Investigating the germinal centre biology of an authentic Epstein-Barr virus strain
File(s)
Author(s)
Li, Anrong
Type
Thesis
Abstract
Epstein-Barr virus (EBV) is a gamma-herpesvirus that infects most of the human population. Although most EBV infection cases are asymptomatic, they are associated with different cancers and autoimmune diseases.
As a herpesvirus, EBV switches between lytic and latent states. The most widely accepted hypothesis of EBV latency establishment (suggested by Thorley-Lawson’s lab) is that viruses exploit the mechanism of the germinal centre (GC) reaction, so the EBV-infected B cells are differentiated into latent memory B cells with plasma cell differentiation, allowing lytic reactivation. In addition, a recent single-cell RNA sequencing experiment showed that EBV-positive lymphoblastoid cell lines (LCLs) exhibited heterogeneity, with some cells showing a germinal centre reaction phenotype.
Both cancer- and lab-adapted EBV strains are widely used as models of EBV. However, these EBVs have mutations and do not exhibit the natural biology of EBV. Thus, a new authentic EBV strain helps determine the true biology of EBV-infected B cells.
To study the germinal centre biology of EBV-infected B cells, a cloning strategy was developed to capture the EBV genome from the lymphoblastoid cell line BM209-2. Then, the BM209-2 virus was characterised: this reportedly Kenya-derived EBV strain was similar to East-Asian EBVs. B cells infected with BM209-2, unlike the common lab EBV strain B95-8, predominantly differentiated into antibody-secreting cells, whereas the transformation of naïve B cells was inefficient. Finally, flow cytometry was used to study the heterogeneity of EBV-infected B cells at the early stage of infection and LCLs. These analyses showed that: (a) Naïve and memory B cells had distinct EBV-driven differentiation pathways. (b) EBV-infected B cells exhibited a GC phenotype. (c) The latent protein EBNA3B was essential for the GC phenotype of infected B cells. (d) The Ig isotypes on B cells changed after EBV infection. (f) EBV infection inhibited the transport of BCRs to cell membranes.
As a herpesvirus, EBV switches between lytic and latent states. The most widely accepted hypothesis of EBV latency establishment (suggested by Thorley-Lawson’s lab) is that viruses exploit the mechanism of the germinal centre (GC) reaction, so the EBV-infected B cells are differentiated into latent memory B cells with plasma cell differentiation, allowing lytic reactivation. In addition, a recent single-cell RNA sequencing experiment showed that EBV-positive lymphoblastoid cell lines (LCLs) exhibited heterogeneity, with some cells showing a germinal centre reaction phenotype.
Both cancer- and lab-adapted EBV strains are widely used as models of EBV. However, these EBVs have mutations and do not exhibit the natural biology of EBV. Thus, a new authentic EBV strain helps determine the true biology of EBV-infected B cells.
To study the germinal centre biology of EBV-infected B cells, a cloning strategy was developed to capture the EBV genome from the lymphoblastoid cell line BM209-2. Then, the BM209-2 virus was characterised: this reportedly Kenya-derived EBV strain was similar to East-Asian EBVs. B cells infected with BM209-2, unlike the common lab EBV strain B95-8, predominantly differentiated into antibody-secreting cells, whereas the transformation of naïve B cells was inefficient. Finally, flow cytometry was used to study the heterogeneity of EBV-infected B cells at the early stage of infection and LCLs. These analyses showed that: (a) Naïve and memory B cells had distinct EBV-driven differentiation pathways. (b) EBV-infected B cells exhibited a GC phenotype. (c) The latent protein EBNA3B was essential for the GC phenotype of infected B cells. (d) The Ig isotypes on B cells changed after EBV infection. (f) EBV infection inhibited the transport of BCRs to cell membranes.
Version
Open Access
Date Issued
2025-04-24
Date Awarded
01/12/2025
Advisor
White, Rob
Denton, Alice
Publisher Department
Department of Infectious Disease
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)