Figure 6.
Skin induced suppression declines with time. CBA/J mice were e.c. immunized with 100 µg/animal of TNP-Ig or exposed to PBS alone (group A) as described previously. On day 7 patches were removed and then mice were actively immunized with 5% TNP-Cl immediately (group B), or 2, 4 or 6 weeks later (groups C-E correspondingly). Mice from all experimental groups were challenged and tested for CS. Statistical significance: groups B and C versus group A; P < 0·001; group D versus group A; P < 0·02.