In vitro activation and maturation of human mononuclear phagocytes by stimulation with liposomes coated with a neoglycolipid containing α1–3, α1–6-mannotriose

In this study, we assessed the potential of liposomes coated with a neoglycolipid containing α1–3,α1–6-mannotriose residues (Man3-DPPE; Manα1–6(Manα1–3)Manitol-DPPE) forin vitro activation and maturation of human mononuclear phagocytes. In response to treatment with Man3-DPPE-coated liposomes (Man3-OMLs), PMA-stimulated human THP-1 cells showed enhanced expression of CD40, CD80 and HLA-DR and secreted significant levels of IL-12p40. Among various linkages of Man2-DPPE-coated liposomes, only liposomes coated with Man α1–6Manitol-DPPE (α1–6Man2-DPPE) induced these cellular responses similarly to Man3-OML treatment. Liposomes coated with Manα1–6(Manα1–3)Manα1–6(Manα1–3)Manitol-DPPE (Man5-DPPE) failed to activate the cells. These results suggest that an unsubstituted α1–6Man branch bound to a m annitol unit at the reducing end in Man3-DPPE is required forin vitro activation of human mononuclear phagocytes. Man3-OML-induced IL-12p40 production was not inhibited by BAY11 –7082, an inhibitor of the MyD88-dependent signaling network, suggesting that TLRs are not involved in activation of human mononuclear phagocytes by Man3-OMLs. Stimulation of inflammatory monocytes or monocyte-derived dendritic cells (moDCs) with Man3-OMLs also induced enhanced expression of co-st imulatory molecules, HLA-DR, and CCR7, and IL-12p40 production from both types of cells. In response to Man3-OML treatment, moDCs but not inflammatory monocytes produced bioactive IL-12p...

Source: Glycoconjugate Journal - April 22, 2019 Category: Biochemistry Source Type: research