Fig. 4

The effect of mast cell tryptase on the migration capacity of HFL-1 cells. Co-cultures with LAD2 and HFL-1 showed an increase in tryptase concentration over time, while conditioned medium had unchanged tryptase concentrations over time. HFL-1 did not show any release of tryptase (a). Tryptase enhanced the migration capacity of HFL-1 at 50 ng/ml and 75 ng/ml, (b). Representative images of migration from starting point 0 h (upper panels) and after 72 h (lower panels) in control wells with only HFL-1 fibroblasts and after stimulation with tryptase (c). The migratory capacity of HFL-1 cells was measured at 24, 48 and 72 h as the percentage of cell-occupied space compared to time = 0 h when the scratch was made. (mean ± SD, n = 3 individual experiments with 2 technical replicates in each experiment). Tryptase (75 ng/ml) increased the proliferative rate of HFL-1 when cultured in 10% (p < 0.03 at 48 h) serum, but did not have any effects on HFL-1 proliferation in 0.4% serum (d) (mean ± SD, n = 3 individual experiments with 4–6 technical replicates in each experiment, *p < 0.05, **p < 0.01 and ***p < 0.001)