Presentation of Structural Determinants of the 2F5 Neutralization Epitope

2F5 中和表位的结构决定因素的介绍

• 批准号: 7609151
• 负责人: David Eliezer
• 金额: $ 21万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-04-15 至 2012-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7609151
• 关键词: AIDS Vaccines; Animals; Antibodies; Antibody Formation; Antigens; Cavia; Coiled-Coil Domain; Communities; Complex; Development; Engineering; Epidemic; Epitopes; Genetic; Goals; HIV Envelope Protein gp120; HIV-1; HIV-1 vaccine; Human; Immunity; Immunization; Lead; Leucine; Mediating; Membrane; Mutagenesis; Oryctolagus cuniculus; Particulate; Pathway interactions; Peptides; Preventive; Protein Chemistry; Proteins; Research; Scanning; Side; Solutions; Structure; Surface; Thinking; Ursidae Family; Vaccine Design; Vaccines; Variant; Virion; analog; design; env Gene Products; human monoclonal antibodies; immunogenicity; nanoscale; neutralizing antibody; peptide structure; public health research; receptor; response; structural biology; success; vaccinology

DESCRIPTION (provided by applicant): Development of envelope protein immunogens capable of eliciting neutralizing antibodies against primary HIV-1 isolates from different genetic subtypes remains the most difficult challenge in the field of HIV-1 vaccinology. The conserved membrane-proximal external region of the gp41 ectodomain bears the epitopes of two broadly neutralizing human monoclonal antibodies, 2F5 and 4E10, and is therefore an important target of HIV-1 vaccine design. However, all attempts to elicit anti-gp41 antibodies comparable to these produced in infected humans by using unstructured peptide immunogens have thus far failed. Success will likely require a deeper understanding of the structural motifs of the gp120/gp41 complex that stabilize the mature envelope trimer on the virion surface. Current thinking postulates that the receptor-mediated activation of gp41 involves a regulated sequence of structural transitions with one or more on-pathway intermediate(s) that may reveal cryptic neutralization epitopes. Our recent identification of a four-stranded coiled-coil structure (C43) encompassing the 2F5 epitope suggests that structural aspects of the 2F5 and 4E10 epitopes may be transiently exposed and required for stimulating neutralizing antibody responses. The broad, long-term objective of this research plan is to use protein chemistry and structural biology approaches to engineer and produce stable forms of the C43 coiled-coil motif for the induction of broadly reactive neutralizing antibodies. The premise of the proposed research is that definition of the structural requirements for optimal presentation of the 2F5 neutralization epitope can lead to the identification of stable immunogen products to generate effective anti-HIV-1 immunity. The Specific Aims of the proposed research are: (1) To design and develop stabilized versions of the C43 coiled-coil domain bearing the 2F5 epitope for immunogenicity studies. We will generate a single-chain analog of the tetraplex coiled coil in which the four mutagenesis to identify specific residue substitutions that favorably influence inter-helical packing interactions in the tetramer in order to stabilize an ordered helical peptide structure of the 2F5 epitope that preserves surface-exposed side chains. (2) To evaluate the immunological responses elicited by stabilized C43 coiled-coil variants in small animals. We will conduct immunogenicity studies in rabbits and guinea-pigs to determine whether the stabilized involve immunization of the animals using the stabilized C43 peptide proteins. We will also evaluate the immunogenicity of the stable coiled-coil molecules captured onto nanometer-sized beads as particulate immunogens. The research and public health communities concur that a preventive vaccine is the obvious long-term solution to bring the global HIV-1 epidemic under control (1-8). Unfortunately, this goal has proven elusive and no such vaccine is available. Overcoming this important biomedical problem will require new and imaginative design strategies to bring us closer to the goal of a successful AIDS vaccine.

描述（由申请人提供）： 开发能够引发针对来自不同遗传亚型的主要HIV-1分离株的中和抗体的包膜蛋白免疫原仍然是HIV-1疫苗学领域中最困难的挑战。gp 41胞外域的保守的近膜外部区域具有两种广泛中和的人单克隆抗体2F 5和4 E10的表位，因此是HIV-1疫苗设计的重要靶标。然而，迄今为止，所有通过使用非结构化肽免疫原来引发与感染的人中产生的抗体相当的抗gp 41抗体的尝试都失败了。成功将可能需要对gp 120/gp 41复合物的结构基序有更深入的了解，这些结构基序稳定了病毒体表面上成熟的包膜三聚体。目前的想法假定，受体介导的gp 41激活涉及一个调节序列的结构转换与一个或多个途径上的中间体，可能揭示隐藏的中和表位。我们最近鉴定了包含2F 5表位的四链卷曲螺旋结构（C43），这表明2F 5和4 E10表位的结构方面可能是瞬时暴露的，并且是刺激中和抗体应答所需的。该研究计划的广泛，长期目标是使用蛋白质化学和结构生物学方法来设计和生产C43卷曲螺旋基序的稳定形式，用于诱导广泛反应性中和抗体。所提出的研究的前提是，定义2F 5中和表位的最佳呈递的结构要求可以导致鉴定稳定的免疫原产物以产生有效的抗HIV-1免疫。本研究的具体目的是：（1）设计和开发稳定的C43卷曲螺旋结构域，用于免疫原性研究。我们将产生四链体卷曲螺旋的单链类似物，其中四个诱变以鉴定有利地影响四聚体中螺旋间包装相互作用的特定残基取代，以稳定保留表面暴露侧链的2F 5表位的有序螺旋肽结构。(2)评价稳定的C43卷曲螺旋变体在小动物中引起的免疫应答。我们将在家兔和豚鼠中进行免疫原性研究，以确定稳定的C43肽蛋白是否涉及动物免疫。我们还将评估作为颗粒免疫原捕获到纳米大小的珠上的稳定卷曲螺旋分子的免疫原性。研究和公共卫生界一致认为，预防性疫苗是控制全球HIV-1流行病的明显长期解决方案（1-8）。不幸的是，这一目标已被证明是难以捉摸的，没有这样的疫苗可用。克服这一重要的生物医学问题将需要新的和富有想象力的设计策略，使我们更接近成功的艾滋病疫苗的目标。