Cytokine induction of a human acute myelogenous leukemia cell line (KG-1) to a CD1a+ dendritic cell phenotype

Dendritic cells (DC) are highly specialized antigen-presenting cells located in many nonlymphoid tissues, and Langerhans cells (LC), a specialized form of DC, are found in the skin. LC as antigen-presenting cells play a critical role in the induction of allergic contact dermatitis. LC research is difficult because few LCs can be isolated from human skin, so efforts have focused on obtaining DCs from alternative sources. Mononuclear cells from peripheral blood and CD34+ stem cells from human cord blood and marrow can be induced to form phenotypic and functional DCs, but experiments of this type are expensive and the DC yield is low. We report here the induction of the myeloid leukemia cell line (KG-1) to a DC morphology and phenotype by culturing the cells in a defined cytokine cocktail. Morphologically, the KG-1-derived DCs are large irregularly shaped cells with prominent dendritic processes and hair-like cytoplasmic projections. Phenotypically, the KG-1-derived DCs lack lineage-specific markers, and express MHC class II, costimulatory molecules CD80 and CD86, and CD83. Functionally, KG-1-derived DCs are capable of phagocytosing latex microspheres and are able to induce a potent allogeneic T-cell response. Within the KG-1-derived DCs, a subpopulation maintains the DC phenotype and morphology described above but further develops CD1a+ marker expression similar to that of resident skin-derived LCs. These findings illustrate that phenotypic, morphologic and functional DCs can be derived from the KG-1 cell line.