Evidence of in vitro differential secretion of human beta-defensins-1,-2, and-3 after selective exposure to Streptococcus agalactiae in human fetal membranes

Objective. The aim of this work was to characterize the individual contribution of the amnion (AMN) and choriodecidua (CHD) regions to the secretion of human beta defensins (HBD)-1, -2, and -3, after stimulation with Streptococcus agalactiae. Methods. Full-thickness membranes were mounted on a Transwell device, constituted by two independent chambers; 1 x 10(6) CFU/ml of S. agalactiae were added to either the AMN or CHD face or to both. Secretion profiles of HBD-1, HBD-2, and HBD-3 to the culture medium were quantified by enzyme-linked immunosorbent sandwich assay (ELISA). Results. Secretion profile of HBD-1 remained without significant changes; HBD-2 secretion level by the CHD increased 2.0 (2.73 +/- 0.19 pg/mu g) and 2.6 (3.62 +/- 0.60 pg/mu g) times when the stimulus was applied only to the CHD region and simultaneously to both compartments, respectively. The bacterial stimulation in the AMN induced a 2.0 times (2.06 +/- 0.29 pg/mu g) increase in this region. HBD-3 secretion level increased significantly in the CHD (15.65 +/- 2.68 pg/mu g) and the AMN (14.94 +/- 1.85 pg/mu g) only when both regions were stimulated simultaneously. Conclusion. The stimulation of human fetal membranes with S. agalactiae induced a differential and tissue-specific profile of HBD-1, HBD-2, and HBD-3 secretion.