A Lentiviral Vector Encoding Two Fluorescent Proteins Enables Imaging of Adenoviral Infection Via Adenovirus-encoded MiRNAs in Single Living Cells

MicroRNAs (miRNAs) are non-coding small RNAs that have been found in various kinds of eukaryotes and viruses. Recently, adenovirus non-coding RNAs, VA RNAs, have been reported to generate miRNAs. Here, we developed a lentiviral vector for monitoring adenovirus-derived miRNAs in living cells. By using red and green fluorescent proteins under the control of bi-directional two distinct promoters, adenoviral infection and consequent miRNA expression was successfully visualized and quantified by the reduction in green fluorescence when 3'-untranslated regions were connected to the target sequences of the adenovirus-derived miRNAs. Our functional analysis using a lentiviral vector is a useful method to examine the activity of miRNA in living mammalian cells.