Animal models and therapeutic molecules

A method for producing a biological sample selected from the group consisting of:

• (i) a polypeptide comprising a human kappa variable region,
• (ii) an Ig kappa light chain comprising a human kappa variable region,
• (iii) an antibody comprising a human kappa variable region,
• (iv) a cell expressing a polypeptide comprising a human kappa variable region,
• (v) a cell expressing an Ig kappa light chain comprising a human kappa variable region,
• (vi) a cell expressing an antibody comprising a human kappa variable region,
• (vii) nucleic acid encoding a polypeptide comprising a human kappa variable region,
• (viii) nucleic acid encoding an Ig kappa light chain comprising a human kappa variable region,
• (ix) nucleic acid encoding a human kappa variable region, and
• (x) nucleic acid encoding a human kappa variable region and a mouse constant region, the method comprising the steps of:
• (a) delivering an antigen to a transgenic mouse
• having a germline comprising a homozygous recombinant immunoglobulin light chain kappa (Igκ) locus comprising unrearranged human Igκ variable region gene segments at an endogenous mouse kappa light chain locus upstream of a kappa enhancer and a constant (C) region comprising an endogenous Cκ gene segment;
• wherein said recombinant Igκ locus comprises in 5′ to 3′ transcriptional orientation:
• unrearranged human Igκ variable region gene segments, a chimeric JC intron comprising truncated human Igκ JC intronic DNA, truncated mouse Igκ JC intronic DNA comprising said kappa enhancer, and said constant (C) region;
• wherein said human Igκ variable region gene segments in said recombinant Igκ locus are operably linked to said C region, and
• wherein said unrearranged Igκ variable region gene segments comprise human Vκ4-1, Vκ5-2, Vκ7-3, Vκ2-4, Vκ1-5, Vκ1-6, Vκ3-7, Vκ1-8, Vκ1-9, Jκ1, Jκ2, Jκ3, Jκ4, and Jκ5 gene segments;
• wherein said mouse genome is homozygous for a chimeric IgH locus comprising unrearranged human IgH variable region gene segments, at an endogenous IgH locus upstream of an enhancer and a constant (C) region comprising an endogenous CH gene segment, wherein said unrearranged human variable region gene segments comprise unrearranged human VH region gene segments comprising a plurality of human VH, JH, and D gene segments in said chimeric IgH locus are operably linked to said enhancer and said C region, wherein said germline comprises all or part of mouse IgH variable region DNA upstream of said unrearranged human VH region gene segments comprising the human VH, D and JH gene segments;
• wherein said mouse is non-functional to express fully mouse Ig comprising a mouse VH region and a mouse CH region;
• wherein said transgenic mouse prior to said antigen delivery comprises B cells comprising said recombinant Igκ locus, and
• wherein after said antigen delivery, said transgenic mouse comprises B cells comprising antibody specific for said antigen and comprising light chain comprising a human kappa variable region,
• wherein said IgH locus of said transgenic mouse is capable of undergoing V, D, J joining and,
• wherein said mouse following delivery of said antigen, is capable of producing a plurality of antibodies specific for said antigen comprising a chimeric Ig heavy chain comprising a plurality of human IgH chain variable regions, and
• wherein said recombinant immunoglobulin light chain kappa (Igκ) locus of said transgenic mouse is capable of undergoing V, J joining and,
• wherein said mouse following delivery of said antigen, is capable of producing a plurality of antibodies specific for said antigen comprising a chimeric Igκ chain comprising a plurality of human Igκ chain variable regions,
• wherein said transgenic mouse is capable of breeding with another said transgenic mouse to provide subsequent generation mice,
• wherein said subsequent generation mouse comprises:
• (i) in its germline said homozygous IgH locus, (ii) in its germline comprising all or part of mouse IgH variable region DNA upstream of said unrearranged human VH region gene segments, and capable of breeding to subsequent generations, and wherein said subsequent generation mouse is capable of breeding with a said subsequent generation mouse to further subsequent generations, and
• (b) isolating from said mouse of step (a) or a cell of said mouse of step (a) said biological sample.