DC-subset-tailored vaccines

项目摘要 我们对为什么只有某些疫苗能促进持久免疫缺陷的形成的理解存在根本性的差距。 和保护性抗体反应。树突状细胞（DC）是专职的抗原呈递细胞，其调节免疫应答。 因此，我们认为，了解DC在调节B细胞应答中的作用将有助于 是开发针对流感和艾滋病毒的通用疫苗的关键。我们的实验数据表明 目前正在使用或开发的相对无效的疫苗的主要局限性可能是： 1)它们不特异性靶向朗格汉斯细胞（LC），和2）抗原剂量不是定制的以最大化 LC的激活。我们的长期目标是了解不同DC群体在体液免疫中的作用， 并利用这些知识设计DC亚群定制疫苗，特别关注流感 和艾滋病病毒。在追求该目标的过程中，本申请的目标是： 稳态LC促进生发中心（GC）依赖的体液免疫应答; 2）表征 高抗原剂量和CD 103 + DC抑制LC诱导的GC依赖性应答的调节环; 以及3）测试DC亚群定制的流感疫苗的可行性。我们的中心假设是LC驱动 以抗原剂量依赖性方式在功能上不同的Tfh细胞，其最终决定是否体液免疫。 免疫应答是否被激发。这项研究的基本原理是，一旦详细了解了 LC启动体液免疫应答并相互调节是已知的，该过程可能是 这些技术被用来产生预防和治疗各种疾病的创新方法。指导 强有力的初步数据，我们的假设将在这三个具体目标进行测试：1。通过以下方式定义机制： 哪些LC促进GC依赖性体液免疫应答; 2）确定高水平LC促进GC依赖性体液免疫应答的机制。 抗原剂量和CD 103 + DC抑制LC诱导的GC依赖性体液免疫应答;和3）确定 抗原剂量对保护性抗病毒应答发展的影响。对于目标1，充分表征了 靶向方法将与LC特异性敲除转基因小鼠模型、骨髓 嵌合体，成像，体外细胞培养和流式细胞术，以确定LC诱导的细胞凋亡的分子要求。 体液免疫反应。在目标2中，体外共培养实验和体内过继细胞转移系统 将用于表征高抗原剂量和CD 103 + DC如何调节LC诱导的免疫应答。 在目标3中，我们将用不同剂量的流感HA通过LC免疫小鼠，然后用活流感病毒攻击 以确定抗原定制流感疫苗的可行性。提出的假设和实验 模型非常新颖和创新。这个项目意义重大，因为它将推动和扩大我们的 了解DC亚群如何诱导和调节体液免疫应答，我们期望 将克服阻碍我们生产有效流感疫苗的问题。

PROJECT SUMMARY There is a fundamental gap in our understanding of why only certain vaccines promote formation of long-lasting and protective antibody responses. Dendritic cells (DC) are professional antigen presenting cells that regulate adaptive immune responses; thus, we think that understanding the role DCs in regulating B cell responses will be key to the development of universal vaccines targeting influenza and HIV. Our experimental data suggest that the major limitations of the relatively ineffective vaccines currently in use or in development might be that: 1) they do not specifically target Langerhans cells (LCs) and 2) the antigen dose is not tailored to maximize the activation of the LCs. Our long-term goal is to understand the role of different DC populations in humoral immune responses and to use that knowledge to design DC-subset-tailored vaccines, with a special focus on influenza and HIV. In pursuit of that goal, the objectives of this application are to: 1) define the mechanisms by which steady state LCs promote germinal center (GC)-dependent humoral immune responses; 2) to characterize the regulatory loop by which high antigen dose and CD103+ DCs inhibit GC-dependent responses induced by LCs; and 3) to test the feasibility of the DC-subset-tailored influenza vaccine. Our central hypothesis is that LCs drive functionally distinct Tfh cells in an antigen dose-dependent manner that ultimately determines whether humoral immune responses are mounted or not. The rationale for the proposed research is that, once the details of how LCs initiate humoral immune responses and regulate each other are known, the process can likely be manipulated to yield innovative approaches for prevention and treatment of a variety of diseases. Guided by strong preliminary data, our hypothesis will be tested in these three Specific Aims: 1. Define the mechanism by which LCs promote GC-dependent humoral immune responses; 2) Determine the mechanism by which high antigen dose and CD103+ DCs inhibit LC-induced GC-dependent humoral immune responses; and 3) Determine the effect of antigen dose on development of protective anti-viral responses. For Aim 1, a well characterized targeting approach will be combined with LC-specific knock out transgenic mouse models, bone marrow chimeras, imaging, in vitro cell cultures and flow cytometry to define the molecular requirements of LC-induced humoral immune responses. In Aim 2, in vitro co-culture experiments and in vivo adoptive cell transfer systems will be used to characterize how high antigen dose and CD103+ DCs regulate LC-induced immune responses. In Aim 3, we will immunize mice through LCs with different doses of flu-HA and then challenge with live influenza to determine the feasibility of the antigen-tailored influenza vaccine. The proposed hypothesis and experimental models are highly novel and innovative. This project is significant because it will advance and expand our understanding on how humoral immune responses are induced and regulated by DC subsets, which we expect will overcome problems that have hindered our ability to generate effective influenza vaccines.