Characterization of the human antibody response to a novel neutralizing HIV-1 epitope

人类抗体对新型中和 HIV-1 表位反应的表征

基本信息

批准号：
10646412
负责人：
Maria Victoria Filsinger Interrante
金额：
$ 1.64万
依托单位：
STANFORD UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-07-01 至 2023-09-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10646412
关键词：
Acquired Immunodeficiency Syndrome Affinity Amino Acids Antibodies Antibody Affinity Antibody Response Antibody-mediated protection Antigens Area B-Lymphocytes Binding Cell Separation Clinical Trials Conserved Sequence Data Dedications Enzyme-Linked Immunosorbent Assay Epitope Mapping Epitopes FDA approved Face Future Goals HIV HIV envelope protein HIV vaccine HIV-1 HIV/AIDS Health Human Immunoglobulin Somatic Hypermutation Immunologics In Vitro Individual Infection Leucine Zippers Libraries Mediating Memory B-Lymphocyte Molecular Conformation Monoclonal Antibodies Patients Peripheral Blood Mononuclear Cell Persons Process Proteins Research Scaffolding Protein Serum Sorting Structure T-20 Testing Time Vaccines Viral Virus Work X-Ray Crystallography alpha helix chronic infection cohort complementarity-determining region 3 design dimer env Gene Products experimental study inhibitor interest mimetics monomer neutralizing antibody novel pandemic disease peptidomimetics response scaffold therapeutic target unpublished works

项目摘要

PROJECT SUMMARY The HIV pandemic is one of the most profound global human health challenges of our time, with 75 million people infected and 32 million dead from AIDS-related illnesses since 19811. Despite decades of dedicated efforts, an effective vaccine has remained elusive. While the discovery and characterization of patient-derived broadly neutralizing antibodies (bnAbs) to various epitopes of the HIV envelope protein (Env) demonstrate that inhibition of the virus by human antibodies is possible, these antibodies have not yet been possible to elicit with a vaccine, due in part to their extensive somatic hypermutation (SHM) or long heavy-chain third complementarity determining regions (CDRH3s). In recent unpublished work, our group has identified a novel epitope for antibody-mediated neutralization in the prehairpin intermediate (PHI) of Env exposed during HIV viral fusion, demonstrating that a previously discovered patient-derived antibody with 94% germline identity (A2) binds to the conserved, helical face of the CHR, and after affinity maturation neutralizes tier-1B viruses across multiple clades in vitro. The limited degree of SHM of the neutralizing antibody and the ability of a germline-inferred version to bind to the original epitope suggest that it may be possible to elicit neutralizing antibodies to this epitope from the germline. In addition, we found that the protein inhibitor 5-Helix, which binds and inhibits via the same helical CHR epitope, is capable of cross-clade neutralization of tier-1, -2, and -3 HIV-1 viruses. Taken together, these data inform the central hypothesis of this work: that higher-affinity antibodies to this epitope, if identified, may be capable of effective cross-clade neutralization. Given that both A2 and 5-Helix inhibit HIV fusion by binding to the CHR as a folded 𝛼-helix, this secondary structure is likely important in attempts to identify additional CHR-directed neutralizing antibodies. Thus, I plan to use C34coil, a helical peptide mimetic of the CHR comprising 19 amino acids from the CHR conserved face grafted onto one monomer of a GCN4 leucine zipper dimer, to investigate antibody-mediated neutralization at this epitope. The long-term goal of this research is to investigate the highly-conserved, helical face of the CHR as a potential HIV-1 immunogen capable of eliciting broadly neutralizing antibodies. In the proposed work, I will (i) identify and characterize additional human-derived monoclonal antibodies that bind to C34coil, (ii) investigate the serum and memory B cell response to C34coil in HIV-1 infected individuals, and (iii) determine human naïve B cell reactivity to C34coil. Collectively, this proposal aims to investigate the hypothesis that high-affinity antibodies to the helical CHR, if identified, may be capable of effective cross-clade neutralization. These studies will inform the potential of a scaffolded, helical mimetic of this epitope to elicit neutralizing antibodies towards an HIV vaccine and guide future iterations of rational immunogen design.

项目摘要艾滋病毒大流行是我们时代最深刻的全球人类健康挑战之一，有7500万人自19811年以来，与艾滋病有关的疾病感染了3200万人。尽管有数十年的努力，但有效的疫苗仍然难以捉摸。而广泛的患者衍生的发现和表征对HIV包膜蛋白（ENV）的各种表位的中和抗体（BNAB）证明了抑制作用可以通过人类抗体病毒的病毒，这些抗体尚不可能引起疫苗，部分原因是它们广泛的体细胞超松（SHM）或长链长链第三完成确定区域（CDRH3S）。在最近的未发表的工作中，我们的小组确定了一种新型的抗体介导的神经化的表位 HIV病毒融合期间暴露的Env的前中间（PHI），证明了先前发现的具有94％种系认同（A2）的患者衍生抗体与CHR的配置，螺旋面孔结合，并结合亲和力成熟后，在体外多个进化枝中中和1B病毒。有限程度的SHM 中和抗体和种系效力与原始表位结合的能力表明可能会从种系中引起对此情节中和抗体的中和抗体。此外，我们发现蛋白抑制剂5-螺旋通过相同的螺旋CHR表位结合和抑制，能够交叉粘土 Tier -1，-2和-3 HIV -1病毒的中和化。综上所述，这些数据为这项工作的核心假设提供了有关：对此的高亲和力抗体如果鉴定出表位，则可能能够有效的交叉神经化。鉴于A2和5螺旋都可以抑制 HIV融合通过与ChR结合为折叠𝛼-螺旋，这种二级结构在尝试中可能很重要确定其他CHR指导的中和抗体。那就是我计划使用C34Coil，一种模仿的螺旋肽 CHR从CHR保守的脸上完成了19个氨基酸，移植到GCN4亮氨酸的一个月拉链二聚体，研究该表位的抗体介导的神经化。这项研究的长期目标是为了研究CHR的高度保存的螺旋面孔，作为能够引发的潜在HIV-1免疫原广泛中和抗体。在拟议的工作中，我将（i）识别并描述其他人类衍生的与C34COIL结合的单克隆抗体（ii）研究血清和记忆B细胞对C34COIL的响应 HIV-1感染的个体，（iii）确定对C34COIL的幼稚B细胞反应性。总的来说，该提案旨在调查以下假设：如果确定的，可能能够有效的跨层神经化。这些研究将为某人的潜力提供信息脚手架，螺旋模拟于此情节，以引起对HIV疫苗的中和抗体的中和抗体理性免疫原设计的未来迭代。