Fig. 5

Human microglial pathways not impacted by fenebrutinib treatment. A Cytokine and chemokine release from LPS-stimulated (0.1 μg/mL) human iMicroglia incubated with fenebrutinib or ibrutinib (both 1 μM) for 24 h. While BTK inhibition reduced levels of GM-CSF and CCL17, limited effects were observed for other cytokines and chemokines that are increased with LPS stimulation. B IL-1β release from human iMicroglia incubated with fenebrutinib or MCC-950 (0.01–1 μM) and stimulated with LPS (0.1 μg/mL; 3 h) followed by nigericin (10 μM; 1 h). Fenebrutinib had no effect on IL-1β release in contrast to MCC-950, which dose dependently reduced IL-1β levels. C Phagocytosis of pHrodo-conjugated myelin by human iMicroglia incubated with fenebrutinib or ibrutinib (0.01–1 μM) for 24 h. Fenebrutinib had no effect on myelin phagocytosis, while ibrutinib reduced myelin phagocytosis at 1 μM only. Data are shown as mean ± SD; individual dots represent replicate wells. Results are representative of two to three independent experiments. Significance is indicated by ****P < 0.0001, ***P < 0.001 and *P < 0.05, determined by one‐way ANOVA and Tukey’s post hoc test. ANOVA analysis of variance, BTK Bruton’s tyrosine kinase, CCL C-C motif chemokine ligand, CXCL C-X-C motif chemokine ligand, GM-CSF granulocyte–macrophage colony-stimulating factor, FEN fenebrutinib, IL interleukin, iMicroglia induced pluripotent stem cell-derived microglia, LPS lipopolysaccharide, NLRP3 NACHT, LRR and PYD domains-containing protein 3, SD standard deviation, TNF tumor necrosis factor