Lam Melanie, Probst Alexandra, Torres Laura, Lantigua Ashley A, Fishbaugher Matthew E, Kumar Jyothsna R, Saldivia Manuel, Torres Allison, Hegde Shreeya, Aleshnick Maya, Jennison Charlie, Roberson Sarah G H, Joyner Chester J, Vaughan Ashley M, Wilder Brandon K, Manneville Carole, Flannery Erika L, Marcellin David, Nyfeler Beat, Thiel Zacharias, Mikolajczak Sebastian A, Harupa Anke, Mitchell Gabriel
Open Innovation at Global Health Disease Area, Biomedical Research, Novartis, Emeryville, CA, USA.
Global Health Disease Area, Biomedical Research, Novartis, Emeryville, CA, USA.
Sci Rep. 2025 May 26;15(1):18323. doi: 10.1038/s41598-025-98257-9.
Targeted protein degradation (TPD) is a novel strategy for developing therapeutics against pathogens. Prior to causing malaria, Plasmodium parasites replicate within hepatocytes as liver stages, surrounded by a parasitophorous vacuole membrane (PVM). We hypothesized that TPD can be employed to trigger host-driven degradation of essential liver stage PVM proteins and lead to parasite death. To explore this, we took advantage of the proteolysis-targeting-chimera HaloPROTAC3, a molecule that recruits the host von Hippel-Lindau (VHL) E3 ligase to the HaloTag (HT). Parasites expressing HT fused to the host cytosol-exposed domain of the PVM protein UIS4 (UIS4-HT) were generated in Plasmodium berghei and Plasmodium cynomolgi, but only P. berghei UIS4-HT enabled productive liver stage infection experiments in vitro. Although HaloPROTAC3 triggered the degradation of HT proteins in host cells, it had no impact on the survival of P. berghei UIS4-HT liver stages. Furthermore, HaloPROTAC3 bound to P. berghei UIS4-HT but did not recruit VHL or trigger ubiquitination of the PVM. Overall, although this study did not establish whether host-driven TPD can degrade Plasmodium PVM proteins, it highlights the challenges of developing TPD approaches against novel targets and offers insights for advancing this therapeutic strategy against pathogens.
靶向蛋白质降解（TPD）是一种开发抗病原体疗法的新策略。在引发疟疾之前，疟原虫作为肝期在肝细胞内复制，被一个寄生泡膜（PVM）包围。我们假设TPD可用于触发宿主驱动的对肝期必需PVM蛋白的降解并导致寄生虫死亡。为了探索这一点，我们利用了靶向蛋白水解嵌合体HaloPROTAC3，这是一种将宿主冯·希佩尔-林道（VHL）E3连接酶募集到HaloTag（HT）的分子。在伯氏疟原虫和食蟹猴疟原虫中产生了表达与PVM蛋白UIS4的宿主胞质暴露结构域融合的HT（UIS4-HT）的寄生虫，但只有伯氏疟原虫UIS4-HT能够在体外进行有效的肝期感染实验。尽管HaloPROTAC3触发了宿主细胞中HT蛋白的降解，但它对伯氏疟原虫UIS4-HT肝期的存活没有影响。此外，HaloPROTAC3与伯氏疟原虫UIS4-HT结合，但没有募集VHL或触发PVM的泛素化。总体而言，尽管这项研究没有确定宿主驱动的TPD是否能降解疟原虫PVM蛋白，但它突出了开发针对新靶点的TPD方法所面临的挑战，并为推进针对病原体的这种治疗策略提供了见解。
