Optimizing AAV delivery of bNAbs for HIV prevention

优化 AAV 的 bNAb 递送以预防 HIV

基本信息

批准号：
10531917
负责人：
Matthew Ryan Gardner
金额：
$ 91万
依托单位：
EMORY UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-11-24 至 2026-10-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10531917
关键词：
AIDS prevention Address Antibodies Antibody Formation Antibody Response Antibody-Producing Cells Area Binding CD4 Positive T Lymphocytes CD8-Positive T-Lymphocytes CTLA4-Ig Capsid Clinical Clinical Trials Combined Modality Therapy DNA cassette Data Dependovirus Development Disease Dose Effectiveness Engineering Evaluation Foundations Future Gene Transduction Agent Goals HIV-1 HIV-1 vaccine Immune Immune Targeting Immune response Immune system Immunity Individual Infection Infusion procedures Intramuscular Investigation Lead Macaca Macaca mulatta Measurement Mediating Monoclonal Antibodies Mus Muscle Muscle Cells Ovalbumin Participant Pathway interactions Patients Pharmaceutical Preparations Pilot Projects Plasma Populations at Risk Prevention Production Recombinants Regulatory T-Lymphocyte SIV Serum System T-Lymphocyte Therapeutic Transgenes Update Vaccines Variant adeno-associated viral vector antiretroviral therapy cellular transduction cost detection limit gene therapy immune checkpoint improved inhibitor neutralizing antibody nonhuman primate novel novel strategies prevent programmed cell death ligand 1 programmed cell death protein 1 promoter protective efficacy research clinical testing simian human immunodeficiency virus transgene expression transmission process vector

项目摘要

PROJECT SUMMARY HIV-1 broadly neutralizing antibodies (bNAbs) are currently under clinical evaluation for their ability to prevent transmission. Until a conventional vaccine is realized, repetitive dosing of a bNAb would be necessary to maintain protective antibody concentrations. An alternative to passive infusion of bNAbs is to use adeno- associated virus (AAV) vectors that can turn muscles into antibody production factories. This one-time treatment would have clear cost advantages over the continuous production, purification, and administration of recombinant monoclonal antibodies. However, host immune responses limit the efficacy of AAV vectors. CD8+ T cell clearance of AAV transduced muscle cells limits the total number of cells producing the antibody, and pre-existing immunity to AAV capsids limit the number of possible individuals that can receive AAV vectors. We and others have previously shown that host immune responses are detrimental to AAV-delivered HIV-1 antibodies resulting in low to no detectable serum concentrations. Thus, overcoming the host immune response to the AAV vector and expressed transgene is critical for future evaluation of AAV-delivered antibody studies in non-human primates. One area of investigation for limiting a host immune response would be to utilize immune checkpoints that regulate immune system pathways. To this end, in a pilot study, we have observed about a 21-fold increase in concentrations of an HIV-1 antibody in rhesus macaques when macaques were co-inoculated with an AAV vector encoding rhesus macaque PD-L1. PD-L1 functions in binding T cell expressed PD-1 to inhibit the cytolytic and degranulation functions. It also helps in the development of regulatory T cells. Thus, we hypothesize that expression of PD-L1 on muscle cells transduced by AAV vectors to express antibodies will avoid T cell clearance and maintain expression of the antibody. Here we seek to demonstrate that co-inoculation of vectors encoding PD-L1 will result in serum concentrations of a bNAb that will protect rhesus macaques from repetitive, low-dose SHIV challenges. Additionally, we will develop this system by evaluating strategies to reduce the dose of AAV vector. Furthermore, we will engineer AAV transgene cassettes and assess novel a novel AAV capsid for increasing expression from intramuscular inoculation. Together, the results from these studies will provide a foundation for AAV gene therapy studies in non-human primates as well as lead to the development of novel AAV vectors for expressing HIV-1 bNAbs.

项目概要 HIV-1 广泛中和抗体 (bNAb) 目前正在临床评估其预防艾滋病毒的能力传播。在实现传统疫苗之前，需要重复施用 bNAb 维持保护性抗体浓度。 bNAb 被动输注的另一种选择是使用腺- 相关病毒（AAV）载体可以将肌肉变成抗体生产工厂。这一次与连续生产、纯化和管理相比，处理具有明显的成本优势。重组单克隆抗体。然而，宿主免疫反应限制了 AAV 载体的功效。 AAV 转导的肌肉细胞的 CD8+ T 细胞清除限制了产生抗体的细胞总数，并且预先存在的对 AAV 衣壳的免疫力限制了可能接收 AAV 的个体数量向量。我们和其他人之前已经表明，宿主免疫反应对 AAV 传递是有害的 HIV-1 抗体导致血清浓度低至不可检测。因此，克服宿主免疫对 AAV 载体和表达的转基因的反应对于未来评估 AAV 递送的抗体至关重要对非人类灵长类动物的研究。限制宿主免疫反应的研究领域之一是利用调节免疫系统途径的免疫检查点。为此，我们在一项试点研究中当恒河猴体内的 HIV-1 抗体浓度增加约 21 倍时猕猴与编码恒河猴 PD-L1 的 AAV 载体共同接种。 PD-L1 的功能在于结合T细胞表达PD-1以抑制溶细胞和脱颗粒功能。它还有助于调节性T细胞的发育。因此，我们假设肌肉细胞上的 PD-L1 表达转导通过AAV载体表达抗体将避免T细胞清除并维持抗体的表达。在这里，我们试图证明编码 PD-L1 的载体的共同接种将导致血清浓度一种 bNAb 可以保护恒河猴免受重复的、低剂量的 SHIV 挑战。此外，我们将通过评估减少 AAV 载体剂量的策略来开发该系统。此外，我们将设计 AAV 转基因盒并评估新型 AAV 衣壳以增加肌内表达接种。总之，这些研究的结果将为 AAV 基因治疗研究奠定基础非人灵长类动物，并导致用于表达 HIV-1 bNAb 的新型 AAV 载体的开发。