RNAi manipulations of DC to enhance HIV immunogenicity

DC 的 RNAi 操作增强 HIV 免疫原性

• 批准号: 8131050
• 负责人: Premlata Shankar
• 金额: $ 36.64万
• 依托单位: TEXAS TECH UNIVERSITY HEALTH SCIS CENTER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-15 至 2014-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8131050
• 关键词: Adjuvant; Alleles; Animal Model; Antibodies; Antigen-Presenting Cells; Antigens; Binding; CD8B1 gene; Cells; Clinical Trials; Dendritic Cells; Development; Drug Formulations; Engineering; Epidemic; Epitopes; Failure; Gagging; Gene Targeting; Generations; Genes; HIV; HIV Antigens; HIV Infections; HIV vaccine; HLA-A2 Antigen; HLA-B27 Antigen; Human; Immune; Immune response; Immunity; Immunization; Immunodeficient Mouse; Immunologic Adjuvants; In Vitro; Infection; Integrins; Interleukin 2 Receptor Gamma; Interleukin-10; Interleukin-2; Intervention; Leukocytes; Ligands; Liposomes; Mediating; Messenger RNA; Methods; Modeling; Molecular; Monkeys; Mouse Strains; Mus; Mutation; Peptide antibodies; Peptides; Peripheral; Physiological; Positioning Attribute; Pre-Clinical Model; Proteins; Publishing; RNA Interference; Reagent; Recombinants; Regimen; Small Interfering RNA; T cell response; T-Lymphocyte; Testing; Therapeutic; Transgenic Organisms; Vaccines; Viral; Virulent; Virus; animal tissue; base; cytokine; design; efficacy testing; immunogenicity; improved; in vivo; inhibitor/antagonist; insight; melanoma; mouse model; novel; novel strategies; novel vaccines; pre-clinical; prevent; receptor; recombinant viral vector; response; targeted delivery; tool; tool development; vector-based vaccine

DESCRIPTION (provided by applicant): To date there is no effective vaccine for HIV infection. Although a major vaccine trial based on homologous recombinant viral prime/boost failed recently, a study undertaken later, in a monkey model, suggests that with a more appropriate heterologous prime/boost regimen, it is possible to elicit a strong T cell response that protects against virulent viral challenge. Thus, for a vaccine to be effective, it should be able to evoke a strong and broad-based T cell response. Moreover, pretesting the relevance of novel vaccine approaches by HIV challenge in preclinical models would greatly help prevent the agony of vaccine failures in human clinical trials. As Dendritic cells are critical for induction of T cell immune responses, we hypothesize that immunization with HIV proteins targeted to dendritic cells in which select negative immunomodulatory molecules such as SOCS-1, PD-L1, L2 and IL-10 have been suppressed by RNA interference will elicit a potent polyfunctional CD8+ T cell response. Our hypothesis is based on our preliminary results in which silencing of SOCS-1 via targeted siRNA delivery to DC was enough to elicit a robust primary T cell response in vitro to several HIV gag epitopes, including subdominant ones. Moreover, we have recently shown the feasibility of using the latest versions of humanized mouse models to test the efficacy of siRNA mediated interventions in HIV infection and are thus are in a position to test whether the human DC- targeted methods are effective in vivo. In Specific Aim 1 of this proposal we will develop methods and reagents for targeted delivery of HIV-antigens and immunomodulatory siRNA reagents to human DCs. These will include a DC targeting peptide modified to bind siRNA as well as to deliver HIV antigens, two DC-targeting antibody fused to HIV proteins and further modified to bind siRNAs and a liposomal formulation that allows targeted delivery of siRNA and HIV antigen in mRNA form. In Aim 2, we will evaluate whether co-delivery of HIV immunogen with the different immunomodulatory siRNA (singly and in combination) by any of these methods is able to induce a broad and polyfunctional primary HIV-specific CD8 T cell response in vitro. In Aim 3, we will validate the in vitro findings as well as test the efficacy of our methods to actually confer protection from in vivo HIV challenge in the humanized BLT mouse model transgenic for HLA-A2 and HLA-B27. This project will develop DC-targeted approaches for HIV antigen delivery and RNAi manipulations as a novel HIV vaccine strategy to induce potent virus-specific T cell immunity. If successful, the studies would provide an alternative to the recombinant viral vector-based vaccines. In addition, the in vivo studies in a preclinical animal model will provide novel insights into the immune correlates of protection.

描述（由申请人提供）：迄今为止，还没有针对 HIV 感染的有效疫苗。尽管基于同源重组病毒初免/加强的主要疫苗试验最近失败了，但后来在猴子模型中进行的一项研究表明，采用更合适的异源初免/加强方案，有可能引发强烈的 T 细胞反应，从而防止致命病毒的攻击。因此，要使疫苗有效，它应该能够引起强烈且广泛的 T 细胞反应。此外，在临床前模型中通过 HIV 攻击来预先测试新型疫苗方法的相关性将极大地有助于防止人体临床试验中疫苗失败的痛苦。由于树突状细胞对于诱导 T 细胞免疫反应至关重要，因此我们假设，针对树突状细胞的 HIV 蛋白免疫将引发有效的多功能 CD8+ T 细胞反应，其中选择的负性免疫调节分子（如 SOCS-1、PD-L1、L2 和 IL-10 已被 RNA 干扰抑制）。我们的假设基于我们的初步结果，其中通过靶向 siRNA 递送至 DC 来沉默 SOCS-1 足以在体外引发对几种 HIV gag 表位（包括次优势表位）的强烈原代 T 细胞反应。此外，我们最近展示了使用最新版本的人源化小鼠模型来测试siRNA介导的HIV感染干预效果的可行性，因此能够测试人类DC靶向方法在体内是否有效。在该提案的具体目标 1 中，我们将开发用于向人类 DC 靶向递送 HIV 抗原和免疫调节 siRNA 试剂的方法和试剂。这些产品将包括经过修饰以结合 siRNA 并递送 HIV 抗原的 DC 靶向肽、两种与 HIV 蛋白融合并进一步修饰以结合 siRNA 的 DC 靶向抗体，以及允许以 mRNA 形式靶向递送 siRNA 和 HIV 抗原的脂质体制剂。在目标 2 中，我们将评估通过任何这些方法共同递送 HIV 免疫原与不同的免疫调节 siRNA（单独或组合）是否能够在体外诱导广泛且多功能的初级 HIV 特异性 CD8 T 细胞应答。在目标 3 中，我们将验证体外研究结果，并测试我们的方法在 HLA-A2 和 HLA-B27 转基因人源化 BLT 小鼠模型中实际提供免受体内 HIV 攻击的保护的有效性。该项目将开发用于 HIV 抗原递送和 RNAi 操作的 DC 靶向方法，作为一种新型 HIV 疫苗策略，以诱导有效的病毒特异性 T 细胞免疫。如果成功，这些研究将为基于重组病毒载体的疫苗提供替代方案。此外，临床前动物模型的体内研究将为保护的免疫相关性提供新的见解。