Critical molecular interactions of VWF and FVIII

VWF 和 FVIII 的关键分子相互作用

• 批准号: 8374526
• 负责人: ROBERT R MONTGOMERY
• 金额: $ 42.74万
• 依托单位: VERSITI WISCONSIN, INC.
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8374526
• 关键词: A Mouse; Address; Agreement; Animal Model; Animals; Antibodies; Binding; Blood Platelets; Bone Marrow Transplantation; Canis familiaris; Cells; Chimera organism; Clinical; Clinical Trials; Complex; Cytoplasmic Granules; DDAVP; Disease; Endothelial Cells; Endothelium; Endotoxins; Exhibits; Frequencies; Funding; Future; Grant; Hematopoiesis; Hematopoietic; Hematopoietic stem cells; Hemophilia A; Hemorrhage; Hemostatic Agents; Hemostatic function; Hepatocyte; Human; Injury; Instruction; Knock-out; Lead; Life; Long-Term Effects; Longitudinal Studies; Maintenance; Mediating; Medicine; Megakaryocytes; Modeling; Molecular; Molecular Chaperones; Mouse Strains; Mus; Patients; Phenotype; Physiological; Plasma; Pre-Clinical Model; Predisposition; Relative (related person); Replacement Therapy; Risk; Role; Safety; Sheep; Target Populations; Therapeutic; Thrombosis; Time; Tissues; Transfusion; Transplantation; Treatment Efficacy; clinical efficacy; fetal; gene therapy; in vivo; lentiviral-mediated; novel; novel strategies; promoter; safety study; von Willebrand Factor

Hemophilia A has been widely studied, and gene therapy has been a clinical approach carried out in animal models and some human clinical trials. Since standard approaches for treating hemophilia A have yet to be successful, alternative novel strategies are thought to be needed. One such approach has been developed in this grant during the past funding cycle, and has focused on expressing FVIII in megakaryo¿¿ cytes and endothelial cells. The natural interactions between VWF and FVIII might facilitate the expression of FVIII and make use of these interactions clinically. This grant has three aims that explore the interactions between FVIII and VWF, and how this could lead to strategies to optimize gene therapy for hemophilia. Even more exciting, this approach might be advantageous for hemophilic patients who have developed treatment-altering inhibitory antibodies. Aim 1 will study the local and systemic effect of VWF complexes with FVIII in the presence of specific FVIII inhibitory antibodies, and determine the safety of delivering FVIII in platelets. Aim 2 will study the delivery of FVIII in platelets, and determine its efficacy in a large animal model of hemophilia. Aim 3 will study a gene therapy approach in which FVIII is synthesized in and stored by endothelial cells, and whether endothelial cells normally synthesize FVIII. These models will dissect the contribution of VWF to the therapeutic efficacy of FVIII in the presence of inhibitory antibodies. Since the murine and canine models are less severe clinical models than the human disorder, and because dog platelets normally lack VWF. another animal model with platelet VWF is needed. The ovine model of hemophilia provides just such a model characterized by clinical severe bleeding, normal VWF in its platelets like humans, and most uniquely, the fetal ovine model has been demonstrated to permit long-term, life-long chimeric expression of human hematopoietic cells where human megakaryocytes/platelets, transduced to express and store FVIII, can be studied for safety and clinical efficacy. These studies will provide much additional critical safety and efficacy on this novel approach to gene therapy for hemophilia and provide a pre-clinical model of highest relevance before considering human trials. RELEVANCE (See instructions): This grant addresses a novel strategy to carry out gene therapy of hemophilia, a severe clinical bleeding disorder. While most studies have targeted liver cells, our unique approach will targets the expressed FVIII to endothelial cells or megakaryocytes - cells that normally synthesize and store VWF. These approaches may not only treat patients with hemophilia, but also treat those patients that have high-titer inhibitory antibodies that would normally mitigate against traditional replacement therapy, or even traditional gene therapy approaches to replace FVIII in plasma.

A型血友病已得到广泛研究，基因治疗已成为一种临床方法 动物模型和一些人体临床试验。由于治疗 A 型血友病的标准方法已 然而，要想取得成功，人们认为需要其他新颖的策略。其中一种方法是 在过去的资助周期中，该赠款中开发了 FVIII，并专注于在巨核体中表达 FVIII。 细胞和内皮细胞。 VWF 和 FVIII 之间的自然相互作用可能促进表达 FVIII 并在临床上利用这些相互作用。这笔赠款有三个目的，探索相互作用 FVIII 和 VWF 之间的关系，以及这如何导致优化血友病基因治疗的策略。 更令人兴奋的是，这种方法可能对已经患有血友病的患者有利 改变治疗的抑制性抗体。目标 1 将研究 VWF 复合物的局部和全身效应 在特定 FVIII 抑制抗体存在的情况下与 FVIII 进行检测，并确定递送 FVIII 的安全性 在血小板中。目标 2 将研究 FVIII 在血小板中的传递，并确定其在大型动物中的功效 血友病模型。目标 3 将研究合成并储存 FVIII 的基因治疗方法 内皮细胞是否正常合成 FVIII。这些模型将剖析 在存在抑制性抗体的情况下，VWF 对 FVIII 的治疗功效的贡献。自从 鼠类和犬类模型的临床模型没有人类疾病那么严重，并且因为狗 血小板通常缺乏 VWF。需要另一种具有血小板 VWF 的动物模型。绵羊模型 血友病正好提供了这样一种模型，其特征是临床严重出血，血小板中的 VWF 正常 与人类一样，最独特的是，胎羊模型已被证明可以实现长期、终生的 人类造血细胞的嵌合表达，其中人类巨核细胞/血小板被转导为 表达和储存 FVIII，可用于安全性和临床疗效研究。这些研究将提供很多 这种血友病基因治疗新方法具有额外的关键安全性和有效性，并提供了 在考虑人体试验之前具有最高相关性的临床前模型。 相关性（参见说明）： 这笔赠款提出了一种对血友病进行基因治疗的新策略，血友病是一种严重的临床出血性疾病 紊乱。虽然大多数研究都针对肝细胞，但我们独特的方法将针对表达的 FVIII 内皮细胞或巨核细胞 - 通常合成和储存 VWF 的细胞。这些方法 不仅可以治疗血友病患者，还可以治疗具有高效价抑制的患者 通常会减轻传统替代疗法甚至传统基因的抗体 替代血浆中 FVIII 的治疗方法。