RAPID: Glycocalyx engineering to probe the role of mucin structure in coronavirus transmission and infection

项目非技术摘要有了这个奖项，生物材料计划在材料研究部和化学生命过程的化学计划在化学部正在资助博士杰西卡R。犹他州大学的克雷默研究粘液成分在冠状病毒（COV）传播中的作用。COV相关疾病已成为严重的公共卫生威胁。感染者咳嗽、打喷嚏甚至说话时产生的飞沫是病毒传播的主要来源。这些液滴来自携带病毒的唾液，并落在下一个潜在宿主（口腔、气道、眼睛）的粘膜上或硬表面上。在那里，病毒被分散，以备下一次感染。粘液以数百种形式产生，在物种之间，甚至在人与人之间都有所不同。存在的形式可能会影响病毒通过粘膜的容易程度，特别是因为某些类型直接与COV结合。粘液形式也可以影响空气飞沫中COV的浓度和活力。该项目的目标是确定导致空气传播和感染增加的粘液形式。这将通过模拟由不同粘液产生的咳嗽液滴并使用涂有不同粘液的人类细胞来实现。这一知识可能导致开发新的治疗方法，破坏COV-粘液结合，或确定更容易受到COV传播和感染的人群。项目技术摘要本研究项目主要研究粘蛋白糖蛋白结构在冠状病毒（COV）通过空气颗粒、污染物传播以及通过糖萼进入细胞中的作用。上皮组织被保护性粘蛋白包被，所述保护性粘蛋白被分泌以形成粘液，并且还被拴系到细胞表面以形成糖萼。COV在进入宿主细胞进行复制之前必须穿过这些层。通过排出的空气中的唾液飞沫传播病毒是一种主要的传播方式。粘蛋白产生有多种对每种宿主特异性的附着聚糖。这些聚糖改变粘膜唾液的粘弹性，并直接结合COV刺突蛋白。这些因素可以影响空气中颗粒的病毒载量和存活力，并且可以影响细胞表面的对接和扩散。然而，这些问题一直具有挑战性的答案，因为天然粘蛋白糖基化是不明确的，不能通过目前的生物学方法调整。PI的实验室将合成具有可调COV结合聚糖模式的粘蛋白类似物，并将使用它们来设计活细胞表面的糖萼。将模拟咳嗽，并通过表征液滴形态、病毒载量和存活力来检查粘蛋白结构在空气呼吸液滴COV传播中的作用。细胞表面的对接和扩散以及复制将在活的上皮细胞上进行量化。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Project Non-Technical AbstractWith this award, the Biomaterials Program in the Division of Materials Research and the Chemistry of Life Processes Program in the Division of Chemistry are funding Dr. Jessica R. Kramer from The University of Utah to study the role of mucus composition in coronavirus (COV) transmission. COV-related diseases have emerged as a serious public health threat. Airborne droplets from an infected person’s cough, sneeze, or even talking are a major source of viral spread. These droplets stem from virus-laden mucosalivary fluid and land on the mucus membranes of the next potential host (mouth, airway, eyes) or on hard surfaces. There, the virus is dispersed for the next infection. Mucus is produced in hundreds of forms that vary between species, and even person-to-person. The forms present could affect how easily the viruses pass through the mucus membrane, especially since some types bind directly to COVs. Mucus forms could also affect the concentration and viability of COVs in airborne droplets. The goal of this project is to identify the forms of mucus that result in increased airborne COV transmission and infection. This will be accomplished by simulation of cough droplets produced from varied mucus and using human cells coated with varied mucus. This knowledge could lead to development of new therapeutics that disrupt COV-mucus binding, or identify populations more vulnerable to COV transmission and infection. Project Technical AbstractThis research project undertakes study of the role of mucin glycoprotein structures in coronavirus (COV) transmission via airborne particles, fomite objects, and in cellular entry through the glycocalyx. Epithelial tissue is coated with protective mucins that are secreted to form mucus and also tethered to the cell surface to form the glycocalyx. COVs must traverse these layers before entry into host cells for replication. Viral transmission through expelled airborne mucosalivary droplets is a major mode of transmission. Mucins are produced with a variety of attached glycans specific to each host. These glycans alter the viscoelasticity of mucosalivary fluid and directly bind to COV spike proteins. These factors could affect virus loading and viability in airborne particles and could affect docking and diffusion at the cell surface. However, such questions have been challenging to answer because native mucin glycosylation is poorly-defined and not tunable by current biological methods. The PI’s lab will synthesize mucin analogs with tunable COV-binding glycan patterns and will use them to engineer the glycocalyx of live cell surfaces. Coughs will be simulated and the role of mucin structure in airborne respiratory droplet COV transmission will be examined by characterization of droplet morphology, and viral loading and viability. Docking and diffusion at the cell surface, as well as replication, will be quantified on live epithelial cells.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.