FIG. 5.

In vitro cytokine production. BALB/c mice were immunized as in Fig. 3. Splenocytes from each mouse group were harvested at week 6, were pooled, and were cultured at 200,000 per well in 96-well plates stimulated with recombinant p24 as antigen. Culture supernatants were collected before adding the tritiated thymidine, and concentrations of IL-4 and IFN-γ were determined by ELISA by using commercial kits (Endogen). For these assays, the limit of detection was 5 pg of IL-4 or IFN-γ per ml. The number above each bar represents standard deviation.