FIG. 2.

Prechallenge (A and B) and postchallenge (C and D) cytokine responses in BALB/c mice vaccinated with TRYP, lmd29, 584C, or vector control DNA. For the prechallenge responses, in vivo recall was performed by footpad injection of FTP 48 h prior to removal of draining LN (n = 4 mice/group). Draining LN were removed 1 day prior to remaining mice receiving challenge infection (= prechallenge), or in a sample of mice 2 weeks postchallenge with L. major promastigotes. Pooled LN cells were plated and restimulated in vitro with FTP and supernatants removed 72 h later for determination of IFN-γ, IL-4, IL-5, IL-10 or IL-13 levels by ELISA. Data in A and B relate to the experiment presented in Fig. 1A to F. The inset in D shows clinical scores for the infection experiment that relates to postchallenge cytokine data presented in C and D. Means ± standard errors of the means are reported for all traits. Asterisks indicate significant between-group differences as determined by Student's t test (*, P < 0.05; **, P < 0.01; ***, P < 0.001). Similar results were obtained for prechallenge cytokine profiles in a replicate experiment, and the observation of a higher Th1/Th2 bias postchallenge for TRYP-vaccinated mice than in lmd29- or 584C-vaccinated mice has been observed in two independent experiments in which cytokine profiles were measured at 4 weeks postchallenge (including those presented in Fig. 4).