Human induced pluripotent stem cells for modeling of herpes simplex virus 1 infections

Herpes simplex virus, type 1 (HSV-1) infection is highly prevalent and globally affects approximately 67% of people under age 50. It causes substantial morbidity, including recurrent ocular disease, cold sores, and rare cases of devastating encephalitis. Its pathogenicity stems primarily from the ability of the virus to cause recurrent lytic lesions, a consequence of its ability to persist for life as a latent infection in neurons. Latency is an elusive, poorly understood, and to date, untreatable process that involves a dynamic interplay between the virus and host cells. While considerable knowledge of the HSV-1 latent state has been gleaned from small animal modeling, we are now at the cusp of needing to examine HSV-1 in more human relevant models, as HSV-1 is a human-specific virus, and the underlying mechanisms of latency have presumably evolved over millennia through human host–virus interactions. Neuron-virus studies have been substantially hampered by the absence of satisfactory human models. Human induced pluripotent stem cell (hiPSC) and embryonic stem cell (hESC) technologies are profoundly changing this picture, as they can provide human neuron models to examine the interaction of pathogens with their hosts. They are also aiding in the development of novel therapeutic approaches. Herein, we describe the use of hiPSCs to derive human models of HSV-1 acute and latent infections and to generate human neuronal platforms for antiviral drug screening.