Effects of heparinase, chondroitinase and anti-syndecan 4 antibodies on PR-39-induced chemotaxis of neutrophils. Heparinase I (left panel) or chondroitinase (middle panel) was added to neutrophils. After an incubation (humidified, 37°C/5% CO2) period of 50 min, cells were washed twice and chemotaxis assays were performed. PR-39 [10 μmol/L] was used as chemoattractant and fMLP [10 nmol/L] served as control attractant. Data are expressed as percent of medium control (pretreatment with medium), with a distance of migration toward fMLP of 79.8 ± 3.1 μm, towards PR-39 of 66.8 ± 1.3 (n = 4). Statistical analysis: Mann-Whitney U-test versus medium control, *, p < 0.05 after Kruskal-Wallis test, p < 0.05. Effects of antibodies to syndecan-4 core protein or syndecan-4 chain epitopes (right panel) were tested by preincubation of neutrophils for 20 minutes (humidified 37°C/5% CO2). After washing, cells were allowed to migrate toward PR-39 [10 μmol/L] in modified Boyden chambers using nitrocellulose micropore filters. Isotype matched IgG served as control. Results are given as mean ± SEM of the chemotaxis index, which is the ratio between the distance of migration toward attractant and that toward control. Distance of random migration was 40.0 ± 2.78 (n = 4). Statistical analysis: Mann-Whitney U-test versus no antibody, * p < 0.05 after Kruskal-Wallis test p < 0.05.