Preclinical Diagnostic Imaging of Amyloid

淀粉样蛋白的临床前诊断成像

• 批准号: 7894656
• 负责人: JONATHAN S WALL
• 金额: $ 45.14万
• 依托单位: UNIVERSITY OF TENNESSEE KNOXVILLE
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-01 至 2013-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7894656
• 关键词: Acute Lymphocytic Leukemia; Affinity; Alzheimer' s Disease; Amyloid; Amyloidosis; Amyotrophic Lateral Sclerosis; Animals; Antibodies; Autoradiography; B lymphoid malignancy; Binding; Biodistribution; Biological Assay; Biological Markers; Blood Circulation; Cardiac; Cerebrum; Chemistry; Chronic; Chronic Myeloid Leukemia; Clinic; Clinical; Clinical Trials; Data; Deposition; Diagnosis; Diagnostic Imaging; Dialysis procedure; Disease; Disease Progression; Enzyme-Linked Immunosorbent Assay; Equilibrium; Evaluation; Excision; Exposure to; Familial Mediterranean Fever; Generic Drugs; Goals; Heparan Sulfate Proteoglycan; Heparin; Heparitin Sulfate; Hepatic; High Dose Chemotherapy; Human; I125 isotope; Image; In Vitro; Incidence; Inflammation; Inflammatory; Inherited; Inorganic Sulfates; Investigation; Kidney; Kinetics; Label; Lesion; Liver; Methods; Modeling; Modification; Monitor; Mus; Non-Insulin-Dependent Diabetes Mellitus; Normal tissue morphology; Organ; Pathology; Patients; Peptides; Peripheral; Phage Display; Physicians; Plasma Cell Neoplasm; Positron-Emission Tomography; Probability; Proteins; Proteoglycan; Radiolabeled; Reagent; Research; Rheumatoid Arthritis; Severities; Surface Plasmon Resonance; Techniques; Testing; Therapeutic; Time; Tissues; Tracer; Transgenic Organisms; Translating; Translations; Tuberculosis; Unspecified or Sulfate Ion Sulfates; Validation; Work; alternative treatment; amyloid formation; amyloid imaging; base; in vivo; man; mouse model; novel; oncology; outcome forecast; pre-clinical; programs; protein misfolding; public health relevance; radiotracer; research clinical testing; response; single photon emission computed tomography; whole body imaging

DESCRIPTION (provided by applicant): Amyloid is associated with a diverse group of often fatal hereditary and sporadic protein misfolding disorders, characterized by the deposition of fibrils and heparan sulfate proteoglycan in vital organs and tissues. Although the most common manifestation is in patients with Alzheimer's disease, the incidence of peripheral (non-cerebral) amyloid diseases in the USA, is estimated to be ~ 5300 per yr which exceeds that for acute lymphocytic leukemia (~ 4,000 per yr). Treatment options for peripheral amyloidosis are limited and focus on reducing synthesis of the amyloidogenic protein e.g., with high dose chemotherapy and there are currently 31 new trials for treating AL, AA, and ATTR amyloidosis underway (clinicaltrials.gov). Unfortunately, there are no methods available in the USA to visualize response to these anti-amyloid therapies directly, nor to determine the extent and severity of amyloid deposits or the target organ in patients. This kind of information can be obtained by imaging, using an amyloid-specific radiotracer. There exists therefore an urgent need to identify tracers that target amyloid for whole body imaging that can be used for monitoring disease progression and response to therapy both within the clinic and as part of clinical trials. The aim of this proposal is to target the amyloid biomarker heparan sulfate proteoglycan and test antibody-derived and peptide tracer molecules that bind specifically to this constituent of all known amyloid deposits. Our approach is based on the fact that all amyloid deposits contain heparan sulfate proteoglycan at levels as high as 250 5g per gram of diseased tissue. We have begun testing a panel of antibody-derived proteins (scFv) known to bind heparan sulfate, for their ability to bind heparan sulfate in amyloid deposits. We have shown that scFvs to hypersulfated heparin sulfate successfully imaged amyloid in vivo even though heparan sulfate was expressed in some normal tissues. Novel heparan sulfate-binding peptides will also be generated and tested. In vitro characterization of the amyloid-reactive scFv and peptides will be performed by surface plasmon resonance and ELISA to identify those scFv with equilibrium binding affinity of < 1 5M - suitable for imaging in patients. Small animal SPECT, PET, and CT imaging will be used to compare the co-localization of the available and novel heparan sulfate- binding tracers and identify those with acceptable (3:1) target to background ratios. We will use an established murine model of systemic peripheral (AA) amyloidosis that recapitulates many aspects of human amyloid disease including the deposition of proteoglycans which enhances the probability that we will identify tracers for imaging amyloidosis that translate favorably into the clinic. Identifying and validating molecules that specifically bind heparan sulfate proteoglycan found in tissue amyloid will provide new reagents for the clinical evaluation of patients with this devastating disease. PUBLIC HEALTH RELEVANCE: Peripheral amyloidosis is a protein-misfolding condition associated with type 2 diabetes, chronic inflammatory disorders such as tuberculosis and rheumatoid arthritis, as well as certain B-cell malignancies. Currently here are no methods available in the USA that can detect the extent of amyloid deposits in patients with peripheral amyloidosis, nor to monitor their progression, or document their removal in response to therapy. This kind of information can be obtained by imaging, using an amyloid-specific radiotracer. To this end, we aim to target the amyloid biomarker heparan sulfate proteoglycan and test antibody-derived and peptide tracer molecules that bind specifically to this constituent of all known amyloid deposits for the purpose of whole body imaging that can be used to monitor disease progression and response to therapy.

