FIG 2.

Human eosinophils polarize into type 2 and type 1 immune subtypes on in vitro cytokine culture. A, Scheme representing experiment. Isolated pure populations of peripheral blood human eosinophils from healthy donors were cultured in vitro with cytokines for 18 hours and then analyzed for various phenotype changes. All cultures had IL-5. E2 eosinophils (blue) were also cultured with IL-4, GM-CSF, and IL-33 and E1 eosinophils (orange) with IFN-γ and TNF-α. E0 (gray) indicates IL-5 only. B, Representative images of E0, E1, and E2 cells after Hema 3 staining. C, Representative normalized to mode histograms are shown (top) as well as mean fluorescence intensity (MFI) (bottom) for cell surface markers. D, Cell-free media from the cultures were measured for cytokines/chemokines by multiplex assay. E, Quantitative RT-PCR for CXCL9 and NOS2 of E1 or E2 eosinophils relative to β-actin and normalized to E0. Data are shown as mean ± SEM. Data are from 3 independent donors using 1-way ANOVA with the Tukey multiple comparisons test (Fig 2, C and D) or the Student t test (Fig 2, E). ****P < .0001; ***P < .001; **P < .01; *P < .05.