Vaccines to Generate Neutralizing Anti-HIV Antibodies

描述(由申请人提供)：HIV疫苗开发的一个主要目标是创造能够诱导针对gp120/gp41包膜(Env)刺突的广泛中和抗体(NAB)的疫苗。实现这一目标的努力遇到了三个障碍：(1)很难在疫苗中复制gp120/gp41三聚体的结构；(2)nabs应该在暴露的粘膜表面具有尽可能高的滴度；(3)env的广泛变异使找到用于疫苗的最佳env序列变得困难。该项目将通过三个目标研究克服这些障碍的创新方法。AIM 1将使用Env质粒和质粒肌肉内DNA疫苗来产生对转基因肌肉细胞具有细胞毒作用的CD8+T细胞。这一策略利用了质粒DNA在接种部位的细胞膜上以正确折叠的天然构象表达Env的能力。细胞毒性CD8+T细胞DNA疫苗的加入将使表达天然Env的细胞碎片能够到达引流淋巴结中的B细胞，这是基于以前未被利用的发现，CD8+T细胞显著增强了对非分泌性抗原DNA疫苗的抗体应答。我们将这种方法称为CD8+T细胞介导的抗体诱导疫苗(CAEVac)。目的2检测编码高表位密度形式Env的DNA疫苗增强抗Env抗体应答的能力。目的检测CD40L、GITRL、BAFF和APRIL四种肿瘤坏死因子超家族配体对AIM 1 DNA疫苗抗体应答的佐剂效应。当这一创新项目完成后，将对引起艾滋病毒nabs的疫苗的新概念进行评估，以促进艾滋病毒疫苗流水线的进一步研究。该项目将开发新的免疫刺激剂，可以显著提高病毒疫苗的强度。虽然这项研究的重点是艾滋病毒，但同样的免疫刺激剂可以应用于许多其他感染的疫苗，包括流感、病毒性肝炎、西尼罗河病毒、天花和具有生物防御意义的制剂。

DESCRIPTION (provided by applicant): A major goal of HIV vaccine development is to create vaccines that elicit broadly neutralizing antibodies (NAbs) to the gp120/gp41 envelope (Env) spikes on virions. Efforts to accomplish this goal have met with three obstacles: (1) it is difficult to replicate the structure of gp120/gp41 trimers in a vaccine; (2) NAbs should be at the highest possible titer on exposed mucosal surfaces; and (3) extensive variation in Env has made it difficult to find the best Env sequence for use in a vaccine. This project will study innovative ways to overcome these roadblocks through three Aims. Aim 1 will use intramuscular DNA vaccination with an Env plasmid along with a plasmid to generate CD8+ T cells that are cytotoxic for the transfected muscle cells. This strategy utilizes the ability of plasmid DNA to express Env in its correctly folded native conformation on the membranes of cells at the vaccination site. The addition of a DNA vaccine for cytotoxic CD8+ T cells will enable cell debris expressing native Env to reach B cells in the draining lymph nodes, based on the previously unexploited finding that CD8+ T cells markedly enhance antibody responses to DNA vaccines for nonsecreted antigens. We call this approach 'CD8+ T cell-mediated Antibody-Eliciting Vaccine' (CAEVac). Aim 2 will test the abilty of DNA vaccines encoding high epitope density forms of Env to augment the anti-Env antibody response. Aim 3 will test the adjuvant effects of CD40L, GITRL, BAFF, and APRIL, four TNF superfamily ligands, on the antibody responses to the DNA vaccines of Aim 1. BAFF in particular has potential as an adjuvant for mucosal IgA responses. When this innovation project is complete, new concepts for vaccines that elicit HIV NAbs will have been evaluated for advancement to further studies in the HIV vaccine pipeline. This project will develop new immunostimulants that could significantly improve the strength of viral vaccines. While this research is focused on HIV, the same immunostimulants could be applied to vaccines against many other infections including influenza, viral hepatitis, West Nile virus, smallpox, and agents of biodefense significance.