3D Printed Human Skin Equivalents Help Identify Potential HSV Treatments

Herpes Simplex Virus (HSV) is estimated to infect 64% of the world’s population, according to the World Health Organization. The virus causes oral and genital herpes, and while it can be asymptomatic, it can also cause painful flare-ups and make those infected susceptible to HIV. Especially for immunocompromised people, the virus can be debilitating. Of course, there are antivirals to treat the disease, the most common being acyclovir—but the treatments are not a cure. Once a person is infected, HSV travels to their nerve cells, where it can start replicating and hide from any antiviral treatments or the immune system. In a few weeks, the immune system can clear up the primary infection, but HSV will remain in those nerve cells it first infected, staying in the body for life. Now, new HSV treatments are being developed thanks to 3D printing.

Current medication is not effective against latent HSV, and it also requires consistent large dosages. Patients can also become resistant to these treatments, which often do not control symptoms adequately. That is why Dr. Jia Zhu, an associate professor in the Fred Hutch Vaccine and Infectious Disease Division who has dedicated her career to studying HSV, is working towards better HSV treatments. In an article for the Fred Hutch Cancer Center, she shared that the key to creating better treatments was understanding why we have our current antiviral treatments in the first place.

Skin layers (Credit: Zhu Lab)

The type of replicating HSV that can be targeted by antivirals primarily occurs in the basal layer of epithelial cells, which is the innermost layer of the epidermis. This explains why the sores and ulcers associated with herpes often appear in barrier epithelial tissues like the oral mucosa and genital skin. “While this is a complex process facilitated by many different cell types that collectively structure your epidermal tissue,” Dr. Zhu said, “the antivirals we use to treat HSV today were developed using in vitro culture of Vero cells and fibroblasts.”