OBJECTIVETo explore the biological characteristics and the immuno-suppression function of tolerogenic dendritic cells (tDC) induced by tacrolimus.

METHODSHuman monocytes derived from peripheral blood were cultured in the cGMP-compliant CellGro DC medium supplemented with GM-CSF and IL-4 to obtain dendritic cells (DCs), and 0.1 μmol/L immunosuppressive drug tacrolimus was added to the culture medium at the third and fifth day to obtain tDCs. The molecular markers of them and the livability were assayed by flow cytometry. Then the tolerance functionality of tDCs induced by many agents and these tDCs modulated allogeneic CD4 T cells was determined via CFSE proliferation assay. And the research also analyzed the biological characters and immunosuppression function of tDCs induced by tacrolimus after storing.

RESULTStDCs induced by tacrolimus exhibit a typical tolerogenic phenotype, whose level of costimulatory molecules CD80, CD83, CD86 and HLA-DR is (2.95 ± 1.32)%, (2.33 ± 1.60)%, (90.02 ± 7.42)% and (91.80 ± 6.18)%, respectively. It's survival rate was (85.2 ± 4.72)%. And immunosuppressive drugs didn't influence the differentiation of tDCs from monocytes. tDCs induced by immunosuppressive drugs dexamethasone, cyclosporin A and tacrolimus had lower immunogenic than control DCs as CD4+ T proliferation rate of tDCs induced by tacrolimus is 0.42% and could not primed allogeneic CD4+ T cells proliferation. Functional analyses showed that tDCs induced by tacrolimus can more effectively suppressed mature DC-induced T cell proliferation than other tDCs, whose inhibition rate can reach (67.01 ± 19.73)%. Importantly, tDCs induced by tacrolimus had phenotypical and functional stability after storing.

CONCLUSIONtDCs induced by tacrolimus with tolerance functionality are a promising cellular therapeutic for immunomodulation.