Investigation of the peak action wavelength of light-activated gene transduction

Abstract

Light-activated gene transduction (LAGT) is an approach to localize gene therapy via preactivation of cells with UV light, which facilitates transduction by recombinant adeno-associated virus vectors. Prior studies demonstrated that UVC induces LAGT secondary to pyrimidine dimer formation, while UVA induces LAGT secondary to reactive oxygen species (ROS) generation. However, the empirical UVB boundary of these UV effects is unknown. Thus, we aimed to define the action spectra for UV-induced LAGT independent of DNA damage, and determine an optimal wavelength to maximize safety and efficacy. Results: UV at 288, 311 and 320nm produced significant dose-dependent LAGT effects, of which the maximum (800-fold) was observed with 4kJ/m2 at 311nm. Consistent with its robust cytotoxicity, 288nm produced significantly high levels of DNA damage at all doses tested, while 311, 320 and 330nm did not generate pyrimidine dimers and produced low levels of DNA damage detected by comet assay. While 288nm failed to induce ROS, the other wavelengths were effective, with the maximum (10-fold) effect observed with 30 kJ/m2 at 311nm. An in vivo pilot study assessing 311nm-induced LAGT of rabbit articular chondrocytes demonstrated a significant 6.6-fold (p<0.05) increase in transduction with insignificant cytotoxicity. Conclusion: 311nm was found to be the optimal wavelength for LAGT based on its superior efficacy at the peak dose, and its broad safety range that is remarkably wider than the other UV wavelengths tested.

Cell death in human articular chondrocyte: a morpho-functional study in micromass model

“…Thus, in chondrocytes, UVB exposure induces apoptosis, probably following other mechanisms, including caspase independent processes [23,53,54]. Moreover, our results of lack of high molecular weight DNA fragments at 1 week following exposure to UVB is in keeping with recently published findings chondrocytes both in vitro and in vivo which show low DNA damage but high ROS production [55]. Our functional findings reveal that only staurosporine could be considered a typical apoptotic inducer.…”

Induction of Alloantigen-specific CD4+ T Regulatory Type 1 Cells by Alloantigen Immunization and Ultraviolet-B Irradiation: A Pilot Study in Murine Transplantation Models With Skin and Cardiac Allografts

“…High-dose UV-B irradiation induces the alternation or modulation of antigen-presenting cell (APC) functions for the induction of antigen-specific Tregs [1,3,5,7,10,26,[29][30][31]42]. The early phase of APC functions after high-dose UV-B irradiation has been well studied [3,6,29,43,44].…”

“…Ultraviolet (UV) light, especially the mid-wave range (UV-B, 280-320 nm), is an important environmental factor that affects human health [1][2][3][4][5]. Although primary carcinogenesis is the most common problem, UV irradiation impairs immune responses to oncologic and infectious antigens [1,4,6].…”

“…To date, our group has focused on applications of UV irradiation [21][22][23][24][25]. To induce alloantigen-specific Tregs, high-dose UV-B irradiation accompanied by alloantigen immunization is required [5,7,10,11,[26][27][28][29]. In the late 1980s, many studies reported that antigen-specific Tregs were induced by highdose UV-B irradiation before antigen immunization [7,10,11,26], because it was thought that UV irradiation-induced alternation/ modulation of antigen-presenting cell (APC) functions were required for antigen-specific Treg induction [1,7,10,26,[29][30][31][32].…”