FIGURE 4.

Inhibition of chemotaxis. A, migration of CXCR3-expressing L1.2 cells. A migration assay with increasing concentrations of CXCL11 was performed using L1.2 cells transfected with cDNA encoding CXCR3. Data are shown as percentage of migrated cells and obtained in three experiments. B, inhibition of CXCL11-induced chemotaxis. Purified Nanobodies were preincubated at the indicated concentrations with CXCL11 (1 nm). Subsequently, CXCL11-induced migration of CXCR3-expressing L1.2 cells was determined. The Nanobodies inhibited CXCL11-induced chemotaxis with the following pIC₅₀ ± S.E. values: 11B1 (●), 9.0 ± 0.1 (n = 4); 11B7 (○), 7.8 ± 0.2 (n = 4). C, migration of L1.2 cells. A migration assay with increasing concentrations of CXCL12 was performed using L1.2 cells. The CXCR4 antagonist AMD3100 (10 μm) inhibited migration toward CXCL12 (1 nm). Data are shown as percentage of migrated cells and was obtained in three experiments. D, inhibition of CXCL12-induced chemotaxis. Purified 12A4 Nanobody was incubated at the indicated concentrations with CXCL12 (1 nm) for 1 h at RT while shaking. Subsequently, CXCL12-induced migration of L1.2 cells was determined. The 12A4 Nanobody inhibited CXCL12-induced chemotaxis with a pIC₅₀ ± S.E. value of 7.9 ± 0.1 (n = 5). Experiments were performed in triplicate.