Gene expression accompanied by differentiation of cord blood-derived CD34+ cells to eosinophils

To clarify the relation between the expression of genes such as eosinophil-specific granular proteins and cytokine receptors and the pathogenesis of allergic disease, cord blood-derived CD34+ cells were cultured and differentiated into eosinophils. Gene expression in the cells during the differentiation was determined by real-time reverse transcription PCR (ABI PRISM 7700). CD34+ mononuclear cells cultured with stem cell factor, granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-3, and IL-5 in Iscove's MEM, and proliferated until the 2nd week, when the cell number reached a plateau. Under these conditions, more than 90% of the cells differentiate into mature eosinophils in 3 weeks. The expression of major basic protein and eosinophil-derived neurotoxin in the treated cells increased until week 2 and decreased between week 2 and 3. However, the expression of membrane receptor genes, such as IL-5 receptor (alpha chain), IL-3 receptor (alpha chain), GM-CSF-alpha receptor, GM-CSF-beta receptor, CC chemokine receptor 3, interferon-gamma receptor, platelet-activating factor receptor and leukotriene D4 receptor, increased until the 3rd week of eosinophil maturation. Our study suggests that the in vitro eosinophil differentiation and maturation model is useful for clarifying the relation between eosinophil-specific gene expression during allergic diseases and the progression of the disease.