A thiol-saccharide therapy to treat COVID-19

摘要COVID 19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。在该授权申请中，我们提出确定MUC-031 -二硫醇修饰的糖-作为COVID 19的治疗的治疗效用。我们目前正在开发MUC-031作为一种新型的粘液溶解剂，基于其切割粘液凝胶中粘蛋白聚合物之间的二硫键交联的能力。这些胱氨酸连接赋予病理性粘液凝胶硬度和刚性。胱氨酸还在维持SARS-CoV 2刺突蛋白（SARS-2-S）的受体结合结构域（RBD）中的天然结合界面中发挥作用，该受体结合结构域作为进入受体结合宿主细胞上的ACE 2。我们假设SARS-2-S中胱氨酸的裂解将改变RBD的天然构象并使SARS-2-S与ACE 2结合失效。在平板结合测定的初步数据中，我们发现MUC-031在抑制SAR-2-S与ACE 2结合方面是高度有效的，并且在防止SARS-CoV 2假病毒体感染肺上皮细胞方面是有效的。我们提出了两个目标来快速生成进一步的数据，以支持MUC-031作为COVID 19的新治疗方法。AIM 1将确定MUC-031是否在体外使SARS-2-S失活以抑制SARS-CoV 2感染。在这个目的中，我们将使用平板结合测定和细胞培养系统来确定MUC-031抑制SARS-2-S与ACE 2结合和SARS-CoV 2感染细胞的剂量和时间决定因素。AIM 2将确定MUC-031是否改善体内COVID 19的结果。在这里，我们将使用COVID 19的叙利亚仓鼠模型，基于最近发表的该模型用于COVID 19研究的实用性。我们的目标将迅速确定MUC-031是否在COVID 19中具有治疗效用。我们的提案利用了现有tPPG的工作，并有望在相对较短的时间内产生新的治疗方法。本文提出的MUC-031的机制与正在测试的所有其他抗病毒疗法不同，并将增加阻止大流行的治疗手段。

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.