Fig. 1: Mettl3 modulates mast cell proliferation and effector functions.

a Mast cells were stimulated with IgE with or without HSA-DNP for the indicated times and expression of Mettl3 was analyzed by western blot. Left, one representative blot. Right, quantification of N = 3 independent experiments. Mean ± SEM. One-way ANOVA. b After ex-vivo expansion, PMCs were stimulated with IgE and antigen complexes and Mettl3 expression was measured by intracellular staining. N = 7 independent experiments. Mean ± SD. Paired t test, two-tailed. c Expression of Mettl3, measured by RT-qPCR, in mast cells transfected with siRNAs against Mettl3 or a non-targeting control. N = 8 independent experiments. Mean ± SEM. Paired t test, two-tailed. d Expression of inflammatory cytokines measured by intracellular cytokine staining in mast cells transfected with siRNAs against Mettl3 or a non-targeting control. Cells were stimulated with IgE and antigen complexes for 4 h. Left, representative FACS plots. Right, quantification of N = 8-10 independent experiments. Mean ± SEM. Paired t test, two-tailed. e Mast cells were transduced with lentiviral vectors to overexpress Mettl3. After selection of the transduced cells and stimulation with IgE and antigen complexes for 4 h, intracellular cytokine staining was performed to measure the expression of inflammatory cytokines. N = 8 independent experiments (ratio compared to controls). Mean ± SEM. Unpaired t test, two-tailed. f Mast cells were transfected with siRNAs against Mettl3 or a non-targeting control. 48 h after transfection, cells were stimulated with IgE and antigen complexes for 4 h, followed by β-hexosaminidase assay to measure the extent of degranulation. N = 4 independent experiments. Mean ± SEM. Unpaired t test, two-tailed. g Mast cells were transfected with siRNAs against Mettl3 or a non-targeting control, followed by BrdU incorporation to measure cell proliferation. N = 10 independent experiments. Mean ± SEM. Paired t test, two-tailed. Source data are provided as a Source data File.