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

摘要 目前还没有治疗隐孢子虫的有效方法，隐孢子虫是一种现已被认识到的水媒寄生虫 作为世界范围内腹泻疾病的重要原因和艾滋病定义的重要病原体。在这个过程中 在海洋共生细菌产生的抗寄生虫活性的挖掘化合物中，我们鉴定了一种 有效抑制微小隐孢子虫体外生长的化合物Tartrolon E(TrtE)以及几种 其他顶端复合体寄生虫，对各自的宿主细胞没有毒性。我们进一步确定trtE是 高效降低新生小鼠隐孢子虫感染。事实上，trtE在以下方面的效率提高了10倍 体外和体内对隐孢子虫的效果比报道的最有效的化合物高2倍 Date，也是唯一一种具有广谱抗心尖复合体治疗作用的化合物。这些 观察结果有力地鼓励进一步探索trtE治疗慢性粒细胞白血病的临床潜力。 隐孢子虫病。在这里提出的研究中，我们将检验trtE具有活性的假设。 必须通过完成以下步骤成为治疗隐孢子虫病的主要候选药物 目的：目的1：评价trtE的物种特异性和生命周期阶段特异性。 隐孢子虫。TrtE将被用来对抗微小隐孢子虫和人隐孢子虫，以及trtE的活性。 将确定卵囊、子孢子、无性和有性阶段。目标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对隐孢子虫的疗效。 在严重免疫抑制和隐孢子虫病反刍动物模型中的感染。一个。 我们将测试trtE在NOD-SCID伽马小鼠中抑制和消除隐孢子虫感染的能力。胡麻B. 由于小鼠不会出现人类疾病的症状，我们将测试trtE抑制感染的能力 和新生羔羊的腹泻疾病。目的4：优化Teredinibacter的trtE生产工艺 Turnerae T7901：像许多天然产物一样，trtE具有复杂的结构，这使得合成具有挑战性 而且贵得令人望而却步。天然产物发现研究所(NPDI)，自然资源领域的专家 产品生产，将使用已建立的方案为这些研究生产trtE。在这个过程中， NPDI将应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 将trtE确立为抗隐孢子虫治疗的主要候选药物至关重要。而且，因为这一点 化合物对多种寄生虫具有高度的活性，这些研究将为未来的研究奠定基础 评估这种化合物作为一种广谱疗法治疗由顶端复合体寄生虫引起的疾病， 但最关键的是隐孢子虫病，这是一种被忽视的世界性重大疾病，目前还没有 很好的治疗选择。

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.