ABSTRACT
Human granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-3 (IL-3) are glycoproteins produced by activated T lymphocytes that control the proliferation, differentiation, functional activation and survival of human eosinophils in vitro. Infusion of GM-CSF and IL-3 in monkeys and humans indicates that at least some of these eosinophil stimulatory properties are also observed in vivo. Human GM-CSF and IL-3 regulate the production and function of human eosinophils in vitro and in vivo. They are produced by activated T cells, and increased mRNA has been detected in T cells in the bronchi and skin of allergic individuals, implicating these factors in the pathogenesis of asthma and skin disease. Human eosinophils are specialized cells believed to play a central role in the control of parasitic infections and allergic reactions. Two important factors that regulate the production and function of eosinophils are the hemopoietic growth factors GM-CSF and IL-3.
