Figure 5.

Induction of contact hypersensitivity in mice that received grafts of UVR‐irradiated epidermis. Panels of C3H/HeN mice received an acute, low‐dose regimen of UVR to ear skin. One hour after the last exposure, the ear skin was removed. Cutaneous sheets were peeled away, then immersed in trypsin at 37° for 50 min. Epidermis was separated from dermis and placed as a graft on thoracic wall beds of naive syngeneic mice. Three days later, DNFB (185 µg) was painted on the surface of the right ear pinna. Five days later, the left ear pinnae of these mice were challenged with 15 µg DNFB, and ear swelling was measured at 24 hr. Control epidermal grafts were prepared from pinnae of mice not exposed to UVR. Asterisk indicates ear‐swelling responses significantly greater than negative control (P < 0·05).