RNA delivery for dendritic cell HIV antigen presentation

描述(由申请人提供)：迫切需要一种安全有效的艾滋病毒疫苗来抗击全球艾滋病的祸害。虽然无论是保护性疫苗还是治疗性疫苗，免疫保护的相关因素都尚未明确，但人们普遍认为，CD4+和CD8+T细胞以及体液免疫都很重要。如何才能产生足够广泛、有效和持续的反应还有待确定，这是我们对如何产生有效疫苗以实现保护性免疫的理解上的一个关键差距。树突状细胞(DC)是天然免疫和获得性免疫之间的交界点，是产生获得性免疫反应最有效和最重要的组成部分。在目前这笔赠款的资助中，我们专注于操纵DC的新方法，以开发它们在抗HIV免疫反应中的潜在作用。除了证明负载mRNA的DC可以诱导CD4+、CD8+和抗体反应外，我们还确定了RNA激活天然免疫受体和开发避免其激活并产生更高翻译效率的RNA的机制。我们的假设是，将抗原编码的非免疫原性mRNA导入DC提供了一种独特的灵活而有效的免疫方法，在RNA传递后DC的激活可以被控制以产生所需的免疫反应(例如辅助免疫、细胞毒性免疫、抑制免疫和系统或粘膜体液免疫)，并且这种方法可以用于HIV疫苗的开发。这项建议的目的是优化DC对信使核糖核酸编码的抗原的提呈，发展体内信使核糖核酸的递送，并为HIV的有效性建立概念验证证据。为了做到这一点，我们将：1)对核苷修饰的mRNA的翻译、稳定性和免疫激活进行分析。2)优化DC的负载和激活，以实现细胞免疫应答。3)体内注射基因疫苗。以及，4)在疫苗-HIV挑战模型中测试mRNA疫苗。在这些研究中，我们将结合两种强有力的方法：基于DC的疫苗和mRNA编码的抗原，以开发一种易于交付的疫苗。MRNA与佐剂络合，给受试者，导致DC的局部负载和激活。我们预计，这项工作将增强我们对RNA免疫、翻译和DC免疫功能的理解；使我们能够以不同的方式操纵免疫反应中的特定元件；并最终使我们能够利用mRNA编码的抗原产生的免疫反应，达到潜在的保护和治疗目的。除了为合理开发新的艾滋病毒疫苗开发方法提供基础外，我们希望这些研究也可能为疫苗开发提供一条新的途径。公共卫生相关性：该项目继续我们开发基于信使核糖核酸的疫苗的研究。随着艾滋病毒疫情的继续蔓延，唯一有效的方法是教育和联合药物治疗。我们希望开发一种有效的疫苗，既可以预防感染，也可以在发生感染时改变病程。

DESCRIPTION (provided by applicant): A safe and effective vaccine for HIV is critically needed to combat the worldwide scourge of AIDS. While the correlates of immune protection have yet to be clearly defined, either for protective or therapeutic vaccines, it is widely believed that both CD4+ and CD8+ T cell as well as humoral immunity are important. How sufficiently broad, potent, and sustained responses can be elicited has yet to be determined, and this represents a critical gap in our understanding of how to generate an effective vaccine such that protective immunity can be achieved. Dendritic cells (DC) represent the interface between innate and adaptive immunity and are among the most potent and important components in generating adaptive immune responses. In the present funding of this grant, we focused on novel approaches to manipulating DC in order to exploit their potential role in anti-HIV immune responses. In addition to demonstrating that mRNA loaded DC could induce CD4+, CD8+, and antibody responses, we identified the mechanisms whereby RNA activates innate immune receptors and developed RNA that avoids their activation and yields superior translational efficiency. Our hypotheses are that delivery of antigen-encoding, non-immunogenic mRNA into DC offers a uniquely flexible and potent approach to immunization, that DC activation after RNA delivery can be controlled to generate the desired immune responses (e.g. helper, cytotoxic, suppressor, and systemic or mucosal humoral immunity), and that this approach can be exploited for the development of HIV vaccines. The aim of this proposal is to optimize antigen presentation by DC of mRNA-encoded antigen, develop an in vivo delivery of mRNA, and establish proof-of-concept evidence for efficacy in HIV. To do this we will: 1) perform an analysis of translation, stability, and immune activation of nucleoside-modified mRNA. 2) optimize loading and activation of DC for cellular immune responses. 3) administer the mRNA vaccines in vivo. And, 4) test the mRNA vaccines in a Vaccinia-HIV challenge model. In these studies, we will combine two powerful approaches; DC based vaccines with mRNA encoded antigen to develop an easily deliverable vaccine. mRNA is complexed with adjuvants and given to subjects resulting in local loading and activation of DC. We anticipate that this work will enhance our understanding of RNA immunity, translation, and DC immune function; enable us to differentially manipulate specific elements in the immune response; and, ultimately, allow us to exploit mRNA encoded antigen generated immune responses for potentially protective and therapeutic purposes. In addition to providing a foundation for the rational development of a novel approach to HIV vaccine development, it is our hope that these studies may also offer a new avenue for vaccine development in general. PUBLIC HEALTH RELEVANCE: This project continues our studies in the development of an mRNA based vaccine. As the HIV epidemic continues to spread, the only effective approaches are education and combination drug therapy. We hope to develop an effective vaccine that will either prevent infection or alter disease course if infection occurs.