Research Centre for Infectious Diseases, Institute for Molecular Infection Biology, Julius Maximilian University of Wuerzburg, Wuerzburg, Germany.
Department of General, Visceral, Vascular and Paediatric Surgery, University Hospital of Wuerzburg, Wuerzburg, Germany.
PLoS Pathog. 2021 Feb 17;17(2):e1009210. doi: 10.1371/journal.ppat.1009210. eCollection 2021 Feb.
Epstein-Barr virus (EBV) is best known for infection of B cells, in which it usually establishes an asymptomatic lifelong infection, but is also associated with the development of multiple B cell lymphomas. EBV also infects epithelial cells and is associated with all cases of undifferentiated nasopharyngeal carcinoma (NPC). EBV is etiologically linked with at least 8% of gastric cancer (EBVaGC) that comprises a genetically and epigenetically distinct subset of GC. Although we have a very good understanding of B cell entry and lymphomagenesis, the sequence of events leading to EBVaGC remains poorly understood. Recently, ephrin receptor A2 (EPHA2) was proposed as the epithelial cell receptor on human cancer cell lines. Although we confirm some of these results, we demonstrate that EBV does not infect healthy adult stem cell-derived gastric organoids. In matched pairs of normal and cancer-derived organoids from the same patient, EBV only reproducibly infected the cancer organoids. While there was no clear pattern of differential expression between normal and cancer organoids for EPHA2 at the RNA and protein level, the subcellular location of the protein differed markedly. Confocal microscopy showed EPHA2 localization at the cell-cell junctions in primary cells, but not in cancer cell lines. Furthermore, histologic analysis of patient tissue revealed the absence of EBV in healthy epithelium and presence of EBV in epithelial cells from inflamed tissue. These data suggest that the EPHA2 receptor is not accessible to EBV on healthy gastric epithelial cells with intact cell-cell contacts, but either this or another, yet to be identified receptor may become accessible following cellular changes induced by inflammation or transformation, rendering changes in the cellular architecture an essential prerequisite to EBV infection.
EB 病毒(EBV)最为人所知的是感染 B 细胞,通常在 B 细胞中建立无症状的终身感染,但也与多种 B 细胞淋巴瘤的发展有关。EBV 还感染上皮细胞,与所有未分化鼻咽癌(NPC)病例有关。EBV 与至少 8%的胃癌(EBVaGC)有病因学联系,后者包括 GC 中遗传和表观遗传上不同的亚群。尽管我们对 B 细胞进入和淋巴瘤发生有了很好的了解,但导致 EBVaGC 的事件序列仍知之甚少。最近, Ephrin 受体 A2(EPHA2)被提议作为人癌细胞系的上皮细胞受体。尽管我们确认了其中的一些结果,但我们证明 EBV 不会感染健康的成人干细胞衍生的胃类器官。在来自同一患者的正常和癌症衍生类器官的配对中,只有癌症类器官可重复性地感染 EBV。虽然在 RNA 和蛋白质水平上,EPHA2 在正常和癌症类器官之间没有明显的差异表达模式,但蛋白质的亚细胞定位有明显差异。共聚焦显微镜显示,EPHA2 在原代细胞的细胞-细胞连接处定位,但不在癌症细胞系中。此外,对患者组织的组织学分析显示,健康上皮组织中不存在 EBV,而炎症组织中的上皮细胞存在 EBV。这些数据表明,在具有完整细胞-细胞接触的健康胃上皮细胞中,EPHA2 受体对 EBV 不可用,但在炎症或转化诱导的细胞变化后,这种或另一种尚未确定的受体可能变得可用,使细胞结构的变化成为 EBV 感染的必要前提。