Fig. 6.

Th1/Th2 balance of postchallenge immunity in the vaccinated/protected mice. Eight weeks after challenge with L. major, BALB/c mice pretreated with either saline or KSAC/MPL-SE were examined for their immune responses to crude parasite antigen (LmSLA). (A) IgG1 and IgG2a levels for LmSLA were measured by ELISA (OD values are shown). Mean and SEM of five mice are shown. (B) IFN-γ and IL-4 produced by spleen cells were analyzed upon antigen recall (open bars, saline placebo; closed bars, KSAC/MPL-SE vaccine). *, P < 0.05 by unpaired t test compared with results for the saline group. This is representative of three independent experiments with similar results.