Vitamin D in combination with photodynamic therapy enhances innate immune response in a murine model of actinic keratosis

Abstract

SignificanceAminolevulinate-based photodynamic therapy (ALA-PDT) is an effective treatment for cutaneous pre-cancer (actinic keratoses; AK) and non-melanoma skin cancer (NMSC), the most common skin malignancies. ApproachIn this study we show that pretreatment of murine AK lesions with vitamin D (VitD), causes significant enhancement of PDT-related immune effects. Hairless (SKH-1) mice with AK (generated by repeated UVB exposure) were treated topically with VitD (Vectical™) for three days prior to application of topical ALA followed by blue light exposure. A time course analysis of immune cell infiltration in AK lesions was conducted by immunofluorescence (IF) microscopy after PDT with or without VitD. ResultsOur IF data showed significant differences between infiltration of innate immune cells (neutrophils, macrophages and dendritic cells) in vehicle versus VitD treated lesions. ConclusionsOur data indicate that a combination of VitD and PDT may have an additive beneficial effect on therapeutic outcome of PDT.