Figure 5. Transcription factor Ikaros negatively regulates the differentiation of hybrid neutrophils.

(A) Flow cytometric analysis of the level of Ikaros and HLA-DR expression in PBNs and BMNs at different stages of maturation Results are shown as Mean Fluorescence Intensity (MFI).

(B) Flow cytometric analysis of the level of Ikaros expression in the HLA-DR⁺ hybrid and HLA-DR⁻ canonical CD11b⁺CD15^hiCD66b⁺ BMNs.

(C) Flow cytometric analysis of CD14 and HLA-DR expression on gated live CD11b⁺CD15^hiCD66b⁺ BMNs cultured in the presence of lenalidomide (10 µM) and hybrid-inducing TCM (30% v/v) for 6 days.

(D) The effect of IFN-γ (50 pg/ml) and GM-CSF (50 pg/ml) on the formation of HLA-DR⁺ CD14⁺ hybrid neutrophils in the absence (top panel) or presence (bottom panel) of lenalidomide (10 µM) in vitro. The level of Ikaros expression (MFI) in BMNs treated with IFN-γ (50 pg/ml) and GM-CSF (50 pg/ml) for 5 days (mean ± SEM, n = 3, *p ≤ 0.01, Wilcoxon matched-pairs rank test).

Representative dot plots from 1 of 6 experiments are shown in (A–D).