Fig. 3: CD47 regulates CD11b/CD18-dependent PMN TEpM in vivo.

a PMN TEpM in vivo in response to LTB₄ (1 nM) was determined in ileal loops of WT and Cd47^−/− mice after intraluminal instillation of blocking mAb against CD11b (clone M1/70; 20 μg/mL), or rat IgG_2b isotype control (20 μg/mL). WT PMN migration was significantly reduced by blocking CD11b in the intestinal lumen compared to mice treated with isotype control. CD47 deficiency also resulted in a significant reduced PMN migration in Cd47^−/− mice compared with WT mice. Importantly, blocking CD11b on Cd47^−/− mice did not further decrease PMN migration compared to Cd47^−/− mice treated with isotype control. Data are Means±SEM of 3 independent experiments, 12–14 mice/group (**p ≤ 0.01) as determined by two-way ANOVA analysis. b After luminal content collection, intestinal sections were enzymatically digested for quantification of PMN in LP-enriched fraction by flow cytometry, or fixed and paraffin-embedded for histological analysis. Numbers of PMN within the LP fraction were similar between different treatments. Data are Means±SEM of 2 independent experiments, 8–14 mice/group. c Representative images of immunohistochemical staining including higher magnification insets, depicting Ly6G⁺ PMN. 40x objective. Scale bars: 50 μm.