Development of an Oral Carrier

描述（由申请人提供）：已开发出一种用于生产口服疫苗的新技术。这项技术是基于一种多肽（约50 kDa）的发现，该多肽具有结合和穿透肠道上皮屏障的能力。该过程的具体步骤为：顶膜结合；受体介导的内吞作用;transcytosis;基底外侧松解。多肽不经过任何结构或功能修饰而穿过上皮屏障。这种新型多肽结构域可以作为一种载体装置将异源物质输送到体内。通过将载体与一系列大小（mw=约200至约45000）和生物活性（即配体、酶、抗原）不同的物质连接起来，已经实现了概念验证。由此产生的载体-货物结构已被证明可以在体外（如人肠道上皮细胞单层）和体内（如小鼠和大鼠模型）跨越上皮屏障。在每种情况下，载体-货物结构都保留了它们原有的结构和它们特有的生物活性。利用这项新技术的主要产品已经确定。该产品将是一种融合蛋白，其包含与破伤风抗原连接的载体多肽，以产生针对破伤风毒素的口服疫苗。在与食品和药物管理局举行正式会议之前，将对主要产品进行一系列研究。拟议研究的主要目标是：1。消除载体与非上皮细胞的结合。降低或消除携带者的免疫原性证实非嗜神经性、非免疫原性载体的疗效。为了证明修饰载体和修饰载体-破伤风抗原结构没有毒性，如果成功，这项工作应该证明粘膜破伤风疫苗值得作为临床产品进行评估。

DESCRIPTION (provided by applicant): A new technology has been developed for the creation of oral vaccines. This technology is based on the discovery of a polypeptide (ca. 50 kDa) that possesses the ability to bind and penetrate gut epithelial barriers. The specific steps in the process are: apical membrane binding; receptor-mediated endocytosis; transcytosis; and basolateral release. The polypeptide crosses epithelial barriers without undergoing any structural or functional modifications. The novel polypeptide domain can be utilized as a carrier device to transport heterologous substances into the body. Proof of concept has been achieved by linking the carrier to a host of substances that differ in size (mw= ca. 200 to ca. 45,000) and in biological activity (i.e., ligand, enzyme, antigen). The resulting carrier~cargo constructs have been shown to cross epithelial barriers in vitro (e.g. monolayers of human gut epithelial cells) and in vivo (e.g., mouse and rat models). In every case, the carrier~cargo constructs retained their native structure and their characteristic biological activity. A lead product has been identified that will utilize the new technology. This product will be a fusion protein that incorporates the carrier polypeptide linked to a tetanus antigen to create an oral vaccine against tetanus toxin. A series of studies will be performed with the lead product in anticipation of a formal meeting with the Food and Drug Administration. The major goals of the proposed studies will be: 1. To eliminate carrier binding to non-epithelial cells 2. To reduce or abolish the immunogenicity of the carrier 3. To confirm the efficacy of the non-neurotropic, non-immunogenic carrier 4. To demonstrate an absence of toxicity of the modified carrier and the modified carrier~tetanus antigen construct If successful, this work should demonstrate that a mucosal tetanus vaccine is worthy of evaluation as a clinical product.