Single molecule imaging of HIV Env

描述（由申请人提供）：尽管作出了巨大努力，但目前尚无有效的艾滋病毒/艾滋病疫苗。这主要是由于病毒有能力逃避中和抗体。三聚体HIV包膜糖蛋白gp160 （HIV Env）暴露在病毒粒子表面的宿主免疫反应中，有效地隐藏抗体的表位，同时保持其促进病毒进入的能力。少数暴露的抗体结合位点在结构上不稳定，并且维持大量的序列变异。因此，很少有广泛中和抗体已被确定。在这里，我们将开发单分子荧光共振能量转移（smFRET）成像，以监测HIV病毒表面单个天然Env分子的构象景观。我们将采用新的酶促方法，在不干扰传染性的位置将有机荧光团引入HIV Env。在一个Env分子内放置两种染料将允许

DESCRIPTION (provided by applicant): Despite enormous efforts, no effective vaccine is currently available against HIV/AIDS. This is largely due to the virus's ability to evade neutralizing antibodies. The trimeric HIV envelope glycoprotein gp160 (HIV Env), which is exposed to the host immune response on the surface of the virion, effectively conceals epitopes from antibodies while maintaining its ability to promote viral entry. The few exposed antibody-binding sites are structurally unstable and sustain substantial sequence variability. Consequently, few broadly neutralizing antibodies have been identified. Here we will develop single molecule Fluorescence Resonance Energy Transfer (smFRET) imaging to monitor the conformational landscape of individual native Env molecules on the surface of an HIV virus. We will apply new enzymatic methods to introduce organic fluorophores into HIV Env at positions that don't interfere with infectivity. The placement of two dyes within one Env molecule will allow the application of smFRET to report conformational changes of the unliganded HIV Env from various angles. Following the characterization of the unliganded HIV Env, we will determine how its conformation dynamics change in response to receptor and antibody binding. Our approach will identify critical conformational states of HIV Env that should be targeted for vaccine development, reveal the molecular mechanism underlying immune evasion, and understand the potency of existing neutralizing antibodies.