title: Myeloid blood CD11c(+) dendritic cells and monocyte-derived dendritic cells differ in their ability to stimulate T lymphocytes.
abstract: Dendritic cells (DCs) initiate and direct immune responses. Recent studies have defined different DC populations, therefore we undertook this study comparing 2 types of myeloid DCs: blood CD11c(+) DCs and in vitro monocyte-derived DCs (Mo-DCs), which are both candidates as cellular adjuvants for cancer immunotherapy. Blood CD11c(+) DCs were prepared by cell sorting from peripheral blood mononuclear cells cultured overnight in RPMI 1640 medium supplemented with autologous or pooled AB serum. Mo-DCs were prepared in the same medium using granulocyte macrophage-colony-stimulating factor (GM-CSF)/interleukin 4 (IL-4) and differentiated/activated with lipopolysaccharide or monocyte-conditioned medium (ActMo-DCs). Morphologically, differences between the DC preparations were noted both at a light and and electron microscopic level. Blood CD11c(+) DCs expressed similar levels of HLA-DR, CD40, CD86, and CD83 as Mo-DCs. CD209 was present on Mo-DCs but not on blood CD11c(+) DCs. Blood CD11c(+) DCs generated a lower proliferative mixed leukocyte response (MLR) than Mo-DCs. Blood CD11c(+) DCs loaded with 0.1 microg/mL tetanus toxoid (TT)-generated greater T lymphocyte proliferative responses than did Mo-DCs or ActMo-DCs, but when loaded with higher TT concentrations no difference in T lymphocyte proliferative response was observed. Keyhole limpet hemocyanin (KLH)-loaded blood CD11c(+) DCs generated greater T lymphocyte proliferative responses than Mo-DCs or ActMo-DCs. Allogeneic MLR- or KLH-specific responses induced by blood CD11c(+) DCs generated more Th1 effectors than the responses induced by Mo-DCs or ActMo-DCs. These data establish several differences in the properties of blood CD11c(+) DCs, Mo-DCs, and ActMo-DCs, which suggest that blood DCs merit further consideration as DC preparations for clinical programs are evolved.
mesh_terms: D000911:Antibodies, Monoclonal; D039521:CD11c Antigen / Q000097:blood*; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology*; D006801:Humans; D007371:Interferon-gamma / Q000097:blood; D008213:Lymphocyte Activation / Q000276:immunology*; D009000:Monocytes / Q000166:cytology / Q000276:immunology*; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D039521:CD11c Antigen; D007371:Interferon-gamma