Objective      To establish a method of inducing and culturing plasmacytoid dendritic cell subsets from mouse bone marrow in vitro

and to investigate the biological features of plasmacytoid dendritic cells by comparing with myeloid dendritic cell subsets in cell morphology

phenotype and function.       Methods      Bone marrow cells were isolated from C57BL/6 mice under sterile condition

and were cultured with Flt3-ligand to diffe

rentiate into plasmacytoid and myeloid dendritic cell subsets. The dynamic changes of the morphology

phenotype and function of the cultured cells were examined by inverted microscopy

flow cytometry and allogeneic mixed lymphocyte reaction during the culturing process.       Results      After being cultured with Flt3-ligand for 8 d

the plasmacytoid dendritic cells (CD11c

+

CD11b

-

B220

+

) were generated from mouse bone marrow cells

which displayed a smooth

round and lymphoid morphology with an eccentric kidney-shaped nucleus.  Compared with its myeloid counterpart

the plasmacytoid dendritic cell subsets displayed an immature phenotype with lower expression levels of costimulatory molecules of CD80

CD86

CD40 and MHC-Ⅱ under steady state. When treated with toll-like receptor 9 (TLR9) agonist CpG ODN

1826

the plasmacytoid dendritic cell subsets could be quickly induced into maturation

but the cells did not respond to the stimulation of LSP

a typical TLR 4 agonist. Besides

the generated plasmacytoid dendritic cell subsets had the ability to stimulate the proliferation of allogeneic mixed lymphocytes

but the ability was less potent than that of the myeloid dendritic cell subsets under the same stimulation．      Conclusion      Mouse bone marrow cells cultured with Flt3-ligand can differentiate into plasmacytoid dendritic cell subsets in vitro

which have a lymphoid morphology with low expression of costimulatory molecules and a certain ability to stimulate the proliferation of allogeneic lymphocytes.