Expression and secretion of CXCL8 (IL-8), release of tryptase and transcription of histidine decarboxylase mRNA by anti-IgE-activated human umbilical cord blood-derived cultured mast cells.

Activation of cytokine receptors and alterations in cytokines are thought to play important roles in neuronal dysfunction and in the pathogenesis of the nervous system diseases. CXCL8 (IL-8) is a CXC chemokine with chemotactic and inflammatory properties. Chemokines control mast cell infiltration in several inflammatory diseases, including stress and neurological dysfunctions. Using isolated human umbilical cord blood-derived cultured mast cells (HUCMC) from hematopoietic stem cells CD34+, mast cells were immunologically activated with anti-IgE at concentrations of 1, 5, 10 and 20 microg/ml leading to the dose-dependent production of IL-8 (p < 0.05). The increase in IL-8 mRNA expression was also noted when the cells were treated with anti-IgE at 10 microg/ml for 6 h. Immunologically activated HUCMC provoked the generation of tryptase in a dose- and time-dependent manner. We also found increased histidine decarboxylase (HDC) expression in activated HUCMC after 6 h of incubation, a rate-limiting enzyme responsible for the generation of histamine from histidine. Taken together, these results confirm that anti-IgE-activated mast cells release inflammatory mediators including CXCL8, a CXC chemokine which regulates several biological effects of mast cells, e.g. chemoattraction, and possibly causes cell arrest.