Development of a new marine natural product for the treatment of cryptosporidiosis, an AIDS-defining disease

摘要 目前还没有有效的疗法来治疗隐孢子虫，这是一种现在公认的水传播寄生虫。 作为世界范围内疟疾的重要原因和重要的艾滋病定义病原体。过程中 海洋共生细菌产生的抗寄生虫活性的采矿化合物，我们确定了一个 一种有效抑制隐孢子虫体外生长的化合物，酒石酮E（trtE），以及几种 其他顶复门寄生虫，对其各自的宿主细胞没有毒性。我们进一步确定，trtE是 在降低新生小鼠隐孢子虫感染方面非常有效。事实上，trtE在 体外和2倍更有效地在体内对隐孢子虫比最有效的化合物报道， 日期，和唯一的化合物持有的广谱抗apicomplexan治疗的承诺。这些 观察结果强烈鼓励进一步探索trtE治疗以下疾病的临床潜力： 隐孢子虫病在这里提出的研究中，我们将测试trtE具有活性的假设， 通过完成以下工作，有必要成为治疗隐孢子虫病的主要候选治疗药物 目的：目的1：评价trtE对大肠杆菌的种特异性和生活史阶段特异性， 隐孢子虫TrtE将针对C进行检测。parvum田间分离物和C.人与trtE活性 针对卵囊、子孢子、无性和有性阶段进行测定。目的2：优化trtE剂量 养生法将进行药效学（A）、药代动力学（B）和生物利用度（C）研究， 设计最佳治疗策略。目的3：评价trtE对隐孢子虫的杀灭效果 在严重的免疫抑制和隐孢子虫病的反刍动物模型中感染。A. 我们将在NOD-SCID γ小鼠中测试trtE抑制和消除隐孢子虫感染的能力。B。 因为小鼠没有表现出人类疾病的症状，我们将测试trtE抑制感染的能力 和新生羔羊的腹泻病。目的4：优化Teredinibacter中trtE的生产工艺 turnerae T7901：与许多天然产物一样，trtE具有复杂的结构，使合成具有挑战性 而且贵得令人望而却步天然产品发现研究所（NPDI），天然产品领域的专家， 产品生产，将使用既定方案生产这些研究的trtE。在这个过程中， NPDI将运用他们在这一领域的专业知识来提高生产效率。这些研究将提供数据 这对于将trtE确立为抗隐孢子虫治疗剂的主要候选物是必不可少的。此外，由于这 化合物对多种寄生虫具有高度活性，这些研究将为未来的研究奠定基础。 评价该化合物作为由顶复门寄生虫引起的疾病的广谱治疗剂， 但最关键的是隐孢子虫病，这是一种被忽视的世界性疾病， 良好的治疗选择。

ABSTRACT There are no effective therapies to treat Cryptosporidium, a waterborne parasite that is now recognized as significant cause of diarrheal disease worldwide and an important AIDS defining pathogen. In the process of mining compounds produced by marine symbiotic bacteria for anti-parasitic activity, we identified a compound, tartrolon E (trtE) that potently inhibits in vitro growth of Cryptosporidium parvum, as well as several other apicomplexan parasites, without toxicity to their respective host cells. We further established that trtE is highly effective at reducing Cryptosporidium infection in neonatal mice. In fact, trtE is 10-fold more effective in vitro and 2-fold more effective in vivo against Cryptosporidium than the most effective compounds reported to date, and the only compound to hold the promise of a broad spectrum anti-apicomplexan therapeutic. These observations strongly encourage further exploration of the clinical potential of trtE for the treatment of cryptosporidiosis. In the studies proposed here, we will test the hypothesis that trtE possesses the activity necessary to be lead candidate therapeutic for the treatment of cryptosporidiosis by completion of the following aims: Aim 1: To evaluate species specificity and life cycle stage specificity of trtE against Cryptosporidium. TrtE will be tested against C. parvum field isolates and C. hominis and the activity of trtE against oocysts, sporozoites, asexual and sexual stages will be determined. Aim 2: To optimize trtE dosing regimens. Pharmacodynamics (A), pharmacokinetics (B) and bioavailability (C) studies will be conducted to design optimal treatment strategies. Aim 3: To evaluate the efficacy of trtE against Cryptosporidium infection in the setting of severe immunosuppression and in a ruminant model of cryptosporidiosis. A. We will test trtE’s ability to inhibit and eliminate Cryptosporidium infection in NOD-SCID gamma mice. B. Because mice do not manifest the symptoms of human disease, we will test the trtE’s ability to inhibit infection and diarrheal illness in neonatal lambs. Aim 4: To optimize production of trtE from Teredinibacter turnerae T7901: Like many natural products, trtE has a complex structure that renders synthesis challenging and prohibitively expensive. The Natural Products Discovery Institute (NPDI), experts in the field of natural product production, will be producing trtE for these studies using established protocols. During that process, NPDI will apply their expertise in this area to increase production efficiency. These studies will provide data essential to establish trtE as a lead candidate for an anti-Cryptosporidium therapeutic. Moreover, because this compound is highly active against multiple parasites, these investigations will underpin future studies evaluating this compound as a broad spectrum therapeutic for diseases caused by apicomplexan parasites, but most critically for cryptosporidiosis, a neglected disease of world-wide significance for which there are no good therapeutic options.