Figure 5. Inhibition of neutrophil differentiation by IRF4.

(A) Wright-Giemsa staining of 32Dcl.3 cells transduced with empty MSCV-puro, MSCV-IRF4FLAG-puro or MSCV-IRF8FLAG-puro and cultured in the presence of IL-3 (upper panels) or G-CSF (for 7 days, lower panels). (B) Immunoblotting analysis of FLAG-tagged IRFs. β-tubulin expression is shown as a loading control. (C) Cell growth curves in the presence of IL-3. Data are expressed as mean ± standard deviation of triplicate determinations. (D) Proportions of cells showing the morphologic characteristics of mature granulocytes. *P<0.01 (Student's t-test). (E) Csf3r mRNA expression levels after 7 days of treatment of G-CSF. The expression levels were determined by qRT-PCR using the ΔΔCT method (mean ± standard deviation). Data are representative of two independent experiments with similar results. *P<0.01 (Student's t-test). (F) Viable cell yields during treatment with G-CSF. Data are expressed as mean ± standard deviation of three independent experiments.