In vitro amplification and ultrastructure of dendritic cells from mouse bone marrow / 中国组织工程研究

ABSTRACT

BACKGROUND: Denddtic cells (DCs) constitute the dominant population of antigen presenting cells (APCs) by possessing potent ability to initiate T cell immunity. The ultrastructure study of DCs is less reported. OBJECTIVE: To investigate the ultrastructure of DCs from mice bone marrow at different maturation stages, and the morphology of DCs between CD40 ligation and tumor necrosis factor-alpha (TNF-α) stimulation in vitro. METHODS: Mice myeloid DCs were generated from bone marrow in vitro using granulocyte-macrophage colony-stimulating factor (GM-CSF)and interleukin-4 (IL-4). Immature DCs were loaded with apoptotic tumor cells (AP-DC), and AP-DC was then stimulated with CD40L-CHO cells and TNF-α for 48 hours, respectively. DCs were routinely sectioned, and ultrastructure was observed under transmission electron microscope. RESULTS AND CONCLUSION: Immature DCs showed a few short and blunt cytoplasmic processes, there were specific morphology lysosomes that liked earphone in some cells; DCs engulfing the apoptotic bodies were observed; sub-cellular structures between CD40 ligation and TNF-α stimulated DCs were different, the former had typical morphology of mature DCs which exhibited many dendritic protrusions, however, some DCs displayed apoptosis and autophagy after TNF-α stimulation. In a conclusion, CD40 ligation plays an essential role in myeloid DCs differentiation and maturation, TNF-α can mediate apoptosis and autophaqy of DCs.