CD31^hiLy-6C^neg cells give rise to eosinophils following culture in IL-5.

(A) Flow cytometric staining of gated CD31^hiLy-6C^neg cells reveals expression of the eotaxin receptor CCR3 (open histogram). Isotype control is indicated by the filled histogram. (B) CD31^hiLy-6C^neg cells were sorted to purity using flow cytometric sorting and cultured in the presence of IL-5 for 6 days. Sorted population was obtained from bone marrow of an OVA-DC/OVA animal, exposed to 3 OVA aerosols. (C) Cultured cells have an eosinophilic cytoplasm and a donut-shaped nucleus. We next investigated whether the enhanced population of CD31^hiLy-6C^neg cells responded differently to growth factor stimulation in mice with or without eosinophilic airway inflammation by comparing the growth of equal numbers of sorted CD31^hiLy-6C^neg obtained from both groups. After sorting and a 7-day culture in GM-CSF there was a significant difference neither in the yield of total cells (P = .1) nor in the percentage of CD11c⁺ DCs derived from the CD31^hiLy-6C^neg of both groups (results not shown). However, when grown in IL-5, the subset sorted from the BM of OVA-challenged animals yielded slightly more eosinophilis compared with the PBS-DC/PBS mice (51.2 ± 1.1% vs 40.5 ± 1.3%,P < .05). Cells were stained with αMBP Ab. Original magnification, × 400.