Blue Laser Light Counteracts HSV-1 in the SH-SY5Y Neuronal Cell Model of Infection.

Herpes simplex virus 1 (HSV-1) is wide-spread virus that triggers painful and recurrent infections, as herpes labialis, causing blister lesions on the lip. HSV-1 infection can be a lifelong condition starting from childhood due to the latency of the virus hidden in the trigeminal ganglia. Despite the use of antiviral treatments, there is not a resolutive cure for herpes. In our study, we tested blue light against HSV-1 in a neuronal cellular model, aimed at mimicking the neuronal tropism of HSV-1. Two laser protocols employing continuous wave and pulse modalities were delivered to infected cell cultures and to the virus alone. A significant reduction of viral replication was observed when the beam was directly applied to the virus, along with an increase in cell survival. Our findings, considering the limitation of the still-unknown mechanisms by which the blue light acts on the virus, suggested a potential use of photobiomodulation therapy for clinical applications against herpes labialis in pediatric patients.