Aptamer therapeutic for safe and low-cost treatment of snake bite envenomation

用于安全且低成本治疗蛇咬伤的适体疗法

基本信息

批准号：
10436803
负责人：
ATUL VARADHACHARY
金额：
$ 97.83万
依托单位：
FANNIN PARTNERS, LLC
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-07-01 至 2024-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10436803
关键词：
Adverse effects Affinity American Antibodies Antivenins Binding Blood Blood Coagulation Disorders Body Weight C-Type Lectins Cessation of life Clinical Pathology Complex Mixtures Copperheads Cottonmouth Creatine Kinase Crotalus DNA Dissociation Dose Drug Costs Drug Kinetics Emergency Care Emergency treatment Enzymes Equus caballus Family Female Formulation Hemorrhage Hemostatic function Hindlimb Histopathology Hypersensitivity Immunize Immunoglobulin Fragments Individual Libraries Limb structure Measurement Measures Metalloproteases Modeling Modification Morbidity - disease rate Mus Neurotoxins Oligonucleotides Ophthalmology Paralysed Patients Peptide Hydrolases Phospholipase A2 Proteins Rattus Recurrence Safety Serine Protease Serum Serum Sickness Sheep Side Single-Stranded DNA Site Snake Bites Snake Venoms Snakes Structure Targeted Toxins Technology Therapeutic Tissues Toxicology Toxin Treatment Cost Venoms aptamer base combinatorial cost disability efficacy study in vivo limb amputation male mouse model nanomolar novel novel strategies polypeptide proteinase B stem

项目摘要

Snake bite envenomation is a significant problem in the US and worldwide that can result in substantial morbidity and even death. Snake venom contains a complex mixture of toxins including neurotoxins and myotoxins, as well as toxins that disrupt normal hemostasis and can produce fatal hemorrhage. Snake venoms also include several classes of digestive and proteolytic enzymes that are responsible for the extensive local tissue destruction from snake bites that can result in permanent disability or require limb amputation. Current antivenom products consist of antibody fragments raised in horses or sheep and are generally effective at stabilizing envenomation patients, however they come with several limitations in that they are not effective against all species of N. American venomous snakes in mitigating tissue damage, and there are adverse effects such as serum sickness, hypersensitivity, and recurrent coagulopathy. In addition, antibody-based formulations have an extremely high cost, with the cost of the drug ranging from $20,000 to $40,000 per patient treatment. We propose to develop a novel antivenom therapeutic based on high-affinity aptamers, which consist of single-stranded oligodeoxynucleotides that form stem-loop structures to bind to their targets. Our proprietary X-Aptamer selection technology utilizes bead-based oligo DNA combinatorial libraries in which certain bases contain protein-like side modifications to enhance binding affinity. In this project, we will generate X-Aptamers against a set of major toxin classes found in N. American venomous snakes, to develop novel antivenom formulation with a better safety profile than current antibody-based antivenoms. Our preliminary studies have demonstrated selection of aptamers capable of neutralizing myotoxin from Southern Pacific rattlesnakes (C. o. helleri) in a hind limb paralysis model in mice. The project aims are: 1) Generate high-affinity oligonucleotide X-Aptamers against the five major classes of N. American snake venom toxins and measure the dissociation constant for each X-Aptamer and its target toxin; 2) Demonstrate in vivo efficacy of X-Aptamers against snake venom toxins and crude venom, using mouse models of hemorrhagic activity, creatine kinase activity, hind-limb paralysis, and lethality, to determine the effective dose for each aptamer; 3) Perform dose-ranging and toxicology studies in rats with the blended aptamer antivenom formulation. The completion of these studies will demonstrate safety and efficacy of a novel aptamer-based formulation which will have a strong impact and market potential in the emergency treatment of snake bite envenomation.

蛇咬伤是美国和世界范围内的一个严重问题，可能导致严重的发病率，甚至死亡。蛇毒含有复杂的毒素混合物，包括神经毒素和肌肉毒素，以及破坏正常的止血并可能产生致命的出血。蛇毒还包括几类消化和毒液蛋白水解酶负责蛇咬伤造成的广泛局部组织破坏，从而导致永久性残疾或需要截肢。目前的抗蛇毒血清产品由在马中饲养的抗体片段组成或绵羊，通常可以有效稳定中毒患者的情况，但它们也有一些局限性它们并非对所有种类的北美毒蛇都能有效减轻组织损伤，并且存在不利的影响血清病、过敏症和复发性凝血病等影响。此外，基于抗体的制剂具有成本极高，每位患者治疗的药物成本从 20,000 美元到 40,000 美元不等。我们建议开发一种基于高亲和力适体的新型抗蛇毒疗法，该适体由单链形成茎环结构以与其靶标结合的寡脱氧核苷酸。我们专有的 X 适体选择技术利用基于珠子的寡 DNA 组合文库，其中某些碱基含有蛋白质样侧面修饰以增强结合亲和力。在这个项目中，我们将针对一组主要毒素类别生成 X 适体在北美毒蛇中发现，用于开发比目前安全性更好的新型抗蛇毒血清制剂基于抗体的抗蛇毒血清。我们的初步研究表明，选择能够中和的适体小鼠后肢麻痹模型中来自南太平洋响尾蛇（C.o. helleri）的肌毒素。该项目的目标是： 1) 生成针对北美五种主要类别的高亲和力寡核苷酸 X 适体蛇毒毒素并测量每个 X 适体及其目标毒素的解离常数； 2) 体内演示使用出血活动、肌酸的小鼠模型，研究 X 适体对蛇毒毒素和粗毒液的功效激酶活性、后肢麻痹和致死率，以确定每种适体的有效剂量； 3) 进行剂量范围调整使用混合适体抗蛇毒血清制剂对大鼠进行毒理学研究。这些研究的完成将证明基于适配体的新型制剂的安全性和有效性，这将产生巨大的影响和市场潜力用于蛇咬伤的紧急治疗。