HSV-1 infection of human skin and skin organoids
HSV-1 is a skin-tropic virus, carrying its life cycle in the highly structured environment of the skin epidermis. Currently, most of our understanding of HSV-1 biology comes from studying infection of cell-lines in 2D cultures.
Our lab is now studying the molecular events that shape HSV-1 infection using both human skin organoids and ex-vivo human skin.
Molecular characterization of abortive infections
Abortive infections (when a cell becomes infected but does not produce progeny) have not been mechanistically studied due to the lack of appropriate tools. Our lab is studying a specific host transcriptional programs that is able to abort infection, even after viral gene expression has begun.
To visualize abortive infections by HSV-1, we created a new viral strain which harbors two fluorescently-tagged proteins; ICP4-YFP and VP26-RFP. ICP4 is an immediate-early gene, expressed as soon as the viral genome enters the nucleus while VP26 is a late gene, expressed only after viral DNA replication.
Using this strain, three subpopulations of infected-cells are seen at 24 hours post-infection: non-infected (ICP4–/VP26–), abortive infections (ICP4+/VP26–) and productive infections (ICP4+/VP26+). RNA-sequencing has identified 554 host genes that are specifically up-regulated in abortively-infected cells . Many of these are uncharacterized and represent potential novel antiviral signaling pathways.
What makes a cell predisposed to become a super producer?
Most infected cells produce few progeny, but a small subset of cells produce thousands. Currently, the cellular events that shape a cell’s fate as a super producer are completely uncharacterized, due to technical limitations in characterizing and studying these cells. Our lab is working to: (1) accurately measure, in a high throughput fashion, the number of progeny produced by individual cells and (2) Developing computer-vision tools to connect the image of a cell before infection with the number of progeny it produces. This will allow us to identify cells that will become super producers and analyze them to reveal the cellular states that support super production.
Discovery and optimization of antiviral compounds
Through drug repurposing screens, our lab has identified multiple safe-in-human drugs that block the replication of various viral families. We are currently studying the mechanism of action of these drugs, as well as work in close collaboration with chemists do develop better antivirals.
The function of Interferon stimulated genes in HSV-1 infection
Interferons are cytokines with robust antiviral activity against many viruses, including HSV-1. When exposed to interferon, cells up-regulate hundreds of genes, only a handful of which is active against any given virus.
Our lab studies the role of the basal expression of Interferon Stimulated Genes (ISGs) in determining HSV-1 infection outcome.
