Genetically modified major histocompatibility complex animals
The invention provides genetically modified non-human animals that express chimeric human/non-human MHC I polypeptide and/or human or humanized β2 microglobulin polypeptide, as well as embryos, cells, and tissues comprising the same. Also provided are constructs for making said genetically modified animals and methods of making the same. Methods of using the genetically modified animals to study various aspects of human immune system are provided.
1. A mouse whose genome comprises
(i) at its endogenous H-2D locus a nucleotide sequence encoding a chimeric human/mouse HLA-B/H-2D polypeptide,
wherein the nucleotide sequence is in operable linkage with an endogenous mouse regulatory element and is operably linked to a MHC I polypeptide leader encoding sequence,
wherein the nucleotide sequence comprises from 5′ to 3′
(a) a first nucleic acid sequence that encodes the α1, α2 and α3 domains of the human HLA-B polypeptide, which first nucleic acid sequence replaces a sequence encoding the α1, α2 and α3 domains of the mouse H-2D polypeptide at the endogenous H-2D locus, and
(b) a second nucleic acid sequence that encodes the transmembrane and cytoplasmic domains of the mouse H-2D polypeptide, and
(ii) at its endogenous mouse β2 microglobulin locus a nucleotide sequence encoding a human or humanized β2 microglobulin polypeptide, wherein the nucleotide sequence is operably linked to the endogenous mouse β2 microglobulin regulatory elements, wherein the nucleotide sequence encoding the human or humanized β2 microglobulin polypeptide comprises from 5′ to 3′: exon 2, exon 3 and exon 4 of a human β2 microglobulin gene, wherein the nucleotide sequence encoding the human β2 microglobulin gene replaces the endogenous mouse nucleotide sequence encoding exon 2, exon 3 and exon 4
wherein the mouse expresses at the surface of nucleated cells the chimeric HLA-B/H-2D polypeptide that comprises the α1, α2 and α3 domains of the human HLA-B polypeptide and transmembrane and cytoplasmic domains of the mouse H-2K polypeptide and the human or humanized β2 microglobulin polypeptide.
2. The animal of claim 1 , wherein the animal does not express a functional endogenous mouse β2 microglobulin from its endogenous mouse β2 microglobulin locus.
3. The animal of claim 1 , wherein the nucleotide sequence encoding the human or humanized β2 microglobulin polypeptide comprises a nucleotide sequence set forth in exon 2 to exon 4 of a human β2 microglobulin gene.
4. The mouse of claim 1 , wherein the human HLA-B polypeptide is an HLA-B27 polypeptide.
5. The mouse of claim 4 , wherein the HLA-B27 polypeptide is a polypeptide encoded by HLA-B27 allele subtypes B*2701-2759.
6. The mouse of claim 1 , wherein the MHC I polypeptide leader encoding sequence is an endogenous mouse H-2D leader encoding sequence.
7. The mouse of claim 1 , wherein the endogenous H-2D locus is an H-2D1 locus.
8. The mouse of claim 1 , wherein the mouse is homozygous at the endogenous H 2D locus for the nucleotide sequence encoding the chimeric human/mouse HLA B/H-2D polypeptide and/or at the endogenous β2 microglobulin locus for the nucleotide sequence encoding the human or humanized β2 microglobulin polypeptide.