Genetically Modified Major Histocompatibility Complex Animals

Abstract

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 making, 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 also provided.

What is claimed is: 
     
         1 . A rat comprising
 (a) at a first endogenous major histocompatibility complex (MHC) II gene locus a first and second nucleotide sequence, each respectively encoding a first chimeric human/rat MHC II α polypeptide and a first chimeric human/rat MHC II β polypeptide, and each respectively expressed under regulatory control of endogenous MHC II α and β promoters at the first endogenous MHC II gene locus,
 wherein the first chimeric human/rat MHC II α polypeptide comprises α1 and α2 extracellular domains of an α polypeptide of a first human MHC II protein and transmembrane and cytoplasmic domains of an α polypeptide of a first endogenous rat MHC II protein, 
 wherein the first chimeric human/rat MHC II β polypeptide comprises β1 and β2 extracellular domains of a β polypeptide of the first human MHC II protein and transmembrane and cytoplasmic domains of a β polypeptide of the first endogenous rat MHC II protein, and 
   (b) at a second endogenous MHC II locus a third and fourth nucleotide sequence, each respectively encoding a second chimeric human/rat MHC II α polypeptide and a second chimeric human/rat MHC II β polypeptide, and each respectively expressed under regulatory control of endogenous MHC II α and β promoters at the second endogenous MHC II gene locus,
 wherein the second chimeric human/rat MHC II α polypeptide comprises α1 and α2 extracellular domains of an α polypeptide of a second human MHC II protein and transmembrane and cytoplasmic domains of an α polypeptide of a second endogenous rat MHC II protein, 
 wherein the second chimeric human/rat MHC II β polypeptide comprises β1 and β2 extracellular domains of a β polypeptide of the second human MHC II protein and transmembrane and cytoplasmic domains of a β polypeptide of the second endogenous rat MHC II protein, and 
   wherein the rat expresses the first chimeric human/rat MHC II α and β polypeptides as a first chimeric human/rat MHC II complex and the second chimeric human/rat MHC II α and β polypeptides as a second chimeric human/rat MHC II complex on the surface of an antigen presenting cell.   
     
     
         2 . The rat of  claim 1 , wherein the first nucleotide sequence is expressed under regulatory control of endogenous rat MHC II α promoter and regulatory elements at the first endogenous MHC II locus,
 wherein the second nucleotide sequence is expressed under regulatory control of endogenous rat MHC II β promoter and regulatory elements at the first endogenous MHC II locus,
 wherein the third nucleotide sequence is expressed under regulatory control of endogenous rat MHC II α promoter and regulatory elements at the second MHC II locus, and 
 wherein the fourth nucleotide sequence is expressed under regulatory control of endogenous rat MHC II β promoter and regulatory elements at the second endogenous MHC II locus. 
 
 
     
     
         3 . The rat of  claim 1 , wherein the first and/or the second human MHC II protein is a human leukocyte antigen (HLA) class II protein selected from the group consisting of HLA-DR, HLA-DQ, and HLA-DP. 
     
     
         4 . The rat of  claim 3 , wherein the first human MHC II protein is a human HLA-DR protein. 
     
     
         5 . The rat of  claim 4 , wherein the first human MHC II protein is a human HLA-DR2 or a human HLA-DR4 protein. 
     
     
         6 . The rat of  claim 4 , wherein the second human MHC protein is a human HLA-DQ protein. 
     
     
         7 . The rat of  claim 6 , wherein the second human MHC protein is a human HLA-DQ2 or a human HLA-DQ8 protein. 
     
     
         8 . The rat of  claim 1 , wherein the rat does not express, on the surface of the antigen presenting cell, endogenous MHC II polypeptides from endogenous rat MHC II loci. 
     
     
         9 . The rat of  claim 1 , wherein the antigen presenting cell is a dendritic cell, macrophage, or CD19 +  B cell. 
     
     
         10 . The rat of  claim 1 , wherein the first and/or the second human MHC II protein is a human leukocyte antigen (HLA) class II protein selected from the group consisting of HLA-DR4, HLA-DR2, HLA-DQ2, and HLA-DQ8. 
     
     
         11 . The rat of  claim 1 , wherein the first and second human MHC II proteins are different. 
     
     
         12 . A non-human animal comprising first and second functional chimeric human/non-human MHC II complexes,
 wherein a human portion of each first and second MHC II complex comprises a human MHC II extracellular domain, and wherein a non-human portion of each first and second MHC II complex comprises a non-human MHC II transmembrane and/or cytoplasmic domain.   
     
     
         13 . The non-human animal of  claim 12 , wherein the animal is a rodent. 
     
     
         14 . The non-human animal of  claim 13 , wherein the rodent is a rat or a mouse. 
     
     
         15 . The non-human animal of  claim 14 , wherein either or both the first and second functional chimeric MHC II complex is selected from HLA-DR4/H-2E, HLA-DR2/H-2E, HLA-DQ2/H-2A, and HLA-DQ8/H-2A. 
     
     
         16 . A chimeric MHC II locus comprising:
 (a) a first and second nucleotide sequence, each respectively encoding a first functional chimeric human/non-human MHC II α polypeptide and a first functional chimeric human/non-human MHC II β polypeptide, wherein the first functional chimeric human/non-human MHC II α polypeptide comprises α1 and α2 extracellular domains of an α polypeptide of a first human MHC II protein and transmembrane and cytoplasmic domains of an α polypeptide of a first endogenous non-human MHC II protein, and wherein the first functional chimeric human/non-human MHC II β polypeptide comprises β1 and β2 extracellular domains of a β polypeptide of the first human MHC II protein and transmembrane and cytoplasmic domains of a β polypeptide of the first endogenous non-human MHC II protein, wherein the first and second nucleotide sequences together encode a first functional chimeric human/non-human MHC II complex, and   a third and fourth nucleotide sequence, each respectively encoding a second functional chimeric human/non-human MHC II α polypeptide and a second functional chimeric human/non-human MHC II β polypeptide, wherein the second functional chimeric human/non-human MHC II α polypeptide comprises α1 and α2 extracellular domains of an α polypeptide of a second human MHC II protein and transmembrane and cytoplasmic domains of an a polypeptide of a second endogenous non-human MHC II protein, and wherein the second functional chimeric human/non-human MHC II β polypeptide comprises β1 and β2 extracellular domains of a β polypeptide of the second human MHC II protein and transmembrane and cytoplasmic domains of a β polypeptide of the second endogenous non-human MHC II protein, wherein the third and fourth nucleotide sequences together encode a second functional chimeric human/non-human MHC II complex.   
     
     
         17 . The locus of  claim 16 , wherein the MHC II locus is located at an endogenous MHC II position in a genome of a non-human animal. 
     
     
         18 . The locus of  claim 16 , wherein the first and second human MHC II proteins are each independently selected from the group consisting of HLA-DR2, HLA-DR4, HLA-DQ2, and HLA-DQ8. 
     
     
         19 . The locus of  claim 16 , wherein the non-human animal is a rat or a mouse. 
     
     
         20 . The locus of  claim 20 , wherein the first and second non-human MHC II proteins are each a mouse MHC II protein independently selected from the group consisting of H-2A and H-2E.