Expediting elicitation of HIV-1 bnAbs with membrane Env vaccines

使用膜包膜疫苗加速 HIV-1 bnAb 的诱导

• 批准号: 10568994
• 负责人: MICHAEL B ZWICK
• 金额: $ 89.12万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-03-09 至 2024-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10568994
• 关键词: AIDS vaccine development; Address; Adenovirus Vector; Adjuvant; Affinity; Animal Model; Antibodies; Antibody Response; Antibody Specificity; Antigens; B-Lymphocytes; B-cell receptor repertoire sequencing; Binding; Binding Sites; Biochemical; Blocking Antibodies; Cell Separation; Cells; Clinic; Consensus; Data; Directed Molecular Evolution; Elements; Engineering; Epitopes; Evolution; Excision; Genetic; Genomics; Genotype; Glycoproteins; Goals; HIV; HIV Envelope Protein gp120; HIV vaccine; HIV-1; HIV-1 vaccine; Helper-Inducer T-Lymphocyte; Heterogeneity; Heterozygote; Homologous Gene; Human; Immune Sera; Immune system; Immunization; Immunize; Joints; Keyhole Limpet Hemocyanin; Knock-in; Knock-in Mouse; Link; Liposomes; Membrane; Modeling; Modification; Molecular Conformation; Mus; Oryctolagus cuniculus; Ovum; Pathway interactions; Peptides; Phenotype; Polysaccharides; Positioning Attribute; Production; Regimen; Reporting; Reproducibility; Scheme; Serum; Site; Solubility; Specificity; Surface; System; T-Lymphocyte; Testing; Transmembrane Domain; Vaccine Design; Vaccines; Variant; Virion; Virus; anergy; base; design; follow-up; glycosylation; immunogenicity; improved; mouse model; neutralizing antibody; next generation sequencing; novel; particle; recruit; response; single-cell RNA sequencing; vaccination outcome; vaccination strategy; vaccine candidate; vaccine delivery; vaccine development; vaccine platform; vaccine strategy; vector vaccine

Project Summary / Abstract A primary goal in HIV/AIDS vaccine development is to elicit broadly neutralizing antibodies (bnAbs) against the HIV-1 envelope glycoprotein spike that is anchored in the membrane (m-Env). To date, experimental vaccines have elicited mostly narrow, weak or non-neutralizing antibodies, typically using soluble Env (s-Env) molecules. Here, we will use membrane Env liposome (MEL) vaccines that incorporate well-ordered and stabilized m-Env trimers into liposomes via the transmembrane domain. MELs thus present a relevant conformation of Env in a multivalent manner and contain important epitopes of the membrane proximal external region (MPER) that are missing from s-Env vaccines. The creation of MELs has been made feasible by recent improvements to m-Env production by creation of high Env producer cells. Meanwhile, B cell anergy is common among HIV-1 bnAb lineages but is not well addressed by traditional vaccines. Preliminary data show initial promise of MELs in eliciting nAb responses in human CD4BS bnAb CH103 UCA heterozygous dKI (HC+LC KI) mice in which ‘on-target’ anergy prone B cells had responded poorly to s-Env vaccines. In Aim 1, we will build on these findings by using consensus Env MELs, and mixed Env MELs, combined with selective removal of N-glycan at position 197 to increase accessibility to the CD4 binding site in order to expedite elicitation of cross-neutralizing antibodies in the prime. This will be followed by sequential boosting with MELs. The ‘Booster MELs’ will be consensus Envs, or those selected in part based on specific binding by antecedent serum antibodies from prior immunization, with the intent to drive affinity maturation of B cells against conserved elements of the target site. In an effort to further broaden nAb responses, we will use an approach described recently that elicits bnAbs to the fusion peptide (FP) in multiple species including mice. In this approach, a prime-boost regimen in CH103 UCA het dKI mice consisting of an FP-KLH prime and MEL boosts is designed to “co-elicit” CD4BS bnAbs and FP bnAbs. In Aim 2, we will test a similar sequential MEL immunization strategy designed to elicit MPER-directed bnAbs in 2F5 KI mice, whose B-cells are also under more significant anergy controls. Hence, we will use strong universal T helper cell epitopes as a strategy to further help break B cell anergy to maximize bnAb responses. This will involve “pre-priming” with universal Th epitopes using a lentiviral vaccine vector (LVV). Finally, in Aim 3, down-selected m-Env vaccine candidates eliciting the best nAb responses, and ideally comprising practical regimens that elicit nAbs to CD4BS, FP and MPER with the least boosts, will be used to immunize in fully polyclonal systems, i.e. rabbits and humanized Ig locus KI (Trianni) mice. The creation of m-Env-based vaccine schemes able to elicit cross-neutralizing antibodies against key vaccine targets, particularly in humanized polyclonal Ig KI mice, should have a significant impact on HIV-1 vaccine development.

