Inhibition of Induced Lymphocyte Proliferation by Lipid and Protein Components of the Syncytiotrophoblast Plasma Membrane

PROBLEM : The aim of this work was to define the respective responsibilities of the lipid and protein components of syncytiotrophoblast plasma membranes on the inhibition of lymphocyte proliferation induced in vitro. METHOD : A fractionation method using octyl-β-D-glucopyranoside enabled lipoprotein, lipid, and protein fractions to be isolated from the membrane. RESULTS: The lipid fraction was shown nonspecifically to inhibit lymphocyte proliferation, to a lower extent compared with the native membrane. Alternatively, the protein fraction used as a proteoliposome contained the totality of the cytostatic effect of the native fraction. CONCLUSION : These results are discussed generally in the context of the immunoregulatory role of membrane lipids and proteins and in relation to the local properties of syncytiotrophoblast plasma membrane components in fetal graft tolerance.