Eosinophils are continuously being generated in the bone marrow from a small pool of hematopoietic stem cells (HSCs). During differentiation into an eosinophil, HSCs go through distinct stages, including a myeloid progenitor followed by commitment to the eosinophil lineage with generation of the eosinophil-lineage committed progenitor (EoP), prior to reaching maturity. The factors that direct the developmental program of myeloid progenitor to EoP to mature eosinophil remain under-investigated, likely due to the rarity of these cells in healthy human bone marrow. We have developed a culture method to generate myeloid progenitors and EoPs from human HSCs to characterize the stages of human eosinophil development and identify the regulators of eosinophilopoiesis.

A photo of eosinophil lineage commitment.