Designing and optimizing candidate HIV vaccines and boosting protocols

摘要 HIV-1疫苗研究的一个主要目标是设计能够广泛诱导的免疫原 与病毒包膜糖蛋白(Env)结合的中和抗体(BNAbs)。虽然许多艾滋病人 从慢性感染患者中分离出bNAbs，通过免疫提高bNAbs的方法已被 很难。主要问题似乎是(1)bNab表位是次要的，因此 反应必须以避免偏离目标的反应和有利于 所需的特异性，(2)大多数形式的环境病毒与bNAbs的未突变前体结合较差，从而 BNab响应通常没有适当地启动，以及(3)我们不知道如何最好地 增强反应一旦准备好，就会产生bNAbs，这种抗体通常具有不寻常的体细胞数量 突变。在这项建议中，我们通过研究bNab中的工程免疫原来解决这些问题 诺克金老鼠。 我们关注两类bNAbs，VRC01和PGT130，我们预测它们将很容易被 使用适当改造的免疫原对人类进行疫苗接种。VRC01是的原型bNab 识别CD4结合位点(CD4bs)的类和PGT130是一类 结合V3环和环境上甘露糖补丁的依赖于糖的bNAbs。两种抗体类别 在许多艾滋病毒感染者中被描述，并特别有效和广泛 这表明一种能够诱导这种抗体的疫苗将在相对较低的抗体水平上提供保护 浓度。 我们之前已经培育出了携带生殖系回复(GL)-VRC01的B细胞的小鼠 免疫球蛋白重(H)链和轻(L)链，在这里我们建议产生新的敲入小鼠 携带gl-PGT130H-链和L链基因。小鼠表达的B细胞受体本应是 触发并成熟以生成VRC01或PGT130类bNAb，并将用于调查 免疫原和免疫策略。对于引爆，我们将使用现有的生殖系靶向 对gl-VRC01有反应的免疫原，我们将产生针对gl-VRC01的新型工程免疫原。 PGT130和.为了增强免疫力，我们将测试一系列工程和天然免疫原，以集中和 加强bNab成熟的中间和最后步骤。 这项研究将测试我们的生殖系靶向方法的通用性，发现新的疫苗 候选人，并教我们如何最大限度地利用次要的抗病毒反应 在总体上告知人类疫苗接种战略。

Abstract A major goal of HIV-1 vaccine research is the design of immunogens capable of inducing broadly neutralizing antibodies (bnAbs) that bind to the viral envelope glycoprotein (Env). While many HIV bnAbs have been isolated from chronically infected patients, raising bnAbs by immunization has been difficult. The principal problems appear to be (1) that bnAb epitopes are sub-dominant and so the response must be primed and boosted in such a way as to avoid off-target responses and favor the desired specificities, (2) that most forms of Env bind poorly to unmutated precursors of bnAbs so that bnAb responses are not typically primed appropriately and (3) we do not understand how best to boost responses once primed to yield bnAbs that typically have an unusual amount of somatic mutation. In this proposal, we address these problems by study of engineered immunogens in bnAb knockin mice. We focus on two classes of bnAbs, VRC01 and PGT130, which we predict will be readily raised by vaccination in humans using appropriately engineered immunogens. VRC01 is the prototype bnAb of a class that recognizes the CD4 binding site (CD4bs) and PGT130 is a representative of a class of glycan-dependent bnAbs that bind the V3 loop and mannose patch on Env. Both antibody classes have been described in many HIV infected individuals and are particularly potent and broad suggesting that a vaccine able to elicit such Abs would provide protection at relatively low Ab concentrations. We have previously generated mice engineered to carry B cells with germline reverted (gl)-VRC01 immunoglobulin heavy (H) and light (L)-chains, and here we propose to generated new knock-in mice carrying gl-PGT130 H- and L-chain genes. The mice express the B cell receptors that should be triggered and matured to generate VRC01 or PGT130 class bnAbs and will be used to investigate immunogens and immunization strategies. For priming, we will use existing germline-targeting immunogens reactive to gl-VRC01 and we will generate novel engineered immunogens targeting gl- PGT130 and. For boosting we will test a range of engineered and natural immunogens to focus and enhance intermediate and final steps in bnAb maturation. This study will test the generality of our germline-targeting approach, discover new vaccine candidates, and teach us lessons on how to maximize subdominant anti-viral responses that should inform human vaccination strategies in general.