The dendritic cell differentiation and antigen-presenting function of the erythroleukemia cells induced by GM-CSF

OBJECTIVE: To investigate the generation of dendritic cells and the change of antigen-presenting function during the differentiation of FBL-3 erythroleukemia cells induced by GM-CSF. METHODS: The effects of GM-CSF on the phenotype, ultrastructure and antigen-presenting function of FBL-3 erythroleukemia cells were observed by FACS, electromicroscopy and 51Cr-release assay. RESULTS: After treatment with 100 ng/ml GM-CSF for 3 days, the expressions of 33 D1 and NLDC 145 which are the specific markers on dendritic cells were increased significantly; MHC-II B7-1, B7-2, ICAM-1, VCAM-1 and CD40 were also upregulated. The membrane of FBL-3 cells was changed into villous surface with dendritic projections. There were plenty of mitochondria in cytoplasm, the nucleus became lobulated. The GM-CSF-treated FBL-3 cells could apparently stimulate the proliferation of allogeneic T lymphocytes, induce the production of IL-2 and improve the specific cytotoxic activity of CTL on FBL-3 cells. CONCLUSION: Erythroleukemia cells were induced to differentiate into the dendritic cells by GM-CSF and obtained the antigen-presenting function.