FIG. 1.
Results of L. amazonensis protection assays. Groups of eight BALB/c mice were immunized with two subcutaneous injections at 15-day intervals with 1 μg of rIL-12 as an adjuvant and 50 μg of rLACK, rA2, or L. amazonensis SLA in the left hind footpads. Each mouse was challenged with 106 late-log-phase L. amazonensis promastigotes in the right hind footpads, as described in Material and Methods. Control mice received PBS. (A) Lesion development (footpad swelling) in immunized groups was monitored weekly with a caliper. Each point represents the average, and error bars represent standard deviations. (B) Parasite loads detected in infected footpads of each immunized group 9 weeks postchallenge. Numbers of viable parasites were determined by a limiting dilution assay as described in Materials and Methods. Each bar represents the average, and error bars represent standard deviations (n = 4). The asterisk indicates that differences are statistically significant (P < 0.05).