CD40L-Adjuvanted Vaccines for HIV/AIDS

基于Ad 5的HIV-1疫苗在人类中的失败，该疫苗旨在强烈诱导主要的抗病毒T细胞 这表明需要开发新的疫苗方法，产生高水平的抗病毒T细胞， 改善功能以及保护性Ab。该项目的目标是辅助细胞和体液 我们的DNA/MVA疫苗引发的免疫力刚刚进入美国人体第二阶段测试。具体地说， 我们提出使用CD 40 L靶向树突细胞（DC）和B细胞上的CD 40途径。刺激cd 40 导致产生IFNg和IL-12，这对于产生高功能抗病毒CDS至关重要 反应通过CD 40激活B细胞是生发中心形成所必需的， B细胞的成熟导致高亲合力Ab的产生。在这里，我们将表达CD 40 L在 SIV病毒样颗粒（CD 40 L-VLP）的表面。这些CD 40 L-VLP是DC和B细胞的有效活化剂， 体外此外，它们可以靶向DC（通过VLP上的gpl 20和DC上的CD 4之间的相互作用）， 允许Env以其天然形式呈递，这对于引发广泛交叉反应性中和Ab至关重要。在 具体目标1.我们将测试CD 40 L-修饰的DNA/MVA SIV疫苗在增强控制 致病性SIV攻毒。此外，我们还将测试通过电穿孔递送DNA是否能增强细胞的增殖。 图10示出了稀释的和未稀释的DN/VMVA疫苗的免疫原性。Rafi博士最近的研究 Ahmed的实验室（项目2的PI）证明，mTOR调节记忆T细胞的发育和抑制记忆T细胞的增殖。 感染或接种雷帕霉素后的这一途径增强了细胞的数量和功能质量 抗原特异性CD 8 T细胞。雷帕霉素还显示下调CCR 5在细胞中的表达。 CD 4 T细胞导致HIV复制显著减少。这可能是艾滋病毒的一个额外优势 疫苗，因为疫苗引发的CCR 5 '病毒特异性CD 4 T细胞可能不会被病毒感染。 从本质上讲，我们可能会减少潜在的病毒靶细胞的频率，同时保留急需的细胞。 感染后CD 4 T细胞保持不变。在具体目标2中，我们将测试抑制mTOR和抑制细胞增殖之间的协同作用。 激活CD 40途径以辅助DNA/MVA疫苗的免疫原性和功效。

The failure of Ad5 based HIV-1 vaccine in humans that is designed to elicit primarily antiviral T cells strongly suggests the need to develop novel vaccine approaches that generate high levels of anti-viral T cells with improved function as well as protective Ab. The goal of this project is to adjuvant the cellular and humoral immunity elicited by our DNA/MVA vaccine that has just entered phase II testing in humans in US. Specifically, we propose to target the CD40 pathway on dendritic cells (DC) and B cells using CD40L. Stimulation of CD40 on DC results in production of IFNg and IL-12 that are critical for generation of highly functional antiviral CDS response. Activation of B cells through CD40 is necessary for germinal center formation where affinitv maturation of B cells occurs leading to generation of high avidity Ab. Here, we will express CD40L on the surface of a SIV virus-like particle (CD40L-VLP). These CD40L-VLPs are potent activators of DC and B cells in vitro. In addition, they can be targeted to DC (through interaction between gpl20 on VLP and CD4 on DC) and allow presentation of Env in its native form that is critical for eliciting broadly cross-reactive neutralizing Ab. In specific aim 1. we will test the potential of CD40L-adiuvanted DNA/MVA SIV vaccine to enhance control of a pathogenic SIV challenge. In addition, we will test whether delivering DNA by electroporation enhances the immunogenicity of the adluvanted and non-adiuvanted DN/VMVA vaccines. Recent studies from Dr. Rafi Ahmed's lab (PI of project 2) demonstrated that mTOR regulates memory T cell development and inhibition of this pathway following infection or vaccination using rapamycin enhances the magnitude and functional quality of antigen-specific CDS T cells. Rapamycin has also been shown to down regulate expression of CCR5 on CD4 T cells that results in marked reduction of HIV replication. This could be an added advantage for HIV vaccines, because the vaccine-elicited CCR5' virus-specific CD4 T cells may not be infected by the virus. Essentially we may be reducing the freguency of potential virus target cells while preserving the much-needed CD4 T cell helD following infection. In specific aim 2, we will test the synergy between inhibiting mTOR and activating CD40 pathways for adjuvanting the immunogenicity and efficacy of DNA/MVA vaccines.