Fig. 5
Iluzanebart (ILU) increases survival and restores morphology of human MDMs and iPSC microglia following CSF1 withdrawal in vitro. A-B Human Monocyte Derived Macrophages (hMDM). Iluzanebart counteracts the effects of CSF1 withdrawal-induced apoptosis and morphology in hMDM cultures from 2 independent monocyte donors (A) hMDM. Withdrawal of CSF1 from the culture media increased caspase 3/7 + cells in human MDM cultures (grey bar). Treatment of cells with iluzanebart (10 µg/ml, blue bar) led to a significant reduction in caspase 3/7 + cells, whereas treatment with IgG (green bar) did not. B hMDM. Withdrawal of CSF1 reduced confluence of cells in human MDM cultures (grey bar). Treatment of cells with iluzanebart (10 µg/ml, blue bar) led to a significant increase in confluence, whereas treatment with IgG (green bar) did not. C-E iPSC Derived Human Microglia (iMGL). C Withdrawal of CSF1 decreased iMGL cell viability (n = 3 independent experiments), as measured by CellTiter Glo (grey bar). Treatment with iluzanebart (75 µg/ml, blue bar) led to a significant restoration of ATP levels, whereas treatment with IgG control (green bars) did not. D iMGL. Withdrawal of CSF1 from the culture media decreased morphological eccentricity (n = 5 independent experiments) of human iPSC-derived microglia in vitro (grey bar). Treatment with iluzanebart (75 µg/ml, blue bar) restored cellular morphology to a more ramified state, whereas treatment with IgG control (green bar) did not. E iMGL. Withdrawal of CSF1 increased caspase 3/7 + cells (n = 5 independent experiments) in iPSC microglia cultures (grey bar). Treatment with iluzanebart (75 µg/ml, blue bar) led to a significant reduction in caspase 3/7 + cells, whereas treatment with IgG control (green bar) did not. F hMDM. Representative images of cells in complete media (CM), cells in withdrawal media treated with IgG control (WD + IgG), and cells in withdrawal media exposed to iluzanebart (WD + ILU). G iMGL. Representative images of cells in complete media (CM), cells in withdrawal media treated with IgG control (WD + IgG), and cells in withdrawal media exposed to iluzanebart (WD + ILU). Significance was determined by one-way ANOVA with Tukey’s multiple comparison’s test, * < 0.05, ** < 0.05, *** < 0.0005, **** < 0.0001