HIV Envelope-based vaccines from superinfection to elicit neutralizing antibodies

基于 HIV 包膜的疫苗可避免重复感染以引发中和抗体

• 批准号: 8651415
• 负责人: Ann Jones Hessell
• 金额: $ 21.88万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-04-05 至 2015-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8651415
• 关键词: Affinity; African; Animal Model; Antibodies; Antibody Formation; Antibody Specificity; Antigen Presentation; Antigens; Autologous; B-Lymphocytes; Base Sequence; Basic Science; Characteristics; Chronic; Cloning; Collection; Computer Simulation; DNA; Data; Development; Drug Formulations; Elements; Epitopes; Event; Evolution; Excision; Genes; Genetic Recombination; Genome; Goals; HIV; HIV Infections; HIV vaccine; HIV-1; Human; Immune; Immune system; Immunization; Immunoglobulin Somatic Hypermutation; Immunoglobulin Variable Region; Individual; Infection; Infection prevention; Length; Link; Maps; Mission; Mutagenesis; Mutation; Oryctolagus cuniculus; Phylogenetic Analysis; Plasma; Polysaccharides; Preparation; Probability; Process; Production; Property; Proteins; Public Health; Regimen; Research; Research Proposals; Resistance; Role; Route; Selection Criteria; Site; Site-Directed Mutagenesis; Source; Testing; Time; Trees; Vaccination; Vaccine Design; Vaccine Research; Vaccines; Variant; Viral; Virus; Virus-like particle; Work; base; cohort; comparative; design; expression vector; gene gun; glycosylation; gp160; immunogenicity; improved; interest; member; neutralizing antibody; neutralizing monoclonal antibodies; novel; novel strategies; pandemic disease; pressure; prevent; protein expression; public health relevance; response; sex; success; superinfection; vaccine candidate; vaccine development

DESCRIPTION (provided by applicant): Many attempts to modify HIV-1 Envelope (Env) for improved immunogenicity have been attempted, with varying rates of success. Some increased potency in neutralizing antibodies (NAbs) has been claimed, but the breadth achieved is very limited and a breakthrough is crucial to make substantial progress towards an effective Env-based vaccine component. Superinfection (SI) provides a unique immunological setting for studying candidate HIV Envs as potential vaccine components. This project focuses on Env sequences derived from superinfected individuals identified to have characteristics of elite neutralization breadth. The Env sequences from these individuals may contain unique determinants that have developed as the result of the persistence of dual antigen presentation during SI. The project objective is to conduct immunogenicity studies using carefully selected panels of vaccine candidates combined with newly emerging vaccine regimens that will result in substantially improved antibody responses - both in time to response and in breadth of neutralization. To achieve the goal of this project, Single Genome Amplification will be used to clone a panel of gp160 Env genes isolated from plasma and targeting time points associated with development of potent neutralization breadth from two intersubtype superinfected elite neutralizers who are members of a well-characterized African sex-worker cohort. A set of selection criteria has defined key time points during SI from which to clone Envs that are expected to have the greatest probability of containing critical determinants that led to a peak in neutralization breadth. In silico analysis will be carried out to assess the evolution of the diversity and divergence of the cloned Envs from each subject by generating a maximum-likelihood phylogenetic tree. Mutations post SI will be mapped, including recombination events between the two infecting viral strains. Potential N-linked glycosylation sites will be examined and other mutations that are known to cause resistance to several broadly neutralizing monoclonal antibodies. Effects of directional selection pressure (dN/dS) will also be evaluated. Following a full in silico analysis of all clones, vaccine candidates will be selected and made as functional pseudoviruses to test for autologous and heterologous neutralization sensitivity. Nucleotide sequences of selected vaccine candidates will be motif optimized and synthesized in preparation for full-length gp160 constructs. Gene Gun bullets will be prepared and site-directed mutagenesis will generate soluble gp140 trimeric protein for expression and purification. Comparative immunogenicity studies will be performed in rabbits using gp160 DNA combined with gp140 trimeric protein to determine which combinations of Envs derived from SI subjects are most effective in generating neutralization breadth. In the process, we expect to define novel, key epitopes that direct the development of neutralizing antibodies. This study will result in a new collection of Env-based immunogens with the potential to advance vaccine research.

描述（由申请人提供）：已经尝试了许多修饰HIV-1包膜（Env）以提高免疫原性的尝试，成功率各不相同。已经声称中和抗体（NAb）的效力有所增加，但所实现的广度非常有限，并且突破对于在有效的基于Env的疫苗组分方面取得实质性进展至关重要。重复感染（SI）为研究作为潜在疫苗组分的候选HIV Env提供了独特的免疫学环境。该项目的重点是Env序列来源于被鉴定为具有精英中和宽度特征的重复感染个体。来自这些个体的Env序列可能含有独特的决定簇，其是由于SI期间持续存在双重抗原呈递而形成的。该项目的目标是使用精心挑选的候选疫苗组结合新出现的疫苗方案进行免疫原性研究，这将大大改善抗体应答-在应答时间和中和广度方面。为了实现该项目的目标，单基因组扩增将用于克隆一组从血浆中分离的gp 160 Env基因，并靶向与来自两个亚型间超感染精英中和者的有效中和宽度的发展相关的时间点，这些中和者是一个特征良好的非洲性工作者队列的成员。一组选择标准已经定义了SI期间的关键时间点，从该时间点克隆预期具有最大可能性包含导致细胞周期峰值的关键决定因素的Env。 中和宽度将进行计算机模拟分析，以通过生成最大似然系统发育树来评估来自每例受试者的克隆Env的多样性和趋异性的演变。将绘制SI后的突变，包括两种感染病毒株之间的重组事件。将检查潜在的N-连接糖基化位点和已知引起对几种广泛中和单克隆抗体耐药的其他突变。还将评估方向选择压力（dN/dS）的影响。在对所有克隆进行完整的计算机模拟分析后，将选择候选疫苗并制备为功能性假病毒，以检测自体和异源中和敏感性。所选候选疫苗的核苷酸序列将进行基序优化和合成，以制备全长gp 160构建体。将制备基因枪子弹，并且定点诱变将产生用于表达和纯化的可溶性gp 140三聚体蛋白。将使用gp 160 DNA与gp 140三聚体蛋白组合在兔中进行比较免疫原性研究，以确定源自SI受试者的Env的哪种组合在产生中和宽度方面最有效。在这个过程中，我们希望定义新的，关键的表位，指导中和抗体的发展。这项研究将产生一个新的基于Env的免疫原集合，有可能推进疫苗研究。