Humoral Correlates of Protection Against HIV

预防艾滋病毒的体液相关性

• 批准号: 8485541
• 负责人: Ruth Margrit Ruprecht
• 金额: $ 7.13万
• 依托单位: DANA-FARBER CANCER INST
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-06-08 至 2013-08-16
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8485541
• 关键词: AIDS Vaccines; AIDS/HIV problem; Acquired Immunodeficiency Syndrome; Address; Amino Acid Sequence; Amino Acids; Antibodies; Antibody Formation; Antigens; Antiviral Agents; B-Lymphocytes; Bacteriophages; Cellular Immunity; Dose; Engineering; Epitopes; Failure; Flow Cytometry; Future; Gagging; Generations; Genes; HIV; Human; Humoral Immunities; Immunity; Immunization; Immunoglobulin Variable Region; Individual; Infection; Interferons; Label; Light; Link; Macaca mulatta; Modeling; Monkeys; Monoclonal Antibodies; Passive Immunization; Peptide Library; Plasma; Primates; Random Peptide Libraries; Recombinant Antibody; Recombinant Proteins; Recombinants; Reporting; Risk; SIV; Serum; Specificity; Sum; Systemic infection; Technology; Testing; Time; Vaccinated; Vaccines; Viral; Viremia; Virus; Virus Diseases; base; cohort; design; gp160; immunogenicity; improved; in vivo; neutralizing antibody; novel; novel strategies; particle; polyclonal antibody; preclinical study; recombinant peptide; research study; response; simian human immunodeficiency virus; tool; viral RNA

DESCRIPTION (provided by applicant): The 31.2% decrease in HIV acquisition reported in the RV144 trial has raised hopes that vaccine protection may be achievable. We have pursued a bimodal vaccine approach to induce both cellular and humoral immunity; in our recent rhesus macaque (RM) study, recombinant protein immunogens (SIV Gag-Pol particles, HIV Tat, and multimeric HIV clade C (HIV-C) gp160) provided complete protection for some RMs against multiple intrarectal challenges with a heterologous R5 clade C SHIV (SHIV-C). Our study simultaneously linked cellular as well as humoral antiviral immunity to protection. Overall, five vaccine-protected RMs remained free of persistent, systemic infection; all had generated high-titer neutralizing antibodies (nAbs) in response to multimeric gp160 of an HIV-C strain that diverged by 22.2% in amino acid sequence from Env of the challenge virus. Our overall hypothesis is that vaccine-induced Abs - either nAbs and/or Abs with antiviral effector functions - can protect against heterologous virus acquisition. We have developed new tools to determine the epitope specificity of protective Abs from polyclonal sera. Our strategy involves a) differentil biopanning with recombinant peptide libraries to isolate mimotopes linked to protection, b) isolation of single RM B cells specific for a given mimotope/epitope, 3) PCR amplification of RM immunoglobulin variable regions, and 4) generation of recombinant Abs. These novel approaches have led to the isolation of two new chimeric simian/human nmAbs with predicted epitope specificity. We now seek to use these new tools for the following Specific Aims: 1. to characterize the epitopes recognized by polyclonal Abs of vaccine-protected RMs by differential biopanning. First, we will positively select recombinant phages encoding random peptide libraries by biopanning with plasma from a vaccine-protected RM, followed by negative counter-selection with plasma from vaccinated, unprotected RMs. After several rounds of positive/negative selection, recombinant phages will reflect mimotopes linked to protection. We will also address the converse question: did RMs with vaccine failure mount unfavorable Ab responses that are not found in vaccine-protected RMs - or is failure simply a lack of protection-linked Abs? To do this, we will reverse the biopanning strategy and characterize the cognate epitopes linked to vaccine failure. 2. to isolate antigen-specific single B cells from the protecte RMs and PCR amplify the heavy/light chain variable immunoglobulin regions, using our newly generated RM-specific primers. 3. to perform passive immunization in RMs with the novel mAbs to demonstrate protection against mucosal challenge with a heterologous R5 SHIV. Our studies, which are based upon a well-characterized cohort of vaccine-protected RMs given upfront heterologous SHIV-C challenges, will identify epitopes that are protective or perhaps also deleterious in vivo and therefore provide important information for future HIV/AIDS immunogen design and optimization.

描述（由申请人提供）：RV144试验中报告的艾滋病毒收购收购的31.2％降低了希望可以实现疫苗保护的希望。我们采用了双峰疫苗方法来诱导细胞和体液免疫。在我们最近的恒河猴（RM）研究中，重组蛋白免疫原（SIV GAG-POL颗粒，HIV TAT和多聚体HIV进化枝C（HIV-C）GP160）为某些RMS提供了一些RMS，可针对多个内部直肠挑战，并具有异型R5进化核管的多个内型挑战C SHIV（SHIV-C）。我们的研究同时将细胞以及体液抗病毒免疫与保护联系起来。总体而言，五个受疫苗保护的RMS仍然没有持续的全身感染；所有这些都响应于HIV-C菌株的多聚体GP160产生了高素质中和抗体（NAB），该抗体的多聚体GP160在氨基酸序列中从挑战病毒的ENV中差异22.2％。我们的总体假设是，疫苗诱导的ABS- NAB和/或具有抗病毒效应功能的ABS可以预防异源性病毒的获取。我们开发了新工具来确定多克隆血清中保护性ABS的表位特异性。我们的策略涉及a）与重组肽库的分化生物植物，以隔离与保护相关的模拟物，b）分离针对给定的模仿/表位特异的单个RM B细胞，3）RM Immunogobobloblobin ailiable Recions的PCR扩增，并腹肌。这些新颖的方法导致了具有预测表位特异性的两个新的嵌合邻氨酸/人NMAB。现在，我们试图将这些新工具用于以下特定目的：1。表征通过差异生物剂量通过多克隆ABS识别的受疫苗保护RMS的表位。首先，我们将通过从受疫苗保护的RM中的血浆进行生物塑料来积极选择编码随机肽库的重组噬菌体，然后用疫苗未经保护的RMS的血浆进行负面反序列。经过几轮正/阴性选择后，重组噬菌体将反映与保护相关的模仿。我们还将解决一个相反的问题：疫苗失效的RMS是否在受疫苗保护的RMS中未发现的不利AB反应 - 还是失败仅仅是缺乏保护链接的ABS？为此，我们将逆转生物综合策略，并表征与疫苗衰竭相关的同源表位。 2。使用我们新生成的RM特异性引物，将抗原特异性单B细胞脱离保护RMS，并放大重/轻链可变的免疫球蛋白区域。 3。用新颖的mAB在RMS中进行被动免疫，以通过异源R5 SHIV证明对粘膜挑战的保护。我们的研究基于疫苗保护的RMS的特征良好的同类，给出了前期异源的SHIV-C挑战，它将确定具有保护性或可能在体内有害的表位，因此为未来的HIV/AIDS免疫原理设计和IADS提供重要信息优化。