Measurement of Antibody Epitope Signatures by Peptide Microarrays to Determine Recency of HIV Infection

 描述(由申请人提供)：在艾滋病毒研究中，迫切需要开发一种快速、廉价和准确的分析方法，可以用来估计世界任何地方和任何样本上的艾滋病毒发病率。在没有这样的测试的情况下，识别高风险是具有挑战性的 人口、传播模型和监测公共卫生干预措施的结果。我们的长期目标是开发新的方法来衡量艾滋病毒发病率，以改善资源匮乏环境下的艾滋病毒流行病学。拟议研究的总体目标是使用一种尖端的免疫学分析方法，即全球艾滋病毒-1肽微阵列，来确定与艾滋病毒感染的不同阶段相关的艾滋病毒特异性抗体的关键表位特征。我们的中心假设是，艾滋病毒感染的持续时间越长，多样性就越大 人类免疫缺陷病毒特异性抗体。提出这项研究的理由是，一旦知道抗体表位特征与艾滋病毒感染的不同阶段有关，那么全球艾滋病毒-1肽微阵列可以进一步发展为衡量艾滋病毒发病率的工具。在强大的初步数据的指导下，这一假设将通过追求两个具体目标来检验：1)确定与艾滋病毒感染的三个不同阶段(近期、慢性病毒血症和ART抑制)相关的艾滋病毒特异性抗体的关键表位特征；以及2)确定艾滋病毒血清学多样性如何与随着时间的推移在病毒症受试者中艾滋病毒多样性的增加有关。在第一个目标下，我们将使用全球HIV-1肽微阵列对感染时间已知的个人进行抗体表位映射。我们将用已建立的发病率分析来补充多肽芯片，以测量抗体的大小和亲和力。当拟议的研究完成后，我们预计，与最近的艾滋病毒感染阶段相比，非近期艾滋病毒感染阶段抗体表位签名的广度将显著增加。在第二个目标下，我们将确定HIV表位特异性抗体反应的多样性(通过肽微阵列测量)和HIV病毒多样性(通过单基因组扩增和Sanger测序测量)之间的关系，以更好地了解抗体的进化及其与HIV发病率的关系。当这些研究完成后，我们期望抗体结合的深度(在任何给定结合部位识别的序列变异体)将与随着时间的推移而增加的艾滋病毒病毒多样性措施正相关。在我们看来，在这项申请中提出的研究是创新的，因为它引入了一种新的高通量基于抗体的检测方法，对于最近的艾滋病毒感染具有与病毒多样性检测一样敏感和特异的潜力。这项拟议的研究意义重大，因为它有望证明抗体表位特异性--通过与HIV多肽结合的抗体的多样性来衡量--可以作为HIV感染不同阶段的生物标记物。最终，这些知识将为设计新的艾滋病毒发病率分析提供依据，这些分析将在艾滋病毒流行病学和诊断学领域具有广泛的重要性。

 DESCRIPTION (provided by applicant): There is a critical need in HIV research to develop a rapid, inexpensive, and accurate assay that can be used to estimate HIV incidence anywhere in the world and on any sample. In the absence of such a test, it is challenging to identify high risk populations, model transmission, and monitor the outcome of public health interventions. Our long term goal is to develop new methods to measure HIV incidence to improve HIV epidemiology in resource-poor settings. The overall objective of the proposed research is to use a cutting-edge immunologic assay, the global HIV-1 peptide microarray, to define the key epitope signatures of HIV-specific antibodies associated with different stages of HIV infection. Our central hypothesis is that the greater the duration of HIV infection, the greater the diversity of HIV-specific antibodies. The rationale for the proposed research is that, once it is known that antibody epitope signatures are associated with different stages of HIV infection, then the global HIV-1 peptide microarray can be further developed as a tool to measure HIV incidence. Guided by strong preliminary data, this hypothesis will be tested by pursuing two specific aims: 1) to identify the key epitope signatures of HIV-specific antibodies that are associated with three different stages of HIV infection (recent, chronic viremia, and ART suppression); and 2) to determine how HIV serologic diversity is associated with increasing HIV viral diversity in viremic subjects over time. Under the first aim, we will perform antibody epitope mapping with a global HIV-1 peptide microarray on individuals with known time since infection. We will complement the peptide microarray with established incidence assays to measure antibody magnitude and avidity. When the proposed studies have been completed, it is our expectation that the breadth of antibody epitope signatures will be significantly increased in non-recent HIV stages compared to in recent HIV infection. Under the second aim, we will determine the relationship between diversity of HIV epitope- specific antibody responses (as measured by peptide microarray) and HIV viral diversity (as measured by single genome amplification and Sanger sequencing) to provide a better pathogenic understanding of antibody evolution and how it relates to HIV incidence. When these studies have been completed, it is our expectation that the depth of antibody binding (# sequence variants recognized at any given binding site) will be positively associated with increasing HIV viral diversity measures over time. The research proposed in this application is innovative, in our opinion, because it introduces a novel high-throughput antibody-based assay that has the potential to be as sensitive and specific for recent HIV infection as a viral diversity assay. The proposed research is significant, because it is expected to be the demonstration that antibody epitope specificity - as measured by the diversity of antibody binding to HIV peptides - can serve as a biomarker of different stages of HIV infection. Ultimately, such knowledge will inform the design of novel HIV incidence assays that will have broad importance in the fields of HIV epidemiology and diagnostics.