Figure 4.

Antigen specificity of unresponsiveness to DNFB – double challenge experiments. Mice sensitized to oxazolone (Fig. 3, Group C) and mice that received 5000 DNP-Mφ#59 treated with TGF-β₂ 7 days after epicutaneous sensitization with oxazolone (Fig. 3, Group F) were sensitized epicutaneously with DNFB 21 days after initial sensitization with oxazolone, Groups A and B, respectively. Positive control animals (Group C) were sensitized epicutaneously with DNFB, received a booster sensitization 21 days later, and were ear challenged with DNFB 5 days after the last sensitization. Negative control animals (Group D) encountered DNFB for the first time during ear challenge. Ear swelling was measured at 24 and 48 hr after challenge. The 48-hr ear swelling measurements are shown. Mean values that are significantly less than the positive control (P < 0·005) are marked by *.