Cellular gene expression that correlates with EBER expression in Epstein-Barr Virus-infected lymphoblastoid cell...

Area of Science:

• Virology
• Molecular Biology
• Immunology

Background:

• Epstein-Barr Virus (EBV) is a human herpesvirus associated with various cancers.
• Epstein-Barr Virus-encoded small RNAs (EBERs), including EBER1 and EBER2, are highly expressed during latency.
• The precise functions of EBERs in host cell modulation remain incompletely understood.

Purpose of the Study:

• To investigate the distinct roles of EBER1 and EBER2 in modulating host cell gene expression.
• To identify cellular pathways regulated by the presence or absence of EBER1 and EBER2.
• To explore the impact of EBERs on B cell transformation and lymphoblastoid cell line (LCL) growth.

Main Methods:

• Construction of novel EBV strains with deletions in EBER1 or EBER2, and corresponding revertant viruses.
• Infection of primary B lymphocytes to generate lymphoblastoid cell lines (LCLs).
• Microarray expression profiling of LCLs to identify differentially expressed genes.
• Analysis of ribosomal protein L22 (rpL22) localization using recombinant viruses and expression vectors.

Main Results:

• Deletion of EBER2 led to greater changes in LCL gene expression compared to EBER1 deletion, despite EBER1's higher abundance.
• Regulated genes were involved in membrane signaling, apoptosis, and interferon/antiviral responses.
• EBER1 and EBER2 deletions had minimal impact on EBV-mediated B cell transformation frequency and LCL growth.
• Nuclear redistribution of rpL22 by EBER1 was observed in 293 cells but not significantly in LCLs, where rpL22 was predominantly cytoplasmic.

Conclusions:

• EBER2 plays a more significant role than EBER1 in modulating host gene expression in LCLs.
• EBER RNAs influence key cellular pathways, including immune responses and apoptosis.
• The findings provide a foundation for elucidating the mechanisms by which EBER RNAs exert their functions.