Efficient generation of dendritic cells from alveolar and pleural macrophages as well as blood monocytes in patients with lung cancer

In this study, we investigated the generation of dendritic cells (DCs) from blood monocytes and mature macrophages from untreated primary lung cancer patients. Blood monocytes were separated by adherence from blood mononuclear cells (MNC) from ten lung cancer patients and ten control subjects, and cultured for 7 days in medium with granulocyte/macrophage colony-stimulating factor (GM-CSF) plus interleukin (IL-) 4. In all cases examined, DCs with typical characteristics were obtained even in lung cancer patients after 7 days culture with these cytokines, and there was no significant difference in phenotype and stimulatory activity in allogeneic lymphocyte proliferation between DCs derived from monocytes from lung cancer patients and those from control subjects. Next, we examined whether alveolar and pleural macrophages in malignant pleural effusion separated by magnetic beads could differentiate to immunostimulatory DCs, Conventional culture conditions with GM-CSF and IL-4 did not induce efficient numbers of DCs from mature macrophages, whereas the addition of tumor necrosis factor-alpha (TNF-alpha) to GM-CSF and IL-4 effectively contributed to generate DCs. These findings suggest that both mature macrophages and blood monocytes from lung cancer patients could differentiate to DCs, and might be a useful source of DCs for immunotherapy. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.