Exosome-display as a strategy to enhance the immunogenicity of SARS-CoV-2 vaccines based on adenoviral vectors

外泌体展示作为增强基于腺病毒载体的 SARS-CoV-2 疫苗免疫原性的策略

• 批准号: 10161344
• 负责人: Lynda Coughlan
• 金额: $ 0.47万
• 依托单位: ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-07-01 至 2020-10-03
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10161344
• 关键词: 2019-nCoV; Address; Adenovirus Vector; Adjuvant; Animals; Antibodies; Antibody Response; Antigen Targeting; Antigens; B-Lymphocytes; Baltimore; Biological Assay; Bronchoalveolar Lavage; CD8B1 gene; Cell Communication; Cells; Cellular Immunity; Chiroptera; Clinical; Clinical Trials; Coronavirus; Coronavirus spike protein; Data; Development; Diagnostic; Disease; Engineering; Enzyme-Linked Immunosorbent Assay; Epitopes; Flow Cytometry; Future; Glycoproteins; Goals; Human; Humoral Immunities; Immune; Immune response; Immunity; Immunization; Immunize; Immunologics; In Vitro; Inactivated Vaccines; Infection; Intramuscular; Knowledge; Length; Light; Lymphocyte; Maryland; Measures; Mediating; Middle East Respiratory Syndrome Coronavirus; Military Personnel; Modeling; Molecular; Mus; Peptides; Phenotype; Plasmids; Play; Population; Production; Proteins; Protocols documentation; Readiness; Reagent; Recombinants; Regimen; Reporter; Research; Research Personnel; Risk; Role; SARS coronavirus; Safety; Scientist; Serum; Spleen; Subfamily lentivirinae; Surface; T cell response; T-Lymphocyte; Tertiary Protein Structure; Testing; Therapeutic; Therapeutic Intervention; Transgenes; Ultracentrifugation; Universities; Vaccination; Vaccine Antigen; Vaccine Design; Vaccines; Validation; Variant; Viral; Viral Vector; Virus; antigen-specific T cells; base; cesium chloride; comparative; cross reactivity; cytokine; design; exosome; experimental study; extracellular vesicles; immunogenic; immunogenicity; immunopathology; immunoregulation; in vivo; innovation; nano-exosomes; nanosized; neutralizing antibody; novel; novel coronavirus; novel vaccines; pandemic disease; pandemic preparedness; particle; preclinical study; prevent; prophylactic; receptor binding; recruit; response; scale up; tool; vaccine candidate; vaccine delivery; vector; vector vaccine

SUMMARY: The emergence of the SARS-CoV-2 coronavirus (CoV) highlighted our lack of preparedness, and has emphasized the importance of rapidly building capacity in the development of reagents, tools, diagnostics and therapeutics for SARS-CoV-2 and related CoVs with pandemic potential. An immediate goal is to produce a vaccine which can elicit rapid, high-level protective immunity against SARS-CoV-2, ideally following a single- shot. Several candidate vaccines have now advanced into clinical trials. However, a longer term goal is to investigate the possibility for a “universal” CoV vaccine, a vaccine or prime:boost vaccination regimen which provides durable and broadly cross-reactive immunity against CoVs with high potential for spillover from bats. The CoV surface spike (S) glycoprotein is a major target for neutralizing antibodies (NAbs) and T cells, and is an attractive target for vaccine design. NAbs which target the receptor binding domain (RBD) confer protection, but are usually strain-specific and lack breadth. The existence of broadly reactive, protective epitopes outside of the RBD are not well-characterized. Therefore, vaccines which compare full length or truncated, stabilized variants of the S immunogen, could shed some light into potential correlates of protection. Another important concern is disease enhancement, which has been observed for related CoV vaccines using selected vaccine delivery platforms such as the whole-inactivated virus (WIV) vaccine. This has been associated with a Th2- biased immune response and to overcome this issue, CoV vaccines should elicit a largely Th1 biased response. Therefore, studies which aim to compare the phenotype of immunity elicited by different vaccine platforms, and to different variants of the S immunogen, could help to better understand which components of the immune response are optimal in mediating protection, without the risk of immunopathology upon infection. We will develop a potently immunogenic, optimized vaccine platform for SARS-CoV-2 using three approaches. (1) Firstly, we will engineer SARS-CoV-2 S in several different forms, a full-length immunogen, a secreted stabilized pre-fusion form or the RBD domain alone. (2) Secondly, we will augment or broaden immune recognition of pre-fusion S by targeting it to host-derived extracellular vesicles (EVs) including exosomes in vivo, by generating fusion-Ag constructs which tether Ag to a protein domain highly enriched in exosomes. Exosomes are nano-sized EVs shown to play important roles in cell:cell communication and in the regulation of immune responses, due to their ability to present Ag to T- and B-cells. (3) Finally, we will develop non-replicating, rare species adenoviral (Ad) vectored vaccines which have established protocols for rapid clinical manufacturing and regulatory approval, can be thermostabilized with minimal losses to immunogenicity and have demonstrated safety in human clinical trials. This study will comprehensively evaluate and phenotype the magnitude and profile of SARS-CoV-2 vaccines in single-shot regimens. These data will provide valuable information for the design of subsequent prime:boost regimens and for challenge experiments in the future.

