Development of a mucosally administered trivalent serotype A,B, E botulinum va

描述(申请人提供)：肉毒杆菌毒素被归类为A类生物制剂，因为它具有很高的效力和用作生物武器的潜力。由于目前还没有FDA批准的疫苗，因此当务之急是快速开发一种可以在发生攻击时使用的疫苗。我们第一阶段项目的总体目标是开发口服多价A型、B型和E型肉毒杆菌疫苗。我们发现，A型和B型Hc50分别在口服时诱导对高水平攻击的免疫。口服疫苗的基础是每种血清型毒素(HC50或片段C)重链的50%羧基末端的固有特性，可以结合和穿过肠道上皮细胞，进入血液和淋巴循环。具体地说，在目标1中，我们将确定Hc50血清型E作为粘膜免疫原的能力。在具体目标2中，我们将制造A、B和E三价疫苗，并在小鼠身上测试疫苗通过鼻腔粘膜给药时诱导保护性免疫的效果。在具体目标3中，我们计划对大鼠进行口服免疫，并确定三价疫苗是否能够诱导保护性免疫，以确定免疫持续时间，以及与注射佐剂疫苗相比免疫反应的稳健性。还将讨论通过鼻腔或口服途径接种疫苗所预期的粘膜免疫的其他组成部分。以多聚体分泌型免疫球蛋白A为形式的粘膜免疫可在毒素进入全身循环之前使其部分失活，从而提供针对毒素暴露的额外水平的保护。肉毒杆菌毒素疫苗可以通过黏膜途径注射，特别是通过口服途径，预计比注射的同类疫苗有几个优势。由于疫苗可以在没有训练有素的人员的情况下接种，它将避免使用侵入性针头和相关的疼痛。预计这将为最终用户带来更大的合规性和便利性，并有可能在传统诊所或医生办公室之外传播疫苗进行接种，从而有可能迅速实施预防性疫苗接种计划。第一阶段工作的最终结果将是为A、B、E型血清型确定一种有效的粘膜联合疫苗。在第二阶段，该项目将涉及1)改善性能的配方研究，2)在其他动物模型中研究疫苗，以及3)更好地描述制造三价疫苗的过程。在第二阶段结束时，我们预计已经确定了一种疫苗，以推进临床研究。

DESCRIPTION (provided by applicant): Botulinum toxin is classified as a category A biothreat due to its high potency and the potential to be used as a bioweapon. Because there is no FDA-approved vaccine, there is a high priority in rapid development of a vaccine that can be used in the event of an attack. The overall goal of our Phase I project is to develop an orally administered multivalent serotype A, B, and E botulinum vaccine. We have discovered that Hc50 of serotypes A and B individually induce immunity against high level challenge when administered orally. The basis for oral vaccination is the inherent property of the carboxyl terminal 50% of the heavy chain of each of the serotypes of the toxin (Hc50 or fragment C) to bind and to cross intestinal epithelial cells and enter blood and lymphatic circulation. Specifically, in aim 1, we will determine the capacity of Hc50 serotype E to act as a mucosal immunogen. In specific aim 2, we will make the trivalent A, B, and E vaccine and test the vaccine in mice for induction of protective immunity when the vaccine is given mucosally by the intranasal route. In specific aim 3, we plan to immunize rats orally and determine whether the trivalent vaccine can induce protective immunity, to determine the duration of immunity, and the robustness of the immune response in comparison to injected vaccine given with an adjuvant. The additional component of mucosal immunity, which is expected from the application of the vaccine by the intranasal or oral route will also be addressed. Mucosal immunity in the form of polymeric secretory IgA may provide an additional level of protection against toxin exposure by inactivating a portion of it before it crosses into general circulation. A vaccine for botulinum toxin that can be administered mucosally, especially by the oral route, is expected to have several advantages over an injected counterpart. As the vaccine can be given without trained personnel, it will avoid the use of invasive needles and the associated pain. This is expected to result in greater compliance and convenience for the end user and the possibility of disseminating the vaccine outside of the traditional clinic or doctor's office setting for vaccination, resulting in the possibility of rapid implementation of a preventive vaccination program. The end result of Phase I work will be the identification of an effective mucosal combination vaccine for serotypes A, B, E. In Phase II, the project will involve 1) formulation studies to improve performance, 2) study of the vaccine in additional animal models, and 3) greater characterization of processes for making the trivalent vaccine. At the end of Phase II, we expect to have identified a vaccine to advance to clinical studies.