Lipid-Enveloped Nanoparticle Vaccines for HIV Neutralizing Antibody Generation

用HIV刺突蛋白免疫激发主要针对天然HIV gp 120/41三聚体中的可变表位的抗体应答，即使有，也几乎没有广泛的中和特异性。然而，几种广泛中和抗体识别gp 41融合蛋白的高度保守的膜近端外部区域（MPER）。为了引起针对gp 41的这种保守片段的抗体应答，我们提出了一种基于MPER肽与“脂质包膜纳米颗粒”（NP）的缔合的策略， 病毒粒子大小的合成纳米颗粒，具有可生物吸收的聚合物或水性核心和脂质表面层。这种方法的动机是初步数据显示与脂质膜相关的MPER肽的结构，其呈现由广泛中和抗体（BNAb）4 E10识别的构象。 这些颗粒的核心可用于提供辅助T细胞表位的共递送，而MPER肽和TLR配体从脂质颗粒表面呈递。具体目标是：（1）我们将根据颗粒表面脂质组成和MPER肽锚定来确定用于BNAb识别的最佳MPER呈递。(2)我们将测试在NP的核心中包裹辅助性T细胞表位是否可以支持产生用于抗体应答的CD 4 + T细胞帮助，而不会误导抗体 反应远离颗粒表面显示的MPER肽。(3)我们将分析TLR配体掺入颗粒表面的影响，以辅助树突状细胞，B细胞和辅助T细胞活化以及由此产生的对MPER肽的抗体应答，并测试NP作为辅助佐剂递送腺苷能信号传导抑制剂的能力。总之，这些策略将用于产生一种HIV疫苗，该疫苗可激发BNAb反应，并与项目1合作分析小鼠体内反应。这种独特 创建HIV疫苗的结构方法寻求将关于HIV病毒保守残基的关键结构信息与基于纳米颗粒的递送策略相结合，以实现能够广泛预防性保护的中和抗体应答。

Immunization with HIV spike proteins elicits antibody responses directed largely against variable epitopes in the native HIV gpl20/41 trimer with little, if any broad neutralizing specificity. However, several broadly neutralizing antibodies recognize the highly conserved Membrane-Proximal External Region (MPER) of the gp41 fusion protein. To elicit antibody responses focused against this conserved fragment of gp41, we propose a strategy based on the association of MPER peptides with 'lipid-enveloped nanoparticles' (NPs), virion-sized synthetic nanoparticles with a bioresorbable polymer or aqueous core and lipid surface layer. This approach is motivated by preliminary data showing the structure of MPER peptides associated with lipid membranes, which assume a conformation recognized by the broadly neutralizing antibody (BNAb) 4E10. The core of these particles can be used to provide co-delivery of T-helper epitopes, while MPER peptides and TLR ligands are presented from the lipid particle surface. The specific aims are: (1) We will determine optimal MPER presentation for BNAb recognition in terms of particle surface lipid composition and MPER peptide anchoring. (2) We will test whether encapsulation of T helper epitopes in the core of NPs can support the generation of CD4+ T cell help for antibody responses without misdirecting the antibody response away from the particle surface-diplayed MPER peptide. (3) We will analyze the impact of TLR ligand incorporation into particle surfaces, to adjuvant dendritic cell, B-cell, and helper T-cell activation and resulting antibody responses to MPER peptides, and test the ability of NPs to deliver adenosinergic signaling inhibitors as co-adjuvants. Together, these strategies will be used to generate an HIV vaccine that elicits BNAb responses, with in vivo responses in mice analyzed in collaboration with Project 1. This unique structural approach to creation of an HIV vaccine seeks to combine key structural information about conserved residues of the HIV virus with a nanoparticle-base delivery strategy to achieve a neutralizing antibody response capable of broad prophylactic protection.