Analysis of the Initiation of an HIV Broadly Neutralizing Antibody Lineage in a Single Host

单一宿主中 HIV 广泛中和抗体谱系的启动分析

• 批准号: 10013493
• 负责人: Daniela Fera
• 金额: $ 32.92万
• 依托单位: SWARTHMORE COLLEGE
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10013493
• 关键词: Affinity; Amino Acids; Antibodies; Antibody Binding Sites; Antigens; Applications Grants; B-Lymphocytes; Binding; Cells; Characteristics; Complementarity Determining Regions; Complex; Cryoelectron Microscopy; Crystallization; Data; Development; Epitopes; Evolution; Glycoproteins; Goals; HIV; HIV vaccine; Immune; Immune response; Immune system; Individual; Infection; Interferometry; KAI1 gene; Length; Masks; Mediating; Mentors; Molecular; Molecular Conformation; Mutation; Outcome; Pattern; Peptides; Polysaccharides; Population; Process; Property; Protein Region; Public Health; Publishing; Race; Regimen; Research; Resolution; Site; Structure; Students; Surface; Techniques; Testing; Time; Training; V3 Loop; Vaccination; Vaccine Design; Vaccines; Variant; Viral; Viral Antibodies; Virus; Work; X-Ray Crystallography; arm; base; career development; design; env Gene Products; glycosylation; improved; member; movie; mutant; neutralizing antibody; pathogen; prevent; progenitor; response; undergraduate research; vaccine development; Affinity; Amino Acids; Antibodies; Antibody Binding Sites; Antigens; Applications Grants; B-Lymphocytes; Binding; Cells; Characteristics; Complementarity Determining Regions; Complex; Cryoelectron Microscopy; Crystallization; Data; Development; Epitopes; Evolution; Glycoproteins; Goals; HIV; HIV vaccine; Immune; Immune response; Immune system; Individual; Infection; Interferometry; KAI1 gene; Length; Masks; Mediating; Mentors; Molecular; Molecular Conformation; Mutation; Outcome; Pattern; Peptides; Polysaccharides; Population; Process; Property; Protein Region; Public Health; Publishing; Race; Regimen; Research; Resolution; Site; Structure; Students; Surface; Techniques; Testing; Time; Training; V3 Loop; Vaccination; Vaccine Design; Vaccines; Variant; Viral; Viral Antibodies; Virus; Work; X-Ray Crystallography; arm; base; career development; design; env Gene Products; glycosylation; improved; member; movie; mutant; neutralizing antibody; pathogen; prevent; progenitor; response; undergraduate research; vaccine development

Human immunodeficiency virus (HIV) is a rapidly evolving pathogen that escapes immune defenses provided by most vaccine-induced antibodies. Proposed strategies to elicit broadly neutralizing antibodies (bnAbs) by vaccination require a deeper understanding of evolution of the immune response to infection, since these protective antibodies typically take ~4-5 years to develop. In HIV infected individuals, viruses and antibody producing B-cells evolve together, creating a virus-antibody “arms race”, with populations of viruses and antibodies present throughout infection. The proposed research is to analyze critical early time-points of the arms race in a donor who developed antibodies of significant breadth, to guide immunogen design. In addition to rapid mutation, HIV also uses heavy glycosylation and conformational masking to evade the immune system. Donor CH848 produced a bnAb lineage, called DH270, which interacts with the glycan “supersite” at the base of the HIV envelope (Env) variable loop V3. Analysis of crystal structures of complexes between mature members and fragments of the HIV Env, together with binding data, suggest that improbable mutations in the antibodies led to the different neutralization properties of antibodies in the different branches of the lineage, without any major structural change in the antibody paratope or antigen epitope. While many V3-glycan “supersite” bnAbs recognize the N332 glycan, their actual epitopes differ in other glycans and Env peptides they recognize. Thus, it remains to be determined what triggered DH270 lineage development. To understand properties of HIV Env and interactions with antibodies that were critical for DH270 lineage development, atomic resolution structures of HIV Envs will be determined by cryo-electron microscopy and/or X-ray crystallography with an early member of the DH270 lineage, DH270.IA4, and with cooperating antibody lineage members, DH475 and DH0022. Cooperating antibodies, also produced in the CH848 donor, triggered virus escape mutations that improved binding to DH270 lineage antibodies and likely accelerated affinity maturation in the DH270 lineage. Hypotheses on how the DH270 lineage progenitor antibody could bind Env may also be deduced from the DH270.IA4 complex structure, since DH270.IA4 differs from the progenitor by five amino acids. Hypotheses will be tested by introducing mutations into the Fabs and/or HIV Env and determining binding affinities by biolayer interferometry. Structures of cooperating antibodies in complex with Env will identify properties of HIV Env (i.e., conformation, glycosylation patterns, etc.) that triggered these non- neutralizing antibodies, and despite their overlapping epitopes, how they aided DH270 lineage development. These data will identify mechanism(s) that triggered the development of broadly neutralizing glycan- dependent antibodies, and guide vaccine design. Undergraduate research students supported by this grant proposal will explore an issue of critical public health importance using cutting edge techniques, be co-authors on published work and be mentored by experts committed to their long-term career development.

