Animal models and therapeutic molecules

1. A method for obtaining a biological sample produced in response to a selected antigen, said sample comprising, encoding or expressing a human λ Variable region, said biological sample being selected from the group consisting of: cells producing a polypeptide comprising said human lambda Variable region and nucleic acid encoding said human lambda Variable region, the method comprising

(a) providing a transgenic mouse having a genome comprising a homozygous recombinant immunoglobulin light chain (IgL) locus,

said locus comprising unrearranged human V region light chain gene segments comprising human Vλ and Jλ gene segments comprising the functional V and J gene segments from Vλ 2-18 to Jλ7 of a human λ , light chain locus, wherein said unrearranged human V region light chain gene segments are positioned

(i) at an endogenous mouse immunoglobulin light chain locus comprising an endogenous light chain locus enhancer and

(ii) upstream of a constant region,

said recombinant light chain locus being functional to rearrange to express an immunoglobulin light chain comprising a human V region,

wherein said mouse comprises splenic B cells expressing immunoglobulin light chains comprising λ Variable regions,

wherein a plurality of said immunoglobulin light chains comprises a plurality of human λ Variable regions;

wherein said plurality of said immunoglobulin light chains further comprises a plurality of mouse λ Variable regions,

wherein said mouse comprises immunoglobulin gamma antibody comprising λ Variable regions, and

wherein the mouse expresses more immunoglobulin light chain comprising a human Vλ region than immunoglobulin light chain comprising a mouse Vλ region,

(b) contacting said transgenic mouse with said selected antigen; and

(c) isolating said biological sample from said mouse of step (b);

wherein if said sample is nucleic acid encoding said human lambda Variable region, said nucleic acid is optionally obtained in an amplification step using reverse transcriptase.

2. The method of claim 1 , wherein said biological sample comprises a cell comprising nucleic acid encoding a polypeptide comprising a human λ Variable region, wherein said cell produces an Ig light chain comprising a human λ Variable region, and wherein the method further comprises:

(d) isolating from said sample a cell producing a polypeptide comprising a human λ Variable region, and

(e) isolating from said cell nucleic acid encoding a polypeptide comprising a human λ Variable region.

3. The method of claim 2 , further comprising the step of:

joining said nucleic acid encoding said human λ Variable region to nucleic acid encoding a human constant region to provide nucleic acid encoding a polypeptide comprising said human λ Variable region and a human λ constant region.

4. The method of claim 3 , further comprising the step of:

transfecting a cell with said nucleic acid encoding said polypeptide to provide a transfected cell expressing said polypeptide.

5. The method of claim 4 , further comprising the step of:

isolating said expressed polypeptide or an antibody comprising said polypeptide.

6. The method of claim 1 , wherein said enhancer comprises a mouse λ enhancer.

7. The method of claim 1 , wherein said enhancer is a mouse κ enhancer.

8. The method of claim 1 , wherein at least 60% of immunoglobulin light chains expressed by said mouse comprise human V regions derived from recombination of human Vλ and Jλ gene segments.

9. The method of claim 1 , wherein said unrearranged human V region light chain gene segments comprise a 3′human Vλ segment which is positioned within 100 kb of said endogenous light chain locus enhancer.

10. The method of claim 1 , wherein the genome comprises endogenous V light chain DNA comprising endogenous Vλ or Vk chain DNA.

11. The method of claim 1 , wherein said immunoglobulin gamma comprising human Vλ regions comprises antigen specific human Vλ.

12. The method of claim 1 , wherein said mouse comprises splenic B cells which express said IgG.

13. The method of claim 1 , wherein said mouse, the usage of human Jλ2 is greater than that of either human Jλ1 or human Jλ3.

14. The method of claim 1 , wherein at least 85% of immunoglobulin light chains expressed by said mouse comprise human V regions derived from recombination of human Vλ and Jλ gene segments.

15. A method for obtaining a biological sample produced in response to a selected antigen, said sample comprising, encoding or expressing a human λ Variable region, said biological sample being selected from the group consisting of: cells producing polypeptide comprising said human lambda Variable region and nucleic acid encoding said human λ Variable region, the method comprising

(a) providing a transgenic mouse having a genome comprising a homozygous recombinant immunoglobulin light chain (IgL) locus,

said locus comprising unrearranged human V region light chain gene segments comprising human Vλ and Jλ gene segments comprising the functional V and J gene segments from Vλ2-18 to Jλ7 of a human λ light chain locus, wherein said unrearranged human V region light chain gene segments are positioned

(i) at an endogenous mouse immunoglobulin light chain locus comprising an endogenous light chain locus enhancer and

(ii) upstream of a constant region,

said recombinant light chain locus being functional to rearrange to express an immunoglobulin light chain comprising a human V region,

wherein said mouse comprises splenic B cells expressing immunoglobulin light chains comprising λ Variable regions,

wherein a plurality of said immunoglobulin light chains comprises a plurality of human λ Variable regions,

wherein said mouse comprises immunoglobulin gamma antibody comprising λ Variable regions, and

wherein the mouse expresses more immunoglobulin light chain comprising a human Vλ region than immunoglobulin light chain comprising a mouse Vλ region,

(b) contacting said transgenic mouse with said selected antigen; and

(c) isolating said biological sample from said mouse of step (b);

wherein said human Vλ gene segments and Jλ gene segments are positioned at an endogenous kappa locus, upstream of a constant region gene, wherein said mouse does not express detectable endogenous κ immunoglobulin light chain, and wherein said mouse comprises splenic B cells which comprise immunoglobulin comprising human λ Variable region to immunoglobulin comprising mouse λ Variable region at a ratio of 80:15.

