Genetically modified major histocompatibility complex mice
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 at an endogenous H-2K locus a nucleotide sequence encoding a chimeric human/mouse HLA-A/H-2K polypeptide, wherein the nucleotide sequence is in operable linkage with an endogenous mouse regulatory element and is operably linked to a MHC class I leader encoding sequence,
wherein the nucleotide sequence comprises from 5′ to 3′
(i) a first nucleic acid sequence that encodes the α1, α2 and α3 domains of the human HLA-A polypeptide, which first nucleic acid sequence replaces a sequence encoding the α1, α2, and α3 domains of the mouse H-2K polypeptide at the mouse H-2K locus and
(ii) a second nucleic acid sequence that encodes the transmembrane and cytoplasmic domains of the mouse H-2K polypeptide,
wherein the mouse expresses, on the surface of nucleated cells, from the endogenous H-2K locus the chimeric human/mouse HLA-A/H-2K polypeptide that comprises the α1, α2 and α3 domains of the human HLA-A polypeptide and the transmembrane and cytoplasmic domains of the mouse H-2K polypeptide.
2. The mouse of claim 1 , wherein the MHC class I leader encoding sequence encodes a human leader peptide of an HLA-A protein.
3. The mouse of claim 1 , wherein the human HLA-A polypeptide is an HLA-A2 polypeptide and wherein the mouse expresses a chimeric HLA-A2/H-2K polypeptide.
4. The mouse of claim 3 , wherein the HLA-A2 polypeptide is an HLA-A2.1 polypeptide.
5. The mouse of claim 3 , wherein the mouse H-2K locus is an H-2Kb locus.
6. A method of modifying an endogenous H-2K locus of a mouse such that it expresses a chimeric human/mouse HLA-A/H-2K polypeptide comprising replacing at the endogenous H-2K locus a nucleotide sequence encoding the α1, α2 and α3 domains of the mouse H-2K polypeptide with a first nucleotide sequence encoding the α1, α2 and α3 domains of the human HLA-A polypeptide such that the first nucleotide sequence is operably linked in 5′ to 3′ direction with a second nucleotide sequence that encodes the endogenous transmembrane and cytoplasmic domains of the mouse H-2K polypeptide to form a nucleic acid sequence that encodes the chimeric human/mouse HLA-A/H-2K polypeptide, and wherein the nucleic acid sequence that encodes the chimeric human/mouse MHC I polypeptide is operably linked to an endogenous mouse regulatory element and is operably linked to an MHC class I polypeptide leader encoding sequence, wherein the mouse expresses, on the surface of nucleated cells, from the endogenous H-2K locus the chimeric human/mouse HLA-A/H-2K polypeptide that comprises the α1, α2 and α3 domains of the HLA-A polypeptide and the transmembrane and cytoplasmic domains of the mouse H-2K polypeptide.
7. The method of claim 6 , wherein the replacement is made in a single ES cell, and the single ES cell is introduced into a mouse embryo to make a mouse.