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

• 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
• 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

 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，在药物滥用患者中尤其普遍，他们经常推迟控制艾滋病毒复制的治疗。 PD-1 是一种免疫抑制受体，也是慢性感染和癌症环境中的耗竭介质，在耗竭的 HIV 特异性 CD8+ T 细胞上上调，体外用抗 PD-L1 抗体阻断其配体可恢复（尽管是部分恢复）其免疫功能。鉴于耗尽的 T 细胞表达多种免疫抑制受体、共同阻断两种受体的协同作用以及 PD-L1 抗体在体外的有限作用，强烈认为单独的 PD-1 阻断不足以挽救耗尽的 HIV 特异性 CD8+ T 细胞的全部功能。随着 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 相同的细胞，并且可以有效且特异性地递送至患者耗尽的T细胞。 所提出的方法是使用 siRNA 形式的 RNAi，通过与寡核苷酸适体配体结合来抑制耗竭的下游介质，如 Blimp-1、Eomes、VHL 或 Sprouty-2，这些 siRNA 靶向耗竭的 HIV 特异性 CD8+ T 细胞，寡核苷酸适体配体与耗竭的 T 细胞上表达的受体结合，如 PD-1、LAG3 或 Tim-3。化学合成的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癌症环境中的免疫，并且最近证明了将适体靶向 siRNA 递送至小鼠循环 CD8+ T 细胞的显着效率。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，其程度优于针对 PD-1 等抑制性受体的单克隆抗体的阻断作用。 研究计划是针对上述抑制性受体产生高亲和力适体，构建适体-siRNA缀合物，并评估其与抗体阻断相比恢复免疫功能的能力（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/猕猴模型。该计划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。