Photomicrographs of zymosan-injected tissue in wild-type and E- and P-selectin–deficient mice. Ear tissue was removed 8 hours after zymosan injection and sections were stained with hematoxylin and eosin. (A) Wild-type mouse (original magnification × 400). Micro-abscess consisting of aggregates of zymosan (Z) surrounded and walled off by a rim of leukocytes (between arrowheads). The leukocytes are predominantly neutrophils, many of which have distorted morphology due to having phagocytized zymosan particles. Adjacent connective tissue also contains a neutrophilic infiltrate. (B) E- and P-selectin–deficient mouse (original magnification × 400). General features are similar to those described in (A). However, the overall intensity of the leukocyte infiltrate is markedly reduced in comparison with the wild-type mouse tissue. (C) Higher magnification of inset from (A) (original magnification × 1,000). Neutrophils (arrows) adherent to endothelial cells lining a venule in the vicinity of a micro-abscess.