Closing the Gaps on Buruli Ulcer Diagnosis, Treatment, and Prevention

 描述(申请人提供)：布鲁里溃疡(BU)是一种毁容和衰弱，但被忽视和新兴的热带疾病，由溃烂分枝杆菌通过其独特的脂肪毒素--分枝杆菌内酯引起。2004年前，唯一的治疗方法是广泛手术切除和植皮。在小鼠足垫模型上的研究首次表明利福平+链霉素(RIF+STR)的疗效。在验证性临床试验后，RIF+STR治疗8周。被世界卫生组织认可为治疗BU的一线药物。在BU控制方面最大的差距是现在缺乏简单、快速、护理点的诊断方法来在疾病早期确认诊断，而RIF+STR是最有效的。为了克服这一关键瓶颈，我们将开发新的、可现场应用的、高灵敏度的血液和组织中霉菌内酯检测方法。虽然许多人试图产生抗真菌内酯抗体，但失败了，我们的方法使用强大的新方法噬菌体和酵母展示，从非常大和多样化的幼稚和患者来源的池中选择可重复的高亲和力抗体，已经被证明成功地选择了针对真菌内酯和结合到已知的体内靶标WASP的真菌内酯的特异性抗体。以前在患者或免疫动物体内检测抗霉菌内酯抗体的努力也是基于毒素在体内以游离形式存在的有缺陷的前提。根据我们以前对其他两亲性生物标志物的经验以及霉菌内酯与脂质双层相互作用的计算模型，我们坚信，在宿主细胞之外，霉菌内酯将始终存在于与宿主载体(如高密度脂蛋白)的复合体中，或与细胞膜或膜衍生囊泡结合。因此，我们的方法是结合我们对可能的携带者的知识和对其他亲水性生物标志物的成功发现方法来识别体内最普遍和相关的宿主真菌内酯复合体和居住的膜结构，选择针对这些物种的抗体，并将这些抗体应用于我们的创新、高灵敏度和可现场检测系统中。8周的RIF+STR方案需要注射相对有毒的药物(STR)和使用RIF，这会导致许多药物-药物相互作用(例如，与抗艾滋病毒药物)。我们将根据结核病药物开发的最新进展和在BU小鼠模型中有希望的初步数据，探索更短、更简单、完全口服方案的开发。我们将利用我们在这两种疾病的临床前药物开发方面的经验，以及我们在临床试验中与新药赞助商建立的关系。这将使用在R01-AI082612的支持下开发的工具来进行，以全面评估用于BU的新药组合并将其优先用于临床评估。最后，由于在治疗过程中和治疗后霉菌内酯在组织中的持续存在可能会阻碍细菌的清除和伤口愈合，我们将利用我们诊断发现工作中的知识，寻求创新的基于抗体和非抗体的“抗毒力”策略，寻求中和霉菌内酯的毒性作用，以获得辅助治疗益处。

 DESCRIPTION (provided by applicant): Buruli ulcer (BU) is a disfiguring and debilitating, yet neglected and emerging, tropical disease caused by Mycobacterium ulcerans via its unique lipid toxin, mycolactone. Before 2004, the only treatment was wide surgical excision and skin grafting. Studies in mouse footpad models first indicated the efficacy of rifampin plus streptomycin (RIF+STR). Following confirmatory clinical trials, RIF+STR for 8 wks. was endorsed by the WHO as a first-line treatment for BU. The greatest gap in BU control is now the lack of simple, rapid, point-of- care diagnostics to confirm the diagnosis at an early stage of disease, when RIF+STR is most effective. To overcome this critical bottleneck, we will develop novel, fieldable, highly sensitive methods for mycolactone detection in blood and tissue. While many have tried and failed to generate anti-mycolactone antibodies, our approach using powerful novel methods of phage and yeast display to select reproducible high-affinity antibodies from extremely large and diverse naïve and patient-derived pools have already proven successful in select- ing specific antibodies to mycolactone alone and mycolactone bound to a known in vivo target, WASP. Previous efforts to detect anti-mycolactone antibodies in patients or immunized animals were also based on the flawed premise that the toxin exists in a free form in vivo. Based on our prior experience with other amphiphilic biomarkers and computational modeling of mycolactone's interaction with lipid bilayers, we strongly believe that, outside host cells, mycolactone will always exist in complexes with host carriers such as high-density lip- oprotein (HDL) or in association with cell membranes or membrane-derived vesicles. Therefore, our approach is to combine our knowledge of putative carriers and a discovery approach proven successful for other am- phiphilic biomarkers to identify the most prevalent and relevant host mycolactone complexes and inhabited membrane architectures in vivo, select antibodies to those species and employ those antibodies in our innova- tive, highly sensitive and fieldable detection system. The 8-wk RIF+STR regimen requires injections with a relatively toxic agent (STR) and use of RIF, which causes many drug-drug interactions (e.g., with anti-HIV drugs). We will explore the development of shorter, simpler, entirely oral regimens based on recent advances in tuberculosis drug development and promising preliminary data in BU mouse models. We will leverage our experience in pre-clinical drug development for both diseases as well as our established relationships with the sponsors of new drugs in clinical trials. This will e carried out with tools developed with support from R01-AI082612, to comprehensively evaluate novel drug combinations for BU and prioritize them for clinical evaluation. Finally, because persistence of mycolac- tone in tissues during and after treatment may retard bacterial clearance and wound healing, we will exploit knowledge from our diagnostic discovery work pursue innovative antibody- and non-antibody-based "anti- virulence" strategies, seeking to neutralize mycolactone's toxic effects for adjunctive therapeutic benefit.