Method for reducing the immunogenicity of antibody variable domains

Abstract

A unique method is disclosed for identifying and replacing immunoglobulin surface amino acid residues which converts the antigenicity of a first mammalian species to that of a second mammalian species. The method will simultaneously change immunogenicity and strictly preserve ligind binding properties. The judicious replacement of exterior amino acid residues has no effect on the ligind binding properties but greatly alters immunogenicity.

1 - 11 . (canceled)  
     
     
         12 . A veneered murine 1B4 antibody exhibiting the antigenicity of human antibody of fragments thereof.  
     
     
         13 . A veneered immunoglobulin having the ligand binding properties of an immunoglobulin from a first mammalian species and the immunogenicity of a second mammalian species, the veneered immunoglobulin is produced by a process comprising the steps of: 
 a) comparing a variable domain of the first species immunoglobulin with variable domains of immunoglobulins from the second species at corresponding framework amino acid sequences;    b) selecting from the variable domains of the second species immunoglobulins the variable domain which is most similar to the variable domain of the first species immunoglobulin at corresponding framework amino acid sequences;    c) identifying framework amino acid residues of the first species variable domain which differ from the amino acid residues at the corresponding position of the selected variable domain, these differing amino acid residues being limited to those determined to be exposed to solvent, which are not directly adjacent to a complementarity determining region; and    d) producing an immunoglobulin having the first species variable domain with only the amino acid residues identified in step c) being replaced with the corresponding residues present in the selected variable domain.    
     
     
         14 . The veneered immunoglobulin of  claim 13  wherein the first mammalian species is mouse.  
     
     
         15 . The veneered immunoglobulin of  claim 13  wherein the second mammalian species is human.  
     
     
         16 . The veneered immunoglobulin of  claim 13  wherein the first species immunoglobulin is murine 1B4 antibody.  
     
     
         17 . A veneered variable domain of a veneered immunoglobulin comprising a framework sequence having, 
 buried amino acid residues being derived from corresponding framework amino acid residues of a variable domain of an immunoglobulin from a first species;    exposed amino acid residues directly adjacent to a complementarity determining region being derived from corresponding framework amino acid residues of the first species variable domain; and    exposed amino acid residues not directly adjacent to a complementarity determining region being derived from corresponding framework amino acid residues of a variable domain of an immunoglobulin from a second species, wherein the second species variable domain is most similar to the first species variable domain at corresponding framework amino acid sequences among a group of variable domains from immunoglobulins of the second species.    
     
     
         18 . The veneered variable domain of  claim 17  wherein the first mammalian species is mouse.  
     
     
         19 . The veneered variable domain of  claim 17  wherein the second mammalian species is human.  
     
     
         20 . The veneered variable domain of  claim 17  wherein the first species immunoglobulin is monoclonal antibody 1B4 that binds to CD18.