Interleukin-1, characterization of the molecule, functional activity, and clinical implications

Hematopoiesis is regulated by a number of growth factors, of which colony-stimulating factors (CSF) have been exclusively defined according to the cell type they grow in vitro in colony assays. A number of cytokines, including interleukin-1 (IL-1), which have been characterized to exhibit multiple activities, are also involved in the control of growth and differentiation of hematopoietic cells. Some CSFs and related cytokines have already been introduced into clinical evaluation. This review summarizes the current knowledge of the IL-1 molecules, their moleculargenetic, and protein features as well as their in vitro and in vivo actions which justify their development as therapeutic agents.