Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, MI, USA.
Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA.
J Antibiot (Tokyo). 2014 May;67(5):379-86. doi: 10.1038/ja.2014.10. Epub 2014 Feb 19.
VirF is an AraC-type transcriptional regulator responsible for activating the transcription of virulence genes required for the intracellular invasion and cell-to-cell spread of Shigella flexneri. Gene disruption studies have validated VirF as a potential target for an anti-virulence therapy to treat shigellosis by determining that VirF is necessary for virulence, but not required for bacterial viability. Using a bacteria-based, β-galactosidase reporter assay we completed a high-throughput screening (HTS) campaign monitoring VirF activity in the presence of over 140,000 small molecules. From our screening campaign, we identified five lead compounds to pursue in tissue culture-based invasion and cell-to-cell spread assays, and toxicity screens. Our observations of activity in these models for infection have validated our approach of targeting virulence regulation and have allowed us to identify a promising chemical scaffold from our HTS for hit-to-lead development. Interestingly, differential effects on invasion versus cell-to-cell spread suggest that the compounds' efficacies may depend, in part, on the specific promoter that VirF is recognizing.
VirF 是一种 AraC 型转录调节因子，负责激活志贺氏菌属细胞内入侵和细胞间传播所必需的毒力基因的转录。基因敲除研究已经验证了 VirF 是一种抗毒力治疗志贺氏菌病的潜在靶点，因为研究表明 VirF 对毒力是必需的，但对细菌的生存力不是必需的。我们使用基于细菌的β-半乳糖苷酶报告基因检测法，在超过 14 万种小分子存在的情况下，完成了一项高通量筛选（HTS）活动，以监测 VirF 的活性。在筛选活动中，我们确定了五种先导化合物，用于组织培养侵袭和细胞间传播试验以及毒性筛选。我们在这些感染模型中的活性观察验证了我们靶向毒力调节的方法，并使我们能够从 HTS 中确定一个有前途的化学支架，用于从命中到先导的开发。有趣的是，对侵袭和细胞间传播的不同影响表明，化合物的疗效可能部分取决于 VirF 识别的特定启动子。
