OBJECTIVETo establish a stable method for obtaining large quantity of highly purified immature dendritic cells (imDCs) in vitro, and identify the morphology, function and surface markers of the cells.

METHODSCD117(+) hemopoietic stem cells (HSCs) were isolated and purified from the bone marrow of healthy C57 mice by magnetic affinity cell sorting. After cell expansion by treatment with stem cell factor (SCF) and interleukin-3 (IL-3), the HSCs were induced for directional differentiation into imDCs by treatment with GM-CSF, IL-4 and IL-10. The imDCs obtained were identified by morphological and functional observation under inverted microscope, scanning electron microscope and transmission electron microscope, followed by detection of the expressions of the surface markers using flow cytometry.

RESULTSAfter 3, 5 and 7 days of culture in the presence of SCF+IL-3, the cells were expanded by 10.34-/+1.43, 22.65-/+2.71 and 54.39-/+3.08 folds, respectively. The HSCs were successfully induced to differentiate into imDCs with phagocytotic activity. The dendrites of the imDCs were short small, and appearing spinous. The expressions of surface markers were detected from the cells showing the phenotype of CD11c(+), I-A/I-E(low), CD40(-), CD80(-), CD86(-).

CONCLUSIONThe method described allows steadily acquisition of large quanty of highly purified imDCs and of their effective identification in vitro.