High-resolution definition of B cell responses to HIV Env for immunogen design

用于免疫原设计的 B 细胞对 HIV 包膜反应的高分辨率定义

基本信息

批准号：
8601423
负责人：
Yuxing Li
金额：
$ 62.34万
依托单位：
SCRIPPS RESEARCH INSTITUTE, THE
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-01-01 至 2014-09-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8601423
关键词：
Address Affinity Animals Antibodies Antibody Affinity Antibody Formation Antigen-Antibody Complex Antigens B cell repertoire B-Lymphocytes Binding Binding Sites CD4 Antigens Cell Separation Cells Chronic Comparative Study Complex Development Elements Epitopes Event Evolution Frequencies Genes Genetic Goals HIV HIV Antibodies HIV Envelope Protein gp120 HIV vaccine HIV-1 Human Immune Immune response Immune system Immunoglobulin G Immunoglobulin Somatic Hypermutation Individual Infection Integration Host Factors Knowledge Light Memory B-Lymphocyte Monoclonal Antibodies Outcome Outcome Study Pathway interactions Primates Process Regimen Resolution Reverse Transcriptase Polymerase Chain Reaction Serum Sorting - Cell Movement System Testing Vaccination Vaccine Design Vaccines Variant Viral Virus adaptive immunity adeno-associated viral vector antibody-dependent cell cytotoxicity base deep sequencing design env Gene Products env Glycoproteins improved insight neutralizing antibody neutralizing monoclonal antibodies nonhuman primate novel novel vaccines pathogen prevent public health relevance receptor binding response vaccine candidate vaccine development vaccine efficacy

项目摘要

DESCRIPTION (provided by applicant): One of the major challenges of HIV-1 vaccine development is the elicitation of broadly neutralizing antibodies (bNAbs) against HIV Env. The recent isolation of several bNAbs from HIV-infected individuals demonstrates that the human B cell repertoire can generate bNAbs targeting the conserved Env region. However, there is still a tremendous knowledge gap regarding how the broad responses are elicited during chronic HIV-1 infection and, additionally, how these compare to the much more limited responses elicited by Env vaccination. To fill this information gap, we propose to define and improve the elicitation of neutralizing antibodies toward the most functionally conserved and accessible element of the HIV-1 Env complex, namely the CD4 binding site (CD4bs), which is crucial for virus engagement with receptor CD4. Previously, we developed a multicolor Env epitope-specific B cell sorting and RT-PCR strategy to exploit the memory B cell compartment of HIV-infected individuals, which led to the isolation of CD4bs bNAb, VRC01, which neutralizes >90% of circulating primary viruses. Interestingly we find that VRC01 and CD4i antibody subsets can mutually enhance binding affinity for gp120, suggesting that CD4i MAbs may be associated with the evolution of VRC01-like bNAbs during the natural infection process. We adapted this epitope-specific memory B cell sorting strategy to extend our study to gain insight of Env B cell response, which is summarized as follows. (1) To characterize the neutralizing antibody response elicited by vaccination of Env-inoculated non-human primates (NHPs). We will perform memory B cell FACS sorting, clonal analysis and IgG gene deep sequencing of Env-specific B cells. (2) To determine the longitudinally evolving neutralizing antibody response in selected HIV-infected individuals. We will investigate factors associated with bNAb response from a few highly selected HIV-1-infected individuals by analyzing their CD4bs bNAbs and their "complementary" antibodies including CD4i antibodies. (3) To advance immunogen design by examining if i) Env-CD4i MAb complex as immunogen can improve the elicitation of CD4bs bNAbs; ii) long-lasting Env antigen exposure via AAV vector platform can improve the B cell affinity maturation. We will test these hypotheses in small animals. The overall outcome of this study will contribute to our basic understanding of HIV neutralizing antibody responses and the development of a safe and protective HIV vaccine.

描述（由申请人提供）：HIV-1疫苗开发的主要挑战之一是引起对HIV Env的广泛中和抗体（BNAB）的启发。最近从HIV感染的个体中分离出几个BNAB，表明人B细胞库可以产生针对保守的ENV区域的BNAB。但是，关于如何在慢性HIV-1感染过程中如何引起广泛反应以及这些如何与ENV疫苗引起的更有限的反应相比，仍然存在巨大的知识差距。为了填补这一信息空白，我们建议定义和改善对HIV-1 Env复合物中功能最保守和可访问元件的中和抗体的启发，即CD4结合位点（CD4BS），这对于病毒与受体CD4至关重要。以前，我们开发了一种多色ENV表位特异性B细胞分选和RT-PCR策略，以利用HIV感染个体的记忆B细胞室，这导致CD4BS BNAB分离，VRC01，中和> 90％的循环主要病毒中和> 90％。有趣的是，我们发现VRC01和CD4I抗体子集可以相互增强对GP120的结合亲和力，这表明CD4I MAB可能与自然感染过程中类似VRC01的BNAB的演变有关。我们调整了这种表位特异性记忆B细胞分类策略，以扩展我们的研究，以了解ENV B细胞反应的见解，这总结如下。（1）表征通过环境接种非人类灵长类动物（NHP）疫苗接种引起的中和抗体反应。我们将对ENV特异性B细胞进行记忆B细胞FACS分类，克隆分析和IgG基因深度测序。（2）确定选定的HIV感染个体中纵向发展的中和抗体反应。我们将通过分析其CD4BS BNAB及其“互补”抗体，包括CD4I抗体，研究与一些高度选择的HIV-1感染个体的BNAB反应相关的因素。（3）通过检查i）INV-CD4I mAb复合物是否可以改善CD4BS BNAB的启发； ii）通过AAV矢量平台持久的ENV抗原暴露可以改善B细胞亲和力的成熟。我们将在小动物中检验这些假设。这项研究的总体结果将有助于我们对艾滋病毒中和抗体反应的基本理解以及安全和保护性的HIV疫苗的发展。