FIG. 4.

Effects of WR279396 ointment on development of acquired immunity. (A) Design of the experimental groups (groups A and B) and the corresponding control group (n = 12 mice per group). An initial inoculation of 10⁴ luciferase-expressing NIH 173 metacyclic promastigotes into the right ear dermis (primary site) of C57BL/6 mice was performed at day 0 in groups A (shaded arrowheads) and B (black arrowheads). At day 47 p.p.i., 10⁴ luciferase-expressing L. major metacyclic promastigotes were inoculated in the dermis of the contralateral ears of mice that had received five applications of WR279396 ointment (red triangles) over 10 days (secondary site [red arrowhead], group B). The L. major-inoculated control mice corresponded to naïve mice that were inoculated at day 47 p.p.i. (black arrowhead). (B) The detection of bioluminescence at the primary site is illustrated by the results for a representative mouse within groups A and B. (C) Quantification of the bioluminescence of the parasitic load (in photons per second per ear; panels 1 and 3) and ear thickness (panels 2 and 4) in groups A and B and the control group. (Panels 1 and 2) Gray areas correspond to the bioluminescence and the ear thickness observed in group A. WR279396 treatment (red triangles) induced a significant decrease in both processes in the ear (open circles). (Panels 3 and 4) We compared the parasitic load and monitored the thickness of the ear lesions of the control mice (Ctrl; black squares) and mice that had successively received five applications of the ointment and challenged in the contralateral ear at day 47 (group B; open circles). Pictures of ears from representative mice from the control group and the WR279396-treated group (group B) at day 76 p.i. are presented.