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/理由：艾滋病毒-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人感染艾滋病毒-1。奥巴马总统2010年的国家艾滋病毒/艾滋病战略以及2011年的退伍军人事务部国家艾滋病毒/艾滋病战略业务计划特别提到预防艾滋病毒-1是3个主要目标之一。我们小组通过研究针对HIV-1的有效抗体，专注于HIV-1的预防性疫苗。少数感染艾滋病毒-1的人产生循环血浆抗体，能够有效中和代表不同基因亚型的各种艾滋病毒-1分离株。人们普遍认为，这些抗体的特征和特异性可以用来指导开发能够在目标人群中引起保护性体液免疫的HIV-1候选疫苗。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的中和抗体的特征(没有潜在的选择偏见)，因为中和抗体特征在多个个体中可见。 更有可能在广泛的人群中饲养。我们注意到了特定的生化特征，这些特征指向HIV包膜上的一个共同的主导酸性表位。目的：该方案的特定假设是，血浆中广泛的HIV-1中和反应是由于gp120包膜上的一个共同的酸性表位所致。该项目的具体目标是1)直接从HIV-1感染者的血浆中分离和测序负责广泛中和的抗体，以及2)映射广泛的中和抗体的相应表位(S)，以检验如下假设：一个共同的酸性表位 Gp120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。亲和蛋白的纯化(抗原、亚类和轻链特异性)和分级(自由流动等电 聚焦)方案可以将感兴趣的抗体直接从血浆缩小到单个物种。这些物种将接受广泛的中和测试。一旦确认，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。新单抗的表位定位将通过酶联免疫吸附试验、诱变研究和X射线结晶学进行。一旦确定了表位，将使用ELISA和诱变研究来测试其他7个人的活性部分，以确定该表位是否对广泛的中和负责。发现：预期的结果将是分离新的单抗，鉴定广谱中和抗体的共同特征，以及鉴定可以指导广泛的HIV-1中和的共同酸性表位。现状：我们已经完成了这里描述的技术(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艾滋病毒-1中和反应可能性的更深层次的理解，它还将确定一个自然产生的表位(S)，该表位可以成为针对艾滋病毒-1的有效交叉抗体的靶标。这将对艾滋病毒疫苗的设计产生影响，一旦开发出来，将通过预防这种终生疾病来改善退伍军人的健康。

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