Discovery of acidic epitopes for HIV-1 broadly neutralizing seroantibodies

发现 HIV-1 广泛中和血清抗体的酸性表位

• 批准号: 9788183
• 负责人: Mohammad Mohseni Sajadi
• 金额: --
• 依托单位: BALTIMORE VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-10-01 至 2019-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9788183
• 关键词: AIDS prevention; AIDS/HIV problem; Affinity; Affinity Chromatography; Agreement; Antibodies; Antibody Response; Antigens; Binding; Biochemical; Blood; Caring; Cells; Characteristics; Data; Development; Disease; Dissection; Ensure; Epitope Mapping; Epitopes; Fractionation; Genetic; Goals; HIV; HIV Envelope Protein gp120; HIV Infections; HIV vaccine; HIV-1; HIV-1 vaccine; Health; Healthcare; Human; Humoral Immunities; IgG1; Immune system; Immunoglobulin Variable Region; Impairment; Individual; Infection; Isoelectric Focusing; Isoelectric Point; Knowledge; Length; Life; Light; Maps; Mediating; Memory B-Lymphocyte; Methods; Modeling; Monoclonal Antibodies; Mutagenesis; N-terminal; Patients; Persons; Plasma; Population; Prevention; Preventive vaccine; Property; Reporting; Research; Resources; Savings; Scheme; Selection Bias; Serum; Source; Specificity; Target Populations; Techniques; Testing; Vaccination; Vaccines; Veterans; Work; X-Ray Crystallography; base; cohort; design; improved; interest; mutant; neutralizing antibody; neutralizing monoclonal antibodies; novel; prevent; protein aminoacid sequence; public health relevance; response; success; vaccine candidate

DESCRIPTION (provided by applicant): Background/Rationale: HIV-1 infection and its prevention are of particular importance to the health of veterans, with 1 out of 250 veterans known to be HIV-1 infected. Prevention of HIV-1 was specifically mentioned as one of the 3 main goals in President Obama's National HIV/AIDS Strategy in 2010, as well as the Department of Veterans Affairs National HIV/AIDS Strategy Operational Plan in 2011. Our group has focused on a preventive vaccine for HIV-1 through study of potent antibodies directed at HIV-1. A limited number of persons infected with HIV-1 develop circulating plasma antibodies able to potently neutralize a wide variety of HIV-1 isolates representing different genetic subtypes. It is widely held that the characteristics and specificitis of such antibodies can be used to guide the development of HIV-1 vaccine candidates capable of eliciting protective humoral immunity in a target population. Current methods for study of these antibodies include isolation of antibodies from memory B cells, which may not always reflect the antibodies circulating in the blood. Our research has focused on the identification of characterization of the broad neutralizing antibodies directly from patient serum (without potential bias of selection), as neutralizing antibody characteristics seen in multiple individuals are more likely be raised in a broad population. We have noted particular biochemical signatures that point to a common dominant, acidic epitope that is targeted on the envelope of HIV. Objectives: The specific hypothesis of this proposal is that the broad HIV-1 neutralizing response in plasma is due to a shared acidic epitope on the gp120 envelope. The specific aims of the project are to 1) Directly isolate and sequence the antibodies responsible for the broad neutralization from the plasma of HIV-1 infected individuals, and 2) Map the corresponding epitope(s) of the broad neutralizing antibodies to test the hypothesis that a shared acidic epitope of gp120 is responsible for the broad HIV-1 neutralization response. Methods: We have identified 10 patients with broad neutralization, of which 3 will be studies in detail. The affinit purification (antigen, subclass, and light chain specific) and fractionation (free-flow isoelectric focusing) scheme can narrow the antibodies of interest, directly, from the plasma to individual species. These species will be tested for broad neutralization. Upon confirmation, the individual antibody bands will be sequenced de novo using both LC-MS and Edman degradation (N-terminal and internal sequencing). Epitope mapping of the new mAbs will be undertaken with Elisa, mutagenesis studies, and X-ray crystallography. Once the epitope is identified, Elisa and mutagenesis studies will be used to test the active fraction on the other 7 individuals to determine if this epitope is responsible for broad neutralization. Findings: Anticipated results wil be isolation of new mAbs, identification of common characteristics of broadly neutralizing abs, and the identification of a common acidic epitope that can direct broad HIV-1 neutralization. Status: We have completed enough work on the techniques described herein (as well as each alternative plan) to ensure that the aims are feasible and will be completed. Impact: If our hypothesis proves correct, then the results will be novel and directly applicable to the study of HIV vaccines. This study will provide a deeper understanding of possibilities of the broad HIV-1 neutralizing response in humans, and it will also have identified a naturally occurring epitope(s) that can be the target of potent cross-clade antibodies against HIV-1. This will have an impact on the designs of an HIV vaccine, which when developed will improve the health of veterans by preventing this life-long disease.

