Blocking and conditional deletion of α₃β₁ inhibits neutrophil migration and improves survival. (A) Total cells were isolated from PL and lungs of septic mice (8 hours after CLP) injected either with LXY2 or control peptide (88 μg or 100 nmole/dose, IV) 2 hours after CLP. Bar graphs show total number of neutrophils (Gr1/Ly6G^highCD11b^high cells), 5 mice/group. (B) CLP surgery was performed and either LXY2 or control peptide (100 nmole/dose) was injected post-CLP, as shown in supplemental Figure 3C. Mouse survival was analyzed using Kaplan-Meier log-rank test (9/group). (C) Serum concentrations of IL-6 (8 hours after CLP) from LXY2- and control peptide–treated mice were measured by sandwich ELISA. Values are expressed in ng/mL (5 mice/group). (D) Bacterial loads from PL of LXY2- and control peptide–treated mice (5/group). Diluted samples were streaked on tryptone soya agar blood agar and colonies counted after 24 hours’ incubation at 37°C. (E) Total cells were isolated from PL and lungs of α₃ cKO mice (Itga3^flox/flox; Ela-Cre) and littermate Ela-Cre controls (Itga3^wt/wt; Ela-Cre) 8 hours after CLP. Neutrophils were gated as described earlier (4 mice/group). (F) CLP surgery was performed and survival analyzed using Kaplan-Meier log-rank test to compare α₃ cKO and Ela-Cre control mice (12/group). (G) Serum levels of IL-6 (8 hours after CLP, 4 mice/group). (H) Bacterial loads in PL of α₃ cKO and Ela-Cre mice 8 hours after CLP (4 mice/group). (A,C,D,E,G,H) Data are expressed as mean ± SEM. *P < .05 (Mann-Whitney test).