Impact of NF-κB decoy ODNs on UV-triggered cytokine production. (a) Pam 212 keratinocytes, NS47 fibroblasts, and XS106 Langerhans cells were transfected with the NF-κB reporter construct (3× κB luc) or the AP-1 reporter construct (4× AP-1 luc). After 6 hours of preincubation with 10 μM NF-κB decoy or scrambled ODNs, cells were washed and exposed to 50 J/m² UVB radiation (FS20 sunlamp) in PBS, cultured for an additional 24 hours in the continuous presence of fresh ODNs, and then examined for Luc activity. Data shown are representative of four independent experiments, showing the mean ± SD from triplicate samples. (b and c) Cells (1 × 10⁶ cells/mL) were incubated for 6 hours with 10 μM NF-κB decoy or scrambled ODNs, washed, and then exposed to the indicated fluences of UV radiation using either FS20 sunlamps (b) or a Xenon arc solar simulator (c). Subsequently, cells were cultured for an additional 24 hours in complete RPMI 1640 in the presence of fresh ODNs, and culture supernatants were examined for the indicated cytokines by ELISA. Data shown are representative of three independent experiments, showing the mean ± SD from triplicate samples. ^AStatistically significant differences (P < 0.05) compared with the UV-irradiated group without added ODNs. ^BStatistically significant differences (P < 0.01) compared with the UV-irradiated group without added ODNs. ^CStatistically significant differences compared with the UV plus scrambled ODN group (P < 0.05). ^DStatistically significant differences compared with the UV plus scrambled ODN group (P < 0.01).