Topical Treatment with Liposomes Containing T4 Endonuclease V Protects Human Skin In Vivo from Ultraviolet-Induced Upregulation of Interleukin-10 and Tumor Necrosis Factor-α

Abstract

Exposing human skin to ultraviolet radiation causes DNA damage, sunburn, immune alterations, and eventually, skin cancer. We wished to determine whether liposomes containing a DNA repair enzyme could prevent any of the acute effects of irradiation when applied after ultraviolet exposure. Fifteen human patients with a prior history of skin cancer were exposed to two minimal erythema doses of ultraviolet radiation on their buttock skin. Liposomes containing T4 endonuclease V or heat-inactivated enzyme were applied immediately and at 2, 4, and 5 h after ultraviolet irradiation. Transmission electron microscopy after anti-T4 endonuclease V-staining and immunogold labeling on biopsies taken at 6 h after ultraviolet exposure revealed that the enzyme was present within cells in the skin. Immunohistochemical DNA damage studies suggested a trend toward improved DNA repair at the active T4 endonuclease V liposome-treated test sites. Although the active T4 endonuclease V liposomes did not significantly affect the ultraviolet-induced erythema response and microscopic sunburn cell formation, they nearly completely prevented ultraviolet-induced upregulation of interleukin-10 and tumor necrosis factor-alpha RNA message and of interleukin-10 protein. These studies demonstrate that liposomes can be used for topical intracellular delivery of small proteins to human skin and suggest that liposomes containing DNA repair enzymes may provide a new avenue for photoprotection against some forms of ultraviolet-induced skin damage.

IL-12 Prevents the Inhibitory Effects of cis-Urocanic Acid on Tumor Antigen Presentation by Langerhans Cells: Implications for Photocarcinogenesis

“…For example, UV impairs APC function (37), it induces the release of immunosuppressive cytokines like IL-10 (38), and it drives T lymphocytes into apoptotic cell death (39). Many of the immunosuppressive effects are much more weakly pronounced when UV-induced DNA lesions are reduced, e.g., by acceleration of DNA repair (40,41). Therefore, UV-induced DNA damage has been recognized as the major, but not the only mediator of the immunosuppressive effects of UVR.…”

An action spectrum (290–320 nm) for TNFα protein in human skinin vivosuggests that basal-layer epidermal DNA is the chromophore

“…Thus, based on human action spectroscopy in vivo, our data strongly suggest that DNA, specifically in the basal layer, is an important chromophore for TNF␣ and supports the in vitro mouse kera- tinocyte studies of Kibitel et al (11), in which T4 endonuclease V (T4N5)-enhanced CPD repair was shown to reduce TNF␣ protein production. A similar in vivo approach was made by Wolf et al (24). However, these authors were not able to demonstrate any significant reduction of epidermal CPD by T4N5 or the presence of TNF␣ protein, although the T4N5 did reduce mRNA levels.…”

Rapid and Efficient Method for Production of T4 Endonuclease V by Heterologous Expression in E.Coli

“…it was already demonstrated that application of t4 endoV on irradiated skin effectively prevents the up-regulation of interleukin-10 and TNF-alpha, therefore significantly lowering the risk for skin neoplastic growth (7).…”