Stem cell factor and IgE-stimulated murine mast cells produce chemokines (CCL2, CCL17, CCL22) and express chemokine receptors

Objective and design: In the present study we investigated the effect of SCF and/or IgE on histamine, TNF-alpha and chemokines released from bone marrow-derived mast cells (BMMC) as well as chemokine receptor expression. Material and methods: BMMC were derived from femoral bone marrow of CBA/J mice. The purity of BMMC was >98% after 3 weeks. BMMC (2.5 x 10(6) cells/well) were incubated in the presence or absence of either SCF, IgE plus DNP or a combination of SCF and IgE for 6 and 18 h. Cell-free supernatants were recovered to measure CC chemokines, TNF-a and histamine release utilizing ELISA assays. CC chemokine family receptors were detected by RT-PCR analysis, and confirmed using functional chemotactic assays. Results: Histamine levels were comparable between SCF and IgE stimulated cells, whereas TNF-alpha production was significantly greater after IgE compared to SCF stimulation. SCF and/or IgE-stimulated BMMC released CC chemokines, CCL22 (MDC), CCL17 (TARC) and CCL2 (MCP-1). Increased mRNA expression of CCR1, CCR2, CCR3, and CCR5 was detected in SCF and IgE-stimulated BMMCs. Functional chemotactic assays confirmed the expression data. Conclusion: SCF and IgE can up-regulate the expression of chemokines and chemokine receptors on mast cells. Thus, SCF may play a significant role in their activation and inflammation during allergic responses.