Targeting RIPK3 in Flu-Associated Lung Injury

项目概要/摘要 季节性甲型流感病毒（IAV）感染每年导致70多万人住院治疗和5万人死亡 仅在美国。此外，尽管目前在传播方面受到限制，但高毒力的H5和H7禽流感病毒株 在人类之间，只有少数突变才能获得广泛传播的能力。作为 目前的疫苗和抗病毒策略要么在其效力方面受到限制，要么易受病毒抗性的影响， 逃避，确定新的治疗切入点的季节性和毒性IAV疾病，最好是那些 针对病原宿主信号传导途径，是一项紧迫的任务。我们已经鉴定了宿主激酶RIPK 3 作为一个有前途的新的切入点，针对IAV的治疗发展。RIPK 3是一个重要的调节因子， 高度促炎形式的细胞死亡称为坏死性凋亡，我们已经发现这是一个主要因素， IAV感染时的肺损伤和炎症。季节性和大流行性IAV毒株均触发RIPK 3- 我们提出的依赖性坏死性肺损伤是急性呼吸窘迫综合征（ARDS）的基础， 以及病毒性和细菌性肺炎，其中每一种都是下列疾病发病和死亡的主要原因： IAV感染。值得注意的是，RIPK 3还介导或放大了一系列慢性TNF-α介导的病理（如 如类风湿性关节炎），使其成为用于多种炎性病症的非常有吸引力的新分子靶标。 奇怪的是，考虑到治疗靶点RIPK 3的潜在重要性，没有选择性的RIPK 3抑制剂 已进入临床试验阶段。我们现在已经开发了一种新的结构类型的RIPK 3抑制剂， 这是一种基于吡啶并[2，3-d]嘧啶骨架的药物，它既靶向ATP， 以及RIPK 3的变构Glu外口袋。我们的初步研究结果表明，UH 15类似物， 一轮优化，已经比目前的RIPK 3抑制剂更有效，并显示出有希望的活性 抗IAV诱导的细胞坏死。这些令人兴奋的结果突出了 UH 15系列引发坏死性肺损伤和随后的ARDS和肺炎的可能性 季节性和强毒株。我们建议的目标是迭代优化基于UH 15的 通过使用RIPK 3-介导的病理学的快速小鼠模型（本发明的化合物）， TNF SIRS模型），优先考虑用于体内的化合物（目的1）。然后，我们建议评估这些UH 15 在各种IAV触发的疾病环境中具有治疗功效的化合物，包括（1） 高风险季节性IAV感染，（2）高致病性禽IAV感染，和（3）继发性肺炎球菌感染 季节性IAV感染后的肺炎（目的2）。这项拟议中的研究汇集了一组研究人员， 在小分子药物化学（Cuny）、RIPK 3激酶生物化学 和炎症中的功能（Degterev），以及IAV发病过程中RIPK 3介导的细胞死亡信号传导 （Balachandran，托马斯）.这些目标的成功完成有可能改变治疗 由坏死性肺损伤引发或扩大的多种IAV诱导的疾病。

PROJECT SUMMARY/ABSTRACT Seasonal influenza A virus (IAV) infections account for over 700,000 hospitalizations and 50,000 annual deaths in the US alone. Moreover, highly virulent H5 and H7 strains of avian IAV, while currently limited in their spread between humans, are only a few mutations from acquiring the capacity for widespread transmissibility. As current vaccines and antiviral strategies are either limited in their efficacy or susceptible to viral resistance and evasion, identifying new therapeutic entry-points for seasonal and virulent IAV disease, preferably those that target pathogenic host signaling pathways, is an urgent imperative. We have identified the host kinase RIPK3 as a promising new entry point for therapeutic development against IAV. RIPK3 is the central mediator of a highly pro-inflammatory form of cell death termed necroptosis, which we have found is a major contributor to lung injury and inflammation during IAV infection. Both seasonal and pandemic strains of IAV trigger RIPK3- dependent necrotic lung damage that we propose underlies Acute Respiratory Distress Syndrome (ARDS), as well as viral and bacterial pneumonia, each of which remain major causes of morbidity and mortality following IAV infection. Notably, RIPK3 also mediates or amplifies a range of chronic TNF-α-mediated pathologies (such as rheumatoid arthritis) making it a very attractive new molecular target for multiple inflammatory conditions. Curiously, given how important a therapeutic target RIPK3 potentially is, no selective RIPK3 inhibitors have been advanced into clinical trials. We now have developed a new structural class of RIPK3 inhibitor, which we call the UH15 series, and which is based on a pyrido[2,3-d]pyrimidine scaffold that targets both the ATP- as well as the allosteric Glu-out pockets of RIPK3. Our preliminary findings reveal that UH15 analogs, after just one round of optimization, are already more potent than current RIPK3 inhibitors and display promising activity against IAV induced necrosis in vitro and in vivo. These exciting results highlight the immediate translational potential of the UH15 series for necrotic lung injury and consequent ARDS and pneumonia triggered by seasonal and virulent strains of IAV. The goals of our proposal are to iteratively optimize UH15-based compounds for RIPK3 blockade in vitro and, by use of a rapid mouse model of RIPK3-mediated pathology (the TNF SIRS model), prioritize compounds for use in vivo (Aim 1). We then propose to assess these UH15 compounds for therapeutic efficacy in a variety of IAV-triggered disease settings, including the scenarios of (1) high-risk seasonal IAV infections, (2) infection by highly pathogenic avian IAV, and (3) secondary pneumococcal pneumonia following seasonal IAV infection (Aim 2). The proposed studies bring together a team of researchers with strong, complementary expertise in small-molecule medicinal chemistry (Cuny), RIPK3 kinase biochemistry and function in inflammation (Degterev), and RIPK3-mediated cell death signaling during IAV pathogenesis (Balachandran, Thomas). Successful completion of these Aims has the potential to transform the treatment of multiple IAV-induced diseases initiated or amplified by necrotic lung injury.