Transgene Expression under the Adenoviral Major Late Promoter, Tripartite Leader Sequence and E1 Genes in Absence and Presence of Adenovirus Infection

Active gene expression driven by the adenoviral major late promoter (MLP) and the tripartite leader sequence (TPL) influenced their utilization to drive vaccines expression. It is unclear if the complete TPL sequence is required for this active expression or if it can be further boosted in presence of the adenoviral E1 genes. In this study, we investigated the effect of TPL exones and E1 genes, out of the viral genome or under adenoviral infection, on green fluorescence protein (GFP) expression driven by the MLP. Gradual increase in the transcript copies with the addition of TPL exons indicated an additive effect especially under infection. The presence of E1 genes significantly enhanced transgene transcription. Infected cells showed higher GFP transcription and translation than non-infected cells. These results indicate higher exogenous gene expression driven by the MLP can be achieved in the presence of adenoviral components other than the TPL and E1 genes.