Department of Molecular Microbiology and Immunology, and the South Texas Center for Emerging Infectious Diseases, University of Texas at San Antonio, San Antonio, Texas, USA.
Antimicrob Agents Chemother. 2024 Oct 8;68(10):e0079324. doi: 10.1128/aac.00793-24. Epub 2024 Sep 10.
parasite resistance to antimalarial drugs is a serious threat to public health in malaria-endemic areas. Compounds that target core cellular processes like translation are highly desirable, as they should be capable of killing parasites in their liver and blood stage forms, regardless of molecular target or mechanism. Assays that can identify these compounds are thus needed. Recently, specific quantification of native liver stage protein synthesis, as well as that of the hepatoma cells supporting parasite growth, was achieved via automated confocal feedback microscopy of the o-propargyl puromycin (OPP)-labeled nascent proteome, but this imaging modality is limited in throughput. Here, we developed and validated a miniaturized high content imaging (HCI) version of the OPP assay that increases throughput, before deploying this approach to screen the Pathogen Box. We identified only two hits; both of which are parasite-specific quinoline-4-carboxamides, and analogs of the clinical candidate and known inhibitor of blood and liver stage protein synthesis, DDD107498/cabamiquine. We further show that these compounds have strikingly distinct relationships between their antiplasmodial and translation inhibition efficacies. These results demonstrate the utility and reliability of the liver stage OPP HCI assay for the specific, single-well quantification of and human protein synthesis in the native cellular context, allowing the identification of selective translation inhibitors with the highest potential for multistage activity.
疟原虫对抗疟药物的耐药性是疟疾流行地区公共卫生的严重威胁。针对翻译等核心细胞过程的化合物是非常理想的,因为它们应该能够杀死肝脏和血液阶段的寄生虫,而不论其分子靶标或机制如何。因此,需要能够识别这些化合物的检测方法。最近,通过对 OPP 标记的新生蛋白质组进行自动化共聚焦反馈显微镜检测,实现了对天然肝期蛋白合成以及支持寄生虫生长的肝癌细胞的特异性定量,但这种成像方式的通量有限。在这里,我们开发并验证了 OPP 检测的微型化高内涵成像 (HCI) 版本,该版本提高了通量,然后我们将该方法用于筛选病原体盒。我们只鉴定出两个命中物;两者都是寄生虫特异性的喹啉-4-羧酰胺,是临床候选药物和已知的血液和肝脏阶段蛋白合成抑制剂 DDD107498/卡巴米嗪的类似物。我们进一步表明,这些化合物在抗疟和翻译抑制功效之间存在明显不同的关系。这些结果证明了肝期 OPP HCI 检测方法在天然细胞环境中对和人蛋白质合成的特异性、单孔定量的实用性和可靠性,允许鉴定具有最高多阶段活性潜力的选择性翻译抑制剂。