Kline Ian, Mokry Rebekah L, Xi Yuecheng, Manzano Magí Passols, Layesa Sidnie, Ali Nowroz Sohrab, Moy Melissa A, Goodrum Felicia D, Purdy John G
Department of Immunobiology, University of Arizona, Tucson, Arizona, USA.
BIO5 Institute, University of Arizona, Tucson, Arizona, USA.
bioRxiv. 2025 Mar 6:2025.03.06.641752. doi: 10.1101/2025.03.06.641752.
Human cytomegalovirus (HCMV) infection reprograms metabolism, including lipid synthesis. While several metabolite-related pathways have been demonstrated to have altered activity in infected cells, the alteration of lipid-related pathways by HCMV has not been examined beyond fatty acid synthesis and elongation. In this study, we addressed this lack of understanding by focusing on phosphatidylcholine (PC), a class of lipids we previously showed is increased by HCMV infection in human foreskin fibroblasts. Here, we found that HCMV infection increases the abundance of PCs in several different fibroblasts and, similarly, in endothelial and epithelial cells. Additionally, HCMV elevates PC levels regardless of the level of confluency, type of growth medium, and presence of serum. Next, we investigated if HCMV alters the activity in the three PC synthesis pathways. We demonstrate that HCMV infection promotes the activity in the PC synthesis pathway using a C-choline isotopic tracer and liquid chromatography high resolution tandem mass spectrometry (LC-MS/MS). Infection did not alter the activity in the other two pathways. Moreover, we examined the kinetics of PC remodeling by HCMV and found that the de novo synthesis pathway is promoted and the PC lipidome shifts 24 hours post infection. That led us to examining if the early stages of replication are sufficient to alter PC levels. After inhibiting late virus replication, we found that HCMV alters the PC lipidome independent of late gene expression. Overall, this work suggests that an immediate-early or early viral protein promotes the reprogramming of host lipid metabolism to ensure the synthesis of a lipidome necessary to support HCMV replication.
人巨细胞病毒（HCMV）感染会重塑代谢，包括脂质合成。虽然已证明几种与代谢物相关的途径在受感染细胞中的活性发生了改变，但除了脂肪酸合成和延长之外，HCMV对脂质相关途径的改变尚未得到研究。在本研究中，我们通过关注磷脂酰胆碱（PC）来解决这一认识不足的问题，我们之前发现一类脂质PC在人包皮成纤维细胞中会因HCMV感染而增加。在此，我们发现HCMV感染会增加几种不同成纤维细胞以及内皮细胞和上皮细胞中PC的丰度。此外，无论汇合程度、生长培养基类型和血清的存在情况如何，HCMV都会提高PC水平。接下来，我们研究了HCMV是否会改变三种PC合成途径中的活性。我们使用C-胆碱同位素示踪剂和液相色谱高分辨率串联质谱（LC-MS/MS）证明，HCMV感染促进了PC合成途径中的活性。感染并未改变其他两条途径中的活性。此外，我们研究了HCMV对PC重塑的动力学，发现从头合成途径在感染后24小时得到促进，并且PC脂质组发生了变化。这促使我们研究病毒复制的早期阶段是否足以改变PC水平。在抑制晚期病毒复制后，我们发现HCMV改变PC脂质组与晚期基因表达无关。总体而言，这项工作表明一种立即早期或早期病毒蛋白促进了宿主脂质代谢的重编程，以确保合成支持HCMV复制所需的脂质组。
