Antigenic fusion protein carrying Galalpha 1,3Gal epitopes

Abstract

The present invention relates to an antigenic fusionprotein, which carries multiple Galα1,3Gal epitopes. The fusion protein according to the invention may also be comprised of a heavily glycosylated mucin part, which mediates binding to selecting, such as PSGL-1, and a part, which exhibits immunoglobulin properties, such as the Fc part of IgG. The fusionprotein according to the invention is preferably used as an absorber to prevent a hyperacute rejection of a xenotransplant, such as a pig tissue or organ transplanted into a human patient. In addition, the invention relates to a method for the prevention of a hyperacute rejection reaction in a patient who is to receive a xenotransplant.

1 . A dimerized fusion polypeptide comprising a first polypeptide operably linked to a second polypeptide, wherein the first polypeptide: 
 (a) comprises the extracellular portion of a P-selectin glycoprotein ligand-1; and    (b) is glycosylated by an α1,3 galactosyltransferase and    the second polypeptide comprises an immunoglobulin Fc region.    
   
   
       2 . The fusion polypeptide of  claim 1 , wherein the first polypeptide comprises multiple Galα1,3Gal epitopes.  
   
   
       3 . The fusion polypeptide of  claim 1 , wherein the α1,3 galactosyltransferase is porcine.  
   
   
       4 . A dimerized fusion polypeptide comprising a first polypeptide operably linked to a second polypeptide, wherein the first polypeptide: 
 (a) comprises a part of a P-selectin glycoprotein ligand-1 that mediates binding to selectin; and    (b) is glycosylated by an α1,3 galactosyltransferase and    the second polypeptide comprises an immunoglobulin Fc region.    
   
   
       5 . The fusion polypeptide of  claim 4 , wherein the first polypeptide comprises multiple Galα1,3Gal epitopes.  
   
   
       6 . The fusion polypeptide of  claim 4 , wherein the α1,3 galactosyltransferase is porcine.  
   
   
       7 . An nucleic acid molecule encoding the fusion protein of  claim 1 .  
   
   
       8 . A vector comprising the nucleic acid molecule of  claim 7 .  
   
   
       9 . A cell transfected with the vector of  claim 8 .  
   
   
       10 . The cell of  claim 9 , further comprising a nucleic acid molecule encoding a al, 3  galactosyltransferase.  
   
   
       11 . A host cell genetically engineered to express the fusion polypeptide of  claim 1 .  
   
   
       12 . A cell comprising: 
 a) a nucleic acid encoding the extracellular portion of a P-selectin glycoprotein ligand-1 operably linked to a nucleic acid encoding am immunoglobulin Fc region polypeptide and    b) a nucleic acid encoding an α1,3 galactosyltransferase polypeptide.    
   
   
       13 . The cell of  claim 12 , wherein the cell is a COS cell, a CHO cell or a 293T cell.  
   
   
       14 . An absorber comprising the fusion polypeptide of  claim 1 .  
   
   
       15 . A method for removing an antibody from blood or plasma, the method comprising 
 (a) contacting said blood or plasma with the fusion polypeptide of claim I to form a fusion polypeptide complex; and    (b) removing the complex from said blood or plasma    thereby removing the antibody from said blood or plasma.    
   
   
       16 . A method for treating or preventing hyperacute rejection in a patient in need thereof, the method comprising 
 (a) contacting blood or plasma from the patient with the fusion polypeptide of  claim 1  to form a fusion polypeptide complex; and    (b) removing the complex from said blood or plasma    thereby treating or preventing hyperacute rejection in said patient.