Haemopoietic Growth Factors as Drugs

The process by which a small number of self renewing stems cells give rise to lineage committed progenitors that subsequently proliferate and differentiate to circulating mature blood cells is regulated by a family of glycoproteins known as colony stimulating factors (CSFs). Classification of these CSFs or growth factors, is based on the types of mature cells seen in colonies of bone marrow cells produced in vitro in response to these compounds. Thus, interleukin 3 (IL-3) stimulates the production of mature cells of most of the haemopoietic lineages including granulocytes, macrophages, eosinophils, megakaryocytes, erythroid cells and mast cells. Granulocyte-CSF (G-CSF) and macrophage-CSF (M-CSF) exhibit relative lineage restricted specificity and stimulate the production of granulocytes and macrophages respectively, while granulocyte-macrophage-CSF (GM-CSF) stimulates the production of both granulocytes and macrophages.