Optimizing AAV delivery of bNAbs for HIV prevention

优化 AAV 的 bNAb 递送以预防 HIV

• 批准号: 10403278
• 负责人: Matthew Ryan Gardner
• 金额: $ 90.67万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 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/10403278
• 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; Production; Recombinants; Regulatory T-Lymphocyte; SIV; Serum; System; T-Lymphocyte; Therapeutic; Time; 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; prevention clinical trial; 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

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。