Reversing HIV T cell dysfunction by aptamer targeting of therapeutic siRNAs

通过适配体靶向治疗性 siRNA 逆转 HIV T 细胞功能障碍

基本信息

批准号：
9004624
负责人：
Eli Gilboa
金额：
$ 75.98万
依托单位：
UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-03-01 至 2020-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9004624
关键词：
Acquired Immunodeficiency Syndrome Affinity Antibodies Antiviral Agents CD8B1 gene Cancer Patient Cell Culture Techniques Cells Chronic Development Disease Progression Drug abuse Engineering Exhibits Functional disorder Goals HIV HIV Infections Health Human Immune Immune System Diseases Immune response Immune system Immunity Immunotherapy In Vitro Infection Lead Ligand Binding Ligands Macaca Malignant Neoplasms Mediator of activation protein Modality Modeling Monoclonal Antibodies Mus Nucleic Acids Oligonucleotides PDCD1LG1 gene Patients Pharmaceutical Preparations RNA Interference Research SIV Severities Small Interfering RNA Specificity T-Lymphocyte Testing Therapeutic Agents aptamer arm base cost cost effective exhaust exhaustion immune function immunogenicity inhibitor/antagonist novel programs receptor reconstitution synergism targeted treatment therapeutic target

项目摘要

DESCRIPTION: HIV specific CD8+ T cells, a pivotal arm of the antiviral immune response, exhibit progressive dysfunction, known as "exhaustion". Severity of immune exhaustion correlates with disease progression, and is especially prevalent among drug abuse patients who often delay treatments that control HIV replication. PD-1, an immune inhibitory receptor and mediator of exhaustion in the setting of chronic infections and cancer, is upregulated on exhausted HIV-specific CD8+ T cells and in vitro blockade of its ligand with anti-PD- L1 antibodies restores, albeit partially, their immune functions. Given that exhausted T cells express multiple immune inhibitory receptors, the synergism of co-blockade of two receptors, and the limited effect of PD-L1 antibodies in vitro, strongly argues that PD-1 blockade alone will not be sufficient to rescue the full functionality of exhausted HIV specific CD8+ T cells. With the aim of developing a clinically feasible, cost-effective, and broadly applicable, treatment to reverse immune dysfunction in HIV-infected patients, our goal is to develop a single, chemically synthesized, nucleic acid based agent that can block the action of multiple inhibitory receptors in the same cell, and can be efficiently and specifically delivered to the exhausted T cells of the patient. The proposed approach is to inhibit downstream mediators of exhaustion like Blimp-1, Eomes, VHL or Sprouty-2, using RNAi in the form of siRNAs that are targeted to exhausted HIV-specific CD8+ T cells by conjugation to an oligonucleotide aptamer ligand that binds to receptors expressed on exhausted T cells, like PD-1, LAG3, orTim-3. The chemically synthesized aptamers, a novel platform for ligands with engineered specificity, offer significant advantages over the monoclonal antibody platform in terms of manufacture, cost, and reduced immunogenicity. Our lab has pioneered the use of aptamers as therapeutic agents and targeting ligands to modulate immunity in the setting of cancer, and have recently demonstrated the remarkable efficiency of aptamer-targeted siRNA delivery to circulating CD8+ T cells in mice. The central hypothesis of this proposal is that PD-1, LAG3, or Tim-3 aptamer targeted siRNA inhibition of mediators of exhaustion like Blimp- 1, Eomes, VHL or Sprout-2 will reverse the dysfunction of HIV-specific CD8+ T cells to an extent that is superior to that of blockade with monoclonal antibodies targeting inhibitory receptors like PD-1. The research plan is to generate high affinity aptamers to the aforementioned inhibitory receptors, construct aptamer-siRNA conjugates, and assess their ability, in comparison to blockade with antibodies, to restore immune functions in (i) Exhausted T cell cultured from HIV infected patients, (ii) HIV infected mice that are fully reconstituted with a human immune system, and (iii) an SIV/macaque model. This program will have developed a cost-effective and broadly applicable lead compound to test in patients chronically infected with HIV.

描述：HIV 特异性 CD8+ T 细胞是抗病毒免疫反应的关键臂，表现出进行性功能障碍，称为“衰竭”。免疫衰竭的严重程度与疾病进展相关，在经常延迟控制治疗的药物滥用患者中尤其普遍。 PD-1 是一种免疫抑制受体，也是慢性感染和癌症情况下的耗竭介质，在耗竭的 HIV 特异性 CD8+ T 细胞上上调，并用抗 PD- 体外阻断其配体。 PD-1 抗体可以部分恢复其免疫功能，因为疲惫的 T 细胞表达多种强免疫抑制性受体，两种受体共同阻断的协同作用，以及 PD-L1 抗体在体外的有限作用。单独的封锁功能不足以挽救耗尽的 HIV 特异性 CD8+ T 细胞。我们的目标是开发一种临床上可行、经济有效且广泛适用的治疗方法来逆转 HIV 感染患者的免疫功能障碍，我们的目标是开发一种单一的、化学合成的、基于核酸的药物，可以阻断多种抑制性受体的作用在所提出的方法是使用 siRNA 形式的 RNAi 来抑制下游的耗竭介质，如 Blimp-1、Eomes、VHL 或 Sprouty-2。通过与寡核苷酸适配体配体结合，靶向耗尽的 HIV 特异性 CD8+ T 细胞，该配体与耗尽的 T 细胞上表达的受体（如 PD-1、LAG3 或 Tim-3）结合。化学合成适体是一种具有工程特异性的新型配体平台，在制造、成本和降低免疫原性方面比单克隆抗体平台具有显着优势，我们的实验室率先使用适体作为治疗剂和靶向配体来调节免疫。该提案的中心假设是 PD-1， LAG3 或 Tim-3 适体靶向 siRNA 对 Blimp-1、Eomes、VHL 或 Sprout-2 等耗竭介质的抑制将逆转 HIV 特异性 CD8+ T 细胞的功能障碍，其程度优于单克隆抗体的阻断针对PD-1等抑制性受体的研究计划是生成针对上述抑制性受体的高亲和力适体，构建适体-siRNA缀合物，并评估其与抗体阻断相比，有能力恢复 (i) 从 HIV 感染患者中培养的耗尽的 T 细胞，(ii) 完全重建人类免疫系统的 HIV 感染小鼠，以及 (iii) SIV/猕猴的免疫功能该项目将开发一种具有成本效益且广泛适用的先导化合物，用于对慢性感染艾滋病毒的患者进行测试。