# US 2014/0154701 A1 · Humanized fc gamma r mice

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- Number: US 2014/0154701 A1
- Document ID: US20140154701A1
- Status: Published application
- Kind: A1
- Application number: 14/152,090
- Filed: 2014-01-10
- Published: 2014-06-05
- Earliest claimed: 2009-12-21
- Assignees: Regeneron Pharmaceuticals, Inc.
- Applicants: Regeneron Pharmaceuticals, Inc.
- Inventors: Lynn Macdonald; Naxin Tu; Cagan Gurer; Sean Stevens; Andrew J. Murphy
- Web page: https://patentgrep.com/patent/US20140154701A1

## CPC

- A61K 49/0008: {Screening agents using (non-human) animal models or transgenic animal models or chimeric hosts, e.g. Alzheimer disease animal model, transgenic model for heart failure}
- A01K 67/0276: Knock-out vertebrates
- A01K 67/0278: Knock-in vertebrates, e.g. humanised vertebrates
- C07K 14/70535: {Fc-receptors, e.g. CD16, CD32, CD64 (CD2314/705F)}
- G01N 33/5014: {for testing toxicity}
- A01K 2207/15: Humanized animals
- A01K 2217/072: maintaining or altering function, i.e. knock in
- A01K 2217/075: inducing loss of function, i.e. knock out
- A01K 2217/15: Animals comprising multiple alterations of the genome, by transgenesis or homologous recombination, e.g. obtained by cross-breeding
- A01K 2227/105: Murine
- A01K 2267/03: Animal model, e.g. for test or diseases
- A01K 2267/0387: Animal model for diseases of the immune system
- A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D)
- A01K: ANIMAL HUSBANDRY; AVICULTURE; APICULTURE; PISCICULTURE; FISHING; REARING OR BREEDING ANIMALS, NOT OTHERWISE PROVIDED FOR; NEW BREEDS OF ANIMALS
- C07K: PEPTIDES (peptides in foodstuffs A23; obtaining protein compositions for foodstuffs, working-up proteins for foodstuffs A23J; preparations for medicinal purposes A61K; peptides containing beta-lactam rings C07D; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, C07D; ergot alkaloids of the cyclic peptide type C07D519/02; macromolecular compounds having statistically distributed amino acid units in their molecules, i.e. when the preparation does not provide for a specific; but for a random sequence of the amino acid units, homopolyamides and block copolyamides derived from amino acids C08G69/00; macromolecular products derived from proteins C08H1/00; preparation of glue or gelatine C09H; single cell proteins, enzymes C12N; genetic engineering processes for obtaining peptides C12N15/00; compositions for measuring or testing processes involving enzymes C12Q; investigation or analysis of biological material G01N33/00)
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)

## Abstract

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.

## Claims

### Claim 1

A mouse comprising a genetic modification, wherein the genetic modification comprises a replacement of endogenous low affinity FcγR genes with at least two low affinity human FcγR genes placed at the endogenous mouse low affinity FcγR gene locus, and wherein the mouse comprises a functional FcR γ-chain.

### Claim 2 (depends on 1)

The mouse of claim 1, wherein the at least two low affinity human FcγR genes are selected from FcγRIIA, FcγRIIB, FcγRIIC, FcγRIIIA and FcγRIIIB.

### Claim 3 (depends on 1)

The mouse of claim 1, wherein the at least two low affinity human FcγR genes are FcγRIIA and FcγRIIIA.

### Claim 4 (depends on 3)

The mouse of claim 3, wherein the human FcγRIIIA is expressed on NK cells of the mouse.

### Claim 5 (depends on 1)

The mouse of claim 1, wherein the at least two low affinity human FcγR genes are FcγRIIB, FcγRIIC, and FcγRIIIB.

### Claim 6 (depends on 3)

The mouse of claim 3, wherein the FcγRIIA and FcγRIIIA genes comprise allelic variants or polymorphisms.

