MICE THAT MAKE VL BINDING PROTEINS
Genetically modified mice and methods for making an using them are provided, wherein the mice comprise a replacement of all or substantially all immunoglobulin heavy chain V gene segments, D gene segments, and J gene segments with at least one light chain V gene segment and at least one light chain J gene segment. Mice that make binding proteins that comprise a light chain variable domain operably linked to a heavy chain constant region are provided. Binding proteins that contain an immunoglobulin light chain variable domain, including a somatically hypermutated light chain variable domain, fused with a heavy chain constant region, are provided. Modified cells, embryos, and mice that encode sequences for making the binding proteins are provided.
1 .- 14 . (canceled)
15 . A mouse comprising an antigen-binding protein that specifically binds an antigen,
wherein the antigen-binding protein comprises a first polypeptide comprising a first human light chain variable region sequence fused with an intact immunoglobulin heavy chain constant region, and a second polypeptide comprising a second human light chain variable region fused with an immunoglobulin light chain constant region,
wherein the first and second human light chain variable regions are cognate and not identical.
16 . The mouse of claim 15 , wherein the first human light chain variable region sequence comprises a human κ variable region sequence, and the second human light chain variable region is selected from a human κ variable region and a human λ variable region.
17 . The mouse of claim 16 , wherein the immunoglobulin heavy chain constant region is selected from a human heavy chain constant region and a mouse heavy chain constant region.
18 . The mouse of claim 16 , wherein the immunoglobulin light chain constant region is selected from a human light chain constant region and a mouse light chain constant region.
19 . The mouse of claim 16 , wherein the first polypeptide is expressed from a modified endogenous mouse immunoglobulin heavy chain locus that lacks a functional endogenous heavy chain V gene segment.
20 . The mouse of claim 19 , wherein the second polypeptide is expressed from a modified endogenous mouse immunoglobulin light chain locus that lacks a functional endogenous light chain V gene segment.
21 . (canceled)
22 . The mouse of claim 15 , wherein the first polypeptide is encoded by a rearranged human immunoglobulin light chain variable κ (hVκ/hJκ) gene sequence operably linked to an endogenous mouse sequence encoding the intact C H region at the endogenous mouse immunoglobulin heavy chain locus.
23 . The mouse of claim 22 , wherein the second polypeptide is encoded by a second rearranged human immunoglobulin light chain variable κ (hVκ/hJκ) gene sequence operably linked to an endogenous mouse sequence encoding the immunoglobulin light chain constant region at the endogenous mouse immunoglobulin light chain locus.
24 . The mouse of claim 23 , wherein the antigen-binding protein comprises two of the first polypeptides and two of the second polypeptide in an antibody-like tetrameric structure.
25 . A method for making a human V L binding protein comprising
(i) isolating from the mouse of claim 1 the first and/or second polypeptides, or
(ii) isolating from the mouse of claim 1 the nucleotide sequence(s) encoding the first and/or second human light chain variable regions and expressing the nucleotide sequence(s) in an expression system.
26 . A polypeptide or nucleotide sequence isolated according to the method of claim 25 .
27 . An antigen-binding protein made according to the method of claim 25 , comprising a hybrid immunoglobulin heavy chain and an immunoglobulin light chain,
wherein the hybrid immunoglobulin heavy chain comprises a first human light chain variable domain (V L 1) fused to an intact heavy chain constant domain,
wherein the immunoglobulin light chain comprises a second human light chain variable domain (V L 2) fused to a light chain constant domain, and
wherein V L 1 and V L 2 are not identical and associate to specifically bind an antigen of interest.
28 . The antigen-binding protein of claim 27 , wherein V L 1 and V L 2 are independently selected from Vκ and Vγ domains.
29 . The antigen-binding protein of claim 27 , wherein the intact heavy chain constant region is an intact mouse heavy chain constant region and the light chain constant domain is a mouse light chain constant domain.
30 . The antigen-binding protein of claim 27 , wherein both V L 1 and V L 2 are each a human Vκ domain.
31 . The antigen-binding of claim 30 , wherein the light chain constant domain is a Cκ domain.
32 . The antigen-binding protein of claim 27 , further comprising
(i) a third polypeptide comprising a third light chain variable domain (V L 3) fused with a second intact immunoglobulin heavy chain constant region; and
(ii) a fourth polypeptide comprising a fourth light chain variable domain (V L 4) fused with a second immunoglobulin light chain constant region;
wherein VL3 and VL4 are not identical.
33 . The antigen-binding protein of claim 32 , wherein (a) V L 1 and V L 3 are identical and/or (b) V L 2 and V L 4 are identical.
34 . The antigen-binding protein of claim 33 , wherein the antigen-binding protein is bispecific.
35 . The antigen-binding protein of claim 34 , wherein the first and second intact immunoglobulin heavy chain constant regions differentially bind protein A.