Modulation of gene expression in a human cell line caused by poliovirus, vaccinia virus and interferon

Background: The project was initiated to describe the response of a human embryonic fibroblast cell line to the replication of two different viruses, and, more specifically, to look for candidate genes involved in viral defense. For this purpose, the cells were synchronously infected with poliovirus in the absence or presence of interferon-alpha, or with vaccinia virus, a virus that is not inhibited by interferon. By comparing the changes in transcriptosome due to these different challenges, it should be possible to suggest genes that might be involved in defense. Results: The viral titers were sufficient to yield productive infection in a majority of the cells. The cells were harvested in triplicate at various time- points, and the transcriptosome compared with mock infected cells using oligo- based, global 35 k microarrays. While there was very limited similarities in the response to the different viruses, a large proportion of the genes up- regulated by interferon- alpha were also up- regulated by poliovirus. Interferon- alpha inhibited poliovirus replication, but there were no signs of any interferons being induced by poliovirus. The observations suggest that the cells do launch an antiviral response to poliovirus in the absence of interferon. Analyses of the data led to a list of candidate antiviral genes. Functional information was limited, or absent, for most of the candidate genes. Conclusion: The data are relevant for our understanding of how the cells respond to poliovirus and vaccinia virus infection. More annotations, and more microarray studies with related viruses, are required in order to narrow the list of putative defence- related genes.