Non-human animals having a humanized signal-regulatory protein gene
Genetically modified non-human animals and methods and compositions for making and using the same are provided, wherein the genetic modification comprises a humanization of an endogenous signal-regulatory protein gene, in particular a humanization of a SIRPα gene. Genetically modified mice are described, including mice that express a human or humanized SIRPα protein from an endogenous SIRPα locus.
1. A nucleic acid vector for humanization of a rodent SIRPα gene in a rodent cell, comprising:
a 5′ homology arm comprising a rodent genomic DNA fragment upstream of exon 2 of the rodent SIRPα gene,
a human genomic DNA fragment comprising exons 2, 3 and 4 of a human SIRPα gene, and
a 3′ homology arm comprising a rodent genomic DNA fragment downstream of exons 4 of the rodent SIRPα gene;
wherein integration of the nucleic acid vector into the genome of the rodent cell based on homologous recombination results in a replacement of exons 2, 3 and 4 of the rodent SIRPα gene at an endogenous rodent SIRPα locus with exons 2, 3 and 4 of the human SIRPα gene to form a humanized SIRPα gene, wherein said humanized SIRPα gene is operably linked to the rodent SIRPα promoter at said endogenous rodent SIRPα locus, and encodes a humanized SIRPα protein comprising an extracellular portion of the human SIRPα protein encoded by said human SIRPα gene and an intracellular portion of the rodent SIRPα protein encoded by said rodent SIRPα gene, and wherein the rodent is selected from a mouse or a rat.
2. The nucleic acid vector of claim 1 , wherein the rodent is a mouse.
3. The nucleic acid vector of claim 1 , wherein the rodent is a rat.
4. The nucleic acid vector of claim 1 , wherein said humanized SIRPα gene comprises exons 1, 5, 6, 7 and 8 of said rodent SIRPα gene.
5. The nucleic acid vector of claim 1 , wherein said human SIRPα protein comprises the amino acid sequence as set forth in SEQ ID NO: 4.
6. The nucleic acid vector of claim 1 , wherein the extracellular portion of said human SIRPα protein comprises amino acid residues 28-362 of said human SIRPα protein.
7. A method, comprising:
(a) introducing a nucleic acid vector into a rodent embryonic stem (ES) cell, wherein the vector comprises
a 5′ homology arm comprising a rodent genomic DNA fragment upstream of exon 2 of the rodent SIRPα gene in said rodent ES cell,
a human genomic DNA fragment comprising exons 2, 3 and 4 of a human SIRPα gene, and
a 3′ homology arm comprising a rodent genomic DNA fragment downstream of exons 4 of the rodent SIRPα gene in said rodent ES cell;
wherein the rodent is selected from a mouse or a rat; and
(b) obtaining a genetically modified rodent ES cell, whose genome comprises a replacement of exons 2, 3 and 4 of the rodent SIRPα gene at an endogenous rodent SIRPα locus with exons 2, 3 and 4 of the human SIRPα gene to form a humanized SIRPα gene, wherein said humanized SIRPα gene is operably linked to the rodent SIRPα promoter at said endogenous rodent SIRPα locus, and encodes a humanized SIRPα protein comprising an extracellular portion of the human SIRPα protein encoded by said human SIRPα gene and an intracellular portion of the rodent SIRPα protein encoded by said rodent SIRPα gene.
8. The method of claim 7 , wherein the rodent is a mouse.
9. The method of claim 7 , wherein the rodent is a rat.
10. The method of claim 7 , wherein said humanized SIRPα gene comprises exons 1, 5, 6, 7 and 8 of said rodent SIRPα gene.
11. The method of claim 7 , wherein said human SIRPα protein comprises the amino acid sequence as set forth in SEQ ID NO: 4.
12. The method of claim 7 , wherein the extracellular portion of said human SIRPα protein comprises amino acid residues 28-362 of said human SIRPα protein.