Recently we demonstrated that human mast cells (MC) express functional TRAIL death receptors. Here we assessed the expression of TRAIL on both mRNA and protein level in cord blood derived MC (CBMC) and HMC-1. The TRAIL release either spontaneous or induced by LPS, IFN-γ and IgE-dependent activation, was evaluated as well. The protein location was restricted to the intracellular compartment in CBMC, but not in HMC-1. The intracellular TRAIL was not localized inside the granules. The treatment with IFN-γ and LPS up-regulated intracellular TRAIL expression in CBMC, but did not induce its release. These in vitro data show that human MC can produce and express intracellular TRAIL whose location could not be altered by different stimuli.
Bibliographical noteFunding Information:
This work was supported in part by Grant No. 3000002966 from the Chief Scientist’s Office of the Ministry of Health, Israel to F.L.S., a grant from the Aimwell Charitable Trust Foundation (UK) to F.L.S. and by the Swiss National Science Foundation (Grant No. 310000-107526) to H.U.S. B.B.M. received a 2005 EAACI Fellowship Award and GA2LEN Fellowship Award.
- Cell activation
- Mast cells