differentiation of monocyte derived dendritic cells in serum free conditions

human peripheral blood monocytes (hpbm) were cultured in the absence of human serum and were converted into a state exhibiting a high accessory function expressed by their ability of supporting lymphocyte proliferation. after a prolonged culture in serum free media the monocyte derived cells were highly viable, increased in size and developed veils and dendritiform elongatio'l1s. paralleling the increase in accessory function, the cells decreased in the expression of markers typical of monocytes and macrophages (m 0), approaching the phenotype of lymphoid dendritic cells. we here define conditions for reproducibly generating these monocyte derived dendritic cells (m-dc) in various serum free media. this study also shows that acidic conditions prevent m0 development and facilitate m-dc differentiation even under serum conditions.