Human amniotic fluid cells are able to produce IL-6 and IL-8

In order to investigate the role of amniotic fluid cells (AFC) in the establishment of feto-maternal immune relationship, we evaluated their phenotype and capacity to produce cytokines.

CK 7-8, human leukocyte antigen (HLA)-I, HLA-DR, HLA-G, CD1d, CD34, CD45, CD14 surface antigens expression and the intracellular production of IL-4, IL-6, IL-8, IL-10, IL-12, interferon-gamma and tumor necrosis factor-1 were studied in cultured AFC and in eight samples immediately after amniocentesis using flow cytometry. IL-6 and IL-8 were detected by ELISA in all amniotic fluids and in all culture supernatants. Moreover, IL-6 and IL-8 mRNA were tested in nine samples.

Cultured AFC express HLA-I, HLA-G and CK 7-8 and are able to produce IL-6 and IL-8, confirmed by presence of their mRNA. We quantified IL-6 and IL-8 levels in all amniotic fluids and in all supernatants.

Surface antigen expression of AFC are not specific of immune cells, but AFC are able to produce cytokines and we can postulate that they may participate in mechanisms involved in normal as well as pathological pregnancy.