sandrine, Jacoby Edgar, Bhaumik Anusarka, Adhikary Suraj, Miller Robyn, Lemmens Cynthia, Lutter Ferdinand H, Pieters Serge, Cooymans Ludwig, Rombouts Geert, Oehlrich Daniel, Tomaso Sonia, Lozada Kate, Garcia Miguel Osorio, Anson Brandon, De Bruyn Suzanne, Smith-Monroy Constance, Neefs Jean-Marc, Conceição-Neto Nádia, Stoops Bart, van Vlijmen Herman, Patrick Aaron, Yu Xiaodi, Wong Victoria, Krosky Daniel, Abeywickrema Pravien, Mason Stephen, Jin Zhinan, Jonckers Tim H M, Sharma Sujata
Janssen Research & Development, LLC, a Johnson & Johnson Company, Spring House, Pennsylvania, USA.
Janssen Pharmaceutica N.V., Beerse, Belgium.
J Virol. 2025 Jul 22;99(7):e0017825. doi: 10.1128/jvi.00178-25. Epub 2025 Jun 2.
Respiratory syncytial virus (RSV) is a major cause of severe respiratory tract infections in infants, young children, and the elderly. We report herein the discovery and characterization of a novel RSV polymerase (RSVpol) non-nucleoside inhibitor (NNI) chemotype that binds to a previously undescribed, highly conserved site in the palm domain of the L protein. Consistent with the observed mode of inhibition, cryogenic electron microscopy (cryo-EM) revealed the site to be adjacent to the nucleotide binding site. Minireplicon assays confirmed on-target activity against RSVpol, and cell-based antiviral assays showed that the lead compound effectively inhibited viral mRNA transcription and replication in clinically relevant A and B strains. Together, our data provides valuable insights into the molecular basis of inhibition for a novel mechanism of action and paves the way for structure-based design to deliver effective therapeutics against RSV.IMPORTANCERespiratory syncytial virus (RSV) is a negative-sense, single-stranded RNA virus belonging to the family of the order . Currently, monoclonal antibody treatments are only approved for infants, and vaccines are reserved for pregnant women and adults aged 60 years and older. Prophylaxis is also limited to the pediatric patient population, and there are currently no direct antiviral therapies for post-exposure treatment. Viral polymerases are considered well-validated drug targets due to their critical role in transcription and genome replication. Herein, we disclose the discovery of a spiro-indolinone series as polymerase inhibitors and describe the preliminary structure-activity relationship (SAR). A cryogenic electron microscopy (cryo-EM) structure obtained with an optimized lead revealed a novel binding site located in the palm domain, which will enable future structure-based drug design efforts. Novel RSV antivirals could be beneficial both as therapeutics following diagnosis and as a prophylactic in patients less likely to respond to vaccines.
呼吸道合胞病毒（RSV）是婴幼儿和老年人严重呼吸道感染的主要病因。我们在此报告一种新型呼吸道合胞病毒聚合酶（RSVpol）非核苷抑制剂（NNI）化学型的发现与特性，该化学型与L蛋白手掌结构域中一个先前未描述的高度保守位点结合。与观察到的抑制模式一致，低温电子显微镜（cryo-EM）显示该位点与核苷酸结合位点相邻。微型复制子试验证实了对RSVpol的靶向活性，基于细胞的抗病毒试验表明，先导化合物可有效抑制临床相关A和B毒株的病毒mRNA转录和复制。总之，我们的数据为一种新作用机制的抑制分子基础提供了有价值的见解，并为基于结构的设计以开发针对RSV的有效治疗药物铺平了道路。
重要性
呼吸道合胞病毒（RSV）是一种负链单链RNA病毒，属于 目 科。目前，单克隆抗体治疗仅被批准用于婴儿，疫苗仅适用于孕妇和60岁及以上的成年人。预防也仅限于儿科患者群体，目前尚无用于暴露后治疗的直接抗病毒疗法。由于病毒聚合酶在转录和基因组复制中起关键作用，因此被认为是经过充分验证的药物靶点。在此，我们披露了作为聚合酶抑制剂的螺吲哚酮系列的发现，并描述了初步的构效关系（SAR）。用优化后的先导化合物获得的低温电子显微镜（cryo-EM）结构揭示了一个位于手掌结构域的新结合位点，这将有助于未来基于结构的药物设计工作。新型RSV抗病毒药物作为诊断后的治疗药物以及作为对疫苗反应可能性较小的患者的预防药物可能都是有益的。
