Epstein - Barr virus Encoded EBER RNAs
Author(s)
Bosshard, Rachel
Type
Thesis
Abstract
Epstein-Barr virus (EBV) establishes a lifelong latent infection in 95% of the world’s
population and is associated with several human cancers. Some of the most abundant viral
products in latent infection are the functional EBV-encoded RNAs EBER1 and EBER2.
The aim of this thesis was the identification of distinct functions of EBER1 and EBER2
during EBV infection.
Epstein-Barr virus bacterial artificial chromosomes with deletion of either EBER1 or
EBER2 and corresponding revertant viral genomes were constructed to analyse broad
range effects of EBER1 or EBER2 on host cell gene expression. The resulting
recombinant viruses were used to infect primary B lymphocytes and establish
lymphoblastoid cell lines (LCLs). Microarray expression profiling revealed clear
changes in host cell gene expression correlating with EBER expression and significant
differences between gene sets regulated with EBER1 and EBER2. Functions of EBER
target genes include membrane signalling, regulation of apoptosis and the interferon
response.
In additional studies, the interaction of EBER1 with ribosomal protein L22 (RPL22), a
component of the large ribosomal subunit, was demonstrated in LCL extracts. Using
recombinant viruses and EBER expression vectors, the nuclear redistribution of RPL22
by EBER1 was investigated. The delocalisation of RPL22 from nucleoli into the
nucleoplasm upon EBV infection was demonstrated in HEK 293, nasopharyngeal
carcinoma and gastric carcinoma-derived cell lines. EBER1 was identified as the only
viral component necessary for the delocalisation of RPL22. In contrast to the
cancer-derived cell lines, LCLs showed a predominantly cytoplasmic expression of
RPL22, which was not significantly changed by EBER1. Subsequently, a possible role of
RPL22 and EBER1 in p53-dependent stress responses was explored.
The data presented in this thesis provide further understanding of the role of EBERs in
EBV infection and several of the EBER-regulated genes might be used as markers to
elucidate the mechanism of EBER action.
population and is associated with several human cancers. Some of the most abundant viral
products in latent infection are the functional EBV-encoded RNAs EBER1 and EBER2.
The aim of this thesis was the identification of distinct functions of EBER1 and EBER2
during EBV infection.
Epstein-Barr virus bacterial artificial chromosomes with deletion of either EBER1 or
EBER2 and corresponding revertant viral genomes were constructed to analyse broad
range effects of EBER1 or EBER2 on host cell gene expression. The resulting
recombinant viruses were used to infect primary B lymphocytes and establish
lymphoblastoid cell lines (LCLs). Microarray expression profiling revealed clear
changes in host cell gene expression correlating with EBER expression and significant
differences between gene sets regulated with EBER1 and EBER2. Functions of EBER
target genes include membrane signalling, regulation of apoptosis and the interferon
response.
In additional studies, the interaction of EBER1 with ribosomal protein L22 (RPL22), a
component of the large ribosomal subunit, was demonstrated in LCL extracts. Using
recombinant viruses and EBER expression vectors, the nuclear redistribution of RPL22
by EBER1 was investigated. The delocalisation of RPL22 from nucleoli into the
nucleoplasm upon EBV infection was demonstrated in HEK 293, nasopharyngeal
carcinoma and gastric carcinoma-derived cell lines. EBER1 was identified as the only
viral component necessary for the delocalisation of RPL22. In contrast to the
cancer-derived cell lines, LCLs showed a predominantly cytoplasmic expression of
RPL22, which was not significantly changed by EBER1. Subsequently, a possible role of
RPL22 and EBER1 in p53-dependent stress responses was explored.
The data presented in this thesis provide further understanding of the role of EBERs in
EBV infection and several of the EBER-regulated genes might be used as markers to
elucidate the mechanism of EBER action.
Date Issued
2012
Date Awarded
2012-06
Copyright Statement
Attribution NoDerivatives 4.0 International Licence (CC BY-ND)
Advisor
Farrell, Paul
Publisher Department
Medicine: Division of Infectious Diseases
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)