Abstract
Dendritic cells (DCs) are bone marrow-derived professional antigen-presenting cells. The in vitro generation of DCs from either bone marrow or blood is routine in mammals. Their distinct morphology and phenotype and their unique ability to stimulate naïve T cells are used to define DCs. In this study, chicken bone marrow cells were cultured in the presence of recombinant chicken granulocyte-macrophage colony-stimulating factor (GM-CSF) and recombinant chicken interleukin-4 (IL-4) for 7 days. The cultured population showed the typical morphology of DCs, with the surface phenotype of major histocompatibility complex (MHC) class II(+) (high), CD11c(+) (high), CD40(+) (moderate), CD1.1(+) (moderate), CD86(+) (low), CD83(-) and DEC-205(-). Upon maturation with lipopolysaccharide (LPS) or CD40L, surface expression of CD40, CD1.1, CD86, CD83 and DEC-205 was greatly increased. Endocytosis and phagocytosis were assessed by fluorescein isothiocyanate (FITC)-dextran uptake and fluorescent bead uptake, respectively, and both decreased after stimulation. Non-stimulated chicken bone marrow-derived DCs (chBM-DCs) stimulated both allogeneic and syngeneic peripheral blood lymphocytes (PBLs) to proliferate in a mixed lymphocyte reaction (MLR). LPS- or CD40L-stimulated chBM-DCs were more effective T-cell stimulators in MLR than non-stimulated chBM-DCs. Cultured chBM-DCs could be matured to a T helper type 1 (Th1)-promoting phenotype by LPS or CD40L stimulation, as determined by mRNA expression levels of Th1 and Th2 cytokines. We have therefore cultured functional chBM-DCs in a non-mammalian species for the first time.