Development of a novel adjuvant for vaccine sparing

描述(由申请人提供)：全世界迫切需要开发新的和改进的疫苗来控制包括流感在内的传染病。疫苗接种仍然是控制这些疾病的最具成本效益的生物医学方法，但事实证明，开发和生产足够数量的流感疫苗是有问题的。到目前为止，铝佐剂(明矾)与大流行性流感病毒疫苗联合使用的临床试验未能提供证据表明，对流感特异性反应有显著的免疫刺激作用。解决供应问题的一个有希望的解决方案是在疫苗配方中加入一种不含抗原的佐剂(S)，促使人们寻找能够安全地提高保护性抗流感抗体效价的替代佐剂，以最大限度地减少免疫原消耗，同时仍能提高疫苗效力，从而增加可用的疫苗剂量。我们已经从螺旋体中鉴定出一种自然产生的具有内在免疫刺激特性的分泌蛋白(rasp-1)，并表明它是一种强大的免疫刺激佐剂；它促进平衡的Th1/Th2抗体反应和对几种可溶疫苗候选抗原的细胞反应，以及商业灭活病毒疫苗，包括三价灭活流感疫苗(TIV)。此外，rasp-1蛋白可诱导未成熟的人DC成熟和激活，并增强其作为APC的活性。它还通过激活树突状细胞(DC)和TLR2和TLR4受体，刺激正常PBMC分泌Th1偏向的细胞因子，提示rasp-1是一种新的免疫刺激佐剂。我们建议通过设计一种有重点的临床前和产品开发方法来最大限度地利用其潜在的有益应用，最终将在简单的水溶液配方中生产出高效和安全的rasp-1佐剂流感疫苗，每剂需要最低的抗原量。通过这种方式提高疫苗效力，我们可以有效地增加可用的疫苗剂量。 我们计划使用酵母表达系统为rasp-1佐剂开发一种可扩展的生产工艺；它将以一系列关键测试为特色，用于过程中、缓冲液配方、释放和稳定性测试。我们将在体外评估功能和效力，然后在使用最低免疫原消耗的情况下，在小鼠和雪貂身上进行一次联合注射TIV流感疫苗后，验证诱导所需抗体和细胞反应的有效性。我们相信，该项目将提供所有必要的信息和程序，以编制/提交IND，并进入临床开发供人类使用的rasp-1佐剂。该申请有三个目的：1)rasp-1佐剂的工艺开发、表征、缓冲剂配方和稳定性测试；2)使用抗原剂量节约对rasp-1佐剂流感疫苗的效力测试；以及3)技术转让、cGMP制造、GLP毒理学和IND制备。

DESCRIPTION (provided by applicant): There is urgent need worldwide for the development of new and improved vaccines to control infectious diseases, including influenza. Vaccination remains the most cost-effective biomedical approach for controlling these diseases, but developing and producing the flu vaccines in sufficient quantities has proved problematic. To date, clinical trials with aluminum-based adjuvants (alum)-the only ones licensed in the U.S.-in combination with pandemic influenza virus vaccines, have failed to provide evidence of a significant immunostimulating effect on influenza-specific responses. A promising solution to the supply problem is to incorporate an antigen-sparing adjuvant(s) into vaccine formulations, prompting the search for alternative adjuvants capable of safely boosting protective anti-influenza antibody titers to minimize immunogen consumption, while still enhancing vaccine efficacy and thus increasing the number of available vaccine doses. We have identified a naturally occurring secreted protein with intrinsic immunostimulatory properties from Onchocerca volvulus (rASP-1) and showed that it is a powerful immunostimulatory adjuvant; it promotes a balanced Th1/Th2 antibody response and cellular responses to several soluble vaccine candidate antigens, and commercial inactivated viral vaccines, including trivalent-inactivated flu vaccines (TIV). Further, the rASP-1 protein induces maturation and activation of naive human DCs and potentiates their activity as APCs. It also stimulates Th1-biased cytokine secretion from normal PBMCs via the activation of dendritic cells (DCs) and the TLR2 and TLR4 receptors, suggesting that rASP-1 is a novel immunostimulatory adjuvant. We propose to maximize its promising beneficial applications by designing a focused preclinical and product development approach that will ultimately produce a highly effective and safe rASP-1 adjuvanted flu vaccine in a simple aqueous formulation that requires a minimal antigen quantity per dose. By enhancing vaccine efficacy in this way, we can effectively increase the number of vaccine doses available. We plan to develop a scalable production process for the rASP-1 adjuvant using the yeast expression system; it will feature a series of critical assays used for in-process, buffer formulation, release, and stability testing. We will evaluate functionality and potency in vitro an then validate the induction of the desired antibody and cellular responses after one immunization with the co-administered TIV flu vaccine in mice and ferrets using minimal immunogen consumption. We are confident the project will produce all the information and processes necessary for compilation/ submission of an IND and entry into clinical development of the rASP-1 adjuvant for human use. The application has three aims: 1) process development, characterization, buffer formulation, and stability testing of the rASP-1 adjuvant; 2) efficacy testing of the rASP-1 adjuvanted flu vaccine using antigen dose sparing; and 3) technology transfer, cGMP manufacture, GLP toxicology, and IND preparation.