FIG. 3.

Salivary ISL 929 and ISL 1373 modulate PMN accumulation in vivo. Uninfected ticks (10 to 15/mouse) were allowed to feed for 3 days on mice that had been immunized with BSA (left) or with ISL 929/1373 (right). (a and b) External pinnae cut at the ear base and “bread loafed” into four approximately equal strips from proximal (*) to distal (#) and rotated 90° for histopathologic analysis (scale bars = 5,000 μm). (c to h) Progressively higher magnification of the boxed areas in the panels above (scale bars, 500 μm [c and d] and 200 μm [e and f]). (g and h) Inflammation at the site of the tick bite in hematoxylin- and eosin-stained sections of ear pinnae from BSA-immunized mice showed mild inflammation with infrequent PMN (panel g, arrowhead), and sections from ISL 929/1373-immunized mice show marked inflammation with frequent PMN (panel h, arrowheads). The severity of inflammation was scored in five sections per ear; n = 3 mice/group.