New Conjugates of Tuftsin and Muramyl Dipeptide as Stimulators of Human Monocyte-Derived Dendritic Cells

Muramyl dipeptide (MDP) and tuftsin are known biologically active compound displaying a significant influence on various cell populations of innate immune response. MDP, as a fragment of bacterial cell wall, stimulates not only macrophages and monocytes, but also dendritic cells. In contrast, little is known about tuftsin influence on these cells. Therefore it seemed vital to access whether tuftsin or its derivatives conjugated with MDP could influence the activity of this subpopulation of antigen presenting cells (APC). Immature dendritic cells (iDCs) were derived from human monocytes through eight-day tissue culture supplemented with hrIL-4 and hrGM-CSF. On the day 9 DCs were stimulated with newly synthesized conjugates of tuftsin and muramyl dipeptide. The influence of the examined compounds on the activity and maturity of monocyte-derived DCs was estimated by flow cytometry analysis. The flow cytometry analysis revealed that tuftsin and some of its analogues do stimulate maturation and activity of DCs but to a lesser extend in comparison to MDP. The obtained results suggest further development of the experiments concerning the influence of MDP and tuftsin analogues on the activity of dendritic cells.