描述（由申请人提供）：淀粉样蛋白与多种通常致命的遗传性和散发性蛋白质错误折叠疾病有关，其特征是重要器官和组织中原纤维和硫酸乙酰肝素蛋白聚糖的沉积。尽管最常见的表现是阿尔茨海默病患者，但美国外周（非脑）淀粉样蛋白疾病的发病率估计约为每年 5300 例，超过了急性淋巴细胞白血病（每年约 4,000 例）。外周淀粉样变性的治疗选择有限，主要集中在减少淀粉样蛋白的合成，例如采用高剂量化疗，目前有 31 项治疗 AL、AA 和 ATTR 淀粉样变性的新试验正在进行中 (clinicaltrials.gov)。不幸的是，美国没有可用的方法来直接可视化对这些抗淀粉样蛋白治疗的反应，也没有确定淀粉样蛋白沉积或患者靶器官的范围和严重性。这种信息可以通过使用淀粉样蛋白特异性放射性示踪剂进行成像来获得。因此，迫切需要识别针对淀粉样蛋白的全身成像示踪剂，该示踪剂可用于在诊所内和作为临床试验的一部分监测疾病进展和对治疗的反应。该提案的目的是针对淀粉样蛋白生物标志物硫酸乙酰肝素蛋白聚糖，并测试与所有已知淀粉样沉积物的这一成分特异性结合的抗体衍生分子和肽示踪分子。我们的方法基于以下事实：所有淀粉样沉积物都含有硫酸乙酰肝素蛋白多糖，其含量高达每克患病组织 250 5 克。我们已经开始测试一组已知可结合硫酸乙酰肝素的抗体衍生蛋白 (scFv)，以确定它们结合淀粉样蛋白沉积物中的硫酸乙酰肝素的能力。我们已经证明，尽管硫酸乙酰肝素在一些正常组织中表达，但超硫酸化硫酸肝素的 scFv 成功地在体内对淀粉样蛋白进行成像。新型硫酸乙酰肝素结合肽也将被生产和测试。淀粉样蛋白反应性 scFv 和肽的体外表征将通过表面等离振子共振和 ELISA 进行，以鉴定平衡结合亲和力 < 1 5M 的 scFv - 适合患者成像。小动物 SPECT、PET 和 CT 成像将用于比较现有和新型硫酸乙酰肝素结合示踪剂的共定位，并确定那些具有可接受的目标与背景比率 (3:1) 的示踪剂。我们将使用已建立的全身性外周（AA）淀粉样变性小鼠模型，该模型概括了人类淀粉样变性疾病的许多方面，包括蛋白聚糖的沉积，这提高了我们识别淀粉样变性成像示踪剂的可能性，从而有利于临床转化。鉴定和验证与组织淀粉样蛋白中发现的硫酸乙酰肝素蛋白多糖特异性结合的分子将为患有这种毁灭性疾病的患者的临床评估提供新的试剂。公共健康相关性：外周淀粉样变性是一种与 2 型糖尿病、结核病和类风湿性关节炎等慢性炎症性疾病以及某些 B 细胞恶性肿瘤相关的蛋白质错误折叠病症。目前，美国还没有可用的方法可以检测外周淀粉样变性患者中淀粉样蛋白沉积的程度，也没有监测其进展或记录治疗后淀粉样蛋白沉积的去除情况。这种信息可以通过使用淀粉样蛋白特异性放射性示踪剂进行成像来获得。为此，我们的目标是针对淀粉样蛋白生物标志物硫酸乙酰肝素蛋白聚糖，并测试抗体衍生分子和肽示踪分子，这些分子与所有已知淀粉样蛋白沉积物的这一成分特异性结合，用于全身成像，可用于监测疾病进展和对治疗的反应。