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对抗全球艾滋病祸害。虽然免疫保护的相关性尚未明确定义，无论是保护性疫苗还是治疗性疫苗，但人们普遍认为，CD 4+和CD 8 + T细胞以及体液免疫都很重要。如何能够引起足够广泛、有效和持续的反应还有待确定，这代表了我们在理解如何产生有效疫苗以实现保护性免疫方面的一个关键差距。树突状细胞（DC）代表先天免疫和适应性免疫之间的界面，并且是产生适应性免疫应答的最有效和最重要的组分之一。在目前的资助中，我们专注于操纵DC的新方法，以利用它们在抗HIV免疫反应中的潜在作用。除了证明负载mRNA的DC可以诱导CD 4+、CD 8+和抗体应答之外，我们还鉴定了RNA激活先天免疫受体的机制，并开发了避免其激活并产生上级翻译效率的RNA。我们的假设是，将编码抗原的非免疫原性mRNA递送到DC中提供了一种独特的灵活和有效的免疫方法，可以控制RNA递送后的DC活化以产生所需的免疫应答（例如辅助、细胞毒性、抑制和全身或粘膜体液免疫），并且这种方法可以用于开发HIV疫苗。该提案的目的是优化DC对mRNA编码抗原的抗原呈递，开发mRNA的体内递送，并建立HIV疗效的概念验证证据。为此，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的负载和活化以用于细胞免疫应答。3)在体内施用mRNA疫苗。以及，4）在疫苗-HIV攻击模型中测试mRNA疫苗。在这些研究中，我们将结合联合收割机两种强大的方法：基于DC的疫苗与mRNA编码的抗原，以开发一种易于递送的疫苗。将mRNA与佐剂复合并给予受试者，导致DC的局部加载和活化。我们预计，这项工作将提高我们对RNA免疫，翻译和DC免疫功能的理解;使我们能够在免疫反应中差异化地操纵特定元素;并最终使我们能够利用mRNA编码的抗原产生的免疫反应，用于潜在的保护和治疗目的。除了为合理开发HIV疫苗开发的新方法提供基础外，我们希望这些研究也可以为疫苗开发提供新的途径。公共卫生相关性：该项目继续我们在基于mRNA的疫苗开发方面的研究。随着艾滋病毒流行病继续蔓延，唯一有效的办法是教育和联合药物治疗。我们希望开发出一种有效的疫苗，既可以预防感染，也可以在感染发生时改变病程。

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.