Inhibitory effects of integrin-specific antibodies on PMN transmigration and flow-cytometric analysis of integrin expression on PMNs dependent on IL-8 and PMN transmigration after S. suis infection or TNFα stimulation. (A) In blocking experiments PMNs were pre-incubated with antibodies specific to the PMN integrins CD11a, CD11b or CD18. PMN transmigration towards an IL-8 gradient (10 ng/ml) through non-stimulated and pre-stimulated PCPEC (S. suis strain 10 (MOI 10) or TNFα (10 ng/ml)) was analyzed hereafter as described in the Method section. Data are presented as percent of migrated PMNs not pre-incubated with antibodies. Data are shown as mean ± SD for four independent experiments each performed in triplicate. *, P value of < 0.05 compared to unstimulated, respectively, stimulated PCPEC not pre-incubated with specific antibody. (B-D) Graph show the influence of different IL-8 concentrations combined with different stimuli on CD11a, CD11b or CD18 expression pre and post-transmigration. Results are presented as mean fluorescence intensities ± SD for 4 independent experiments.***, P value of < 0.0001; **, P value of < 0.01; *, P value of < 0.05 compared to PCPECs not stimulated with IL-8, #, P value of < 0.01 compared to cells treated with 10 ng/ml IL-8, ##, P value of < 0.01 compared S. suis-treated and control cells.