Extracellular PDI regulates αMβ2 integrin-mediated adhesion and crawling of neutrophils during vascular inflammation. Control IgG (mIgG2a) or anti-PDI antibody (RL90, 1 or 3 μg/g BW) was infused into WT mice. (A-E) Rolling, adherent, and crawling neutrophils were monitored and analyzed as described in the Figure 2 legend. (A) Representative images. Small (white, gray, and black) and large arrows show rolling neutrophils and blood flow, respectively. Data represent mean ± SEM (n = 24-28 venules in 3-5 mice per group). *P < .05 and **P < .01 vs control IgG after ANOVA and the Dunnett test. (F-I) Control IgG (rat IgG2a, rat IgG2b, or mouse IgG2a) or a blocking antibody against αM, αL, or PDI, 2 μg/g BW, was infused into αLβ2 or αMβ2 null mice. Adherent neutrophils and rapidly rolling (>10 μm/s) and embolized cells were counted. Data represent mean ± SEM (n = 18-22 venules in 3 mice per group). **P < .01 or ***P < .005 vs control IgG after the Student t test.