Human lung mast cells cocultured with human lung fibroblasts are activated by MBP with a dose-dependent pattern.

Human lung mast cells (90%-99% mast cells) were maintained in coculture with human lung fibroblasts for 4 days before activation. Histamine release was assessed after 30 minutes of incubation with MBP at the concentrations indicated. Data are the means of ± SEM of 5 experiments performed in triplicates. P < .001 compared with cells incubated in buffer alone.