Leukocyte adhesion, extravasation, and bacterial clearance are impaired at low kindlin-3 levels. (A-B) Leukocyte adhesion and rolling in TNF-α–stimulated cremaster muscle venules assessed in 12 venules of 4 K3+/+ mice, in 21 venules from 4 K3+/n mice, in 19 venules of 4 K3n/n mice, and in 17 venules of 3 K3n/− mice. (A) Leukocyte adhesion efficiency determined as the number of adherent leukocytes per mm² vascular surface area divided by the systemic leukocyte count. (B) Leukocyte rolling flux fraction determined as rolling leukocytes passing an imaginary perpendicular line over the vessel corrected by the total number of passing leukocytes. Values are mean ± SEM. (C-D) Whole-mount immunofluorescence staining of ear flaps at 1 hour (C) and 4 hours (D) after phorbol ester treatment. Tissues were stained with a pan-laminin antibody (LN; green) to visualize endothelial basement membrane and a Gr-1 antibody (red) to visualize neutrophils. The scale bar represents 200 µm. (E) Phagocytosis of fluorescently labeled E coli particles by K3+/+, K3+/n, K3n/n, K3n/−, and K3−/− PMNs (N = 3, 5, 4, 4, 3). Data are shown as mean ± SD and were statistically analyzed by Student t test. (F-H) Infection of kindlin-3 hypomorphic mice with H pylori. (F) Colonization density of gastric mucosa of K3+/+, K3n/n, and K3n/− mice, which were either not infected or were orally infected with H pylori PMSS1 for 12 weeks. (G) Histologic grading of gastric mucosa from K3+/+, K3n/n, and K3n/− mice challenged with H pylori PMSS1 for 12 weeks compared with age-matched noninfected controls. (H) Recruitment of granulocytes to the gastric mucosa of K3+/+, K3n/n, and K3n/− mice challenged with H pylori PMSS1 for 12 weeks compared with age-matched noninfected controls. Data were statistically analyzed by Mann-Whitney U test for unpaired groups. *P < .05; **P < .01; ***P < .001. n.s., not significant.