Colony Stimulating Factors: Regulation of Production

Life span of mature blood cells is ephemeral, reqUIrIng hematopoiesis throughout life. A complex network of hematopoietic progenitor cells and cytokines maintain an enormous daily production of granulocytes, monocytes, erythrocytes, platelets, and lymphocytes. This population of hematopoietic cells must be able to respond rapidly to changing needs such as bleeding, infections, cancer, or exposure to cytotoxic agents. Colony stimulating factors (CSFs) are a family of glycoproteins that promote growth and differentiation of hematopoietic progenitor cells and also enhance the function of the mature blood cells. production of CSFs is under tight control since either their overor underproduction will result in dysregulation of hematopoiesis. Proliferation of hematopoietic progenitor cells require the continuous presence of these factors. A variety of cells including nonhematopoietic cells such as fibroblasts, endothelial cells, and smooth muscle cells are capable of producing many kinds of