Figure 3

Monocyte chemoattractant protein 1 (MCP1) and haptoglobin (Hp) show reciprocal interference on the capacity of cells to migrate. (a) Bar graph showing the effect of pretreatment (45 min at 37°C) with MCP1 (500 ng/ml), Hp (1 mg/ml) or bovine serum albumin (BSA) (1 mg/ml) on the capacity of U937 cells to migrate towards MCP1 (100 ng/ml white bars) and Hp (0.5 mg/ml, black bars). For each treatment the number of cells that migrated towards a chemotactically neutral agent (BSA 1 mg/ml) was considered as a baseline and subtracted from the numbers obtained for migration against MCP1 and Hp. Data are expressed as means ± standard error of the mean (SEM) of migrated cells for at least four experiments. Two-way analysis of variance (ANOVA) on the effect of pretreatment, P < 0.001. Bonferroni post-test versus pretreatment with BSA **P < 0.01 for migration towards MCP1, ^P < 0.01 for migration towards Hp. (b) As (a), using human primary monocytes. Two-way ANOVA on the effect of pretreatment, P < 0.001. Bonferroni post-test versus pretreatment with BSA ***P 0.001 **P < 0.01 for migration towards MCP1, ^P < 0.05 for migration towards Hp. (c) Bar graph showing the effect of pretreatment with the chemokine (C-C motif) receptor 2 (CCR2) synthetic antagonist RS102895 (5 μM) or BSA (1 mg/ml) on the capacity of U937 cells to migrate towards MCP1 (100 ng/ml white bars) and Hp (0.5 mg/ml, black bars). For each treatment the number of cells migrated towards a chemotactically neutral agent (BSA 1 mg/ml) was considered as a baseline and subtracted from the numbers obtained for migration against MCP1 and Hp. Data are expressed as means ± SEM of migrated cells for at least four experiments. Two-way ANOVA on the effect of pretreatment, P < 0.001. Bonferroni post-test versus pretreatment with BSA ***P < 0.001 for migration towards MCP1, ^^^P < 0.001 for migration towards Hp. (d) Same as (c) performed with primary monocytes. Data are expressed as means ± SEM of migrated cells for at least four experiments. Two-way ANOVA on the effect of pretreatment, P < 0.0001. Bonferroni post-test versus pretreatment with BSA ***P < 0.001 for migration towards MCP1, ^^^P < 0.001 for migration towards Hp.