Designing HIV-1 envelope immunogens to maximize neutralization breadth through use of multiple founder envelope antigens

项目摘要/摘要 一种能诱导广泛有效的HIV包膜中和抗体的HIV-1(HIV)疫苗 (环境)仍然难以捉摸。HIV有很高的变异率，Env是高度糖基化的，以及构象上的 迄今报告的动态和特征良好的广泛中和反应在以下情况下产生 慢性艾滋病毒感染，而不是通过候选艾滋病毒疫苗。最近，我们广泛地报道了这种前体 中和抗体(BNAbs)可在HIV感染早期形成，且中和广度较大 当多个HIV变种在一个个体中建立感染时经常发生，这里定义为多个创始人 变异(MFV)感染。此外，初次感染期间的环境多样性在以下人群中更高 发展了中和广度。我们的结论是，在最初的一个月内，环境特异性B细胞的发展 HIV感染可以预测几年后中和的广度；这一现象突显了关键的重要性 在这些最初的相互作用中，在艾滋病毒感染的最早阶段为B细胞做好准备。要确定 HIV疫苗的免疫原性设计基于MFV的概念，我们配制了五个Env三聚体的鸡尾酒 MFV在急性感染中衍生的蛋白质。环境基因序列对应于其中的5个创始人谱系 参与者。通过使用‘修复和修复’将它们稳定在封闭的构象中，进一步优化了它们 由扬森制药公司开发的“稳定”战略。最小距离、稳定的环境的鸡尾酒 用新型疫苗佐剂陆军脂质体制剂加QS-21(ALFQ)配制蛋白质。 对兔子的初步免疫原性数据表明，该候选疫苗引起了更大的广度 与同等总剂量的单一稳定的Env三聚体蛋白相比，中和抗体反应的效率更高。这些 距离最远的免疫原也能引起对HIV的较高程度的IgM反应； 在我们对早期感染的研究中，随后的中和广度。因此，我们建议选择一个最优的 模拟中和多样性和发展的最小距离HIV环境免疫原的组合 在体外和体内MFV急性感染中所见的AB宽度。我们将优化HIV环境的抗原性 通过比较天然稳定的三聚体和缩短了高变量的环境三聚体获得三聚体免疫原 (Hv)环和糖链修饰，试图提高其抗原性(目标1)。我们将优化 免疫基因递送和展示策略，包括作为信使RNA递送的多价三聚体环境蛋白 (MRNA)和多价免疫原在自组装脂质体上的显示 (CoPoP)提供环境基础屏蔽(目标2)。我们将利用预先指定的通过/不通过标准来向下选择 评价保护性免疫的最优最小距离HIV候选疫苗方案 非人灵长类SHIV挑战研究中的反应(目标3)。我们的长期目标是开发一种多价 HIV候选疫苗，可引起保护性的广谱中和抗体反应，用于后续生产和 在人体临床试验中的评估。

Project Summary/Abstract An HIV-1 (HIV) vaccine capable of eliciting broad and potent neutralizing antibody (Ab) response to HIV envelope (Env) remains elusive. HIV has a high mutation rate, Env is highly glycosylated as well as conformationally dynamic and, well-characterized broadly neutralizing responses reported to date have been generated after chronic HIV infection, rather than by candidate HIV vaccines. Recently, we reported that precursor broadly neutralizing antibodies (bNAbs) can develop during early HIV infection and neutralization breadth was more frequent when multiple HIV variants established infection in an individual, defined here as multiple-founder variant (MFV) infection. Furthermore, Env diversity during initial infection was higher in individuals who developed neutralization breadth. We concluded that Env-specific B cell development within one month of initial HIV infection can predict neutralization breadth years later; this phenomenon highlights the critical importance of these initial interactions, which prime B cells at the earliest stages of HIV infection. To determine the immunogenicity of an HIV vaccine design based on the MFV concept, we formulated a cocktail of five Env trimer proteins derived from MFV in acute infection. The Env sequences corresponded to 5 founder lineages in one participant. They were further optimized by stabilizing them in a closed conformation using the ’Repair and Stabilize’ strategy developed by Janssen Pharmaceuticals. The cocktail of minimally distant, stabilized Env proteins were formulated with the novel vaccine adjuvant, Army Liposome Formulation plus QS-21 (ALFQ). Preliminary immunogenicity data in rabbits demonstrated that this vaccine candidate elicited a greater breadth of neutralizing Ab responses than an equivalent total dose of a single stabilized Env trimer protein. These minimally distant immunogens also elicited a higher magnitude of IgM responses to HIV; a predictor of subsequent neutralization breadth in our studies of early infection. Therefore, we propose to select an optimal combination of minimally distant HIV Env immunogens that mimic the diversity and development of neutralizing Ab breadth seen in acute infections with MFV in vitro and in vivo. We will optimize the antigenicity of the HIV Env trimer immunogens by comparing native stabilized trimers with Env trimers that have shortened hypervariable (HV) loops and glycan modifications in an attempt to improve their antigenicity (Aim 1). We will optimize immunogen delivery and display strategies, including multivalent trimeric Envs delivered as messenger RNA (mRNA) and, multivalent immunogen display on self-assembling liposomal cobalt porphyrin phospholiposomes (CoPoP) that afford Env base shielding (Aim 2). We will utilize pre-specified Go/No-Go criteria to downselect the optimal vaccine regimen of optimized minimally distant HIV vaccine candidates, to evaluate protective immune responses in non-human primate SHIV challenge studies (Aim 3). Our long-term goal is to develop a multivalent HIV vaccine candidate that elicits protective broadly neutralizing Ab responses for subsequent manufacture and evaluation in human clinical trials.