Research Projects
Molecular Mechanism of Epstein-Barr Virus Persistence and Transformation

Objective and Significance:

Epstein-Barr virus (EBV) persistently infects 95% of adult population but causes lymphocytic and epithelial malignancies in a small subset of people. Among EBVassociated cancers, nasopharyngeal carcinoma (NPC) is particularly prevalent in Hong Kong and adjacent areas of China. Neither vaccines nor specific antivirals are available for prevention or treatment EBV infection. In nasopharyngeal epithelial cells latently infected with EBV, only a limited number of viral genes are expressed. It is not known which of these genes might be critical in governing viral persistence and oncogenesis. This key question remains unanswered for many decades due to technical difficulties. Particularly, there was no BAC clone for NPC-derived EBV. On the other hand, manipulation of EBV genes is another technical challenge. The recent availability of an epitheliotropic EBV strain M81 and the new development of CRISPR/Cas9 technology allow us to revisit this question with the aim of providing an unambiguous clue. We have been in a leading position internationally in the application of CRISPR/Cas9 technology in EBV research.

Tacking the question on the roles of EBV latent genes will substantially advance the field by breaking new grounds. In this project, we will further develop the technology platform for CRISPR/ Cas9 editing of EBV genome with three specific aims. First, additional NPCderived EBV strains will be cloned and characterized. Second, genetic study of NPCderived EBV strains will be performed. Particularly, the roles of EBV latent genes in viral infection and transformation of B lymphocytes and nasopharyngeal epithelial cells will be determined. Finally, CRISPR/Cas9 targeting of EBV essential genes will be used to eliminate EBV infection from human cells. Our work will provide new technology platforms for both genetic study and therapeutic cure of EBV. These platforms will also prove useful in combating other DNA viruses such as hepatitis B virus.

Research Plan and Methodology:

Methods for targeted editing of EBV genome by CRISPR/Cas9 have been detailed in our recent paper listed below (Yuen et al, 2015). For cloning of NPC-derived EBV strains, E. coli F factor will be inserted into EBV through CRISPR/Cas9. The complete EBV genome will be recovered in E. coli as a bacterial artificial chromosome (BAC). For genetic study of NPC-derived EBV, a combination of BAC and CRISPR/Cas9 technologies will be employed. Viral genes expressed in latently infected nasopharyngeal epithelial cells will be knocked out one by one. The impact on viral persistence and transformation will be assessed. For cure of EBV infection in human epithelial cells, CRISPR/Cas9 targeting of EBNA1 gene and OriP absolutely required for EBV infection will be conducted in EBVinfected nasopharyngeal carcinoma cells. A replication-defective recombinant EBV that facilitates the elimination of wild-type EBV will also be designed and used to deliver the CRISPR/Cas9 system to EBV-infected cells.

Professor DY Jin, School of Biomedical Sciences

Biography
dyjin@hku.hk

For more information or to express interest for this project, please email the supervisor or the specified contact point in the project description.  Interested candidates are advised to enclose with your email:

1. your CV,
2. a brief description of your research interest and experience, and
3. two reference letters (not required for HKUMed UG students seeking MRes[Med]/URIS projects).

Information on the research programme, funding support and admission documentations could be referenced online at the Research Postgraduate Admissions website. General admission enquiries should be directed to rpgmed@hku.hk.

HKUMed MBBS students interested in the Master of Research in Medicine (MRes[Med]) programme may visit the programme website for more information.  

HKUMed UG students interested in the Undergraduate Research Internship Scheme (URIS) may visit the scheme’s website for more information.