Role of EBV in Human Normal Epithelial Cell Differentiation (I)

Epstein-Barr virus (EBV) infection of human B lymphocytes and epithelial cells is through different routes; virus mainly establishes latent infection in B cells, but esters lytic replication cycles in epithelial cell. It has been noted that EBV undergoes lytic replication in oropharyngeal epithelial, resulting in production of infectious viral particles evident by EBV in saliva of patients with infectious mononucleosis, and in lesions of oral hairy leukoplakia. EBV is also present in nasopharyngeal carcinoma (NPC) tissues; however, virus maintains in latent infection satge. In addition, EBV infection of epithelial cells has not been demonstrated in normal nasopharyngeal biopsies from individuals at high risk of developing NPC. Thus, it is interesting and important to understand what the difference is between cells from these two sites in response to EBV infection. In this study, we plan to evaluate and identify the viral genes and cellular genes that express in EBV-infected human normal epithelial cells from oropharynx and nasopharynx grown on raft culture (to mimic in vivo epithelial cell differentiation). We plan to identify the EBV genes and cell-differentiation associated genes that express in the raft culture cells. We will then examine the effect of EBV infection on cellular differentiation based on the genes with altered expression. EBV-encoded oncogene product latent membrane protein 1 (LMP1) can inhibit epithelial cell differentiation. Thus, we will investigate the effect of LMP1 on epithelial cell differentiation of EBV-infected raft culture. To systematically analyze EBV gene expression and cellular differentiation gene expression, an EBV array and a human CpG DNA array will be used. The EBV genomic library and the CpG DNA library will be used. EBV array and CpG DNA array will be generated using the facility in Chang-Gung Microarray Center located in Chang-Gung Memorial Hospital. To identify the targeted cell differentiation-associated genes, the CHIP-on-the-chip assay, focusing on epithelial-cell differentiation-specific AP1, NF-κB, and Ets -mediated gene regulation will be performed. In this research plan, we intend to understand the relationship of EBV infection and normal epithelial cell differentiation, and the role of LMP1 in this process. This study may allow us to explore the multi-step pathogenesis of NPC.

Project ID:PA9405-0118
External Project ID:NSC94-3112-B182-005