Manipulating Epitope Immunodominance and Tracking B-cell-Antigen Interactions for Vaccine Design.

项目摘要/摘要 传染病是严重的、反复出现的健康威胁。尤其令人担忧的是具有 在短时间内变异并产生从头开始的多样性。这些病毒适应新的宿主和 环境，并不断逃避宿主的抗病毒免疫反应。预防性疫苗是 非常可取；然而，没有明确的指导方针来设计有效的疫苗，以防止快速 变异病毒，如HIV-1、流感或目前的SARS-CoV2，具有多种不同的循环变种。 尽管它们具有高度的多样性，但病毒变异体呈现出保守的区域，这些区域对于病毒的适应性和 传染性。这些保守的表位是它们的致命弱点，也是基于抗体的疫苗设计的焦点 努力。一种针对高度变异病毒的疫苗应该引起特异性针对该病毒的抗体反应 病毒的保守区域，因为它将识别和中和其变异的广泛多样性。 该领域的重大努力集中在改造病毒免疫原以使其具有保守的表位。 更适用于抗体识别。不幸的是，针对特定保守的靶向抗体反应 令人感兴趣的表象具有令人难以置信的挑战性。复杂的抗原，如病毒刺突蛋白，可诱导多克隆 以非保守表位抗体为主的应答。这些抗体没有广泛传播的潜力。 中和病毒，并干扰生发中心广泛保护性抗体的成熟。 为了诱导针对HIV-1保守表位的广谱中和抗体，我们最近 设计并评价了一种新的基于HIV-1包膜(Env)的免疫原，该抗原可诱导出类似bNAb的免疫原 野生型小鼠和猕猴中针对Env保守表位的抗体；尽管取得了这一成就，但这些 抗体对HIV-1没有中和活性，这表明额外的免疫将是 诱导bNAbs所需的。然而，在猕猴体内进一步免疫会产生多克隆抗体。 仅有限的效力和广度的反应，主要由针对env非保守表位的抗体主导。 基于这些观察，我假设减少对非保守病毒的干扰性抗体反应 表位和追踪有可能成为bNAb的抗体反应，将为bNAb铺平道路。 开发疫苗并为疫苗设计工作提供信息。在这个提案中，我们将设计和评估一部小说 调节表位免疫优势的策略，这将使我们能够记录和跟踪 体内抗原-B细胞相互作用的历史。建议的技术将用于定制 复合抗原的免疫优势特性，以引导抗体对表位的反应 利息。此外，我们将使用我们的新技术对多次免疫反应的B细胞进行条形码编码， 追踪他们的命运并记录他们遭遇抗原的历史。这项突破性的技术将提供非常 有价值的信息有助于阐明B细胞对疫苗接种和感染的反应机制。 并将对制定疫苗设计指南作出重大贡献。

PROJECT SUMMARY/ ABSTRACT Infectious diseases are serious and recurrent health threats. Particularly concerning are viruses with the capacity to mutate and generate de novo diversity in short periods of time. These viruses adapt to new hosts and environments, and continuously escape from the host anti-viral immune response. Preventative vaccines are highly desirable; however, no defined guidelines exist for the design of efficacious vaccines against rapidly mutating viruses such as HIV-1, influenza, or the current SARS-CoV2, with multiple different circulating variants. Despite their high diversity, viral variants present conserved regions that are essential for viral fitness and infectivity. These conserved epitopes are their Achilles heels, and the focus of antibody-based vaccine design efforts. A vaccine against a highly mutating virus should elicit an antibody response that specifically targets the conserved regions of the virus, as it would recognize and neutralize the broad diversity of its variants. Significant efforts in the field have focused on engineering viral immunogens to make their conserved epitopes more available for antibody recognition. Unfortunately, targeting antibody responses to specific conserved epitopes of interest is incredibly challenging. Complex antigens, such as viral spike proteins, elicit polyclonal responses dominated by antibodies to non-conserved epitopes. These antibodies have no potential to broadly neutralize the virus, and also interfere with the maturation of broadly protective antibodies in the germinal centers. Aiming to elicit broadly neutralizing antibodies (bNAbs) against a conserved epitope of HIV-1, we recently designed and evaluated a new HIV-1 Envelope (Env)-based priming immunogen, which elicited bNAb-like antibodies against a conserved epitope of Env in wild type mice and macaques; despite this achievement, these antibodies showed no neutralization activity against HIV-1, suggesting that additional immunization would be required to induce bNAbs. Nevertheless, further immunization in macaques elicited a polyclonal antibody response of only limited potency and breadth, dominated by antibodies to non-conserved epitopes of Env. Based on these observations, I hypothesize that reducing interfering antibody responses to non-conserved viral epitopes, and tracking the antibody responses with potential to become bNAbs, will pave the path towards bNAb development and inform vaccine design efforts. In this proposal, we will design and evaluate a novel strategy to modulate epitope immunodominance, which in addition, will allow us to record and track the history of antigen-B-cell interactions in vivo. The proposed technology will be used to customize the immunodominance properties of complex antigens in order to direct the antibody response to the epitopes of interest. In addition, we will use our new technology to barcode B cells responding to multiple immunizations, track their fates and record their history of antigen encounters. This groundbreaking technology will provide very valuable information to elucidate the mechanisms governing the B cell responses to vaccination and infection, and will significantly contribute to establish guidelines for vaccine design.