Interleukin-1β Secretion From Cord Blood Mononuclear Cells In Vitro Involves P2X7 Receptor Activation

Abstract

The purinergic receptor P2X₇ is activated by extracellular adenosine 5′-triphosphate (ATP) and promotes the efficient release of interleukin-1β. The authors examine protein and molecular expression of the P2X₇ receptor and its ability to stimulate interleukin-1β 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-1β 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-1β in both groups was blocked by preincubation with oxidized ATP, a P2X₇ receptor antagonist. The authors provide evidence for a novel inflammatory pathway in the release of interleukin-1β, which may be linked to the onset of labor.