项目概要/摘要 HIV/AIDS 疫苗开发的主要目标是引发针对 HIV-1 的广泛中和抗体 (bnAb) 锚定在膜上的包膜糖蛋白刺突 (m-Env) 迄今为止，实验疫苗已引发大部分。 窄的、弱的或非中和的抗体，通常使用可溶性 Env (s-Env) 分子在这里，我们将使用膜。 Env 脂质体 (MEL) 疫苗通过以下方式将有序且稳定的 m-Env 三聚体整合到脂质体中 因此，MEL 以多价方式呈现 Env 的相关构象，并包含重要的信息。 s-Env 疫苗中缺失的近膜外部区域 (MPER) 表位 最近通过创建高 Env 生产细胞对 m-Env 生产进行了改进，这已变得可行。 B 细胞无反应在 HIV-1 bnAb 谱系中很常见，但传统疫苗并未很好地解决这一问题。 显示 MEL 在人类 CD4BS bnAb CH103 UCA 杂合 dKI (HC+LC KI）小鼠，其中“目标”无反应倾向 B 细胞对 s-Env 疫苗反应不佳。在目标 1 中，我们将在此基础上进行发展。 这些发现是通过使用共识 Env MEL 和混合 Env MEL 并结合选择性去除 N-聚糖 位置 197 增加 CD4 结合位点的可及性，以加速交叉中和抗体的引发 随后将使用 MEL 进行连续提升，“Booster MEL”将是共识环境，或 部分基于先前免疫接种中先前血清抗体的特异性结合而选择的那些，目的是 驱动 B 细胞针对靶位点保守元件的亲和力成熟，以进一步拓宽 nAb。 响应，我们将使用最近描述的一种方法，在多个物种中引发融合肽 (FP) 的 bnAb 在该方法中，CH103 UCA het dKI 小鼠的初免-加强方案由 FP-KLH 初免和 MEL 增强旨在“共同引发”CD4BS bnAb 和 FP bnAb 在目标 2 中，我们将测试类似的顺序 MEL。 旨在在 2F5 KI 小鼠中引发 MPER 导向的 bnAb 的免疫策略，该小鼠的 B 细胞也受到更多 因此，我们将使用强大的通用 T 辅助细胞表位作为进一步帮助打破 B 的策略。 细胞无反应性以最大化 bnAb 反应，这将涉及使用慢病毒对通用 Th 表位进行“预启动”。 最后，在目标 3 中，向下选择的 m-Env 候选疫苗可引发最佳 nAb 反应，以及 理想情况下，包括以最少的增强量引发 CD4BS、FP 和 MPER 的 nAb 的实用方案，将用于 在完全多克隆系统中进行免疫，即兔子和人源化 Ig 位点 KI (Trianni) 小鼠 基于 m-Env 的创建。 疫苗方案能够引发针对关键疫苗靶点的交叉中和抗体，特别是在人源化多克隆抗体中 Ig KI 小鼠，应该会对 HIV-1 疫苗的开发产生重大影响。