Production of Interleukin-6 by Fetal and Maternal Cells in Vivo during Intraamniotic Infection and in Vitro after Stimulation with Interleukin-1

Abstract

ABSTRACT. Amniotic fluid samples were obtained by transabdominal amniocentesis from 20 women in preterm labor (534 wk gestation). Concentrations of I M in culture-positive amniotic fluids (mean 8706 pg/mL, range 5100-14 446 pg/mL) were higher than those in culturenegative fluids (mean 1133 pg/mL, range 15-6534 pg/mL, p < 0.0001) or fluids from healthy term pregnancies (mean 196 pg/mL, range 55-790 pg/mL, p c 0.001). To assess possible sources of the IL-6 in amniotic fluid, we tested the ability of a variety of fetal and maternal cells to produce I M in vitro after stimulation with IL-1, a cytokine known to stimulate IL-6 production. Very low concentrations of I M were present in supernatants of cells not stimulated with IG1; however, high concentrations were observed in supernatants of stimulated umbilical venous endothelial cells, decidual cells, and fetal and maternal blood mononuclear cells. To determine whether cells from adults produce IL-6 with kinetics similar to those of neonates, we incubated mononuclear cells obtained from blood of adults and term and preterm neonates with IL-1. After 6 h, I M was detected in supernatants of adult cells and term neonatal cells, but not in supernatants of preterm cells. Concentrations at 18, 24, and 48 h were similar for adult and term cell supernatants, but were lower in supernatants of preterm cells. We also observed considerably more IL-6 mRNA accumulation in circulating mononuclear cells from adults than in those from neonates. (Pediatr Res 29: 1-4, 1991) Abbreviations CSF, colony stimulating factor Intraamniotic infection is one of the causes of preterm labor ( 1-5). Thus, in women with preterm labor, efforts are often made to establish whether or not intraamniotic infection is present (4, 5). Such information can influence the management of the

Defective Production of Interleukin-6 by Monocytes: A Possible Mechanism Underlying Several Host Defense Deficiencies of Neonates

“…For instance, using "light-density" blood cells, composed predominantly of lymphocytes and monocytes, we previously observed less IL-6 accumulation in supernatants of cells of preterm neonates than in cells of adults (34). Using whole blood cell cultures, Yachie et al (35) found no differences between term neonatal and adult cells in IL-6 accumulation after incubation with LPS derived from Escherichia coli.…”

Ureaplasma urealyticumModulates Endotoxin-Induced Cytokine Release by Human Monocytes Derived from Preterm and Term Newborns and Adults

“…Previous studies have reported conflicting findings concerning the responsiveness of LPS-stimulated neonatal monocytes. LPS-stimulated cord blood monocytes from term infants produced amounts of IL-6 similar to (41,51,74) or less than (47) those produced by adult monocytes. LPS-stimulated monocytes from preterm cord blood produced significantly less IL-6 (41, 51) than stimulated monocytes from term infants or adults.…”

The developing human preterm neonatal immune system: A case for more research in this area

“…Specifically, preterm neonates have significantly reduced proinflammatory cytokine (i.e. IL-1β, IL-6, TNF-α, figure 1) responses when stimulated with endotoxin (lipopolysaccharide, a potent TLR4 agonist) [24; 25; 26; 27; 28], IL-1 [29] or whole micro-organisms in vitro [30; 31; 32; 33]. They also produce limited amounts of antiviral interferon-α even though their proportion of blood plasmacytoid dendritic cells, main source of this cytokine, is comparable to term neonates or adults [34].…”