High-Throughput Analysis of Viral Inhibition of Intracellular Innate Immunity

Normal mammalian cells respond to transient introduction of foreign nucleic acids by strongly downregulating transcription and translation and priming for apoptosis. This anti-growth response, called “intracellular innate immunity” (III) and evolved as a response to viral infection, makes it difficult to quickly engineer new function into cells using transient introduction of foreign nucleic acids, whether those are DNA, mRNA, or siRNA. However, in order to replicate successfully viruses have evolved a multitude of ways to inhibit the III response. Therefore, mining the underexplored viral proteome may yield a wealth of new tools to improve mammalian synthetic biology.

We have designed fluorescence microscopy-based functional assays to quickly screen virus genes for their ability to inhibit the III response. Using these assays, we will screen a broad selection of uncharacterized genes from viruses known to infect mammalian hosts. In addition to the tremendous amount of novel functional information this screen will generate, the data will enable engineering of proteins that will protect cells against the negative effects of introducing foreign nucleic acids into the cytoplasm, which in turn will enable much more effective cellular engineering. These assays also facilitate rapid assessment of the priority level of emerging viral threats.