Mouse dendritic cells express the P2X(7) purinergic receptor: Characterization and possible participation in antigen presentation

Immune cells express P2 purinoceptors of the P2Y and P2X subtypes. In the p resent work, we show that three dendritic cell (DC) lines, D2SC/1, CB1, and FSDC, representative of immature DCs, express the P2X, (formerly P2Z) rece ptor, as judged from RT-PCR amplification, reactivity to a specific antiser um, and pharmacological and functional evidence. Receptor expression is hig her in FSDC cells, a cell line that is functionally more mature than D2SC/1 and CB1, From the wild-type DC population, we selected cell clones lacking the P2X(7)R (P2X(7)less), We also used a P2XR blocker, oxidized ATP, to ir reversibly inhibit the P2X(7)R, Ability of P2X(7)less FSDCs or of oxidized ATP-inhibited FSDCs to stimulate Ag-specific T-H lymphocytes was severely d ecreased although Ag endocytosis was minimally affected. During coculture w ith T-H lymphocytes, wild-type FSDC secreted large amounts of IL-1 beta, Re lease of this cytokine was reduced in P2X,less DCs, These data show that DC s express the P2X(7) purinoceptor and suggest a correlation between P2X(7)R expression and Ag-presenting activity.