TRANSGENIC ANIMALS EXPRESSING CHIMERIC ANTIBODIES FOR USE IN PREPARING HUMAN ANTIBODIES

• US 20090260093A1
• Filed: 03/30/2007
• Published: 10/15/2009
• Est. Priority Date: 03/31/2006
• Status: Active Grant

• Current Assignee: ER Squibb & Sons LLC (Bristol-Myers Squibb Company)
• Original Assignee: Medarex Incorporated (Bristol-Myers Squibb Company)
• Inventors: Brams, Peter, Tanamachi, Dawn M., Black, Amelia
• Granted Patent: US 7,910,798 B2
• Time in Patent Office: Days
• US Class Current: 800/6
• CPC Class Codes: A01K 2207/15 Humanized animals
• CPC Class Codes: A01K 2217/00 Genetically modified animals
• CPC Class Codes: A01K 2217/05 Animals comprising random inserted nucleic acids (transgenic)
• CPC Class Codes: A01K 2217/075 inducing loss of function, i.e. knock out
• CPC Class Codes: A01K 2227/105 Murine
• CPC Class Codes: A01K 2267/01 Animal expressing industrially exogenous proteins
• CPC Class Codes: A01K 67/0278 Knock-in vertebrates, e.g. humanised vertebrates
• CPC Class Codes: C07K 16/00 Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies antibodies with enzymatic activity, e.g. abzymes C12N9/0002
• CPC Class Codes: C07K 16/1282 from Clostridium (G)
• CPC Class Codes: C07K 16/24 against cytokines, lymphokines or interferons
• CPC Class Codes: C07K 16/462 Igs containing a variable region (Fv) from one specie and a constant region (Fc) from another
• CPC Class Codes: C07K 2317/21 from primates, e.g. man
• CPC Class Codes: C07K 2317/24 containing regions, domains or residues from different species, e.g. chimeric, humanized or veneered
• CPC Class Codes: C07K 2317/76 Antagonist effect on antigen, e.g. neutralization or inhibition of binding
• CPC Class Codes: C07K 2317/92 Affinity (KD), association rate (Ka), dissociation rate (Kd) or EC50 value
• CPC Class Codes: C12N 15/8509 for producing genetically modified animals, e.g. transgenic

Abstract

The invention provides transgene constructs for expressing chimeric antibodies, and transgenic non-human host animals carrying such constructs, wherein the chimeric antibodies comprise human variable regions and constant regions of the non-human transgenic host animal. The presence of immunoglobulin constant regions of the host animal allows for generation of improved antibodies in such transgenic host animals. Subsequently, the chimeric antibodies can be readily converted to fully human antibodies using recombinant DNA techniques. Thus, the invention provides compositions and methods for generating human antibodies in which chimeric antibodies raised in vivo in transgenic mice are used as intermediates and then converted to fully human antibodies in vitro.

Claims

1. A transgene construct comprising a plurality of unrearranged human immunoglobulin (Ig) variable region sequences operatively linked to at least one immunoglobulin (Ig) constant region sequence of a non-human host animal,

wherein said transgene construct undergoes rearrangement in the non-human host animal and expresses chimeric antibodies in the non-human host animal, the chimeric antibodies comprising a human variable region and a constant region of the non-human host animal.

2. The construct of claim 1, wherein the plurality of unrearranged human Ig variable region sequences are heavy chain variable region sequences.

3. The construct of claim 2, wherein the heavy chain variable region sequences comprise V-D-J sequences.

4. The construct of claim 3, which comprises, in 5′

to 3′

direction, a plurality of human V_H regions, a plurality of human D segments, a plurality of human J_H segments, a J-μ

enhancer from a non-human host animal, a μ

switch region from a non-human host animal and a μ

constant region from a non-human host animal.

5. The construct of claim 4, which, when integrated into a non-human host animal genome, undergoes trans-switching with an endogenous constant region of the non-human host animal.

6. The construct of claim 4, wherein the non-human host animal is a mouse.

7. The construct of claim 6, which comprises four human V_H regions, 15 human D segments and six human J_H segments.

8. The construct of claim 7, which comprises a 9B2 transgene.

9. The construct of claim 4, which further comprises a γ

constant region from a non-human host animal.

10. The construct of claim 9, wherein the non-human host animal is a mouse.

11. The construct of claim 4, which comprises all Ig constant regions of the non-human host animal.

12. The construct of claim 11, wherein the non-human host animal is a mouse.

13. The construct of claim 1, wherein the unrearranged human Ig variable region sequences are human light chain variable region sequences.

14. The construct of claim 13, wherein the human light chain variable region sequences are human kappa V-J sequences.

15. The construct of claim 14, which comprises, in 5′

to 3′

direction, a plurality of human V_κ

regions, a plurality of human J_κ

segments, a J-κ

enhancer from a non-human host animal and a C_κ

coding region from a non-human host animal.

16. The construct of claim 15, wherein the non-human host animal is a mouse.

18. A transgenic non-human host animal comprising the transgene construct of claim 1, wherein the animal expresses chimeric antibodies comprising human Ig variable regions and non-human host animal Ig constant regions.

25. A method of making a chimeric antibody specific for an antigen of interest comprising immunizing the transgenic non-human host animal of claim 18 with the antigen of interest and obtaining from the animal a chimeric antibody specific for the antigen of interest.

26. The method of claim 25, further comprising isolating from the animal a nucleic acid encoding the chimeric antibody and replacing nucleic acid encoding the non-human host animal Ig constant region with nucleic acid encoding a human Ig constant region to thereby convert the chimeric antibody to a human antibody and expressing the human antibody.

17. A trans gene construct which comprises, in 5′

to 3′

direction, a plurality of human V_H regions, a plurality of human D segments, a plurality of human J_H segments, a mouse J-μ

enhancer, a mouse μ

switch region and a mouse μ

constant region, wherein the transgene construct, when integrated into a mouse genome, undergoes trans-switching with an endogenous mouse γ

constant region such that chimeric antibodies comprising human V regions and mouse constant regions of IgM and IgG isotype are produced in the mouse.

19-24. -24. (canceled)

27. (canceled)