title: A murine monoclonal antibody (RV3-27) raised against isolated human placental endogenous retroviral particles and reactive with syncytiotrophoblast.
abstract: Particles with the characteristic shape of enveloped retroviral particles and maximal specific reverse transcriptase (RTase) activity at buoyant density of 1.15-1.17 g/ml have been isolated from human first-trimester chorionic villous tissue. Murine monoclonal antibodies (mAbs) to these isolated particles were generated. One IgM mAb (RV3-27) showed granular staining of cytoplasmic structures within syncytiotrophoblast by immunohistochemistry. Immunoelectron microscopic studies have demonstrated focal localisation to small submembranous regions of syncytiotrophoblast, as well as reaction with detergent-disrupted isolated placental retroviral-like particles. The RV3-27 mAb did not stain other human tissues in this focal manner, although increased generalised cytoplasmic staining was not uncommon; also, this mAb did not react strongly with the surface or cytoplasm of a variety of human cell lines (including choriocarcinoma cells). Immunoblotting and HPLC analyses have indicated the reactive placental antigen to be a 17-25 kDa protein. It is suggested that the RV3-27 mAb may be reactive with a syncytiotrophoblast antigen encoded by an endogenous retroviral sequence.
authors.affiliation: Department of Immunology, University of Liverpool, UK.
authors.forename: J M
authors.initials: JM
authors.lastname: Mwenda
authors.forename: P M
authors.initials: PM
authors.lastname: Maher
authors.forename: G C
authors.initials: GC
authors.lastname: Melling
authors.forename: T W
authors.initials: TW
authors.lastname: Lyden
authors.forename: P M
authors.initials: PM
authors.lastname: Johnson
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000914:Antibodies, Viral / Q000276:immunology*; D002822:Choriocarcinoma / Q000473:pathology / Q000821:virology; D002824:Chorionic Villi / Q000821:virology*; D005321:Extraembryonic Membranes / Q000276:immunology; D005260:Female; D006801:Humans; D007075:Immunoglobulin M / Q000276:immunology; D007158:Immunologic Techniques; D051379:Mice; D008807:Mice, Inbred BALB C; D008854:Microscopy, Electron; D009369:Neoplasms / Q000473:pathology; D009928:Organ Specificity; D012194:RNA-Directed DNA Polymerase / Q000032:analysis; D012190:Retroviridae / Q000201:enzymology / Q000276:immunology / Q000302:isolation & purification* / Q000648:ultrastructure; D014327:Trophoblasts / Q000276:immunology* / Q000821:virology; D014407:Tumor Cells, Cultured; D014594:Uterine Neoplasms / Q000473:pathology / Q000821:virology; D014764:Viral Proteins / Q000032:analysis
chemical_list: D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D007075:Immunoglobulin M; D014764:Viral Proteins; D012194:RNA-Directed DNA Polymerase