Human mast cells express receptors for IL-3, IL-5 and GM-CSF;: a partial map of receptors on human mast cells cultured in vitro

Backgrouind: Mast cells have long been recognized as the principal cell type that initiates the inflammatory response characteristic of acute allergic type 1 reactions. Our goal has been to further characterize maturation of progenitors to mast cells. Methods: Mast cells were cultured from human cord blood derived CD133(+) progenitors. Mast cell function was tested using histamine release. During differentiation mast cells surface marker expression was monitored by flow cytometry. Results: CD133(+) progenitors expressed the early haematopoietic and myeloid lineage markers CD34, CD117, CD13 and CD33. Mature mast cells expressed CD117, CD13 and CD33, and expression of the high affinity immunoglobulin E recpetor FcepsilonRI increased during culture. Cytokine receptors interleukin (IL)-5R, IL-3R, granulocyte-macrophage-colony stimulating factor (GM-CSF)R and IL-18R were expressed at high levels during maturation. Chemokine receptors CXCR4 and CXCR2 were highly expressed on both newly purified CD133(+) cells and mature cells. Conclusion: Human mast cells can be cultured from a CD34(+)/CD117(+)/CD13(+)/CD33(+) progenitor cell population in cord blood that is tryptase and chymase negative. Developing and mature mast cells express a wide range of chemokine and cytokine receptors. We found high levels of expression of CD123, IL-5R and GM-CSF receptors, also found on eosinophils and basophils, and high levels of expression of the receptor for the inflammatory cytokine IL-18.