- Top of page
- Serum samples
- Cytokines, reagents and antibodies
- Cell preparation
- Suspension cultures
- Flow cytometric analysis
- Clonal cell cultures
- Cytochemical and immunologic staining
- Assay of histamine, tryptase, cytokine and retinol levels
- Statistical analysis
- Effects of human serum on SCF-dependent human mast cell development
- Contribution of retinol to human serum-mediated inhibition of mast cell growth
- Differential regulation by human serum during hematopoiesis
- RARα antagonist decreases the FBS-induced suppression of human mast cell growth supported by SCF
Background:In vitro culture systems have been used to study the physiological and pathological characteristics of human mast cells. However, there are some differences in proliferation and maturation of mast cells between fetal bovine serum (FBS)-containing and serum-deprived cultures. Accordingly, we attempted to identify circulating factor(s) affecting the development of human mast cells.
Methods: We measured the serum levels of retinol and several cytokines. To elucidate the antiproliferative effects of the serum, a retinoic acid receptor (RARα) antagonist and neutralizing antibodies against cytokines were used.
Results: Similar to FBS, human serum dose-dependently suppressed the growth of tryptase+ cells from CD34+ cord blood cells or 20-week cultured mast cells under stimulation with stem cell factor (SCF). The serum-mediated inhibition might be based on a decline in proliferation rate. Among inhibitors for mast cell growth, retinol and transforming growth factor (TGF)-β1 were present at high levels in human serum. In contrast with anti-TGF-β1 antibody, an RARα antagonist counteracted the serum-induced suppression of human mast cell proliferation.
Conclusions: Our results suggest that retinol and its derivatives act as a circulating regulator for human mast cell growth. The RARα antagonist may be a useful tool to obtain higher numbers of mast cells in FBS-containing cultures.