描述（由申请人提供）： 背景/依据：HIV-1感染及其预防对退伍军人的健康特别重要，已知每250名退伍军人中就有1人感染HIV-1。奥巴马总统2010年的《国家艾滋病毒/艾滋病战略》以及退伍军人事务部2011年的《国家艾滋病毒/艾滋病战略行动计划》特别提到预防艾滋病毒-1是三大目标之一。我们小组通过研究针对HIV-1的强效抗体，专注于HIV-1的预防性疫苗。有限数量的HIV-1感染者产生循环血浆抗体，能够有效中和代表不同基因亚型的各种HIV-1分离株。人们普遍认为，这些抗体的特性和特异性可用于指导能够在目标人群中引发保护性体液免疫的HIV-1候选疫苗的开发。目前研究这些抗体的方法包括从记忆B细胞中分离抗体，这可能并不总是反映血液中循环的抗体。我们的研究集中于直接从患者血清中鉴定广泛中和抗体的特征（无潜在的选择偏倚），因为在多个个体中观察到中和抗体特征 更有可能在大范围的人群中长大。我们已经注意到特定的生物化学特征，这些特征指向一个共同的显性酸性表位，该表位靶向HIV的包膜。目的：这一提议的具体假设是，血浆中广泛的HIV-1中和反应是由于gp 120包膜上共享的酸性表位。该项目的具体目标是：1）从HIV-1感染者的血浆中直接分离负责广泛中和的抗体并进行测序，2）绘制广泛中和抗体的相应表位，以检验共享酸性表位 gp 120的表达负责广泛的HIV-1中和反应。方法：我们确定了10例广泛中和的患者，其中3例将进行详细研究。亲和纯化（抗原、亚类和轻链特异性）和分级分离（自由流动等电层析）可以在体外进行。 聚焦）方案可以直接将感兴趣的抗体从血浆缩窄到单个种类。将对这些物质进行广泛中和试验。确认后，将使用LC-MS和Edman降解（N-末端和内部测序）对单个抗体条带进行从头测序。新单克隆抗体的表位定位将采用Elisa、诱变研究和X射线晶体学进行。一旦鉴定了表位，将使用Elisa和诱变研究来测试其他7个个体上的活性级分，以确定该表位是否负责广泛中和。调查结果：预期结果将是分离新的mAb，鉴定广泛中和抗体的共同特征，以及鉴定可以指导广泛HIV-1中和的共同酸性表位。状态：我们已经完成了本文所述技术（以及每个替代计划）的足够工作，以确保目标是可行的，并将完成。影响：如果我们的假设被证明是正确的，那么结果将是新颖的，并直接适用于艾滋病毒疫苗的研究。这项研究将提供对人类广泛的HIV-1中和反应的可能性的更深入的理解，并且它还将确定一个天然存在的表位，该表位可以成为针对HIV-1的有效交叉进化枝抗体的靶标。这将对艾滋病毒疫苗的设计产生影响，一旦开发出来，将通过预防这种终身疾病来改善退伍军人的健康状况。

项目成果

4,4'-Bipyridine-pyridine-3,5-dicarb-oxy-lic acid (3/4).

• DOI: 10.1107/s160053681102719x
• 发表时间: 2011-08-01
• 期刊: Acta crystallographica. Section E, Structure reports online
• 作者: Liu SB;Xu C;Duan T;Chen Q;Zhang QF
• 通讯作者: Zhang QF

Identification of Near-Pan-neutralizing Antibodies against HIV-1 by Deconvolution of Plasma Humoral Responses.

• DOI: 10.1016/j.cell.2018.03.061
• 发表时间: 2018-06-14
• 期刊: Cell
• 影响因子: 64.5
• 作者: Sajadi MM;Dashti A;Rikhtegaran Tehrani Z;Tolbert WD;Seaman MS;Ouyang X;Gohain N;Pazgier M;Kim D;Cavet G;Yared J;Redfield RR;Lewis GK;DeVico AL
• 通讯作者: DeVico AL