Trapping membrane proteins with adjuvant-carrying amphipols for vaccine formulati

描述(申请人提供)：沙眼衣原体感染在世界各地广泛传播。这种细菌病原体影响多个器官系统，产生急性症状和持续感染，可能导致长期后遗症。如果及时实施，抗生素治疗在控制沙眼衣原体感染方面是有效的。不幸的是，许多病例没有症状，其他病例治疗较晚，和/或处理不成功。生产沙眼疫苗的努力是在几十年前开始的。最近，随着沙眼衣原体在性传播感染中的作用被发现，几家实验室将重点放在了生产预防生殖器感染的疫苗上。我们的长期目标是设计出一种能够预防沙眼衣原体感染的疫苗。我们想要检验的假设是，一种用与两栖动物相关的衣原体(APOL)的天然主要外膜蛋白(MOMP)配制的疫苗可以保护雌性小鼠免受阴道内攻击。通常，膜蛋白(MPS)使用洗涤剂在水溶液中保持可溶。然而，洗涤剂往往会破坏MPS的稳定性，这可能会导致保护性构象表位的丢失。APOL是一种可替代洗涤剂的新型高分子表面活性剂。它们被证明特别有利于维持MP的结构、功能和稳定性。我们的初步实验表明，用APOL捕获的MOMP配制的候选疫苗比以洗涤剂为基础的等价物更有效。我们建议以这一观察为基础，通过i)研究MOMP/APOL复合体在不同类型疫苗配方中的稳定性和结构，以及ii)测试携带佐剂的apol的保护作用。事实上，由于载脂蛋白与MPS永久结合，可与抗原性MPS一起用于向靶细胞递送佐剂，这有望有利于产生强大的系统和粘膜免疫反应。雌性小鼠将在阴道内接受挑战，感染过程将进行阴道培养。将根据阴道培养阳性动物的数量以及感染的严重程度和持续时间来确定保护措施。随后，将对小鼠进行交配，以确定受精率。为了优化候选疫苗，我们将比较不同的接种方案使用不同的佐剂以不同的方式连接到不同的载脂蛋白，从而调节佐剂在不同细胞隔间的释放。总之，沙眼衣原体感染在发达国家和欠发达国家都是一个主要的健康问题。这项提议的目标是研制一种被携带佐剂的载脂蛋白捕获的MOMP疫苗。通过疫苗降低这些感染的发病率和流行率将对世界范围内的健康产生重大影响。此外，以两酚溶解的膜蛋白为基础的疫苗配方的开发有可能影响广泛的病原体。 公共卫生相关性：这项提案的目标是研制一种被携带佐剂的载脂蛋白捕获的MOMP疫苗。通过疫苗降低这些感染的发病率和流行率将对世界范围内的健康产生重大影响。此外，以两酚溶解的膜蛋白为基础的疫苗配方的开发有可能影响广泛的病原体。

DESCRIPTION (provided by applicant): Chlamydia trachomatis infections are widespread throughout the World. This bacterial pathogen affects multiple organ systems producing acute symptomatology and persistent infections that can result in long-term sequelae. If implemented in a timely manner, antibiotic therapy is effective in controlling C. trachomatis infections. Unfortunately, many cases are asymptomatic, others are treated late, and/or are unsuccessfully managed. Efforts to produce a vaccine against trachoma were initiated decades ago. More recently, with the uncovering of the role of C. trachomatis in sexually transmitted infections, several laboratories have focused their efforts on producing a vaccine against genital infections. Our long-term goal is to engineer a vaccine that can protect against C. trachomatis infections. The hypothesis we want to test is that a vaccine formulated with the native major outer membrane protein (MOMP) of Chlamydia associated with amphipols (APols) can protect female mice against an intravaginal challenge. Generally, membrane proteins (MPs) are kept soluble in aqueous solutions using detergents. However, detergents tend to destabilize MPs, which can lead to the loss of protective conformational epitopes. APols are a novel type of polymeric surfactants that can substitute to detergents. They have been shown to be particularly favorable towards maintaining MP structure, function and stability. Our preliminary experiments indicate that candidate vaccines formulated with APol-trapped MOMP are more effective than their detergent-based equivalents. We propose to build on this observation by i) studying the stability and structure of MOMP/APol complexes in various types of vaccine formulations and ii) testing the protective effect of adjuvant-carrying APols. Indeed, as they associate permanently with MPs, APols can be used to deliver adjuvants to target cells concomitantly with antigenic MPs, which is expected to favor a strong systemic and mucosal immune response. Female mice will be challenged intravaginally and the course of the infection will be followed with vaginal cultures. Protection will be determined based on the number of animals with positive vaginal cultures and the severity and length of the infection. Subsequently, the mice will be mated to determine the fertility rates. In order to optimize the candidate vaccines, we will compare the immune response elicited by different vaccination protocols using various adjuvants linked in various ways to various APols, so as to modulate the release of the adjuvant in different cellular compartments. In conclusion, C. trachomatis infections are a major health problem in both developed and underdeveloped countries. The goal of this proposal is to formulate a vaccine with MOMP trapped by adjuvant-carrying APols. Decreasing the incidence and prevalence of these infections with a vaccine would have a major health impact worldwide. Furthermore, the development of vaccine formulations based on amphipol solubilized membrane proteins has the potential to impact a broad spectrum of pathogens. PUBLIC HEALTH RELEVANCE: The goal of this proposal is to formulate a vaccine with MOMP trapped by adjuvant-carrying APols. Decreasing the incidence and prevalence of these infections with a vaccine would have a major health impact worldwide. Furthermore, the development of vaccine formulations based on amphipol solubilized membrane proteins has the potential to impact a broad spectrum of pathogens.