Fig. 2.

RA and/or PIC treatments enhance TT-specific lymphocyte proliferation and production of IL-5 and IFN-γ. One-week-old C57BL/6 mice were pretreated with RA or oil for 1 day, followed by TT with or without RA and/or PIC as described in Materials and Methods. Five weeks after priming, the mice were reimmunized with TT only. Two weeks later, spleen cells were isolated and stimulated with TT for 96 h in vitro.(A) Lymphocyte proliferation determined by [methyl-³H]thymidine incorporation. (B and C) Cytokines in supernatant detected by ELISA. (D) Ratio of IL-5:IFN-γ as an indicator of type 2 to type 1 cytokine balance. Shown are means ± SE, n = 10 per group. Different letters above bars within panels indicate significant differences (P < 0.05, a < b < c). Results of two-way ANOVA are also shown in each panel.