Figure 5. UV suppresses contact hypersensitivity even in the absence of epidermal Langerhans cells.
Lang-DTR mice were untreated or treated with diphtheria toxin 7 days prior to treatment to selectively deplete epidermal LC, while allowing dermal DC to repopulate. Mice were then irradiated with UV for 3 consecutive days, and 24 hours after the last UV treatment, immunized with 25 μl of 0.3% DNFB on the shaved back. 5 days after immunization, mice were challenged with 5 μl of 0.15% DNFB on the ear. Ear thickness was measured before and 24 hour after challenge. The immune response= ear swelling (after challenge-before challenge).