Lentiviral Gene Therapy of X-Linked Agammaglobulinemia

X连锁无丙种球蛋白血症的慢病毒基因治疗

• 批准号: 8825754
• 负责人: David J Rawlings
• 金额: $ 8.78万
• 依托单位: SEATTLE CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-15 至 2016-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8825754
• 关键词: Address; Affect; Agammaglobulinaemia tyrosine kinase; Alleles; Antigens; Autologous; B-Cell Development; B-Lymphocytes; Bacterial Infections; Biological Assay; Bone Marrow; Cell Lineage; Cell physiology; Cells; Chromatin; Clinical; Clinical Protocols; Clinical Trials; Codon Nucleotides; Complementary DNA; Data; Development; Disease; Elements; Enhancers; Evolution; Exhibits; Future; Gene Expression; Gene Transfer; Generations; Genes; Genetic Recombination; Goals; Hematopoietic stem cells; Histopathology; Human; Immune System Diseases; Immune response; Immunoglobulins; Immunologic Deficiency Syndromes; Immunologics; In Vitro; Laboratories; Lead; Lentivirus Vector; Life Expectancy; Marrow; Mediating; Modeling; Molecular Profiling; Mus; Mutagenesis; Myelogenous; Myeloid Cells; Patients; Quality of life; Rare Diseases; Receptor Signaling; Receptors, Antigen, B-Cell; Recovery; Recurrence; Regimen; Relative (related person); Retroviral Vector; Risk; Role; Safety; Staining method; Stains; Stem cells; Testing; Toll-like receptors; Transgenes; Transplantation; Vertebral column; Viral; Work; X-Linked Agammaglobulinemia; base; conditioning; congenital immunodeficiency; design; gene therapy; genotoxicity; human disease; improved; in vivo; novel; pressure; progenitor; promoter; receptor; reconstitution; response; restoration; vector

DESCRIPTION (provided by applicant): X-linked agammaglobulinemia (XLA) results from deficient function of Bruton's tyrosine kinase (Btk) and is characterized by a severe block in early B-cell development. B cells that express wildtype Btk exhibit a strong selective advantage in vivo; suggesting that introduction of a normal Btk cDNA into autologous hematopoietic stem cells (HSC) may lead to long-term immunologic reconstitution in XLA. In previous work, we demonstrated that both gamma-retroviral and B lineage-specific, lentiviral (LV) Btk gene therapy can lead to rescue of Btk-dependent, B lineage development and function in vivo. Notably, in addition to its role in B cells, Btk is activated via multiple receptors expressed on myeloid cells implying a broader role for Btk in host immune responses. To optimize the expression profile of the Btk transgene in both B and myeloid lineage cells, we developed a novel LV platform using the endogenous Btk promoter (Btkp) in association with two alternative elements [the IgH chain enhancer Em or a ubiquitous chromatin opening element (UCOE) element]. Using these LV to express codon-optimized human Btk, we observed rescue of Btk-dependent, B-lineage development and function; and restoration of Toll-like receptor (TLR) signaling in myeloid cells. Together, these data strongly support our goal of using a Btkp-based LV in a future gene therapy trial for patients with XLA. Several key issues; however, remain to be addressed before this approach can be moved forward into patients. First, we need a comprehensive in vivo comparison of the safety and efficacy of EmBtkp vs. UCOE.Btkp LV in both murine XLA and primary stem cells derived from XLA patients. Second, we need a detailed assessment of potential genotoxicity of these candidate LV. Accordingly, this proposal is designed to test the hypotheses that: (1) LV utilizing the endogenous Btk promoter will mediate sustained, temporally appropriate levels of Btk gene expression and rescue of B and myeloid function in murine and human cells; (2) Efficient Btk rescue will also be achieved using a non-myeloablative marrow conditioning regimen that closely mimics a future clinical approach in XLA; and (3)These LVs will exhibit little or no risk of vector- mediated mutagenesis.

描述（由申请人提供）：X连锁无丙种球蛋白血症（XLA）是由布鲁顿酪氨酸激酶（Btk）功能缺陷引起的，其特征是早期B细胞发育严重受阻。表达野生型Btk的B细胞在体内表现出强大的选择优势；这表明将正常的 Btk cDNA 引入自体造血干细胞 (HSC) 可能会导致 XLA 的长期免疫重建。在之前的工作中，我们证明了γ-逆转录病毒和B谱系特异性慢病毒（LV）Btk基因治疗可以挽救Btk依赖性的B谱系体内发育和功能。值得注意的是，除了在 B 细胞中发挥作用外，Btk 还可以通过骨髓细胞上表达的多种受体激活，这意味着 Btk 在宿主免疫反应中发挥着更广泛的作用。为了优化 Btk 转基因在 B 细胞和骨髓系细胞中的表达谱，我们开发了一种新型 LV 平台，使用内源性 Btk 启动子 (Btkp) 与两个替代元件 [IgH 链增强子 Em 或普遍存在的染色质开放元件 ( UCOE）元素]。使用这些 LV 表达密码子优化的人类 Btk，我们观察到 Btk 依赖性 B 谱系发育和功能的拯救；以及骨髓细胞中 Toll 样受体 (TLR) 信号传导的恢复。总之，这些数据有力地支持了我们在未来针对 XLA 患者的基因治疗试验中使用基于 Btkp 的 LV 的目标。几个关键问题；然而，在将这种方法推广到患者身上之前，仍有待解决。首先，我们需要对 EmBtkp 与 UCOE.Btkp LV 在小鼠 XLA 和源自 XLA 患者的原代干细胞中的安全性和有效性进行全面的体内比较。其次，我们需要对这些候选慢病毒的潜在遗传毒性进行详细评估。因此，本提案旨在测试以下假设：（1）利用内源性 Btk 启动子的 LV 将介导持续的、暂时适当的 Btk 基因表达水平，并挽救小鼠和人类细胞中的 B 和骨髓功能； (2) 高效的 Btk 救援也将通过使用非清髓性骨髓调理方案来实现，该方案与 XLA 未来的临床方法非常相似； (3)这些 LV 将表现出很少或没有载体介导的诱变风险。