[Endomorphine-1 inhibits maturation and functions of human peripheral blood-derived dendritic cells]

To investigate the effects of endomorphine-1 (EM-1) on the functional features of lipopolysaccharide (LPS)-stimulated peripheral blood-derived dendritic cells (PBDCs), including PBDC phenotypes, cytokine profile and its capability of promoting T cell proliferation.

PBDCs were isolated from peripheral blood and differentiated in the presence of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) and interleukin-4 (rhIL-4). Then the cells were further activated by LPS or EM-1. Several surface markers were detected by flow cytometry including CD80, CD86, CD83, HLA-DR and CCR7. ELISA was used to detect cytokine levels of IL-10, IL-12, IFN-γ in the supernatants of the cultured PBDCs. Using co-culture of T lymphocytes and PBDCs stimulated by EM-1, the proliferation of T cells induced by PBDCs was determined by 5, 6-carboxyfluorescein succinimidyl ester (CFSE) staining.

EM-1 down-regulated the expressions of CD80, CD86, CD83, HLA-DR and CCR7 on the activated PBDCs. Moreover, EM-1 decreased the secretion of IL-12 and IL-10 in these PBDCs. In co-culture of T lymphocytes and EM-1-treated PBDCs, T cell proliferation was impaired, and less IL-12 and IFN-γ were produced in the culture supernatant.

EM-1 could inhibit the maturation and immune functions of PBDCs.