Animal models and therapeutic molecules

Abstract

The invention discloses methods for the generation of chimaeric human-non-human antibodies and chimaeric antibody chains, antibodies and antibody chains so produced, and derivatives thereof including fully humanised antibodies; compositions comprising said antibodies, antibody chains and derivatives, as well as cells, non-human mammals and vectors, suitable for use in said methods.

1 . (canceled) 
     
     
         2 . The method of  claim 30 , wherein said isolated cell comprises nucleic acid encoding a human immunoglobulin variable region, and said method further comprises the step of:
 isolating nucleic acid encoding said human immunoglobulin variable region.   
     
     
         3 . The method of  claim 2 , further comprising the step of:
 joining said isolated human immunoglobulin variable region encoding nucleic acid to a human constant region encoding nucleic acid to provide nucleic acid encoding an antibody comprising said human variable region and a human constant region.   
     
     
         4 . The method of  claim 30 , wherein said antibody comprises a human variable region and a mouse constant region and said method further comprises the step of:
 isolating said antibody from said isolated biological sample so as to provide said antibody.   
     
     
         5 . (canceled) 
     
     
         6 . The method of  claim 30 , wherein said enhancer comprises a mouse μ enhancer. 
     
     
         7 . The method of  claim 30 , wherein said C region comprises a mouse Cμ gene segment. 
     
     
         8 - 9 . (canceled) 
     
     
         10 . The method of  claim 7 , wherein said C segment comprises a mouse 129 strain C segment. 
     
     
         11 - 12 . (canceled) 
     
     
         13 . The method of  claim 30 , wherein said human DNA contiguous with said 3′most human JH gene segment comprises 400 base pairs of human JC intron DNA. 
     
     
         14 . The method of  claim 30 , wherein said antigen is comprised by a vaccine. 
     
     
         15 . The method of  claim 30 , wherein said enhancer comprises a μ enhancer and said C region comprises a Cμ gene segment and wherein one or both of said μ enhancer and said Cμ gene segment comprises DNA of an IgH locus of a 129 strain mouse. 
     
     
         16 . (canceled) 
     
     
         17 . The method of  claim 3 , further comprising the step of:
 expressing the antibody from said nucleic acid, wherein said nucleic acid encodes an antibody comprising said human variable region and a human constant region, and isolating the antibody.   
     
     
         18 - 22 . (canceled) 
     
     
         23 . The method of  claim 30 , wherein said human/mouse chimeric DNA junction is contiguous to mouse 129 strain JC intronic DNA. 
     
     
         24 - 27 . (canceled) 
     
     
         28 . The mouse of  claim 23 , said mouse 129 strain DNA being mouse 129Sv DNA. 
     
     
         29 . The mouse of  claim 30 , wherein said all or part of the endogenous IgH variable region of said transgenic mouse is away from said endogenous CH gene segment or is inverted. 
     
     
         30 . A method for producing an antibody specific for a selected antigen, a cell producing antibody specific for a selected antigen, a nucleic acid encoding antibody specific for a selected antigen, and/or a biological sample comprising antibody specific for a selected antigen, the method comprising:
 a) immunizing a transgenic mouse with said selected antigen for a time and under conditions which permit the immunized mouse to produce antibody specific for said antigen; wherein said transgenic mouse comprises a genome comprising a homozygous chimeric immunoglobulin heavy chain (IgH) locus comprising unrearranged human IgH variable region gene segments positioned upstream of and operably linked to an enhancer and a constant (C) region comprising an endogenously-located CH gene segment;   wherein said homozygous chimeric IgH locus comprises in 5′ to 3′ transcriptional orientation:
 (i) unrearranged human immunoglobulin heavy chain (IgH) variable region (VH) DNA comprising one or more human IgH V gene segments, one or more human D gene segments and human JH gene segments comprising a 3′-most human JH gene segment, 
 (ii) a chimeric J/C intron comprising human JC intronic DNA contiguous with said 3′-most human JH gene segment and mouse JC intronic DNA, and wherein said human JC intronic DNA joins said mouse JC intronic DNA at a human/mouse chimeric DNA junction upstream of said enhancer, and 
 (iii) said enhancer and said C region, 
   wherein said human 3′-most JH gene segment is less than 2 kb upstream of said chimeric junction,   wherein said transgenic mouse is functional to form rearranged human VH, DH and JH gene segments and, upon stimulation with antigen, is capable of producing an antibody specific for said antigen and comprising a chimeric Ig heavy chain comprising a human IgH variable region; and   wherein the genome of said transgenic mouse comprises all or part of the endogenous mouse IgH variable region, and is capable of breeding to produce subsequent generation mice having in their germline an IgH locus comprising unrearranged human IgH variable region gene segments positioned upstream of an IgH constant C region comprising an endogenously-located CH gene segment; and   b) isolating from said immunized mouse one or more of: antibody specific for said antigen, a cell producing antibody specific for said antigen, a nucleic acid encoding antibody specific for said antigen, and/or a biological sample comprising antibody specific for said antigen.