Dendritic cell differentiation pathways of CD341 cells from the peripheral blood of head and neck cancer patients

Abstract: Patients with head and neck squamous cell carcinoma (HNSCC) have increased levels of immune-suppressive peripheral blood CD341 cells. This study showed that the peripheral blood CD341 cells of HNSCC patients are capable of differentiat-ing into dendritic cells. Because CD341 cells can differentiate through several pathways into den-dritic cell subpopulations, the intermediate cells through which the blood CD341 cells of HNSCC patients differentiate were identified. After 6–7 days of culturing the CD341 cells of HNSCC pa-tients with granulocyte-macrophage colony-stimu-lating factor, stem cell factor, and tumor necrosis factor a, there appeared CD141CD1a1 and a lesser proportion of CD142CD1a1 cells resembling the precursor cells of the bipotential and commit-ted dendritic cell differentiation pathways that have been described for cord blood CD341 cells. To functionally analyze whether these populations were in fact precursor cells, they were isolated and cultured for an additional 10–12 days. Each of these populations was shown to function as pre-cursor cells because they were able to develop into cells that resembled dendritic cells, al-though a higher proportion developed from the CD142CD1a1 cells. In contrast, expression of the dendritic activation/maturation marker CD83 was highest on the cells that developed from CD141CD1a1 cells. Thus, the CD341 cells whose levels are increased in HNSCC patients can develop into both committed and bipotential dendritic pre-cursor cells, which can subsequently give rise t