Blockage of Eosinopoiesis by IL-17A Is Prevented by Cytokine and Lipid Mediators of Allergic Inflammation

Figure 3

IL-17, effect on progenitor responses and requirement for IL-17RA. (a, b) Semisolid cultures were established for 7 days, from 2 × 10⁵ bone-marrow cells of naive BALB/c mice, in the presence of GM-CSF (2 ng/mL), alone or in association with IL-17A at the indicated concentrations. Total (a) and differential (b) colony counts were carried out under the inverted microscope, directly (a) or after staining dried agar layers for EPO and counterstaining by Harris’ Hematoxylin (b). Colony types in (b) are [36] pure granulocyte-macrophage (GM), mixed granulocyte-macrophage-eosinophil (GMEos), pure eosinophil (Eos), pure granulocyte (G), and pure macrophage (M). GM-CSF alone, black bar. GM-CSF in association with IL-17A (0.1 to 1 ng/mL), white bars. (c) Liquid cultures were established as described by Gaspar-Elsas et al. [38], in a two-phase culture with progenitor expansion in Flt3L and SCF, followed by eosinophil differentiation for up to 10 days with GM-CSF, IL-3, and IL-5, in the absence (white bar) or presence (black bar) of IL-17A (1 ng/mL). (d) Liquid cultures were established as in Figure 1(a), with bone-marrow from BALB/c mutants lacking IL-17RA. Data are mean ± SEM. . Significant differences relative to GM controls (a, b) or IL-5 controls (c, d). All groups, .

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