Antibiotic Potentiators Targeting SOS Induction

描述（由申请人提供）：几种临床上重要的抗生素强烈诱导细菌的SOS反应。SOS缺陷菌对喹诺酮类、氟喹诺酮类和2-内酰胺类抗生素的敏感性明显高于野生型菌。SOS反应的诱导增加了抗生素耐药性的进化和毒力因子的水平转移。因此，SOS诱导途径是发现药物的重要靶点，这些药物可以作为临床重要抗生素的增强剂，减少抗生素耐药性的演变。本STTR提案的总体目标是通过特异性抑制SOS反应的诱导，发现和开发临床相关氟喹诺酮类药物的增强剂。这种方法代表了细菌感染治疗方式的一种创新。这些创新药物将在低剂量下提高现有临床相关抗生素的疗效，防止耐药性的演变和毒力因子的传播。在STTR的I期研究中，我们将使用基于细胞的报告基因试验，在多种药物样小分子文库的高通量筛选（HTS）中鉴定SOS诱导抑制剂。我们将通过一系列二级分析来评估这些抑制剂的效力、特异性和活性谱。SOS抑制剂的活性将在药物化学和评价的迭代中得到优化。符合二级分析指定标准的抑制剂将被指定为验证命中。作用机制（MOA）研究将对有希望的验证命中进行。在第二阶段，通过合理的药物设计优化其活性和特异性，将具有确定MOA的经过验证的hit开发成先导化合物。具体目的如下：目的1-开发基于细胞的SOS诱导抑制剂报告因子HTS。目的2：筛选多种化合物文库，鉴定并确认SOS诱导抑制剂。目的3：使用二次分析验证已确认的SOS抑制剂，并确定已验证的Hit系列。目标4：确定有效命中的作用机制/确定目标。公共卫生相关性：细菌通过产生增加其存活率的蛋白质来应对环境损害。目前用于治疗细菌感染的几种抗生素，如氨苄西林、阿莫西林和环丙沙星，可激活一组蛋白质的产生，统称为SOS反应。这种重要的应激反应在修复DNA损伤和增加对DNA损伤剂的耐受性方面起着关键作用。不能激活SOS反应的细菌对上述抗生素高度敏感，不太可能产生耐药性。该项目的目标是发现防止SOS激活的药物，并提高几种重要抗生素的疗效。

DESCRIPTION (provided by applicant): Several clinically important classes of antibiotics strongly induce the SOS response in bacteria. SOS defective bacteria are significantly more sensitive to quinolone, fluoroquinolone, and 2-lactam antibiotics than are wild type bacteria. Induction of the SOS response increases the evolution of antibiotic resistance and the horizontal transfer of virulence factors. Therefore, the SOS induction pathway is an important target for discovery of drugs that act as potentiators of clinically important antibiotics and reduce the evolution of antibiotic resistance. The overall goal of this STTR proposal is to discover and develop drugs that are potentiators of clinically relevant fluoroquinolones by specifically inhibiting induction of the SOS response. This approach represents an innovation in the way bacterial infections will be treated. These innovative drugs will increase the efficacy of existing clinically relevant antibiotics at low doses, prevent evolution of resistance and transmission of virulence factors. In Phase I of this STTR, we will identify inhibitors of SOS induction using a cell-based reporter assay in a high-throughput screen (HTS) of a diverse library of drug-like small molecules. We will evaluate these inhibitors for potency, specificity, and spectrum of activity using a series of secondary assays. The activity of the SOS inhibitors will be optimized in iterative rounds of medicinal chemistry and evaluation. Inhibitors that meet the criteria specified for secondary assays will be designated Validated Hits. Mechanism of Action (MOA) studies will be carried out for promising Validated Hits. In Phase II, Validated Hits with a confirmed MOA will be developed into Lead Compounds by optimizing their activity and specificity using rational drug design. The Specific Aims are as follows. Aim 1- Develop a cell-based reporter HTS for inhibitors of SOS induction. Aim 2-Screen a diverse compound library, identify, and confirm inhibitors of SOS induction. Aim 3-Validate confirmed SOS inhibitors using secondary assays and identify a validated Hit series. Aim 4-Determine mechanism of action of Validated Hits/Identify target. PUBLIC HEALTH RELEVANCE: Bacteria respond to environmental insults by producing proteins that increase their survival. Several antibiotics that are currently used to treat bacterial infections, such as ampicillin, amoxacillin, and ciprofloxacin, activate the production of a set of proteins collectively referred to as the SOS response. This important stress response plays a critical role in repairing DNA damage and increasing tolerance to DNA damaging agents. Bacteria that are unable to activate the SOS response are highly sensitive to the antibiotics listed above and are less likely to develop resistance. The goal of this project is to discover drugs that prevent SOS activation and increase the efficacy of several important antibiotics.