Neurotrophin-3, but not nerve growth factor, promotes survival of human intestinal mast cells

Neurotrophins are potent regulators of neuronal cell survival and function. Nerve growth factor (NGF) was shown to reduce apoptosis in cord blood-derived mast cells. Here, we examined the effect of the neurotrophins NGF and neurotrophin (NT)-3 on survival and mediator release of human intestinal mast cells. Mast cells isolated from normal intestinal tissue were cultured in the presence of NGF, NT-3, or stem cell factor (SCF) alone or in the presence of SCF together with each neurotrophin. NGF or NT-3 alone did not promote mast cell survival. In contrast, mast cell recovery was increased twofold when mast cells were cultured with NT-3 in addition to SCF for 14 days compared with control. Mast cell recovery was further increased following a combined addition of NT-3, SCF and IL-4. NT-3 mediated mast cell growth was dependent on the primary receptor for NT- 3 TrkC. NGF in combination with SCF or with SCF and IL-4 showed no effect on mast cell survival. His- tamine release and histamine content per mast cell remained unchanged, whereas leukotriene C4 release decreased if mast cells were cultured with NGF or NT- 3 in addition to SCF. In summary, NT-3 affects mature human mast cells by promoting mast cell survival, whereas NGF does not.