Generation of phagocytic MAK and MAC-DC for therapeutic use: Characterization and in vitro functional properties

Phagocytic cells with macrophage or dendritic cell phenotype, able to capture and ingest tumor cells, were derived in large numbers from peripheral blood mononuclear cells using two different activation procedures, Peripheral blood mononuclear cells were stimulated in nonadherent conditions in the presence of human AB serum with either granulocyte-macrophage colony-stimulating factor and dihydroxy-vitamin D-3 for 7 days and with interferon-gamma for the last 18 hours to obtain activated macrophages (MAK) or with granulocyte-macrophage colony-stimulating factor and interleukin-13 for 7 days (with fresh interleukin-13 added on day 4) to obtain macrophage-dendritic cells (MAC-DC), A strong ability of MAC-DC to phagocytose yeasts was observed, in contrast to a low-intermediate phagocytosis capacity by MAK, Both CD14(+) FC gamma R+ (Fc gamma RI/CD64, Fc gamma RII/CD32, Fc gamma RIII/CD16) MAR and CD1a(+)/CD86(+), CD14(-) RAG-DC were able to phagocytose whole tumor cells. However, only MAK phagocytosis was enhanced by Fc gamma R engagement, MAK but not MAC-DC could lyse tumor cell in antibody-dependent cell cytotoxicity assays, via Fc gamma RI, Thus, MAK as well as MAC-DC mag represent valuable tools for different in vivo therapy strategies that do or do not include the use of monoclonal antibodies, (C) 1999 International Society for Experimental Hematology. Published by Elsevier Science Inc.