### Claim 7 (depends on 5)

The mouse of claim 5, wherein the mouse comprises human low affinity FcγR allelic variants, and the allelic variants are selected from the group consisting of (a) FcγRIIA allelic variant 131H, (b) FcγRIIIA allelic variant 158V, (c) FcγRIIB allelic variant 232I, (d) FcγRIIIB allelic variant characterized by a neutrophil antigen 2 (NA2) allele, and, (e) a combination thereof.

### Claim 8

A genetically modified mouse, wherein the genetic modification comprises a replacement of endogenous mouse genes encoding FcγRIIB, FcγRIII, and FcγRIV α-subunits with a gene encoding a human FcγRIIIA α-subunit, wherein the mouse expresses a human FcγRIIIA protein associated with an endogenous mouse FcR γ-subunit, wherein the human FcγRIIIA protein is expressed on the surface of a mouse NK cell.

### Claim 9 (depends on 8)

The genetically modified mouse of claim 8, wherein mouse NK cell is a circulating NK cell in the blood of the mouse, and the FcγRIIIA protein expressed on the surface of the mouse NK cell binds an immunoadhesin or an antibody that comprises a human Fc or a modified human Fc, wherein the immunoadhesin or antibody specifically binds a target cell in the mouse, and binding of the immunoadhesin or the antibody to the FcγRIIIA of the NK cell mediates NK cell killing of the target cell.

### Claim 10 (depends on 9)

The genetically modified mouse of claim 9, wherein the target cell is infected with a human pathogen, and the immunoadhesin or antibody specifically binds an epitope of the human pathogen.

### Claim 11 (depends on 9)

The genetically modified mouse of claim 9, wherein the target cell is a tumor cell, and the immunoadhesin or antibody specifically binds an epitope of the tumor cell.

### Claim 12

A method for measuring therapeutic-dependent cell killing, comprising:
(a) administering to a genetically modified mouse a therapeutic agent that specifically binds a target cell that is not an NK cell in the mouse, wherein the therapeutic agent comprises a human Fc;
(b) measuring a level of NK-mediated target cell killing in the mouse or in a tissue sample of the mouse; and,
(c) determining the amount of target cell killing that is mediated by the therapeutic agent, thereby measuring therapeutic-dependent cell killing;
wherein the genetic modification comprises a deletion of a gene encoding the α-subunit of mouse FcγRIIB, a deletion of a gene encoding the α-subunit of mouse FcγRIII, and a deletion of a gene encoding the α-subunit of mouse FcγRIV, and wherein the mouse comprises a gene encoding an α-subunit of a human FcγRIIIA at the endogenous mouse α-subunit locus and wherein the mouse expresses a functional FcR γ-chain subunit.

### Claim 13 (depends on 12)

The method of claim 12, wherein the mouse further comprises at the endogenous mouse α-subunit locus a gene encoding a human FcγR α-subunit selected from an FcγRIIA α-subunit, FcγRIIB α-subunit, an FcγRIIC α-subunit, an FcγRIIIB α-subunit, and a combination thereof.

### Claim 14 (depends on 12)

The method of claim 12, wherein the target cell is a human pathogen, and the therapeutic specifically binds an epitope of the human pathogen.

### Claim 15 (depends on 12)

The method of claim 12, wherein the target cell is a mouse cell infected by a human pathogen, and the therapeutic specifically binds an epitope of the human pathogen.

### Claim 16 (depends on 12)

The method of claim 12, wherein the target cell is a human cell infected by a human pathogen, and the therapeutic specifically binds an epitope of the human pathogen.

### Claim 17 (depends on 12)

The method of claim 12, wherein the target cell is a human tumor cell, and the therapeutic specifically binds an epitope of the human tumor cell.

### Claim 18 (depends on 12)

The method of claim 12, wherein the tissue sample is a blood sample.

### Claim 19 (depends on 12)

The method of claim 12, wherein the therapeutic is an antibody.

### Claim 20 (depends on 17)

The method of claim 17, wherein the antibody is a human antibody.