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.

We claim: 
     
         1 . A cell comprising a chimeric immunoglobulin kappa locus comprising a human kappa variable (V) region and a mouse kappa constant region comprising an endogenous mouse kappa C gene,
 wherein said human kappa V region comprises unrearranged human immunoglobulin kappa V and J gene segments.   
     
     
         2 . The cell of  claim 1 , wherein the unrearranged human kappa V and J gene segments are capable of undergoing rearrangement sufficient to form a human kappa VJ gene operatively joined to a mouse kappa C gene. 
     
     
         3 . The cell of  claim 2 , wherein upon rearrangement of said human kappa VJ gene operatively joined to a mouse kappa C gene, said cell is capable of expressing a chimeric kappa light chain encoded by said human kappa VJ gene joined to a mouse kappa C gene. 
     
     
         4 . The cell of  claim 3 , wherein upon rearrangement, said cell is capable of expressing an antibody comprising a chimeric kappa light chain encoded by said human kappa VJ gene joined to a mouse kappa C gene. 
     
     
         5 . The cell of  claim 2 , wherein upon rearrangement, said cell comprises unrearranged human immunoglobulin kappa V gene segments upstream of DNA comprising a rearranged human kappa V gene segment and human J kappa gene segment and produces an antibody comprising a chimeric kappa light chain comprising a human kappa variable region and a mouse kappa constant region. 
     
     
         6 . The cell of  claim 1 , wherein said cell does not comprise a human immunoglobulin kappa chain constant region. 
     
     
         7 . The cell of  claim 1 , wherein all or part of mouse IgK variable region DNA is present upstream of said unrearranged human immunoglobulin kappa V and J gene segments, and wherein expression of Ig kappa chains comprising a mouse variable region is reduced or prevented. 
     
     
         8 . The cell of  claim 5 , wherein all or part of mouse IgK Variable region DNA is present upstream of said rearranged human immunoglobulin kappa V and J gene segments. 
     
     
         9 . The cell of  claim 1 , said cell being an ES cell, a B cell, or a hybridoma. 
     
     
         10 . The cell of  claim 1 , wherein said chimeric immunoglobulin kappa locus comprising in 5′ to 3′ transcriptional order said unrearranged human kappa variable region gene segments, truncated human IgK JC intronic DNA, a human/mouse junction, truncated mouse IgK JC intronic DNA comprising a kappa enhancer, and said mouse kappa constant region comprising said endogenous mouse kappa C gene segment. 
     
     
         11 . The cell of  claim 10 , wherein the distance between said human/mouse junction and said mouse enhancer comprises 782 bp. 
     
     
         12 . The cell of  claim 10 , wherein DNA between said human/mouse junction and said enhancer comprises mouse 129 strain JC intronic DNA. 
     
     
         13 . The cell of  claim 10 , wherein said unrearranged human kappa variable region gene segments comprise a 3′ human Jκ gene segment and wherein the distance from said 3′ human Jκ gene segment to said human/mouse junction is less than 2 kb. 
     
     
         14 . The cell of  claim 1 , further comprising a heavy chain immunoglobulin locus comprising a human heavy chain variable region comprising unrearranged human heavy chain variable region gene segments comprising human VH, D and JH gene segments. 
     
     
         15 . The cell of  claim 14 , wherein said heavy chain immunoglobulin locus comprising said human heavy chain variable region gene segments further comprises a mouse heavy chain constant region comprising an endogenous mouse constant gene segment. 
     
     
         16 . The cell of  claim 14 , wherein said unrearranged human heavy chain variable region gene segments are at an endogenous heavy chain IgH locus upstream of an enhancer and said mouse heavy chain constant region comprising said endogenous mouse constant gene segment; and wherein said unrearranged human heavy chain variable region gene segments are operably linked to said mouse heavy chain constant region. 
     
     
         17 . The cell of  claim 13 , wherein said heavy chain immunoglobulin locus is homozygous. 
     
     
         18 . The cell of  claim 17 , wherein said homozygous heavy chain Ig locus comprises in 5′ to 3′ transcriptional orientation: said unrearranged human heavy chain variable region gene segments comprising human IgH V gene segments, human D gene segments and human IgH J gene segments, truncated human IgH JC intronic DNA, a human/mouse junction, truncated mouse IgH JC intronic DNA, said enhancer and said mouse heavy chain constant region comprising said endogenous mouse constant gene segment. 
     
     
         19 . The cell of  claim 18 , wherein DNA between said human/mouse junction of said homozygous heavy chain Ig locus and said enhancer comprises mouse 129 strain JC intronic DNA. 
     
     
         20 . The cell of  claim 18 , wherein said unrearranged human IgH variable region gene segments comprise a 3′ human JH gene segment and wherein the distance from said 3′ human JH gene segment to said human/mouse junction is less than 2 kb. 
     
     
         21 . The cell of  claim 18 , wherein said enhancer is a mouse 129 strain μ enhancer. 
     
     
         22 . The cell of  claim 18 , wherein all or part of said mouse IgH variable region DNA is upstream of said truncated mouse IgH JC intronic DNA and said human heavy chain variable region gene segments, and wherein expression of Ig heavy chains comprising a mouse variable region is reduced or prevented. 
     
     
         23 . The cell of  claim 20 , wherein said 3′ JH gene segment comprises a human JH6 gene segment. 
     
     
         24 . The cell of  claim 19 , wherein said 129 strain DNA is 129Sv. 
     
     
         25 . The cell of  claim 1 , wherein said mouse heavy chain constant region comprises a mouse Cμ gene segment.