FIG. 5.
Antigen-stimulated cytokine production in vitro after four doses of vaccine. Only three monkeys from group 1 were tested, as one animal was euthanized prior to sample collection due to unrelated pathology (see legend to Fig. 4). Results were obtained from 5 × 106 PBMC/ml in 24- or 48-well cell culture plates, with antigen (WN-80E) at 5 μg/ml. Values represent the difference between cytokine levels for WN-80E-stimulated animals and either “mock” antigen-stimulated or unstimulated controls, whichever was higher. For IFN-γ, this difference was at least 2.5-fold for all but one positive animal. For IL-5, this difference was at least threefold for each positive animal. Pokeweed mitogen-stimulated IFN-γ production was at least 2,000 pg/ml for all animals (data not shown). Pokeweed mitogen-stimulated IL-5 production was ≤20 pg/ml (data not shown). SD, standard deviation.