Detection of Immunoregulatory Lipid‐Like Factors in Human Amniotic Fluid

Abstract

The immunosuppressive activity of amniotic fluid (AF) is extensively documented in the mouse. Although this property is due in part to the presence of alpha-fetoprotein (alpha-FP), other immunosuppressive factors are suspected. In this article, we demonstrate that human amniotic fluid lipid extract (AFLE) is inhibitory of, although not cytotoxic to, PHA-activated human lymphocytes, of mouse bone marrow cells, and of different established cell lines of human and mouse source. This effect is shown to be reversible. Under preparative thin layer chromatography (TLC) using chloroform:methanol:water (60:38:8) as solvents, the activity of AFLE migrates to two peaks of inhibition with Rf values of 0.46-0.62 and 0.84-1, respectively. These lipid-like factors may play a role as a nonspecific immunoregulatory mechanism which prevents maternally mediated immune rejection of the conceptus.

Detection of complex gangliosides in human amniotic fluid

“…and both murine [6,7.9,10] and human [8.36] amniotic fluid have immunosuppressive properties. The total lipid extract of crude human amniotic fluid (which would contain any gangliosides) also inhibits ['Hlthymidine uptake by PHA-activated human peripheral blood mononuclear leukocytes [36]. as do the lipid components of the syncytiotrophoblast plasma membrane [37].…”