title: Expression of phosphatidylserine-dependent antigens on the surface of differentiating BeWo human choriocarcinoma cells.
abstract: OBJECTIVE
  Antiphospholipid antibodies (aPLs) are associated with pregnancy loss, pregnancy-induced hypertension, and intrauterine growth retardation. We have previously reported that phosphatidylserine (PS)-dependent antigens are expressed in formalin-fixed cells concurrent with differentiation in a choriocarcinoma model (BeWo) of cytotrophoblast. That study, however, could not differentiate between cytoplasmic or surface antigen expression.
  
  
  METHODS
  Three monoclonal aPLs that differentiate between PS- and cardiolipin (CL)-dependent antigens were reacted with BeWo, with or without forskolin activation, before fixation, and antibody binding was evaluated by immunoperoxidase techniques.
  
  
  RESULTS
  Activation with forskolin induced a PS-dependent antigenic determinant on the surface on BeWo cells. CL-reactive monoclonal antibodies did not react with the cell surface, whether forskolin treated or not.
  
  
  CONCLUSIONS
  These observations demonstrate that a PS-dependent antigen is expressed on the surface of a model of differentiating cytotrophoblastic cells and should be accessible in vivo to circulating aPLs.
authors.affiliation: Department of Microbiology and Immunology, Wright State University School of Medicine, Dayton, Ohio 45435, USA.
authors.forename: N S
authors.initials: NS
authors.lastname: Rote
authors.forename: J
authors.initials: J
authors.lastname: Chang
authors.forename: H
authors.initials: H
authors.lastname: Katsuragawa
authors.forename: A K
authors.initials: AK
authors.lastname: Ng
authors.forename: T W
authors.initials: TW
authors.lastname: Lyden
authors.forename: T
authors.initials: T
authors.lastname: Mori
mesh_terms: D017152:Antibodies, Antiphospholipid / Q000276:immunology*; D000911:Antibodies, Monoclonal / Q000276:immunology; D000951:Antigens, Neoplasm / Q000276:immunology*; D000954:Antigens, Surface / Q000276:immunology*; D002454:Cell Differentiation; D002460:Cell Line; D002822:Choriocarcinoma / Q000276:immunology* / Q000473:pathology; D005576:Colforsin / Q000494:pharmacology; D003593:Cytoplasm / Q000276:immunology; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D010718:Phosphatidylserines / Q000276:immunology*; D014594:Uterine Neoplasms / Q000276:immunology* / Q000473:pathology
chemical_list: D017152:Antibodies, Antiphospholipid; D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D010718:Phosphatidylserines; D005576:Colforsin