Institute for Microbiology, Immunology and Hygiene, Technische Universität München, Munich, Germany.
Center for Global Health, TUM School of Medicine, Technische Universität München, Munich, Germany.
PLoS Negl Trop Dis. 2021 May 25;15(5):e0009432. doi: 10.1371/journal.pntd.0009432. eCollection 2021 May.
Anthelminthic treatment options against schistosomiasis are limited. The current treatment relies almost exclusively on a single drug, praziquantel (PZQ). As a consequence, the development of resistance to PZQ and limited activity of PZQ against earlier development stages are respectively a risk and a limitation to achieving the goals of the new WHO roadmap towards elimination. For the discovery of new chemical starting points, the in vitro drug screening on Schistosoma mansoni (S. mansoni) against newly transformed schistosomula (NTS) is still the most predominant approach. The use of only NTS in the initial screening limits sensitivity to potential new compounds which are predominantly active in later developmental stages. Using our recently described highly standardized, straightforward and reliable culture method that generates high rates of juvenile worms, we aimed to repurpose a subset of the National Center for Advancing Translational Sciences (NCATS) Pharmaceutical Collection (340 compounds) to identify new hits with an in vitro worm culture assay.
METHODOLOGY/PRINCIPAL FINDINGS: Cercariae were mechanically transformed into skin-stage (SkS) schistosomula and continuously cultured for 3-6 weeks to the liver stage (LiS). A commercial source of serum was identified, and decrease of NTS/well along with optimal drug testing conditions was established to test compounds on early and late LiS worms. The library was screened in 96-well format assays using praziquantel (PZQ) as a positive control. Primary screening allowed a 5.9% hit rate and generated two confirmed hits on adult worms; a prophylactic antianginal agent and an antihistaminic drug.
With this standardized and reliable in vitro assay, important S. mansoni developmental stages up to LiS worms can be generated and cultured over an extended period. When exposed to a subset of the NCATS Pharmaceutical Collection, 3 compounds yielded a defined anti-schistosomal phenotype on juvenile worms. Translation of activity on perfused adult S. mansoni worms was achieved only for perhexiline (a prophylactic antianginal agent) and astemizole (an antihistaminic drug).
抗血吸虫病的驱虫治疗选择有限。目前的治疗几乎完全依赖于一种药物，即吡喹酮（PZQ）。因此，对 PZQ 的耐药性发展以及 PZQ 对早期发育阶段的有限活性分别是实现新的世界卫生组织消除路线图目标的风险和限制。为了发现新的化学起点，体外药物筛选曼氏血吸虫（S. mansoni）对新转化的尾蚴（NTS）仍然是最主要的方法。在最初的筛选中只使用 NTS 会限制对潜在新化合物的敏感性，这些化合物主要在后期发育阶段具有活性。我们使用最近描述的高度标准化、直接和可靠的培养方法，该方法产生高比例的幼体蠕虫，旨在重新利用国家转化医学科学中心（NCATS）药物库（340 种化合物）的一部分，通过体外蠕虫培养测定来鉴定具有新活性的化合物。
方法/主要发现：通过机械转化尾蚴为皮肤期（SkS）尾蚴，并连续培养 3-6 周至肝期（LiS）。鉴定了一种商业来源的血清，并确定了 NTS/孔的减少以及优化的药物测试条件，以测试早期和晚期 LiS 蠕虫上的化合物。该文库在 96 孔格式测定中进行筛选，使用吡喹酮（PZQ）作为阳性对照。初步筛选的阳性率为 5.9%，并在成虫上产生了两个确认的阳性；一种预防心绞痛药物和一种抗组胺药物。
通过这种标准化和可靠的体外测定，可以生成重要的曼氏血吸虫发育阶段，直至 LiS 蠕虫，并在延长的时间内进行培养。当暴露于 NCATS 药物库的一部分时，3 种化合物在幼体蠕虫上产生了明确的抗血吸虫表型。仅对 perfused 成年曼氏血吸虫蠕虫进行了活性翻译，结果仅为丙吡胺（一种预防心绞痛药物）和阿司咪唑（一种抗组胺药物）。
