Cutaneous ultraviolet radiation inhibits herpes simplex virus-induced lymphoproliferation in latently infected subjects.

Exposure of herpes simplex virus (HSV) latently infected subjects to ultraviolet irradiation (UVR) (1 minimum erythema dose, 90% body surface) caused a significant inhibition of HSV and phytohemagglutinin-induced lymphoproliferation. The inhibition was observed on Day 3 post-UVR and lasted at least 9 days. UVR-induced downregulation of HSV-specific lymphoproliferation was associated with increased levels of activated transforming growth factor beta. However, the relationship between UVR-induced immune downregulation and the development of recurrent HSV lesions was incomplete.