Characterization of the membrane attack complex inhibitory protein CD59 antigen on human amniotic cells and in amniotic fluid.
A functional complement system and the potential for its activation are present in human amniotic fluid. We have recently demonstrated that CD59 antigen is present and functionally active on human amniotic epithelial cells (HAEC). We have now further examined the role of this protein on HAEC and have also demonstrated its presence in amniotic fluid (AF). CD59 Ag on HAEC is similar in size to the erythrocyte protein and is anchored via glycosyl phosphatidylinositol. The AF protein retained the capacity to incorporate into target cells and protect against lysis by complement. These data suggest that HAEC secrete into AF a form of CD59 Ag which retains inhibitory activity and which may be important in protection of the foetus from maternal complement in utero.
Rooney
I A
IA
Department of Medical Biochemistry, University of Wales College of Medicine, Cardiff, U.K.
Morgan
B P
BP
D000650:Amnion / Q000276:immunology*; D000653:Amniotic Fluid / Q000276:immunology*; D015703:Antigens, CD / Q000737:chemistry / Q000276:immunology*; D015153:Blotting, Western; D018957:CD59 Antigens; D002478:Cells, Cultured; D004591:Electrophoresis, Polyacrylamide Gel; D006461:Hemolysis / Q000187:drug effects / Q000276:immunology; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000276:immunology; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000276:immunology*; D043265:Phosphatidylinositol Diacylglycerol-Lyase; D010727:Phosphoric Diester Hydrolases / Q000494:pharmacology
D015703:Antigens, CD; D018957:CD59 Antigens; D007140:Immunoglobulin Fab Fragments; D008562:Membrane Glycoproteins; D010727:Phosphoric Diester Hydrolases; D043265:Phosphatidylinositol Diacylglycerol-Lyase