Production of Extracellular Adenosine by CD73+ Dendritic Cells is Crucial for Induction of Tolerance in Contact Hypersensitivity Reactions

Dendritic cells (DC) express the ecto-5'-nucleotidase CD73 that generates immunosuppressive adenosine (Ado) by dephosphorylation of extracellular adenosine mono- and -diphosphate. To investigate whether CD73-derived Ado has immune suppressive activity, 2,4-dinitrothiocyanobenzene (DNTB) was applied to skin of wildtype (WT) or CD73 deficient (CD73-/-) mice, followed by sensitization and challenge with 2,4-dinitrofluorobenzene (DNFB). In this model we demonstrate induction of tolerance by DNTB against DNFB only in W T but not in CD73-/- mice.