[Effect of soluble anti-CD47 monoclonal antibody on the differentiation and function of human dendritic cells].

OBJECTIVE: To explore the influences of anti-CD47 monoclonal antibody (mAb) B6H12 on the differentiation and function of cultured dendritic cells (DCs).

METHODS: Human peripheral monocyte derived DCs were propagated with granulocyte-macrophage colony-stimulating factor (GM-CSF) and lipopolysaccharide (LPS) plus interleukin-4 (IL-4) in the presence or absence of soluble B6H12. Flow cytometry was used to analyze the immunophenotypes of cells, semi-quantitative RT-PCR and ELISA methods to analyse the mRNA and protein expression levels of interleukin-12 (IL-12). The antigen-presenting function of DCs was determined in one-way mixed leukocyte reaction by Brdu-ELISA technique.

RESULTS: There was a high expression rate (94% approximately 98%) of CD47 molecules in DCs. The cell immunophenotypes in B6H12 mAb treated and untreated DC groups were as follows: CD80(+) (68.14 +/- 7.41)% vs (89.17 +/- 8.59)%; CD86(+) (67.33 +/- 4.71)% vs (87.27 +/- 3.56)%; CD83 (40.08 +/- 14.80)% vs (72.77 +/- 8.68)%; CD1a(+) (66.45 +/- 4.06)% vs (95.93 +/- 3.03)%; and HLA-DR (40.67 +/- 13.48) vs (98.97 +/- 1.01)%, respectively. The expression levels of mRNA and protein of IL-12 were strongly inhibited in B6H12 mAb treated DC (P < 0.01). The quantity of Brdu was also lower in B6H12 mAb treated DC than that in untreated DCs (P < 0.01).

CONCLUSION: The anti-CD47 McAb exerts a negative effect on the maturation and functions of cultured DCs.