Rescue of broadly neutralizing mAbs using native trimer

使用天然三聚体拯救广泛中和的单克隆抗体

• 批准号: 8411099
• 负责人: JAMES M BINLEY
• 金额: $ 45.5万
• 依托单位: TORREY PINES INST FOR MOLECULAR STUDIES
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-05-01 至 2017-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8411099
• 关键词: Address; Antibodies; Antigens; B-Lymphocytes; Binding; Biological Assay; Chimera organism; Data; Development; Enzyme-Linked Immunosorbent Assay; Epitope Mapping; Epitopes; Exhibits; Genes; Growth; HIV; HIV-1; Heating; Immune Sera; Immunity; Immunoglobulin G; Individual; Infection; Knowledge; Label; Maps; Memory B-Lymphocyte; Methods; Nature; Parents; Patients; Population; Reagent; Recovery; Research Personnel; Reverse Transcriptase Polymerase Chain Reaction; Sampling; Screening procedure; Serum; Site; Solutions; Specificity; Structural Biologist; Technology; Testing; Therapeutic; Transfection; Ursidae Family; Vaccination; Vaccine Design; Vaccines; Virion; Virus; Virus-like particle; base; design; env Glycoproteins; high throughput screening; immunogenicity; indexing; innovation; insight; member; neutralizing antibody; neutralizing monoclonal antibodies; novel; prophylactic; public health relevance; response; success; vaccine development

DESCRIPTION (provided by applicant): Broadly neutralizing antibodies (bNAbs) may be crucial component of the protective immunity conferred by an effective HIV-1 vaccine. Ab responses in natural HIV-1 infection are overwhelmingly non-neutralizing. However, a fraction of patients do eventually develop exceptionally broad and potent bNAb responses. We hypothesize that a better understanding of the specificities that underlie this broad serum neutralization will enable us to identify the most desirable targets and develop a full spectrum of vaccine design strategies. New epitopes may be particularly amenable to design or attractive by being unusually broad or potent. Researchers have recently accessed various monoclonal bNAbs (mbNAbs) by high throughput functional screening and/or by targeted selection of memory B cells from infected donors who exhibit broad serum NAb responses. However, these efforts remain challenging, in part due to the rarity of desirable memory B cells and the lack of authentic baits to select new specificities. Based on the premise that native Env trimers are the exclusive targets of NAbs, here we propose using virus-like particles (VLPs) bearing only native Env trimers as baits to retrieve novel mbNAbs that will illuminate novel sites of vulnerability. Our Specific Aims are: Specific Aim 1: To investigate monoclonal bNAb relationships on native trimer VLPs. We will determine the binding relationships of various mbNAb pairs by trimer VLP ELISA. Any antagonistic or synergistic combinations we identify could impact the therapeutic or prophylactic applications of mbNAb combinations. Selected mbMAb combinations will be further investigated in neutralization synergy assays. Specific Aim 2: To map the specificities of broadly neutralizing sera using native trimer VLPs. We will evaluate the ability of a panel of broadly neutralizing HIV+ sera to inhibit trimer VLP binding by the panel of mbNAbs used in Aim 1. This will allow us to prioritize B cell selections (Aim 3) from donor PBMCs whose sera exhibit novel NAb specificities. Specific Aim 3: To rescue mbNAbs using fluorescent trimer VLPs as baits. With an expert collaborator, we will develop methods to use fluorescently labeled trimer VLPs as baits and probe donor PBMCs to label and retrieve mbNAb clones responsible for broad serum neutralization. We will prioritize donors whose sera appear to target unique epitopes from mapping studies in Aim 2. Specific Aim 4: To characterize new mbNAbs. We will determine the specificity, breadth and potency of new mbNAbs. We will examine their binding relationships with other mbNAb specificities on the native trimer, as in Aim 1. To better understand their ontogeny, we will also examine their sequences, segment usage and divergence from nearest germline. PUBLIC HEALTH RELEVANCE: The public health relevance of this proposal is to better understand why bNAbs generated in HIV-1-infected individuals are far more effective than any NAbs thus far induced by vaccination. We will focus on expanding the repertoire of completely new specificities. This will provide new knowledge on the vulnerable sites on HIV-1 and impetus to induce similar responses in vaccine setting. New antibodies may also be useful in prophylactic or therapeutic settings, especially if they recognize novel sites on the virus are potent, broad and/or act in synergy with others.

描述（由申请人提供）：广泛中和抗体（bNAbs）可能是有效的HIV-1疫苗所赋予的保护性免疫的关键组成部分。自然HIV-1感染中的Ab反应绝大多数是非中和性的。然而，一小部分患者最终会出现异常广泛和有效的bNAb反应。我们假设，更好地了解这种广泛血清中和的特异性将使我们能够确定最理想的目标并开发出全谱的