Targeting RIPK3 in Flu-Associated Lung Injury

项目摘要/摘要 季节性甲型流感病毒(IAV)感染每年导致70多万人住院和5万人死亡 仅在美国。此外，高毒力的H5和H7禽流感病毒株目前传播有限 在人类之间，只有少数几个突变才能获得广泛传播的能力。AS 目前的疫苗和抗病毒策略要么疗效有限，要么容易产生病毒耐药性， 逃避，为季节性和致命性IAV疾病确定新的治疗切入点，最好是那些 靶向致病宿主信号通路，是当务之急。我们已经鉴定了宿主激酶RIPK3 作为针对IAV的治疗开发的一个有前途的新切入点。RIPK3是 高度促炎的细胞死亡形式称为坏死性下垂，我们发现它是导致 IAV感染时的肺损伤和炎症。季节性和大流行的IAV毒株都会触发RIPK3- 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，AS 以及病毒性肺炎和细菌性肺炎，每一种肺炎都是以下疾病的主要致病和死亡原因 IAV感染。值得注意的是，RIPK3还介导或放大了一系列慢性肿瘤坏死因子-α介导的病理(如 如类风湿性关节炎)，使其成为治疗多种炎症条件的非常有吸引力的新分子靶点。 奇怪的是，考虑到RIPK3潜在的治疗靶点是多么重要，没有选择性的RIPK3抑制剂 已进入临床试验阶段。我们现在已经开发出一种新的RIPK3抑制剂的结构类别，我们 称为UH15系列，它基于以ATP-AS为靶点的吡啶[2，3-d]嘧啶支架 以及RIPK3的变构Glu-out口袋。我们的初步发现显示，UH15类似物，在刚刚 一轮优化，已经比目前的RIPK3抑制剂更有效，并显示出良好的活性 体外和体内抗IAV诱导的坏死。这些令人兴奋的结果突出了即时的翻译 UH15系列对坏死性肺损伤以及由此引发的ARDS和肺炎的潜在作用 季节性和强毒的IAV株。我们提案的目标是迭代优化基于UH15的 化合物在体外阻断RIPK3，并通过使用RIPK3介导的病理的快速小鼠模型( 肿瘤坏死因子SIRS模型)，对体内使用的化合物进行优先排序(目标1)。然后，我们建议评估这些UH15 化合物在各种IAV引发的疾病环境中的治疗效果，包括(1) 高危季节性IAV感染，(2)高致病性禽类IAV感染，(3)继发性肺炎球菌 季节性IAV感染后肺炎(目标2)。拟议的研究将一组研究人员聚集在一起 在小分子药物化学(CUNY)方面拥有强大的互补专业知识，RIPK3激酶生物化学 和炎症中的功能(Degterev)，以及在IAV致病过程中RIPK3介导的细胞死亡信号 (托马斯·巴拉钱德兰)。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放大的多种IAV诱发的疾病。

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.