A+B. Lymphocyte proliferation following addition of anti-MHC II or anti-CD4 ab is unchanged in unstimulated CBMC and following stimulation with the innate stimulus Ppg. Following addition of anti-MHC II or anti-CD4 ab, lymphocyte proliferation is decreased after stimulation with the allergen Derf1 (p < 0.05). A+B. Lymphocyte proliferation is shown in counts per minute (cpm) and was determined after stimulation with the indicated dose of Ppg and Derf1 (30 μg/ml) for 72 h by 3H-Thymidine uptake as described in Methods (n = 50). Anti-MHC II or anti-CD4 ab was applied in a dose of 10 μg/ml each.