Effect of human DAI expressed by an oncolytic vaccinia virus on the gene expression of tumor cells (HS294T) and monocytes (THP-1)

Human melanoma tumor cells (HS294T) and monocytes (THP-1) were infected with a double deleted (-VGF, -TK) oncolytic vaccinia virus expressing human DAI (DNA-dependent activator of interferon-regulatory factors). Total RNA was collected and gene expresson profiles were determined with Agilent microarray. An oncolytic vaccinia virus that does not express DAI was used to control the effect of DAI and uninfected cells (PBS treated) were used to control the effect of virus infection. In oncolytic virotherapy the ability of the virus to activate the immune system against tumors is nowadays generally understood to be a key mechanism in full eradication of cancer and for long-term anti-tumor effects. We armed an oncolytic vaccinia virus with DAI to increase the immunogenicity and the vaccine potency of the virus. The aim of this study was to study if the expression of DAI by a replicating vaccinia virus would alter the gene expression profile of infected cells and to study what are the differentially expressed genes. Three-condition experiment: vvdd-tdTomato-hDAI vs. vvdd-tdTomato vs. PBS treated cells. 2 cell lines: HS294T tumor cells and THP-1 monocytes. 3 biological replicates of virus infected cells per cell line and 2 uninfected replicates per cell line. HS294T and THP-1 cells were treated with vvdd-tdTomato-hDAI or vvdd-tdTomato control virus, or with PBS only to have an uninfected control. 16 hours after infection total RNA was extracted and whole genome gene pfofiles were analyzed and differentially expressed genes determined.