Human peripheral blood contains two distinct lineages of dendritic cells

Abstract

Human peripheral blood contains two populations of dendritic cells (DC) but their developmental relationship has not been established. Freshly isolated CD11c– DC possessed a lymphoid morphology, lacked myeloid markers but expressed lymphoid markers (CD4+ CD10+) whilst the CD11c+ DC were monocytoid in appearance and expressed myeloid markers. Although both populations were allostimulatory, only the CD11c+ DC were able to take up antigen. Irrespective of the culture conditions the CD11c– cells developed into CD11c– CD13– CD33– CD4+ CD1a– CD83+/– DC. In contrast, cultured CD11c+ cells developed the phenotype CD11c+ CD13+ CD33+/– CD4– CD1a+ CD83+ CD9+. Only the CD11c+ DC expressed macrophage colony‐stimulating factor (M‐CSF) receptor and gave rise to CD14+, esterase+, phagocytic macrophages when cultured in M‐CSF. These data suggest that these two populations of DC represent distinct lineages of antigen‐presenting DC.

Altered maturation of peripheral blood dendritic cells in patients with breast cancer

“…We applied flow cytometric methods that allow the enumeration and the immunophenotypical as well as functional characterisation of DCs directly in whole peripheral blood samples (Robinson et al, 1999;Arpinati et al, 2000;Upham et al, 2000). With this method, we observed that Lin-/HLA-DR þ DCs are significantly reduced in the peripheral blood of breast cancer patients compared with healthy donors.…”

“…To further investigate the significance of the increase of PB CD34 þ cells in breast cancer patients, ongoing studies are planned to characterise the immunophenotype and the functional activity of these cells in our patients. Since human PB DCs can be divided, on the basis of expression of the b-integrin CD11c (Robinson et al, 1999), into two subpopulations that differ in the origin, expression of phenotypic markers, route of activation and immunological activity, we evaluated their distribution in our patients. We found that the number of myeloid DCs, and not plasmacytoid DCs, was significantly decreased in breast cancer patients compared to controls.…”

“…This alteration may have a relevant impact on immune defences against cancer. In fact, CD11c þ myeloid DCs originate from myeloid bone marrow precursors, express myeloid antigens, and upon stimulation produce high amounts of IL-12, which in turn promotes cell-mediated immune responses that are crucial for the detection and elimination of malignant cells (Cella et al, 1996;Rissoan et al, 1999;Robinson et al, 1999). CD11c-plasmacytoid DCs originate from lymphoid bone marrow precursors, lack myeloid markers, express high levels of the IL-3-receptor-a chain (CD123) and secrete lower amounts of IL-12 (Rissoan et al, 1999;Robinson et al, 1999;Reid et al, 2000;Liu et al, 2001).…”

Cerebrospinal fluid affects phenotype and functions of myeloid dendritic cells

“…This may result in an inefficient adaptive response against pyogenic bacteria, but augment the innate response against these microogranisms. Other factors present in BM CSF, for instance M-CSF [37], may also convert myeloid DC into macrophages [38]. In LM CSF, on the other hand, myeloid DC are abundant (up to 5000 cells/ml) [13], levels of IL-10 are relatively low, and IFN-g is present, augmenting production of IL-12 by myeloid DC.…”

IFN-α production by human mononuclear cells infected with varicella-zoster virus through TLR9-dependent and -independent pathways

“…At least two subsets of DCs were originally identified in peripheral blood, including myeloid DCs (mDCs) and plasmacytoid DCs (pDCs). [3][4][5][6] The mDCs express CD11c and CD1c (BDCA-1) antigens. In contrast, pDCs express CD123, BDCA-2 and BDCA-4 antigens.…”