Alkaline Phosphatase, Defensin Gene Expression and Effect of Myeloid Cell Growth Factors in Normal and Leukemic Cells

In neutrophils, four different granules are defined, i.e. azurophil, specific, gelatinase and secretary vesicles. In these granules many neutrophil-specific constituents are identified. Some of these constituents have already been cloned and their gene expressions studied. In such constituents, alkaline phosphatase (ALP) and defensin are well known, although their functions are not yet fully clarified. ALP is present in secretary vesicles and has important roles in the diagnosis of some myeloid disorders. On the other hand, defensin is the most abundant functional peptide of neutrophils and is present in azurophillic granules. Which are subdivided into defensin-rich and defensin-poor granules. This review describes the expression of ALP and the defensin gene in normal and leukemic cells and the effect on these genes of myeloid growth factors, such as granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor and interleukin 3.