FIGURE 1.

Transferring lymph node cells from UV-irradiated, FITC-sensitized mice to normal recipients induces tolerance. A, Mice are exposed to 15 kJ/m² of UVB radiation and 4 days later were painted with FITC on the unirradiated ventral skin. Eighteen hours later, the draining lymph nodes were collected and injected into naive recipient mice. The right ear of each mouse was challenged 6 days later. CHS was read the next day, and the mice were rested for 21 days. They were then sensitized with FITC, and the left ear was challenged 6 days later. The induction of tolerance was measured 1 day later. B, The recipient mice received cells from hapten-sensitized mice (FITC⁺), or cells from mice that were exposed to UV and then sensitized with hapten (UV-FITC⁺), or were not injected (None).*, Statistically significant difference (p < 0.001) from the FITC⁺ control.