Isolation of human myeloid dendritic cells from tumor tissue and peripheral blood

Background: Human myeloid dendritic cells (MDC) have been identified in human solid tumor tissue of head and neck squamous cell carcinoma (HNSCC), their cellular functions being strongly affected in this environment. The characterization of MDC differentiation and functions requires the establishment of highly efficient isolation procedures. Materials and Methods: Human MDC were isolated from peripheral blood and solid HNSCC using density gradient centrifugation or preparation of single cell suspensions, respectively. The cells were isolated by "magnetic bead separation" using magnetically-labelled antibodies and were analyzed by flow cytometry. Results: The isolation of human MDC from peripheral blood or solid HNSCC tissue resulted in highly enriched cell populations and revealed cell purities of about 90%. Conclusion: The scale of molecular investigations on human myeloid dendritic cells is restricted by the limited proportion of this cell type. Thus, highly efficient and gentle MDC isolation procedures are essential to characterize in vivo matured MDC.