Methods of Generating Variant Proteins with Increased Host String Content

Abstract

The present invention relates to novel methods for generating variant proteins with increased host string content, and proteins that are engineered using these methods.

1 . An antibody that binds the CD30 antigen, wherein said antibody comprises:
 a) a heavy chain comprising a heavy chain variable region and a constant heavy region, wherein said variable heavy region is selected from the group consisting of:
 i) the sequence of SEQ ID NO:223; 
 ii) the sequence of SEQ ID NO:223 with a valine at position 2; 
 iii) the sequence of SEQ ID NO:226; 
 iv) the sequence of SEQ ID NO:226 with a valine at position 2; 
 v) the sequence of SEQ ID NO:227; 
 vi) the sequence of SEQ ID NO:227 with a valine at position 2; 
 vii) the sequence of SEQ ID NO:228; 
 viii) the sequence of SEQ ID NO:228 with a valine at position 2; and 
   b) a light chain comprising a light variable region and a light constant region, wherein said light variable region is selected from the group consisting of:
 i) the sequence of SEQ ID NO:220; 
 ii) the sequence of SEQ ID NO:224; and 
 iii) the sequence of SEQ ID NO:225; 
   
       wherein numbering of the variable region is according to the Kabat numbering system. 
     
     
         2 . The antibody according to  claim 1 , wherein said variable light chain is the sequence of SEQ ID NO:224. 
     
     
         3 . The antibody according to  claim 1  or  2 , wherein said variable heavy chain is the sequence of SEQ ID NO:227 with a valine at position 2. 
     
     
         4 . The antibody according to  claim 3 , wherein said heavy chain constant region comprises a substitution at a position selected from the group consisting of 239, 264, 330 and 332, wherein number of the constant region is according to the EU index. 
     
     
         5 . The antibody according to  claim 4 , wherein said substitution comprises 332E. 
     
     
         6 . The antibody according to  claim 4 , wherein heavy chain constant region comprises 239D and 332E. 
     
     
         7 . A mammalian host cell line comprising polynucleotides encoding the heavy and light chains of a human monoclonal antibody that competes for binding to human CD30 with an antibody comprising the heavy chain FR1 through FR4 amino acid sequence d of SEQ ID NO:227 and the light chain FR1 through FR4 amino acid sequence of SEQ ID NO:224.