• Leukocytes;
  • maternal-fetal tolerance;
  • phosphoinositide 3-kinase

Problem  During pregnancy, it is crucially important that the mother’s immune system tolerates the developing embryo. Although a number of mechanisms of immunological tolerance have been described, little is known about intracellular signaling events, causing a decrease in the mother’s leukocyte activity.

Method of study  We investigated the expression and activity of phosphoinositide 3-kinases (PI3K) in maternal blood cells of healthy volunteers by Reverse Transcription PCR and Western blotting.

Results  Our data reveal a selective downregulation of the p110α catalytic isoform. This correlated with a slight decrease in PI3K activity as judged by the levels of phosphorylated Akt.

Conclusion  As PI3K are involved in signal transduction of various leukocyte receptors, this downregulation may comprise a means of holding immune functions at bay.