A thiol-saccharide therapy to treat COVID-19

摘要COVID19正在全球范围内引发前所未有的全球卫生紧急情况，迫切需要新的治疗方法。在这项赠款申请中，我们建议确定MUC-031-一种二硫醇修饰的糖-作为治疗COVID19的治疗效用。我们目前正在开发MUC-031作为一种新型的粘液剂，基于它在粘液凝胶中裂解粘蛋白聚合物之间的二硫键的能力。这些半胱氨酸连接使病理性粘液凝胶变硬。半胱氨酸还在维持SARS-CoV2Spike(S)蛋白(SARS-2-S)受体结合结构域的天然结合界面方面发挥作用，该蛋白作为进入受体与宿主细胞上的血管紧张素转换酶2结合。我们推测，SARS-2-S中半胱氨酸的裂解将改变RBD的天然构象，并使SARS-2-S与血管紧张素转换酶2的结合失效。在平板结合试验的初步数据中，我们发现MUC-031对SAR2-S与血管紧张素转换酶2的结合有很强的抑制作用，并能有效地阻止SARS-CoV2假病毒感染肺上皮细胞。我们提出了两个目标，以快速产生更多的数据来支持MUC-031作为治疗COVID19的新疗法。目的1确定MUC-031是否体外阻断SARS-2-S抑制SARS-CoV2感染。为此，我们将利用平板结合实验和细胞培养系统来确定MUC-031抑制SARS-2-S与血管紧张素转换酶结合和SARS-CoV2感染细胞的剂量和时间决定因素。目的2将确定MUC-031是否可以改善体内的COVID19结果。在这里，我们将使用叙利亚仓鼠的COVID19模型，基于最近发表的该模型用于COVID19研究的实用程序。我们的目标将很快确定MUC-031是否在COVID19中具有治疗作用。我们的提案利用了现有tPPG的工作，并承诺在相对较短的时间内产生一种新的治疗方法。这里提出的MUC-031的机制与所有其他正在测试的抗病毒疗法不同，并将增加阻止大流行的治疗方法。

ABSTRACT COVID19 is causing an unprecedented global health emergency worldwide and new treatments are urgently needed. In this grant application we propose to determine the therapeutic utility of MUC-031 - a dithiol modified saccharide - as a treatment for COVID19. We are currently developing MUC-031 as a novel mucolytic based on its ability to cleave disulfide crosslinks between mucin polymers in mucus gels. These cystine linkages confer stiffness and rigidity to pathologic mucus gels. Cystines also have roles in maintaining the native binding interface in the receptor binding domain (RBD) of the SARS-CoV2 spike (S) protein (SARS-2-S), which binds ACE2 on host cells as an entry receptor. We hypothesize that cleavage of cystines in SARS-2-S will alter the native conformation of the RBD and disable SARS-2-S binding to ACE2. In preliminary data in a plate-binding assay, we find that MUC-031 is highly potent in inhibiting SAR-2-S binding to ACE2 and effective in preventing SARS- CoV2 pseudovirions from infecting lung epithelial cells. We propose two aims to quickly generate further data to support MUC-031 as a novel treatment for COVID19. AIM 1 will determine if MUC-031 disables SARS-2-S in vitro to inhibit SARS-CoV2 infection. In this Aim we will use a plate binding assay and cell culture systems to determine the dose and time determinants of MUC-031 inhibition of SARS-2-S binding to ACE2 and SARS-CoV2 infection of cells. AIM 2 will determine if MUC-031 improves COVID19 outcomes in vivo. Here we will use a Syrian hamster model of COVID19 based on recent publication of the utility of this model for COVID19 research. Together our aims will quickly determine if MUC-031 has therapeutic utility in COVID19. Our proposal leverages work in an existing tPPG and holds promise to yield a novel treatment in a relatively short timeframe. The mechanism of MUC-031 proposed here is distinct from that of all other anti-viral therapies being tested, and will add to the arsenal of treatments to stop the pandemic.