IgE promotes the survival of cultured human lung mast cells through IL-6. A) Survival assay time course following cytokine withdrawal. Human lung mast cells (HLMC) die rapidly following cytokine withdrawal and this cell death is attenuated with the addition of IgE. B) IgE-induced HLMC survival is eliminated with the addition of an anti-IL-6 antibody and unaffected with the addition of an anti-SCF antibody following 7 days of culture. C) IgG does not promote HLMC survival when compared to the sodium azide control. Data is presented as the mean ± SEM from 6 different donors performed in triplicate. Blocking experiments are the mean ± SEM from 3 donors. Data for the IgG control experiments are the mean ± SEM from 4 donors. Donors in C are different to those in A and B.