Figure 1

Effects of IFN-γ on mast cell growth in vitro. (A) mRNAs encoding for GAPDH and IFNGRI detected by RT-PCR in MCs following culture for 14 days in the presence of SCF (50 ng/ml) or SCF and IL-4 (2 ng/ml) and subsequent challenge for 60 minutes with mAb22E7 (+) or buffer control (−). (B) Dose-dependent growth inhibition of MCs by IFN-γ. MCs were cultured for 14 days in the presence of SCF (50 ng/ml) or SCF and IL-4 (2 ng/ml) and without or with different concentrations of IFN-γ (indicated in the graph). One representative experiment performed in duplicates out of two is shown. (C-D) MC recovery after culture in different conditions for indicated time periods with or without the addition of IFN-γ (100 ng/ml). (C) Culture in medium alone ± IFN-γ (n = 5). (D) Culture in the presence of SCF (5 ng/ml) ± IFN-γ (n = 5). (E) Culture in the presence of SCF (50 ng/ml) ± IFN-γ (n = 7 for day 3 and day 14, n = 5 for day 7). (F) Culture in the presence of SCF (50 ng/ml) + IL-4 (2 ng/ml) ± IFN-γ (n = 7). All data are shown as mean ± SEM. **p < 0.01.