Fig 2: Leukocyte adhesion as a function of treatments and varying extensional stresses. (a) Mean number of adherent cells per ROI in response to LFA-1 activating antibody mAb24, LFA-1 blockade antibody AF1730, pertussis toxin, and Heparinase III. Of these, only AF1730 had a significant effect. Each point is the mean value for one participant. N = 5 donors. Boxes indicate mean and standard error. Isotype controls and untreated channels are averaged into ‘baseline’ for display clarity purposes – statistics were calculated for antibodies vs. paired isotype. (b) Spatial linear model fit for the contribution of AF1730 to adhesion probability for wall adherent leukocytes in straight channels. The strongest effect of AF1730 blockade of LFA-1 is observed immediately after the expansion.

Fig 3: Signaling downstream of ß2 is not required for sensitivity of U-937 cells to HlyA cytotoxic activity. (A) Schematic diagram of ITGB2 full-length protein and cytoplasmic-tail deletion. (B) ß2 expression was assessed by flow cytometry on intact cells from the wild-type and ?ß2 lines and two clones each of the complemented ?ß2 plus wild-type ß2 or ?ß2 plus ?tail-ß2 cell lines. Bars represent the average median fluorescence intensity (MFI) and SEM from 3 biological replicates with at least 50,000 events recorded per replicate. One-way ANOVA with Bonferroni’s multiple-comparison test was performed in GraphPad Prism, with significance of each cell type compared to U-937 ?ß2 cells represented. (C) PEG-precipitated HlyA was incubated at various concentrations with cell lines described in panel B at 2 × 106 cells/ml for 1 h. Cells were washed, and cell viability was measured by XTT assay. The percentage of cytotoxicity was normalized to Triton X-100-treated cells at 100% and RPMI-only-treated cells at 0%. The CD50 was calculated in GraphPad Prism, and bars represent the average and SEM from 3 biological replicates. One-way ANOVA with Bonferroni’s multiple-comparison test was performed in GraphPad Prism, with significance of each cell type compared to U-937 cells represented. ***, P < 0.001.