Extramedullary development of hematopoietic progenitor cells in IL-5trg mice.

Spleen cells were harvested from IL-5trg and WT mice and plated into methylcellulose cultures in the presence of lineage-specific cytokines. GM-CSF or M-CSF was added to estimate numbers of granulocyte-macrophage– or macrophage-CFCs, and IL-5 (50 ng/mL) or IL-7 was added to estimate the numbers of eosinophil or B-lymphoid progenitors. Colonies were cultured in quadruples, calculated after 7 days of culture, and expressed as mean ± SD.