Genetically modified major histocompatibility complex mice
The invention provides genetically modified non-human animals that express a humanized MHC II protein (humanized MHC II α and β polypeptides), as well as embryos, cells, and tissues comprising the humanized MHC II protein. Also provided are constructs for and methods of making the genetically modified non-human animals. Methods of using the genetically modified non-human animals to study various aspects of the human immune system are provided.
1. A mouse comprising at an endogenous Major Histocompatibility Complex II (MHC II) α gene locus a nucleotide sequence encoding a chimeric human/mouse MHC II α polypeptide that comprises a human portion and a mouse portion,
wherein the nucleotide sequence is expressed under regulatory control of an endogenous mouse MHC II α promoter,
wherein the human portion of the chimeric MHC II α polypeptide comprises a human MHC II α2 domain,
wherein the mouse portion comprises transmembrane and cytoplasmic domains of a mouse MHC II α polypeptide, and
wherein the mouse expresses the chimeric human/mouse MHC II α polypeptide on a surface of an antigen presenting cell of the mouse.
2. The mouse of claim 1 , wherein the human portion of the chimeric MHC II α polypeptide further comprises a human MHC II α1 domain.
3. The mouse of claim 1 , wherein the nucleotide sequence is expressed under regulatory control of the endogenous mouse MHC II α promoter and endogenous regulatory elements.
4. The mouse of claim 1 , wherein the human portion of the chimeric human/mouse MHC II α polypeptide is encoded by a human leukocyte antigen (HLA) class II gene selected from the group consisting of any α chain gene of HLA-DR, HLA-DQ, and HLA-DP.
5. The mouse of claim 4 , wherein the human portion of the chimeric human/mouse MHC II α polypeptide is encoded by a human HLA-DR4 α gene.
6. A method of making the mouse of claim 1 , comprising modifying an endogenous MHC II α locus by replacing at the endogenous mouse MHC II α locus a nucleotide sequence encoding a mouse MHC II α2 domain with a nucleotide sequence encoding a human MHC II α2 domain,
wherein the modified MHC II α locus encodes, under regulatory control of an endogenous mouse MHC II α promoter, a chimeric MHC II α polypeptide that comprises a human portion and a mouse portion,
wherein the human portion of the chimeric MHC II α polypeptide comprises a human MHC II α2 domain, and
wherein the mouse portion comprises transmembrane and cytoplasmic domains of a mouse MHC II α polypeptide.
7. The method of claim 6 , wherein the human portion of the chimeric MHC II α polypeptide is encoded by a human HLA class II gene selected from the group consisting of any α chain gene of HLA-DR, HLA-DQ, and HLA-DP.
8. The method of claim 6 , wherein the mouse portion of the chimeric MHC II α polypeptide is encoded by a mouse H-2E α gene, and the human portion of the chimeric MHC II complex is encoded by a human HLA-DR4 α gene.
9. 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.
10. The method of claim 6 , further comprising replacing at the endogenous mouse MHC II α locus a nucleotide sequence encoding a mouse MHC II α1 domain with a nucleotide sequence encoding a human MHC II α1 domain.