Peptide Derivatives to treat Urinary Tract Infections

描述(申请人提供)：人类与细菌之间的战争进入了一个新的阶段。随着抗菌素耐药细菌菌株的迅速传播，目前使用的药物家族开始失败，人们经常发出绝望的呼声，要求建立新的药物武器库。事实上，除了从植物和动物中发现的天然抗菌肽外，近年来几乎没有开发出新的抗生素。在这种绝望的情况下，昆虫衍生的富含脯氨酸的阳离子抗菌肽家族可以伸出援手。与大多数其他破坏细菌膜通透性屏障的天然抗菌肽不同，Droocin、Prrrocoricin和Apidaecin被证明可以使一种细胞内细菌特异性蛋白失活，并且在体外和体内对哺乳动物细胞和活着的小鼠完全无毒。 我们对这些多肽的体外活性光谱、体内有效性和作用模式进行了表征，特别是对该抗菌药物家族中最具活性的成员焦皮环素的活性进行了研究。吡咯角蛋白和屈萝卜素似乎通过与70 kDa热休克蛋白DNAK的多螺旋盖区结合而杀死细菌，并抑制伴侣辅助的蛋白质折叠。吡咯皮质素及其设计的类似物在纳摩尔或低微摩尔浓度下杀灭耐内酰胺、四环素和氨基糖苷类的大肠埃希菌、肺炎克雷伯菌、鼠伤寒沙门氏菌和流感嗜血杆菌等临床菌株。此外，这些多肽还能保护小鼠免受实验性全身性大肠杆菌或局部流感嗜血杆菌肺部感染。或者作为气雾剂。我们的多重保护二聚铅类似物保持了天然化合物的所有高体外活性，并在哺乳动物血清中表现出显著的稳定性。焦皮环素类似物的活性光谱，治疗人类尿路感染(UTI)的迫切需要新的抗微生物化合物，以及通常可观察到的多肽类药物的组织分布和肾脏清除表明，如果开发得当，焦皮环素衍生物将成为临床治疗UTI的合适候选药物。这项拨款申请是为了开发这样一种基于多肽的候选药物。 在研究的第一阶段，我们将使用两种不同的检测类型，在体外表征目前的二聚体焦磷酸胆碱铅类似物对一系列泌尿系统致病菌的疗效。此外，体内效力、近似剂量和有效给药途径(静脉注射、皮下注射或口服)将在被广泛接受的小鼠UTI上升模型中进行表征，该模型使用从人类肾盂肾炎病例中分离的大肠杆菌菌株。如果先导化合物在体外和体内显示出良好的疗效数据，在第二阶段，我们将进一步优化先导化合物，以进一步提高体外对泌尿系统致病菌菌株的有效性、稳定性、口服生物利用度、无毒性和降低制造成本。将选择四个肽类似物进行进一步的小鼠体内活性研究。当所有数据都可用时，将确定最终的吡咯角菌素衍生物，并将研究其在兔模型中治疗实验性尿路感染的能力。此外，最终的候选药物将接受详细的老鼠毒性研究。 我们希望，在授权期结束时，我们将能够为随后的美国食品和药物管理局批准的尿路感染的临床前和临床评估提供焦磷酸皮质素衍生的多肽。

DESCRIPTION (provided by applicant): The war between man and bacteria entered a new phase. With the rapid spread of antimicrobial resistant bacterial strains the currently used drug families start to fail and desperate calls for a new armory of agents are regularly voiced. Indeed, apart from the discovery of natural antibacterial peptides from plants and animals, there have been few new antibiotics developed in recent years. In this desperate situation the insect-derived cationic proline-rich antibacterial peptide family can come to the rescue. Unlike most other native antimicrobial peptides that interrupt the bacterial membrane permeability barrier, drosocin, pyrrhocoricin and apidaecin were shown to deactivate an intracellular bacteria-specific protein, and were shown to be completely non-toxic in vitro and in vivo to mammalian cells and live mice. We characterized the in vitro activity spectrum, in vivo efficacy and mode of action of these peptides, especially those of pyrrhocoricin, the most active member of this antimicrobial family against selected bacterial strains. Pyrrhocoricin and drosocin appear to kill bacteria by binding to the multihelical lid region of the 70 kDa heat shock protein DnaK and inhibit chaperone-assisted protein folding. Pyrrhocoricin and its designed analogs kill (-lactam-, tetracycline- and aminoglycoside-resistant Escherichia coli, Klebsiella pneumoniae, Salmonella typhimurium, and Haemophilus influenzae clinical isolates, among many others, in nanomolar or low micromolar concentrations. In addition, these peptides protect mice from experimental systemic E. coli or local H. influenzae lung infection when added intravenously (i.v.) or as an aerosol. Our multiply protected dimeric lead analogs retain all the high in vitro activities of the native compound, and show remarkable stabilities in mammalian sera. The activity spectrum of the pyrrhocoricin analogs, the urgent need for new antimicrobial compounds to treat human urinary tract infections (UTI) and the generally observable tissue distribution and renal clearance of peptidic drugs suggest that if appropriately developed, pyrrhocoricin derivatives will be suitable candidates for the treatment of UTI in the clinical setting. This grant application is concerned with the development of such a peptide-based drug candidate. In the Phase I stage of the studies, we will characterize the efficacy of the current dimeric lead pyrrhocoricin analog against a series of uropathogenic bacteria in vitro by using two different assay types. In addition, the in vivo potency, approximate dose and efficacious administration routes (i.v., subcutaneous or oral) will be characterized in a widely accepted mouse ascending UTI model, which uses an E. coli strain isolated from a human pyelonephritis case. If the lead compound shows promising in vitro and in vivo efficacy data, in Phase II, we will optimize the lead compound for further increased in vitro efficacy against uropathogenic bacterial strains, stability, oral bioavailability, lack of toxicity and reduced manufacturing costs. Four peptide analogs will be selected for further in vivo activity studies in mice. When all data are available, a final pyrrhocoricin derivative will be identified, and it will be investigated for its ability to treat experimental UTI in a rabbit model. In addition, the final drug candidate will be subjected to detailed toxicity studies in rats. Our hope is that by the end of the grant period, we will be able to provide a pyrrhocoricin-derived peptide for ensuing US Food and Drug Administration-approved preclinical and clinical evaluation against urinary tract infections.