16. The method of claim 15 , wherein said genome as a whole retains endogenous light chain V region DNA.

17. The method of claim 16 , wherein said immunoglobulin λ light chains comprise a plurality of human λ Variable regions.

18. The method of claim 15 , wherein 84% of light chains of total splenic B cells grouped as B220/CD45R positive of said mouse comprise human λ Variable regions.

19. A method for obtaining a biological sample produced in response to a selected antigen, said sample comprising, encoding or expressing a human λ Variable region, said biological sample being selected from the group consisting of: cells producing a polypeptide comprising said human lambda Variable region and nucleic acid encoding said human λ Variable region, the method comprising

(a) providing a transgenic mouse having a genome comprising a homozygous recombinant immunoglobulin light chain (IgL) locus,

said locus comprising unrearranged human V region light chain gene segments comprising human Vλ and Jλ gene segments comprising the functional V and J gene segments from Vλ2-18 to Jλ7of a human λ light chain locus, wherein said unrearranged human V region light chain gene segments are positioned

(i) at an endogenous mouse immunoglobulin light chain locus comprising an endogenous light chain locus enhancer and

(ii) upstream of a constant region,

said recombinant light chain locus being functional to rearrange to express an immunoglobulin light chain comprising a human V region,

wherein said mouse comprises splenic B cells expressing immunoglobulin light chains comprising λ Variable regions,

wherein a plurality of said immunoglobulin light chains comprises a plurality of human λ Variable regions,

wherein said mouse comprises immunoglobulin gamma antibody comprising λVariable regions, and

wherein the mouse expresses more immunoglobulin light chain comprising a human Vλ region than immunoglobulin light chain comprising a mouse Vλ region,

(b) contacting said transgenic mouse with said selected antigen; and

(c) isolating said biological sample from said mouse of step (b);

wherein said human Vλ gene segments and human Jλ gene segments are upstream of a λ constant region, and wherein said mouse does not comprise immunoglobulin comprising an endogenous κ immunoglobulin light chain,

wherein B cells of said mouse comprise immunoglobulin comprising human λ Variable region relative to immunoglobulin comprising mouse λ Variable region at a ratio of 93:5.

20. The method of claim 19 , wherein 95% of total splenic B cells grouped as B220/CD45R positive of said mouse comprise human λ Variable regions.

21. A method for obtaining a biological sample produced in response to a selected antigen, said sample comprising, encoding or expressing a human λ Variable region, said biological sample being selected from the group consisting of: cells producing a polypeptide comprising said human λ Variable region and nucleic acid encoding said human λ Variable region, the method comprising

(a) providing a transgenic mouse having a genome comprising a homozygous recombinant immunoglobulin light chain (IgL) locus,

said locus comprising unrearranged human V region light chain gene segments comprising human Vλ and Jλ gene segments comprising the functional V and J gene segments from Vλ2-18 to Jλ7 of a human λ light chain locus, wherein said unrearranged human V region light chain gene segments are positioned

(i) at an endogenous mouse immunoglobulin light chain locus comprising an endogenous light chain locus enhancer and

(ii) upstream of a constant region,

said recombinant light chain locus being functional to rearrange to express an immunoglobulin light chain comprising a human V region,

wherein said mouse comprises splenic B cells expressing immunoglobulin light chains comprising λ Variable regions,

wherein a plurality of said immunoglobulin light chains comprises a plurality of human λ Variable regions,

wherein said mouse comprises immunoglobulin gamma antibody comprising λ Variable regions, and

wherein the mouse expresses more immunoglobulin light chain comprising a human Vλ region than immunoglobulin light chain comprising a mouse Vλ region,

(b) contacting said transgenic mouse with said selected antigen; and

(c) isolating said biological sample from said mouse of step (b); wherein said mouse exhibits relative usage of human Jλ gene segments in splenic B cells that is similar to the usage of Jλ segments in splenic B cells of humans.

22. The method of claim 21 , wherein said mouse exhibits relative usage of human Vλ gene segments in splenic B cells similar to the usage of Vλ gene segments in splenic B cells of humans.