摘要：SARS-COV-2冠状病毒（COV）的出现强调了我们缺乏准备和 强调了快速建立能力在试剂，工具，诊断的重要性的重要性 和具有大流行潜力的SARS-COV-2和相关COV的治疗。一个直接的目标是生产 一种可以引起快速，高级保护的免疫力的疫苗，对SARS-COV-2，理想情况下是在单次疫苗 射击。现在，几种候选疫苗已进入临床试验。但是，长期目标是 调查“通用” COV疫苗，疫苗或素数的可能性：增强疫苗方案，该方案 提供持久且广泛的交叉反应性免疫力，以抗蝙蝠的高潜力的COV。 COV表面峰（S）糖蛋白是中和抗体（NABS）和T细胞的主要靶标，并且是 疫苗设计的有吸引力的目标。针对接收器绑定域（RBD）会议保护的NABS， 但通常是特定于应变的并且缺乏广度。外面的广泛反应性，受保护的表位的存在 RBD的特征没有很好。因此，比较全长或截短，稳定的疫苗 S免疫原的变体可以将一些照明带入保护的潜在相关性。另一个重要 关注的是疾病增强，已经使用选定的疫苗观察到相关的COV疫苗 输送平台，例如全灭活病毒（WIV）疫苗。这与Th2- 有偏见的免疫反应并克服了这个问题，COV疫苗应引起很大的Th1偏见 回复。因此，旨在比较不同疫苗引起的免疫表型的研究 平台以及S免疫原的不同变体可以帮助更好地了解哪些组成部分 免疫反应在介导保护方面是最佳的，没有感染后免疫病理的风险。 我们将使用三个 方法。 （1）首先，我们将以几种不同形式的SARS-COV-2 S来设计全长免疫原，A 分泌的稳定前融合形式或单独的RBD域。 （2）其次，我们将增强或扩大 通过将其靶向宿主衍生的细胞外蔬菜（EV），对融合前的识别（包括）免疫识别 体内外泌体，通过产生融合 - AG构建体，将Ag绑在高度富集的蛋白质域中 外泌体。外泌体是显示在细胞通信和在细胞中扮演重要作用的纳米大小的电动汽车。 免疫反应的调节，因为它们能够将Ag呈现为T和B细胞。 （3）最后，我们将发展 非复制的稀有物种腺病毒（AD）矢量疫苗，已建立了快速方案 临床制造和监管批准可以恒温，免疫原性损失最小 并在人类临床试验中表现出安全性。这项研究将全面评估和表型 单发方案中SARS-COV-2疫苗的大小和轮廓。这些数据将提供有价值的 随后的素数设计的信息：增强方案和未来的挑战实验。