LONDON, UK, 15th January 2026, ZEX PR WIRE, Stelios Tzellos, Ph.D., is the co-author of multiple peer-reviewed research studies focused on gene regulation by the Epstein-Barr virus (EBV), particularly the molecular differences between EBV type 1 and type 2 strains. His contributions to the field of viral oncology and transcriptional regulation were developed during his doctoral training at Imperial College London, where he earned a Ph.D. in Molecular Biology following undergraduate and master’s degrees in Biochemistry.

His work has been published in journals such as the Journal of General Virology, where he is listed as first author on the 2014 study titled “EBV EBNA-2 type 1 and type 2 proteins induce expression of the cellular CXCR7 and EBI2 genes through a mechanism involving a common motif in their transactivation domains.” This study is indexed in PubMed under PMID 25436768.

The study investigates how a single amino acid substitution (S442D) in the EBNA-2 protein from EBV type 2 can convert it to a phenotype more similar to that of type 1 EBNA-2, which is more efficient at transforming B cells. The findings contribute to the understanding of how sequence variation in viral proteins can lead to differences in their ability to activate both viral and host cell genes involved in cell proliferation and transformation.

The researchers found that type 1 EBNA-2 induced stronger activation of the viral LMP-1 gene and the cellular CXCR7 gene, both of which are associated with enhanced B-cell growth and survival. Using chromatin immunoprecipitation (ChIP) assays, the study showed that type 1 EBNA-2 had stronger binding to regulatory regions of these genes compared to type 2 EBNA-2. Motif analysis identified an ETS-IRF composite element that may account for these differences in transcriptional activation.

This work adds to the field’s understanding of how EBV contributes to the development of lymphoproliferative diseases and certain types of cancer. The research has implications for the study of viral oncogenesis and may inform future therapeutic approaches that target EBV-mediated signaling pathways.

In addition to the 2014 study, Stelios Tzellos is listed as a co-author on other EBV-related publications that investigate the molecular basis of differential gene activation by EBNA-2. These include contributions to studies that used 5′ RACE to identify transcription start sites in EBNA-2-regulated genes and that evaluated how amino acid changes influence protein-DNA interactions at key promoter regions.

During his time at Imperial College London, Dr. Tzellos worked in a laboratory environment applying molecular biology techniques such as site-directed mutagenesis, luciferase reporter assays, and chromatin immunoprecipitation to explore these mechanisms. His work involved generating and testing EBNA-2 variants to better understand how small sequence changes can result in functional differences in gene expression.

Although he transitioned to a career in pharmaceutical analytics and forecasting after completing his Ph.D., Dr. Tzellos’ academic work continues to be cited in molecular virology and EBV-related research. His publications remain part of the foundational literature exploring the transcriptional control functions of EBV nuclear antigens and their relevance to B-cell biology.

For access to the full publication, readers may refer to:
PubMed: PMID 25436768

Dr. Tzellos currently resides in the United Kingdom and continues to work in the pharmaceutical sector in analytics roles. His early scientific work in viral gene regulation continues to inform his approach to evidence evaluation and scientific rigor.