Zanghi Gigliola, Patel Hardik, Camargo Nelly, Smith Jenny L, Bae Yeji, Flannery Erika L, Chuenchob Vorada, Fishbaugher Matthew E, Mikolajczak Sebastian A, Roobsoong Wanlapa, Sattabongkot Jetsumon, Hayes Kiera, Vaughan Ashley M, Kappe Stefan H I
Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, United States of America.
Research Scientific Computing, Seattle Children's Research Institute, Seattle, Washington, United States of America.
bioRxiv. 2023 Jan 5:2023.01.05.522945. doi: 10.1101/2023.01.05.522945.
() is causing the greatest malaria burden, yet the liver stages (LS) of this most important parasite species have remained poorly studied. Here, we used a human liver-chimeric mouse model in combination with a novel fluorescent NF54 parasite line (NF54GFP) to isolate LS-infected hepatocytes and generate transcriptomes that cover the major LS developmental phases in human hepatocytes. RNA-seq analysis of early LS trophozoites two days after infection, revealed a central role of translational regulation in the transformation of the extracellular invasive sporozoite into intracellular LS. The developmental time course gene expression analysis indicated that fatty acid biosynthesis, isoprenoid biosynthesis and iron metabolism are sustaining LS development along with amino acid metabolism and biosynthesis. Countering oxidative stress appears to play an important role during intrahepatic LS development. Furthermore, we observed expression of the variant PfEMP1 antigen-encoding genes, and we confirmed expression of PfEMP1 protein during LS development. Transcriptome comparison of the late liver stage schizonts with () late liver stages revealed highly conserved gene expression profiles among orthologous genes. A notable difference however was the expression of genes regulating sexual stage commitment. While schizonts expressed markers of sexual commitment, the LS parasites were not sexually committed and showed expression of gametocytogenesis repression factors. Our results provide the first comprehensive gene expression profile of the human malaria parasite LS isolated during intrahepatocytic development. This data will inform biological studies and the search for effective intervention strategies that can prevent infection.
（某物种）正造成最大的疟疾负担，然而这种最重要的寄生虫物种的肝期（LS）却一直未得到充分研究。在此，我们使用人肝嵌合小鼠模型结合一种新型荧光NF54寄生虫株（NF54GFP）来分离受LS感染的肝细胞，并生成涵盖人肝细胞中主要LS发育阶段的转录组。对感染两天后的早期LS滋养体进行RNA测序分析，揭示了翻译调控在细胞外侵袭性子孢子向细胞内LS转化中的核心作用。发育时间进程基因表达分析表明，脂肪酸生物合成、类异戊二烯生物合成和铁代谢与氨基酸代谢和生物合成一起维持着LS的发育。抵抗氧化应激似乎在肝内LS发育过程中起重要作用。此外，我们观察到编码变异PfEMP1抗原的基因的表达，并证实了PfEMP1蛋白在LS发育过程中的表达。将晚期肝期裂殖体的转录组与（某物种）晚期肝期进行比较，发现直系同源基因之间的基因表达谱高度保守。然而，一个显著差异是调节性阶段承诺的基因的表达。虽然裂殖体表达了性承诺的标志物，但LS寄生虫没有性承诺，并显示出配子体发生抑制因子的表达。我们的结果提供了在肝内发育过程中分离出的人类疟原虫LS的首个全面基因表达谱。这些数据将为生物学研究以及寻找可预防感染的有效干预策略提供信息。
