Epstein-Barr virus reprograms human B-lymphocytes immediately in the pre-latent phase of infection

Abstract

Epstein-Barr virus (EBV) is a human tumor virus and a model of herpesviral latency. The virus efficiently infects resting human B-lymphocytes and induces their continuous proliferation in vitro, which mimics certain aspects of EBV’s oncogenic potential in vivo. This seminal finding was made 50 years ago, but how EBV activates primary human B-lymphocytes and how lymphoblastoid cell lines (LCLs) evolve from the EBV-infected lymphocytes is uncertain. We conducted a systematic time-resolved longitudinal study of cellular functions and transcriptional profiles of newly infected naïve primary B-lymphocytes. EBV reprograms these human cells comprehensively and globally. Rapid and extensive transcriptional changes occur within 24 hours of infection and precede any metabolic and phenotypic changes. Within the next 48 hours, the virus activates the cells, changes their phenotypes with respect to cell size, RNA and protein content and induces metabolic pathways to cope with the increased demand for energy, supporting an efficient cell cycle entry on day three post infection. The transcriptional program that EBV initiates consists of three waves of clearly discernable clusters of cellular genes that peak on day one, two, or three and regulate RNA synthesis, metabolic pathways and cell division, respectively. Upon the onset of cell doublings on day four the cellular transcriptome appears to be completely reprogrammed to support the activated and proliferating cell, but three additional clusters of EBV regulated genes adjust the infected immune cells to fine-tune cell signaling, migration, and immune response pathways, eventually. Our study reveals that more than 98 % of the 13,000 expressed genes in B-lymphocytes are regulated upon infection demonstrating that EBV governs the entire biology of its target cell.

From infection to cancer: how DNA tumour viruses alter host cell central carbon and lipid metabolism

“…The effects of EBV infection on B cell glucose metabolism have been investigated for many years, and it has been established that the overall metabolic profile of EBV-infected B cells is altered 3 days post infection. In agreement with these findings, glucose uptake increases following EBV infection within 4 days [6]. In proliferation-arrested EBV-infected primary B cells, decreased expression of genes involved in the tricarboxylic acid (TCA) cycle and oxidative phosphorylation compared to other B cell populations was observed, which could lead to the promotion of autophagy and senescence [7].…”

The first days in the life of naïve human B-lymphocytes infected with Epstein-Barr virus

“…(Fig. 2 and Mrozek-Gorska et al, 2019). Similarly, the inferred volume of the cells increased from 87x10 -18 m 3 to 357x10 -18 m 3 on day 4 p.i.…”

“…We also learnt that the newly infected cells express very high levels of EBNA2 initially (Fig. 12A, Mrozek-Gorska et al, 2019), which now appear sufficient to reprogram the infected cells until other latent viral gene products support and stabilize the reprogrammed cells long-term. Such a secondary role has been proposed for LMP1 (Price et al, 2012).…”

“…( Fig. 12A, Mrozek-Gorska et al, 2019) probably causes the timely expression of MYC to reach its highest level on day 2 p.i. (Fig.…”

“…7) and the volumes of cells were calculated assuming a spherical shape. The incorporation of TMRE has been described recently (Mrozek-Gorska et al, 2019).…”