Modulating antigenic and immunogenic properties of HIV Env by altering signal sequence

通过改变信号序列调节 HIV Env 的抗原和免疫原性特性

基本信息

批准号：
9898267
负责人：
Chitra Upadhyay
金额：
$ 65.24万
依托单位：
ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-03-21 至 2024-02-29
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9898267
关键词：
Acute Affect Amino Acid Substitution Amino Acids Anabolism Antibodies Antibody Response Antigen-Presenting Cells Antigens Cell Communication Cells Competence Complex Data Development Dissociation Epitopes Fc Receptor Goals HIV HIV Envelope Protein gp120 HIV vaccine HIV-1 Helper-Inducer T-Lymphocyte Human Immune response Immunization Immunize Investigation Lectin Mannose Mass Spectrum Analysis Mediating Monoclonal Antibodies Mus Mutation Oligosaccharides Peptide Signal Sequences Peptides Phagocytosis Phenotype Play Polysaccharides Post-Translational Protein Processing Property Proteins Recombinants Regimen Resistance Risk Role T cell response Testing Vaccines Virion Virus antibody-dependent cell cytotoxicity antigen processing base design env Gene Products experimental study glycosylation humanized mouse immunogenic immunogenicity improved interest mouse model mutant nonhuman primate novel novel strategies protective efficacy stem sugar uptake vaccine efficacy vaccine trial

项目摘要

Project Summary Modest protection of RV144 trial correlated with non-neutralizing antibodies targeting the V1V2 and V3 region of HIV Env and antibody-dependent cellular cytotoxicity (ADCC) activity. These findings reinvigorated the interest in HIV vaccine approaches that can induce protective Abs, neutralizing and non-neutralizing, with Fc functional competency. This proposal will investigate the role of Env signal sequence (SS) in modulating the capacity of HIV Env to elicit protective anti-Env Abs with Fc functions. The proposed study is based on our preliminary findings that, by swapping the SS of HIV isolate AA05 with SS from another isolate AC02, we produced gp120 (AA05-02SS) that induced V1V2 and V3 Ab response with increased breadth, higher titers, and most importantly greater Fc function in immunized mice. Abs induced by gp120 AA05-02SS cross-reacted with V2 peptides of JRFL, MN, HxB2 and A244, while the WT gp120 AA05 bound weakly to V2 of HxB2 only. Notably, Abs induced by AA05-02SS displayed V1V2-specific ADCP activity while the WT gp120 AA05 did not. Indeed, SS-swap altered the proportion of high-mannose and complex glycans on the AA05- 02SS vs WT AA05 gp120 as shown by mass spectrometry; these changes were at N-glycans that are in the V1V2, C2, V3 and the V4 loop of gp120. We also found that swapping AA05 and AC02 SS onto HIV REJO Env rendered REJO virus more resistant to neutralization by V1V2-specific mAbs. SS-induced changes of Env immunogenicity and virus neutralization phenotype correlated with altered Env recognition by mAbs and lectins specific for high-mannose and complex sugars. In a separate study, single mutations introduced to the Env SS of REJO or JRFL also affected oligosaccharide compositions of N-glycans on virion-associated Env, which in turn modulated Env recognition and virus sensitivity to neutralization by V1V2- and V3-specific mAbs. Hence, we propose an overall hypothesis that, by altering the Env SS, we can regulate the glycosylation of HIV Env to impact on epitope exposure/stability and immunogenicity, and by selecting a particular SS or SS residue/s we can generate Env immunogen with enhanced capacity to elicit functional Abs. We will test this idea by assessing the SS-swapped/mutant Env immunogens for changes in epitope exposure and stability by probing with Abs and for changes in N-glycan sugars by high energy C-trap dissociation mass spectrometry (Aim 1). We will immunize mice with selected SS-modified Env immunogens and compare their capacity to induce Env-specific Abs with Fc functions. We will also identify the SS signature associated with induction of functional Abs. Immunization regimen that produced Abs with or without Fc functions will be used to isolate mAbs (Aim 2). We will evaluate the protective efficacy of vaccine-induced Abs elicited by SS- modified Env immunogens in passive transfer/HIV challenge experiments using humanized mouse model (Aim 3). Data from this study will provide vital information about HIV Env SS that can be exploited to design more effective HIV vaccine capable of eliciting protective Ab response against HIV.

项目概要 RV144 试验的适度保护与针对 V1V2 和 V3 的非中和抗体相关 HIV Env 区域和抗体依赖性细胞毒性 (ADCC) 活性。这些发现重新焕发了活力对能够诱导保护性抗体、中和性和非中和性抗体的 HIV 疫苗方法的兴趣， Fc 功能能力。该提案将研究 Env 信号序列 (SS) 在调制中的作用 HIV Env 诱导具有 Fc 功能的保护性抗 Env Ab 的能力。拟议的研究基于我们的初步发现，通过将 HIV 分离株 AA05 的 SS 与另一个分离株 AC02 的 SS 交换，我们产生的 gp120 (AA05-02SS) 诱导 V1V2 和 V3 Ab 反应，且反应宽度增加、更高滴度，最重要的是免疫小鼠的 Fc 功能更强。 gp120 AA05-02SS 诱导的 Abs 与 JRFL、MN、HxB2 和 A244 的 V2 肽发生交叉反应，而 WT gp120 AA05 与 V2 弱结合仅 HxB2。值得注意的是，AA05-02SS 诱导的 Abs 显示出 V1V2 特异性 ADCP 活性，而 WT gp120 AA05没有。事实上，SS-交换改变了 AA05- 上高甘露糖和复杂聚糖的比例 02SS 与 WT AA05 gp120 的比较，如质谱分析所示；这些变化发生在 N-聚糖上 gp120的V1V2、C2、V3和V4循环。我们还发现将 AA05 和 AC02 SS 交换到 HIV REJO Env 上使 REJO 病毒对 V1V2 特异性单克隆抗体的中和具有更强的抵抗力。 SS 引起的环境变化免疫原性和病毒中和表型与单克隆抗体和凝集素改变的 Env 识别相关专门针对高甘露糖和复合糖。在另一项研究中，Env SS 中引入了单一突变 REJO 或 JRFL 也影响病毒体相关 Env 上 N-聚糖的寡糖组成，这在通过 V1V2 和 V3 特异性 mAb 调节 Env 识别和病毒对中和的敏感性。因此，我们提出了一个总体假设，即通过改变 Env SS，我们可以调节 HIV 的糖基化 Env 对表位暴露/稳定性和免疫原性的影响，并通过选择特定的 SS 或通过 SS 残基，我们可以产生具有增强的引发功能性抗体能力的 Env 免疫原。我们将通过评估 SS 交换/突变 Env 免疫原的表位暴露变化来测试这个想法通过 Abs 探测来确定稳定性，并通过高能 C 陷阱解离质量来确定 N-聚糖的变化光谱测定（目标 1）。我们将用选定的 SS 修饰的 Env 免疫原对小鼠进行免疫，并比较它们的诱导具有 Fc 功能的 Env 特异性抗体的能力。我们还将识别与相关的 SS 签名功能性 Abs 的诱导。将使用产生具有或不具有Fc功能的Ab的免疫方案分离 mAb（目标 2）。我们将评估 SS- 引起的疫苗诱导抗体的保护功效使用人源化小鼠模型进行被动转移/HIV攻击实验中修饰的Env免疫原（Aim 3）。这项研究的数据将提供有关 HIV Env SS 的重要信息，可用于设计更多能够引发针对 HIV 的保护性抗体反应的有效 HIV 疫苗。