title: Monoclonal anti-A activity against the FORS1 (Forssman) antigen.
abstract: BACKGROUND
  The FORS blood group system (originally recognized as the Apae phenotype) was discovered by sporadic activity against polyclonal anti-A reagents and activity against the lectin Helix pomatia. The extent of monoclonal anti-A reagent activity against the FORS1 antigen is serologically and immunochemically incomplete.
  
  
  METHODS
  In the absence of natural FORS1-positive red blood cells (RBCs), kodecytes were created with synthetic disaccharide and pentasaccharide Forssman function-spacer-lipid (FSL) constructs, Fsdi -kodecytes, and FORS1-kodecytes, respectively. FSL constructs were also applied to solid surfaces and used in solid-phase enzyme immunoassays. A range of characterized monoclonal anti-A and anti-B reagents were then serologically and immunochemically characterized against these Forssman antigens. Polyclonal human anti-A, anti-B, the lectin H. pomatia serologic reagents; and canine RBCs were used as serologic controls.
  
  
  RESULTS
  None of 19 different monoclonal anti-A reagents were able to detect the pentasaccharide Forssman on FORS1-kodecytes, while three reagents were able to detect disaccharide Forssman on Fsdi -kodecytes. Most anti-A reagents were immunochemically reactive with both the di- and the pentasaccharide Forssman antigens in the solid-phase assays. Historic polyclonal human anti-A and the lectin H. pomatia reacted strongly with the FORS1-kodecytes, correlating with the discovery of the Apae phenotype and supporting the use of FORS1-kodecytes as FORS1 surrogates.
  
  
  CONCLUSIONS
  Monoclonal anti-A reagents, despite showing reactivity against the FORS1 antigen in solid-phase assays are unlikely to cause the agglutination of FORS1 antigen-positive RBCs.
authors.affiliation: Biotech Innovation Centre, School of Engineering, Faculty of Design and Creative Technologies, Auckland University of Technology, Auckland, New Zealand.
authors.forename: Katie
authors.initials: K
authors.lastname: Barr
authors.forename: Elena
authors.initials: E
authors.lastname: Korchagina
authors.forename: Inna
authors.initials: I
authors.lastname: Popova
authors.forename: Nicolai
authors.initials: N
authors.lastname: Bovin
authors.forename: Stephen
authors.initials: S
authors.lastname: Henry
mesh_terms: D000818:Animals; D000910:Antibodies, Heterophile / Q000276:immunology*; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000937:Antigen-Antibody Reactions; D002240:Carbohydrate Sequence; D004187:Disaccharides / Q000276:immunology; D004285:Dogs; D004910:Erythrocyte Membrane / Q000737:chemistry / Q000276:immunology; D005577:Forssman Antigen / Q000032:analysis* / Q000276:immunology; D005915:Globosides / Q000276:immunology; D006801:Humans; D007124:Immunoenzyme Techniques; D037102:Lectins / Q000276:immunology; D008051:Lipid Bilayers / Q000737:chemistry; D008567:Membranes, Artificial; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009844:Oligosaccharides / Q000032:analysis* / Q000276:immunology; D010714:Phosphatidylethanolamines; D011134:Polysaccharides / Q000276:immunology
chemical_list: C410262:1,2-dioleoyl-glycero-3-phosphatidyl ethanolamine; D000910:Antibodies, Heterophile; D000911:Antibodies, Monoclonal; D004187:Disaccharides; C402893:Forssman pentasaccharide; D005915:Globosides; C038095:Helix lectin; D037102:Lectins; D008051:Lipid Bilayers; D008567:Membranes, Artificial; D009844:Oligosaccharides; D010714:Phosphatidylethanolamines; D011134:Polysaccharides; D005577:Forssman Antigen