Development of a next generation vaccine to prevent pertussis

摘要 百日咳杆菌引起百日咳(百日咳)，这是一个新出现的全球公共卫生威胁。20世纪40年代，一种灭活的全细胞百日咳疫苗被引入，极大地降低了百日咳引起的死亡率。20世纪90年代，一种新的、毒性可能较低的脱细胞疫苗被开发并引入美国和世界其他地区。尽管无细胞百日咳疫苗副作用较少，但其保护效果低于全细胞疫苗，这可能是由于无细胞百日咳疫苗不能阻止百日咳杆菌在鼻咽的定植而导致的。 像许多革兰氏阴性病原体一样，波尔德氏菌。拥有III型分泌器(T3SA)。它就像一个分子注射器和针头，针头上有两个蛋白质复合体：一个尖端蛋白和第一个转位蛋白。这些蛋白是波氏杆菌致病所必需的。在波尔德氏菌中保守95%-98%。我们之前已经融合了志贺氏菌。T3SA末端蛋白和转位蛋白构建DBF，用于研制新型志贺氏菌疫苗亚单位抗原。当经鼻(IN)或肠外(IM)给药时，DBF与产肠毒素大肠杆菌的粘膜佐剂双突变不稳定毒素(DmLT)混合，可保护小鼠免受福氏链球菌和异源病原体宋内氏链球菌和痢疾链球菌的致命攻击。我们同样为波尔德泰拉制造了一种融合。在最初的小鼠实验中，融合保护了100%的小鼠免受支气管败血杆菌的致命肺部攻击，支气管败血杆菌是犬舍咳嗽的病原体。此外，尽管在挑战中注射了高细菌负荷，但在肺部观察到38%的灭菌免疫力。 因此，我们假设我们的融合将引起强大的免疫反应，以防止支气管败血杆菌和百日咳杆菌感染。此外，我们假设融合将在呼吸道引起灭菌免疫，从而打破传播链。因此，这项研究的具体目的是：1)评估IN和IM融合所引发的体液和细胞免疫应答；2)确定融合对支气管败血杆菌和百日咳杆菌攻击的保护效果。

SUMMARY Bordetella pertussis causes pertussis (whooping cough), which is a reemerging global public health threat. In the 1940s an inactivated, whole-cell pertussis vaccine was introduced that dramatically reduced the mortality caused by pertussis. A new, potentially less toxic acellular vaccine was developed and introduced in the United States and other parts of the world in the 1990s. Although the acellular pertussis (aP) vaccine has fewer side effects, its protective efficacy is lower than that of the whole cell vaccine potentially due to the inability of aP to prevent nasopharyngeal colonization leading to transmission of B. pertussis. Like many Gram-negative pathogens, Bordetella spp. possess a type III secretion apparatus (T3SA). It resembles a molecular syringe and needle and two protein complexes localize atop the needle: a tip protein and the first translocator protein. These proteins are required for pathogenesis of Bordetella spp. and are 95-98% conserved among Bordetella spp. We have previously fused the Shigella spp. T3SA tip and translocator proteins to create DBF, which was used to successfully develop a novel subunit vaccine antigen against Shigella spp. When administered intranasally (IN) or parenterally (IM), DBF, admixed with the mucosal adjuvant double-mutant labile toxin (dmLT) from Enterotoxigenic E. coli, protects mice against a lethal challenge by S. flexneri and the heterologous pathogens S. sonnei and S. dysenteriae. We have similarly produced a fusion for Bordetella. In the initial mouse experiment the fusion protected 100% of the mice from a lethal pulmonary challenge with B. bronchiseptica, the causative agent of canine kennel cough. Furthermore, 38% sterilizing immunity was observed in the lungs despite the high bacterial load administered in the challenge. Thus, we hypothesize that our fusion will elicit a robust immune response that protects against B. bronchiseptica and B. pertussis infection. Additionally, we hypothesize that the fusion will elicit sterilizing immunity in the respiratory tract to break the transmission chain. Thus, the specific aims of this investigation are: 1) Assess the respective humoral and cell-mediated immune responses elicited by the fusion delivered IN and IM and 2) Determine the protective efficacy of the fusion against B. bronchiseptica and B. pertussis challenge.