MICE THAT MAKE HEAVY CHAIN ANTIBODIES
Genetically modified non-human animals and methods and compositions for making and using them are provided, wherein the genetic modification comprises a deletion in an immunoglobulin constant region CH1 gene (optionally a deletion in a hinge region) of an IgG, IgA, IgD, and/or IgE, and wherein the mouse is capable of expressing a functional IgM. Genetically modified mice are described, including mice having a functional IgM gene and modified to have a deletion of a CH1 domain and a hinge region in a heavy chain constant domain that is not an IgM, e.g., in an IgG heavy chain constant domain. Genetically modified mice that make human variable/mouse constant chimeric heavy chain antibodies (antibodies that lack a light chain), fully mouse heavy chain antibodies, or fully human heavy chain antibodies are provided.
1 .- 20 . (canceled)
21 . A transgenic mouse comprising a germline modification, which modification comprises:
(a) a deletion of a nucleic acid sequence encoding a CH1 domain and a hinge region of an endogenous IgG1 constant region gene;
(b) a deletion of an endogenous IgD constant region gene;
(c) a deletion of an endogenous IgG3 constant region gene;
(d) a deletion of an endogenous IgG2a constant region gene;
(e) a deletion of an endogenous IgG2b constant region gene;
(f) a deletion of an endogenous IgE constant region gene;
(g) a deletion of an endogenous IgA constant region gene; and
(h) an inclusion of one or more human heavy chain variable region gene segments, wherein the one or more human heavy chain variable region gene segments is operably linked to the endogenous IgG1 constant region of (a);
wherein the mouse comprises an intact IgM constant region gene.
22 . The transgenic mouse of claim 21 , characterized in that the mouse expresses an IgG1 heavy chain antibody comprising a human variable domain, lacking a CH1 domain and a hinge region, in whole or in part, and lacking a cognate light chain, and secretes said IgG1 heavy chain antibody into its serum.
23 . The transgenic mouse of claim 22 , wherein the IgG1 heavy chain antibody lacks the CH1 domain and the hinge region in whole.
24 . The transgenic mouse of claim 22 , wherein the IgG1 heavy chain antibody comprises the human variable domain, an IgG1 CH2 domain, and an IgG1 CH3 domain.
25 . The transgenic mouse of claim 21 , wherein the mouse comprises a functional immunoglobulin light chain gene locus.
26 . The transgenic mouse of claim 25 , wherein the immunoglobulin light chain locus is a κ light chain gene locus.
27 . The transgenic mouse of claim 25 , wherein the immunoglobulin light chain gene locus is a λ light chain gene locus.
28 . The transgenic mouse of claim 21 , wherein the mouse is selected from the group consisting of a 129 strain, a C57BL/6 strain, and a mixed 129×C57BL/6 strain.
29 . The transgenic mouse of claim 28 , wherein the mouse is 50% 129 and 50% C57BL/6.
30 . A mouse cell comprising a germline modification, which modification comprises:
(a) a deletion of a nucleic acid sequence encoding a CH1 domain and a hinge region of an endogenous IgG1 constant region gene;
(b) a deletion of an endogenous IgG2a constant region gene;
(c) a deletion of an endogenous IgG2b constant region gene;
(d) a deletion of an endogenous IgG3 constant region gene;
(e) a deletion of an endogenous IgE constant region gene;
(f) a deletion of an endogenous IgA constant region gene;
(g) a deletion of an endogenous IgD constant region gene; and
(h) an inclusion of one or more human heavy chain variable region gene segments, wherein the one or more human heavy chain variable region gene segments is operably linked to the endogenous IgG1 constant region of (a);
wherein the mouse cell comprises an intact IgM constant region gene.
31 . The mouse cell of claim 30 , wherein the cell is a B cell.
32 . The B cell of claim 31 , characterized in that the B cell expresses a IgG1 heavy chain antibody, which IgG1 heavy chain antibody comprises a heavy chain variable domain, an IgG1 hinge, an IgG1 CH2 domain, and an IgG1 CH3 domain.
33 . A hybridoma made from the B cell of claim 31 .
34 . A hybridoma made from the B cell of claim 32 .
35 . A nucleic acid encoding a human heavy chain variable region isolated from the hybridoma of claim 33 .
36 . A nucleic acid encoding a human heavy chain variable region isolated from the hybridoma of claim 34 .
37 . A nucleic acid encoding a human heavy chain variable region isolated from the B cell of claim 31 .
38 . A nucleic acid encoding a human heavy chain variable region isolated from the B cell of claim 32 .
39 . The mouse cell of claim 30 , wherein the cell is an embryonic stem (ES) cell.
40 . The mouse ES cell of claim 39 , wherein the cell is from a strain selected from the group consisting of a 129 strain, a C57BL/6 strain, and a mixed 129×C57BL/6 strain.
41 . The mouse ES cell of claim 40 , wherein the cell is 50% 129 and 50% C57BL/6.
42 . The mouse ES cell of claim 41 , wherein the cell has a genome comprising a functional immunoglobulin light chain gene locus.
43 . A mouse embryo made from or comprising the ES cell of claim 39 .
44 . A mouse embryo made from or comprising the ES cell of claim 41 .
45 . A mouse embryo made from or comprising the ES cell of claim 42 .