Figure 4.

IFN-γ response of B10 mice immunized with KLH. Lymph node cells of the indicated MHC class II haplotypes were isolated on day 7 after immunization, depleted of endogenous APCs, and restimulated with KLH (250 μg/ml) and BMDMs of either of the parental haplotypes. Between 15 and 19 h later, the cytokine production of the T cells was determined by triple staining using antibodies recognizing CD69, cytoplasmic IFN-γ, and IL-4. Data shown are percentages of IFN-γ⁺ cells (mean ± SEM; three to five mice per group) and are representative of three experiments. The P value for the differences in the amounts of cytokine producing cells is 0.0417 and was calculated by pooling the data from Figs. 4 and 5.