23. A method for obtaining a biological sample produced in response to a selected antigen, said sample comprising, encoding or expressing a human λ Variable region, said biological sample being selected from the group consisting of: cells producing a polypeptide comprising said human λ Variable region and nucleic acid encoding said human λ Variable region, the method comprising

(a) providing a transgenic mouse having a genome comprising a homozygous recombinant immunoglobulin light chain (IgL) locus,

said locus comprising unrearranged human V region light chain gene segments comprising human Vλ and Jλ gene segments comprising the functional V and J gene segments from Vλ2 -18 to Jλ7 of a human λ light chain locus, wherein said unrearranged human V region light chain gene segments are positioned

(i) at an endogenous mouse immunoglobulin light chain locus comprising an endogenous light chain locus enhancer and

(ii) upstream of a constant region,

said recombinant light chain locus being functional to rearrange to express an immunoglobulin light chain comprising a human V region,

wherein said mouse comprises splenic B cells expressing immunoglobulin light chains comprising λ Variable regions,

wherein a plurality of said immunoglobulin light chains comprises a plurality of human λ Variable regions,

wherein said mouse comprises immunoglobulin gamma antibody comprising λ Variable regions, and

wherein the mouse expresses more immunoglobulin light chain comprising a human Vλ region than immunoglobulin light chain comprising a mouse Vλ region,

(b) contacting said transgenic mouse with said selected antigen; and

(c) isolating said biological sample from said mouse of step (b);

wherein said mouse exhibits relative usage of human Vλ gene segments in splenic B cells similar to the usage of Vλ gene segments in splenic B cells of humans.

24. A method for obtaining a biological sample produced in response to a selected antigen, said sample comprising, encoding or expressing a human λ Variable region, said biological sample being selected from the group consisting of: cells producing a polypeptide comprising said human lambda Variable region and nucleic acid encoding said human lambda Variable region, the method comprising

(a) providing a transgenic mouse having a genome comprising a homozygous recombinant immunoglobulin light chain (IgL) locus,

said locus comprising unrearranged human V region light chain gene segments comprising human Vλ and Jλ gene segments comprising the functional V and J gene segments from Vλ2 -18 to Jλ7 of a human λ light chain locus, wherein said unrearranged human V region light chain gene segments are positioned

(i) at an endogenous mouse immunoglobulin light chain locus comprising an endogenous light chain locus enhancer and

(ii) upstream of a constant region,

said recombinant light chain locus being functional to rearrange to express an immunoglobulin light chain comprising a human V region,

wherein said mouse comprises splenic B cells expressing immunoglobulin light chains comprising λ Variable regions,

wherein a plurality of said immunoglobulin light chains comprises a plurality of human λ Variable regions; wherein said plurality of said immunoglobulin light chains further comprises a plurality of mouse λ Variable regions,

wherein said human Vλ segments and Jλ segments are positioned upstream to a κ constant region,

wherein said mouse comprises immunoglobulin gamma antibody comprising λ Variable regions, and

wherein the mouse expresses more immunoglobulin light chain comprising a human Vλ region than immunoglobulin light chain comprising a mouse Vλ region,

(b) contacting said transgenic mouse with said selected antigen; and

(c) isolating said biological sample from said mouse of step (b);

wherein if said sample is nucleic acid encoding said human lambda Variable region, said nucleic acid is optionally obtained in an amplification step using reverse transcriptase.

25. The method of claim 24 , wherein said biological sample comprises a cell comprising nucleic acid encoding a polypeptide comprising a human λ Variable region, wherein said cell produces an Ig light chain comprising a human λ Variable region, and wherein the method further comprises:

(d) isolating from said sample a cell producing a polypeptide comprising a human λ Variable region, and

(e) isolating from said cell nucleic acid encoding a polypeptide comprising a human λ Variable region.

26. The method of claim 25 , further comprising the step of:

joining said nucleic acid encoding said human λ Variable region to nucleic acid encoding a human constant region to provide nucleic acid encoding a polypeptide comprising said human λ Variable region and a human λ constant region.

27. The method of claim 26 , further comprising the step of: transfecting a cell with said nucleic acid encoding said polypeptide to provide a transfected cell expressing said polypeptide.

28. The method of claim 27 , further comprising the step of: isolating said expressed polypeptide or an antibody comprising said polypeptide.

29. The method of claim 24 , wherein said enhancer is a mouse κ enhancer.

30. The method of claim 24 , wherein at least 60% of immunoglobulin light chains expressed by said mouse comprise human V regions derived from recombination of human Vλ and Jλ gene segments.

31. The method of claim 24 , wherein said unrearranged human V region light chain gene segments comprise a 3′ human Vλ segment which is positioned within 100 kb of said endogenous light chain locus enhancer.

32. The method of claim 24 , wherein the genome comprises endogenous V light chain DNA comprising endogenous Vλ or Vk chain DNA.

33. The method of claim 24 , wherein said immunoglobulin gamma comprising human Vλ regions comprises antigen specific human Vλ.

34. The method of claim 24 , wherein said mouse comprises splenic B cells which express said IgG.

35. The method of claim 24 , wherein said mouse, the usage of human Jλ2 is greater than that of either human Jλ1 or human Jλ3.

36. The method of claim 24 , wherein at least 85% of immunoglobulin light chains expressed by said mouse comprise human V regions derived from recombination of human Vλ and Jλ gene segments.