Lentiviral Vector-Based Gene Therapy and The Host Genetic Background

基于慢病毒载体的基因治疗和宿主遗传背景

基本信息

批准号：
9302512
负责人：
TAL KAFRI
金额：
$ 75.81万
依托单位：
UNIV OF NORTH CAROLINA CHAPEL HILL
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：
2015-09-02 至 2019-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9302512
关键词：
Activated Partial Thromboplastin Time measurement Adverse effects Affect Animal Model Animals Antibodies Biological Assay Breeding Candidate Disease Gene Cell Line Cells Cessation of life Clinical Trials Data Development Disease Dose Embryo Enzyme-Linked Immunosorbent Assay Epitopes Factor IX Fibrin fragment D Fibroblasts Firefly Luciferases Future Gene Delivery Gene Expression Genes Genetic Genetic Variation Genome Goals Hepatic Hepatocyte Hereditary Disease Human Human Genetics Image Immune response In Vitro Inbreeding Inheritance Patterns Kinetics Lentivirus Vector Life Cycle Stages Liver Luc Gene Luciferases Maintenance Mediating Modeling Mouse Strains Mus Nuclear Import Oryctolagus cuniculus Outcome Pathology Patients Pattern Pharmaceutical Preparations Phenotype Plasma Process Protocols documentation RNA Recombinants Regimen Resistance Rodent Model Role Safety System T-Lymphocyte Testing Therapeutic Variant Viral Vector Virus Integration aptamer base design expression vector fusion gene gene delivery system gene replacement therapy gene therapy gene therapy clinical trial genetic variant in vivo individual patient integration site knock-down mouse genome mouse model novel outcome forecast outcome prediction overexpression preclinical study preclinical trial promoter public health relevance response screening trait transduction efficiency transgene expression vector vector biodistribution vector genome

项目摘要

DESCRIPTION: In contrast to conventional medications, therapeutic viral vectors are given as a single dose and their levels cannot be adjusted to meet the therapeutic needs of an individual patient. Thus, one cannot overestimate the importance of animal model-based preclinical studies as a means to characterize the efficacy and safety of gene therapy regimens. Most preclinical trials are based on a rodent model comprising a large number of animals of the same strain, and a large animal model involving a smaller number of animals. Importantly, the effects of the genetic background of mouse strains employed in preclinical studies on the safety and efficacy of viral vectors has not been characterized. Similarly the effects of the patient's geneti background on the outcome of gene therapy regimens cannot be evaluated. Consequently, several gene therapy clinical trials have resulted in major adverse effects, which could not be observed in relevant earlier preclinical studies. The overall goal of the proposed studies is to characterize the effects of the host genetic variation on the efficacy and safety of lentiviral vector-based gene replacement therapy. Our experimental approach is premised on the Collaborative Cross (CC) mouse strains, which were derived by a funnel breeding of 8 genetically diverse, inbred founder strains. The genomes of these mouse strains are well defined, and will be utilized to study the overall effects of the host genetic background on the overall efficacy and safety of lentiviral vectors, as well as to identify putative genetic loci affecting these processes, test these variants' effects on the safety and efficiency of transducing human cells, and to evaluate the approach of employing an in vitro strain (potentially patient)-specific mouse embryo fibroblast (MEF's)-based system as a means to predict the safety and efficacy of hepatic gene delivery. In Aim 1, we will focus on characterizing the effects of the hos genetic background on the ability of lentiviral vectors to deliver and maintain long-term hepatic transgene expression, as well as lentiviral vector pattern of integration. F2 intercrosses of CC strains with contrasting phenotypes will be employed to identify genetic loci and the putative candidate genes involved in these processes. The optimal mouse strains for lentiviral vector-based hepatic gene delivery (demonstrating highest long-term transgene expression) will be identified. In Aim 2, we will employ MEF's from the above CC strains to study the effects of the host genetic background on the early steps of, as well as overall lentiviral vector transduction. Gene loci involved in these processes will be identified and their effects on safety and efficacy of vector transduction of human cells will be determined. The ability of the MEF-based model to predict in vivo transduction efficiency will be determined, as will this prediction's efficacy acros genetically diverse strains. In Aim 3, we will characterize the effects of the host genetic background on: the ability of lentiviral vectors to maintain therapeutic levels of factor IX (FIX) n vivo, the immune responses to FIX and vector- transduced hepatocytes, and on the development of thrombotic pathologies in the presence of high levels FIX.

描述：与常规药物相反，治疗病毒载体是单剂量的，无法调整其水平以满足单个患者的治疗需求。这是一个人不能高估基于动物模型的临床前研究的重要性，以表征基因治疗方案的效率和安全性。大多数临床前试验都是基于啮齿动物模型，该模型完成了大量相同菌株的动物，以及涉及少量动物的大型动物模型。重要的是，尚未表征临床前研究中用小鼠菌株对病毒载体安全性和有效性的遗传背景的影响。同样，无法评估患者基因背景对基因治疗方案结果的影响。因此，几项基因治疗临床试验导致了重大不良反应，这在相关性早期无法观察到。拟议研究的总体目标是表征宿主遗传变异对基于慢病毒载体的基因置换疗法的有效性和安全性的影响。我们的实验方法以协作十字（CC）小鼠菌株为前提，该菌株是由8个通常多样化的近交易所菌株的漏斗育种得出的。这些小鼠菌株的基因组已很好地定义，并将用于研究宿主遗传背景对慢病毒载体的整体效率和安全性的总体影响，并确定推定的遗传局部影响这些过程，测试这些变体对传输安全性和效率的影响人类细胞，并评估采用体外菌株（潜在患者）特异性小鼠胚胎成纤维细胞（MEF）的系统的方法，作为预测肝基因递送的安全性和有效性的手段。在AIM 1中，我们将专注于表征HOS遗传背景对慢病毒载体传递和维持长期肝转化表达的能力的影响，以及慢病毒载体的整合模式。 CC菌株与对比鲜明的表型的F2间交叉将用于识别遗传局部和推定的候选基因。将鉴定出基于慢病毒载体的肝基因递送的最佳小鼠菌株（证明长期转化表达最高）。在AIM 2中，我们将利用上述CC菌株的MEF研究宿主遗传背景对早期步骤以及整体慢病毒载体翻译的影响。将确定将这些过程定位于这些过程中的基因，并确定它们对人类细胞向量转移的安全性和有效性的影响。将确定基于MEF的模型预测体内转移效率的能力，这一预测在遗传多样性菌株中的有效性也将得到确定。在AIM 3中，我们将表征宿主遗传背景的影响：慢病毒载体保持因子IX（FIX）N VIVO的治疗水平的能力，固定和矢量翻译的肝细胞的免疫反应，以及在高水平固定存在下的血栓性病理学的发展。