Figure 3.
α-GalCer synergizes with dexamethasone to promote eosinophil maturation. Bone marrow cultures were established from BALB/c bone marrow for 7 days with IL-5 (1 ng·mL−1), alone or together with dexamethasone (10−7 M, D7), α-GalCer (10−8 M, GC8) or both. Panels (A) and (C): Effects of dexamethasone, α-GalCer or both on total and differential EPO+ cell counts. Data are mean + SEM of the counts (panel A, total; panel C, differential) of EPO+ cells in 7 day cultures established in the indicated conditions. Panel (A): Cultures established with IL-5 alone or together with α-GalCer (10−8 M), were maintained without (−) or with (+) dexamethasone (10−7 M). Panel (B): Representative images of eosinophils (recognizable by EPO+, brown-stained, coarse cytoplasmic granules) in the indicated culture conditions. Immature eosinophils, a prominent feature of dexamethasone-exposed cultures, show variable size and nucleocytoplasmic ratios, with incomplete nuclear segmentation, and often form homotypic aggregates. Mature eosinophils are smaller, with regular size and donut-shaped nuclei, usually found as single cells. Apoptotic eosinophils, more frequent in α-GalCer-exposed cultures, are pyknotic and occasionally found attached to the surface of macrophages. Panel (C): Cultures established with IL-5 alone or together with dexamethasone (10−7 M) (+D7), α-GalCer 10−8 M (+GC8) or both (+GC8 + D7) were examined for the proportions of mature and immature eosinophils in the total EPO+ cell numbers. *P ≤ 0.01, significantlydifferent as indicated; n = 3.