Inflammatory mediators regulate interleukin-8 production by cultured gestational tissues: evidence for a cytokine network at the chorio-decidual interface.

The physiology of parturition, and the pathophysiology of preterm labor, is incompletely understood. Infection of gestational tissues may account for a significant proportion of women who experience preterm labor. Interleukin-8 (IL-8), or neutrophil-activating protein (NAP-1), is a potent chemotactic and activating factor for neutrophils and has been implicated in the pathogenesis of inflammatory injury to skin and lung, but has yet to be described in gestational tissues. Cultured chorion and decidual cells obtained from normal human pregnancies were used to evaluate whether these tissues produce IL-8 basally and in response to inflammatory cytokines. As measured by specific IL-8 RIA, chorion and decidual cells produce IL-8 constitutively and in response to IL-1 beta and tumor necrosis factor. Cotreatment of chorion cells or decidual cells with IL-1 beta and actinomycin D or cycloheximide abrogated IL-8 production. Northern blot analysis confirmed that IL-1 beta stimulation of chorion and decidual cells resulted in increased IL-8 messenger RNA expression. Our data support the concept that a complex cytokine network between maternal and fetal gestational tissues exists, and that activation of inflammatory cytokine production in these tissues, including IL-8, likely contributes to the pathophysiology of infection-induced preterm labor.