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 human variable region Vk and Jk gene segments, said locus comprising a rearranged human VkJk gene operably linked to a mouse kappa chain constant region gene,
 wherein the rearranged human VkJk gene was generated by the rearrangement of unrearranged human immunoglobulin Vk and Jk gene segments that operatively replace endogenous mouse immunoglobulin kappa V and J gene segments,   wherein the rearranged human kappa VkJk gene segments and the mouse kappa C gene encode an Ig light chain polypeptide comprising a human kappa chain variable region linked to a mouse kappa chain constant region,   said cell being capable of expressing a chimeric light chain polypeptide comprising a human kappa variable region and a mouse kappa constant region.   
     
     
         2 . The cell of  claim 1 , wherein said cell expresses said chimeric kappa light chain comprising a human kappa variable region and a mouse kappa constant region. 
     
     
         3 . The cell of  claim 2 , wherein said cell produces an antibody comprising said chimeric kappa light chain. 
     
     
         4 . The cell of  claim 1 , further comprising:
 a chimeric immunoglobulin heavy (IgH) chain locus comprising human variable region VH, D and JH gene segments, said locus comprising a rearranged human VHDJH gene operably linked to a mouse heavy chain constant region comprising an endogenous mouse heavy chain constant region gene, wherein the rearranged human VHDJH variable region gene was generated by the rearrangement of unrearranged human immunoglobulin heavy chain V, D, and J gene segments that replace endogenous mouse immunoglobulin heavy chain V, D, and J gene segments.   
     
     
         5 . The cell of  claim 1 , further comprising: a chimeric immunoglobulin heavy (IgH) chain locus comprising human variable region VH, D and JH gene segments, said locus comprising a rearranged human VHDJH gene operably linked to a mouse heavy chain constant region comprising an endogenous mouse heavy chain constant region gene, wherein the rearranged human VHDJH variable region gene was generated by the rearrangement of unrearranged human immunoglobulin heavy chain V, D, and J gene segments, and wherein all or part of mouse IgH Variable region gene segments is present upstream of said rearranged human VHDJH gene. 
     
     
         6 . The cell of  claim 4 , wherein the cell produces a hybrid antibody that comprises a human heavy chain variable region encoded by the rearranged human immunoglobulin heavy chain variable region gene, a mouse heavy chain constant region encoded by the mouse heavy chain constant region gene, a human kappa chain variable region encoded by the rearranged human immunoglobulin kappa chain variable region gene, and a mouse kappa chain constant region encoded by the mouse kappa chain constant region gene. 
     
     
         7 . The cell of  claim 1 , wherein said cell does not comprise a human immunoglobulin kappa chain constant region. 
     
     
         8 . The cell of  claim 1 , wherein all or part of mouse IgK variable region DNA is present upstream of said rearranged human immunoglobulin kappa V and J gene segments, and wherein expression of IgK chains comprising a mouse variable region is reduced or prevented. 
     
     
         9 . The cell of  claim 5 , 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. 
     
     
         10 . The cell of  claim 1 , said cell being a B cell or a hybridoma. 
     
     
         11 . The cell of  claim 4 , wherein said mouse heavy chain constant region comprises a mouse Cμ gene segment. 
     
     
         12 . 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 Igκ JC intronic DNA, a IgK human/mouse junction, truncated mouse Igκ JC intronic DNA comprising a kappa enhancer, and said mouse kappa constant region comprising said endogenous mouse kappa C gene segment. 
     
     
         13 . The cell of  claim 12 , wherein the distance between said IgK human/mouse junction and said mouse enhancer comprises 782 bp. 
     
     
         14 . The cell of  claim 12 , wherein DNA between said human/mouse junction and said enhancer comprises mouse 129 strain JC intronic DNA. 
     
     
         15 . The cell of  claim 12 , 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 IgK human/mouse junction is less than 2 kb. 
     
     
         16 . The cell of  claim 4 , said cell being a B cell or a hybridoma. 
     
     
         17 . The cell of  claim 9 , 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 IgH chimeric 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 IgH chimeric junction and said enhancer comprises mouse 129 strain JC intronic DNA. 
     
     
         20 . The cell of  claim 18 , wherein said unrearranged human heavy chain 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.