title: Surface decoration of red blood cells with maleimidophenyl-polyethylene glycol facilitated by thiolation with iminothiolane: an approach to mask A, B, and D antigens to generate universal red blood cells.
abstract: BACKGROUND
  The surface decoration of red blood cells (RBCs) by polyethylene glycol (PEG) chains has been an approach developed to camouflage the blood group antigens from their antibodies. A PEGylation protocol, however, that can mask the antigens appropriately to inhibit the agglutination of RBCs with the respective antibodies is not available so far.
  
  
  METHODS
  A new approach for PEGylation of RBC membrane proteins has been designed with thiolation-mediated maleimide chemistry. The accessibility of the surface lysine residues of membrane proteins to bulky PEG reagents was increased by linking an extension arm carrying a thiol group.
  
  
  RESULTS
  RBCs have been PEGylated by thiolation-mediated chemistry with maleimidophenyl-PEG (Mal-Phe-PEG) reagents of different chain lengths. Mal-Phe-PEG-5000 chains alone masked the most important antigens of the Rh system (C, c, E, e, and D) from their antibodies. The masking of the A and B antigens needed a combination of Mal-Phe-PEG-5000 and Mal-Phe-PEG-20000 chains to inhibit the agglutination of RBCs completely with anti-A or anti-B.
  
  
  CONCLUSIONS
  Thiolation-mediated PEGylation of RBCs with Mal-Phe-PEG-5000 and Mal-Phe-PEG-20000 converts Group A Rh(D)+ and B Rh(D)+ RBCs into RBCs with serologic behavior comparable to Group O Rh(D)- RBCs that are considered as universal RBCs for transfusion.
authors.affiliation: Department of Medicine, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
authors.forename: Parimala
authors.initials: P
authors.lastname: Nacharaju
authors.forename: Fouad N
authors.initials: FN
authors.lastname: Boctor
authors.forename: Belur N
authors.initials: BN
authors.lastname: Manjula
authors.forename: Seetharama A
authors.initials: SA
authors.lastname: Acharya
mesh_terms: D000017:ABO Blood-Group System / Q000276:immunology*; D000918:Antibody Specificity; D000094902:Blood Banking / Q000379:methods*; D000939:Epitopes / Q000737:chemistry* / Q000276:immunology; D004912:Erythrocytes / Q000276:immunology*; D005434:Flow Cytometry; D006801:Humans; D008301:Maleimides; D008970:Molecular Weight; D011092:Polyethylene Glycols / Q000737:chemistry; D012204:Rh-Hr Blood-Group System / Q000276:immunology*; D013438:Sulfhydryl Compounds
chemical_list: D000017:ABO Blood-Group System; D000939:Epitopes; D008301:Maleimides; D012204:Rh-Hr Blood-Group System; C026410:Rho(D) antigen; D013438:Sulfhydryl Compounds; D011092:Polyethylene Glycols