Injection of the <i>P. semirufa</i> bristle extract induces neutrophil infiltration at the inoculation site.

<p>BALB/c mice were repeatedly injected with 50 µL of pyrogen-free saline with or without 10 μg (protein) of the extract in the footpad and, after the 1^st, 3^rd, 5^th and 7^th inoculations, the footpads were removed and frozen for immunohistochemistry and immunofluorescence analyses. Representative photomicrographs of left hind footpads stained with Ly6G, injected once (<b>A</b> and <b>B</b>) or seven times (<b>D</b> and <b>E</b>) with saline and <i>P. semirufa</i> bristle extract, respectively. (<b>C</b>) Negative control, injected with extract, marked with matched isotype and (<b>F</b>) positive control injected with Carrageenan (200 µg/ paw). Positive immunostaining is indicated by a red-brown colour. Images in panel <b>a</b> are at 200× magnification, and images in panel <b>b</b> are at 400× magnification. Photomicrograph (400× magnification/100× magnification in the left upper quadrant) panels <b>G</b> and <b>H</b> show immunofluorescence analysis of groups inoculated one and seven times, respectively, with <i>P</i>. <i>semirufa</i> bristle extract, while panel <b>I</b> shows the group inoculated with Carrageenan. DAPI-labelled nuclei appear blue, while the TRITC-labelled target molecules appear red/magenta.