人类免疫缺陷病毒（HIV）是一种迅速发展的病原体，可以逃脱免疫范围 由大多数疫苗诱导的抗体提供。提出的策略以广泛中和抗体 （BNAB）通过疫苗接种需要更深入地了解对感染的免疫反应的进化，因为 这些受保护的抗体通常需要〜4 - 5年才能开发。在艾滋病毒感染的人，病毒和 产生B细胞的抗体共同发展，形成病毒抗体“武器竞赛”，并具有大量病毒 和整个感染中存在的抗体。拟议的研究是分析关键的早期时间点 捐赠者的军备竞赛开发出显着广度的抗体，以指导免疫原设计。 除了快速突变外，艾滋病毒还使用大量的糖基化和构象掩盖来逃避 免疫系统。供体CH848产生了一个称为DH270的BNAB谱系，它与Glycan相互作用 HIV信封（Env）变量循环V3的“超级站点”。分析复合物的晶体结构 在成熟的成员和HIV Env的碎片以及具有约束力的数据之间表明不可能 抗体中的突变导致不同分支中抗体的不同中和特性 谱系，没有任何抗体伞形或抗原表位的任何重大结构变化。而很多 V3-聚糖“ Supersite” BNABS认可了N332 Glycan，其实际表位在其他聚糖中和Env中不同 他们识别的肽。那尚待确定是什么触发了DH270谱系的发展。 了解艾滋病毒的特性 Env和与DH270至关重要的抗体的相互作用 谱系发展，艾滋病毒的原子分辨率结构 ENV将由低温电子显微镜确定 和/或X射线晶体学具有DH270谱系的早期成员，DH270.IA4，并进行合作 抗体谱系成员，DH475和DH0022。在CH848捐赠者中也生产的合作抗体， 触发了病毒逃生突变，改善了与DH270谱系抗体结合的结合，并可能加速 DH270谱系中的亲和力成熟。 DH270谱系祖细胞抗体如何结合的假设 ENV也可以从DH270.IA4复合结构中推导，因为DH270.IA4与祖先有所不同 由五个氨基酸。假设将通过将突变引入Fabs和/或HIV Env以及 通过生物层干扰确定结合亲和力。与复杂抗体合作的结构 ENV将确定HIV Env（即构象，糖基化模式等）的特性，该特性触发了这些非 - 中和抗体以及使其重叠的表位使他们如何帮助DH270谱系发展。 这些数据将确定触发广泛中和聚糖的发展的机制 依赖性抗体，并引导疫苗设计。本赠款支持的本科研究学生 提案将使用尖端技术探索至关重要的公共健康重要性问题，成为合着者 关于已发表的工作，并由致力于其长期职业发展的专家考虑。