Jacqueline Jackson, MS

Research Topic: Expression of Epstein Barr Virus Latency Genes

Research Description: Epstein-Barr virus (EBV) positive epithelial cancers, such as gastric carcinomas and nasopharyngeal carcinomas, have been difficult to study in part due to the lack of a ‘normal’ keratinocyte cell line that can be efficiently infected by EBV and then harbor and replicate the EBV genome while maintaining long-term infection. The Kenny laboratory established a Normal Oral telomerase-immortalized Keratinocyte (NOK) cell line infected with EBV. EBV infected cells can harbor three different type of EBV latency programs. Jacqueline Jackson performed RT-PCR analysis to examine the expression of different EBV latency genes, and showed that EBV-infected NOKs have the most stringent form of EBV latency (type 1), and thus express only the EBV nuclear antigen 1 (EBNA1) protein along with viral microRNAs and the small non-coding nuclear RNAs (EBERs). She showed that NOKs cell lines maintain low levels of lytic reactivation which is increased by treatment of cells with the phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA). Interestingly, the RT-PCR analysis also suggested that the viral BNLF2a gene, previously shown to be expressed in B-cells only during lytic infection, may also be expressed in EBV-infected NOKs epithelial cells during latent infection. This is a potentially important discovery because BNLF2a has been shown to inhibit transportation and presentation of antigens on the cell surface of infected cells, thus causing a defect in host immune response. Jacqueline then asked whether EBV-infected and uninfected NOKs retain the ability to respond to interferon alpha and transforming growth factor beta (TGF-β). She confirmed that NOKs (EBV-positive as well as EBV-negative) retain the ability to activate pStat1 and pSmad2 in response to interferon alpha (INF-α) and (TGF-β) respectively, functions that are lost in most established epithelial carcinoma cell lines currently used. To further characterize the phenotypic effects of EBV infection in NOKs, Jacqueline carried out growth and survival assays with varying concentrations of growth factor supplements to determine whether EBV will offer a growth advantage to infected cells. She also performed microarray studies to compare the cellular gene expression of EBV positive versus EBV negative NOKs and identified a number of interesting cellular genes that are differentially regulated in the cells. These studies may help determine whether down regulation (or activation) of these confirmed cellular genes in NOKs cells by EBV confers a growth advantage.

Ms. Jackson is currently a production scientist at Promega, Inc.