Interleukin-1 beta secretion from cord blood mononuclear cells in vitro involves P2X 7 receptor activation

The purinergic receptor P2X(7) is activated by extracellular adenosine 5'-triphosphate (ATP) and promotes the efficient release of interleukin-1 beta. The authors examine protein and molecular expression of the P2X(7) receptor and its ability to stimulate interleukin-1 beta release in cord blood mononuclear cells (CBMCs) from placentae of term nonlaboring and laboring women. They show both mRNA and protein (78 kDa) expression for the P2X( 7) receptor in CBMCs of parturient and nonparturient women. Costimulation of CBMCs in vitro with bacterial endotoxin and ATP resulted in significantly (P < .05) enhanced interleukin-1 beta release in laboring (54.17 +/- 24.78 pg/mL(-1); n = 8) compared with nonlaboring (13.60 +/- 3.20 pg/mL(-1); n = 7) deliveries. Release of interleukin-1 beta in both groups was blocked by preincubation with oxidized ATP, a P2X(7) receptor antagonist. The authors provide evidence for a novel inflammatory pathway in the release of interleukin-1 beta, which may be linked to the onset of labor.