Production of fibrogenic cytokines by cord blood–derived cultured human mast cells

Background: Mast cells are a potential source of cytokines, but their contribution to nonallergic inflammatory conditions, such as fibrosis, remains unclear. Objective: We investigated whether cord blood–derived cultured human mast cells could produce fibrogenic cytokines by IgE-mediated activation. Methods: Mast cells were obtained from human cord blood mononuclear cells by culture with stem cell factor and IL-6. The mast cells were incubated with human myeloma IgE and were activated with anti-IgE. The expression of messenger RNA for fibrogenic cytokines was examined by the reverse-transcription polymerase chain reaction, and cytokine protein was assayed by enzyme-linked immunosorbent assay, or bioassay. Results: Cultured human mast cells constitutively expressed mRNA for transforming growth factor-β1, and its expression was not increased by anti-IgE stimulation. The cells released this factor into the culture medium spontaneously, which showed bioactivity after heat treatment. The mast cells also expressed mRNA for platelet-derived growth factor A, which was enhanced with a peak at 3 hours by stimulation with anti-IgE. Conditioned medium from nonactivated mast cells did not contain basic fibroblast growth factor, but this cytokine was released into the medium in a time-dependent manner after stimulation with anti-IgE. Conclusion: Human mast cells activated by IgE-mediated stimulation show production of fibrogenic cytokines that varies depending on the cytokine, which suggests possible involvement of mast cell cytokines in the development of fibrosis. (J Allergy Clin Immunol 2000;106:S85-90.)