LOW AFFINITY FcyR DEFICIENT MICE
Genetically modified non-human animals and methods and compositions for making and using them are provided, wherein the genetic modification comprises a deletion of the endogenous low affinity FcγR locus, and wherein the mouse is capable of expressing a functional FcRγ-chain. Genetically modified mice are described, including mice that express low affinity human FcγR genes from the endogenous FcγR locus, and wherein the mice comprise a functional FcRγ-chain. Genetically modified mice that express up to five low affinity human FcγR genes on accessory cells of the host immune system are provided.
1 - 15 . (canceled)
16 . A targeting vector comprising:
(i) a 5′ homology arm comprising a nucleic acid sequence that is homologous to a genomic sequence upstream of an endogenous mouse low affinity FcγR α-chain locus,
(ii) a contiguous human nucleic acid sequence encoding at least two low affinity human FcγR α-chain genes, and
(iii) a 3′ homology arm comprising a nucleic acid sequence that is homologous to a genomic sequence downstream of an endogenous mouse low affinity FcγR α-chain locus.
17 . The targeting vector of claim 16 , wherein the at least two low affinity human FcγR α-chain genes are selected from the group consisting of a human FcγRIIA α-chain gene, a human FcγRIIB α-chain gene, a human FcγRIIC α-chain gene, a human FcγRIIIA α-chain gene and a human FcγRIIIB α-chain gene.
18 . The targeting vector of claim 16 , wherein the at least two low affinity human FcγR α-chain genes are a human FcγRIIA α-chain gene and a human FcγRIIIA α-chain gene.
19 . The targeting vector of claim 18 , wherein the human FcγRIIA α-chain gene encodes a FcγRIIA α-chain with a 131Arg polymorphism or a 131His polymorphism.
20 . The targeting vector of claim 18 , wherein the human FcγRIIIA α-chain gene encodes a FcγRIIA α-chain with a 158Val polymorphism or a 158Phe polymorphism.
21 . The targeting vector of claim 16 , wherein the at least two low affinity human FcγR α-chain genes comprise a human FcγRIIB α-chain gene, a human FcγRIIC α-chain gene, and a human FcγRIIIB α-chain gene.
22 . The method of claim 21 , wherein the human FcγRIIB α-chain gene encodes a FcγRIIB α-chain with a 232Ile polymorphism or a 232Thr polymorphism.
23 . The targeting vector of claim 16 , wherein 5′ homology arm is homologous to a genomic region that is 5′ to a mouse FcγRIIB gene in an endogenous mouse genome and the 3′ homology arm is homologous to a genomic region that is 3′ to a mouse FcγRIII in an endogenous mouse genome.
24 . The targeting vector of claim 16 , further comprising a selection cassette.
25 . The targeting vector of claim 24 , wherein the selection cassette is flanked by recombination sites that allow deletion of the selection cassette upon treatment with an appropriate recombinase.
26 . The targeting vector of claim 24 , wherein the selection cassette is upstream of (i) the nucleic acid sequence encoding the at least two low affinity human FcγR α-chain genes.
27 . The targeting vector of claim 18 , further comprising a human FcγRIIA promoter sequence operably linked to the human FcγRIIA α-chain gene.
28 . The targeting vector of claim 16 , wherein the targeting vector does not comprise a functional human FcγRIIA promoter sequence.
29 . An isolated mouse cell comprising the targeting vector of claim 16 .
30 . The isolated mouse cell of claim 29 , wherein the cell is a mouse embryonic stem cell.
31 . A method of modifying an isolated mouse ES cell, comprising introducing, into the isolated mouse ES cell, the targeting vector of claim 16 .
32 . The method of claim 31 , wherein the introducing comprises electroporating the mouse ES cell in the presence of the targeting vector.
33 . A targeting vector for deletion of endogenous mouse FcγRIIB, FcγRIV and FcγRIII genes, the targeting vector comprising:
(i) a 5′ homology arm comprising a nucleic acid sequence that is homologous to a genomic sequence that is 5′ to a mouse FcγRIIB gene in an endogenous mouse genome,
(ii) a selection cassette, and
(iii) a 3′ homology arm comprising a nucleic acid sequence that is homologous to a genomic sequence that is 3′ to a mouse FcγRIII in an endogenous mouse genome.
34 . The targeting vector of claim 33 , wherein the selection cassette is flanked by recombination sites that allow deletion of the selection cassette upon treatment with an appropriate recombinase.