OBJECTIVETo establish a method for in vitro amplification of immature dendritic cells from murine bone marrow, and to identify it with morphological, immunological phenotype determination, and functional examination.

METHODSDendritic cells from murine bone marrow were cultured with different dosage of rmGM-CSF. The suspending cells were examined with scanning electronic microscope, and the non-sensitized T lymphocyte proliferation was observed by mixed lymphocyte reaction.

RESULTSDendritic cells (DC) cultured in lower dosage of rmGM-CSF (Gm(low)DC) exhibited typical characteristics of DCs with high expression of CD11c and low expression of CD40 and I-A/I-E, and non-expression of B7-1 on the surface of the cells. The capacity of Gm(low)DC to stimulate the proliferation of non-sensitized T lymphocyte in vitro was weaker than that of Gm(high)DC.

CONCLUSIONGm(low)DC exhibited typical characteristics of DC, immature in cell phenotype and cell functions, suggesting that our methods of immature DCs culturing was feasible. The dosage of rm GM-CSF has direct relationship with the maturation degree of DC. Generally speaking, mature DC was mainly induced by high dosage of rmGM-CSF, while immature DC by low dosage.