Coinduction of Granulocyte-Macrophage Colony-Stimulating Factor Release and Lymphokine-Activated Killer Cell Susceptibility in Monocytes by Interleukin-2 Via Interleukin-2 Receptor

Human monocytes express interleukin-2 receptor f i (IL-2RB) constitutively; however, the function of these receptors has not been fully delineated. W e discovered that IL-PRB directs two biologic activities in human monocytes, the release of granulocyte-macrophage colony-stimulating factor (GMCSF) and increased susceptibility to lysis by lymphokineactivated killer cells (LAK) cells. Human monocytes were purified from peripheral blood mononuclear cells by plastic adherence and anti-CD2 plus complement lysis. By a 5hour ”Cr-release assay, monocytes cultured in IL-2 were found to gain increasing susceptibility to LAK cells with time and this effect was dose dependent. Maximal susceptibility was obtained with a 4-day culture in 1,000 U/