Stable needleless vaccine against Shigella spp

描述（由申请人提供）：福氏志贺氏菌是发展中国家儿童痢疾的主要原因，也是发达国家旅行者腹泻的主要原因。虽然已投入大量资源开发有效的肠道疫苗，但尚未研制出可行的志贺氏菌病疫苗。作为一种新的方法，我们已经确定了两种较高保守和必需的III型分泌系统装置（TTSA）蛋白作为对抗志贺氏菌感染的保护性抗原。我们已经证明，当在佐剂的存在下作为溶液鼻内给药时，入侵质粒抗原IpaD和IpaB可以保护小鼠免受弗氏沙门氏菌和异源sonnei沙门氏菌的致命攻击。此外，为了简化配方和降低生产成本，我们构建了一种IpaD-IpaB融合蛋白（DB fusion），该蛋白在鼻内和皮内给药时对弗氏沙门氏菌、索内沙门氏菌和痢疾沙门氏菌也有保护作用。在该提案中，我们打算开发一种基于ipa的疫苗的片剂配方，使用新型dmLT作为舌下免疫（SL）的佐剂。这些舌下片剂在舌下迅速溶解，但比水状疫苗更稳定，可自行服用。我们假设，除了增加稳定性和易于自我给药外，这种DB Fusion+dmLT片剂疫苗将提供针对志贺氏菌的同源和异源保护。为了验证这一假设，本研究的具体目的是：将DB Fusion配制成片剂用于舌下给药，并评估片剂内蛋白质的稳定性；2. 通过SL途径测定片剂疫苗的免疫原性和保护效果。我们认为，R21机制适合于这个项目，因为这种新颖的配方将对全球公共卫生产生重大影响。我们有初步的数据表明DB Fusion可以转化为舌下片剂，然而，这种形式下的稳定性和保护效果尚不清楚。如果这种配方取得成功，我们将拥有一种不需要针头、不需要冷链、不需要医务人员给药的稳定疫苗。

DESCRIPTION (provided by applicant): Shigella flexneri is the primary cause of childhood dysentery in the developing world and a major cause of travelers' diarrhea in the developed world. While significant resources have been dedicated to developing effective enteric vaccines, a viable vaccine against shigellosis has yet to be realized. As a novel approach we have identified two higher conserved and required proteins of the type III secretion system apparatus (TTSA) as protective antigens against Shigella spp infections. We have demonstrated that, when administered intranasally as a solution in the presence of an adjuvant, the invasion plasmid antigens IpaD and IpaB protect mice against a lethal challenge by S. flexneri and the heterologous S. sonnei using the mouse lung model. Furthermore, in an effort to simplify formulation and reduce production costs, we constructed an IpaD-IpaB fusion protein (DB Fusion) which is also protective when administered intranasally and intradermally against S. flexneri, S. sonnei and S. dysenteriae. Within this proposal we intend to develop a tablet formulation of this Ipa-based vaccine using the novel dmLT as an adjuvant for sublingual (SL) immunization. These sublingual tablets dissolve rapidly under the tongue but will be more stable than an aqueous form of vaccine and can be self-administered. We hypothesize that in addition to increased stability and ease of self-administration, this DB Fusion+dmLT tablet vaccine will provide homologous and heterologous protection against Shigella spp. To test this hypothesis, the specific aims of this investigation are to: 1. Formulate the DB Fusion into a tablet for sublingual administration and assess the protein stability within the tablet; 2. Determine the immunogenicity and protective efficacy of the tablet vaccine via SL route. We believe that the R21 mechanism is appropriate for this project because the high impact that such a novel formulation would have on worldwide public health. We have preliminary data suggesting the DB Fusion can be converted to a sublingual tablet, however, their stability and their protective efficacy in such a form remains unknown. Should this formulation be successful, we will have a stable vaccine that does not require a needle, does not require a cold-chain and does not require medical personal for administration.