Transgenic transchromosomal rodents for making human antibodies

1. An isolated nucleic acid encoding the heavy and light chain variable region sequences isolated and amplified from cDNA generated from mRNA, wherein the mRNA is isolated and amplified from B lymphocytes comprising rearranged immunoglobulin sequences, wherein the rearranged immunoglobulin sequences are produced by a method comprising:

providing a transgenic mouse that comprises two human immunoglobulin loci, wherein one human immunoglobulin locus is a human heavy chain locus located on an autonomous transchromosome comprising a fragment of human chromosome 14 having a human chromosome 14 centromere, and the other human immunoglobulin locus is a human light chain locus transgene integrated into the mouse genome, and

obtaining the rearranged immunoglobulin sequences from the transgenic mouse.

2. An isolated nucleic acid encoding the heavy chain variable region sequence isolated and amplified from cDNA generated from mRNA, wherein the mRNA is isolated and amplified from B lymphocytes comprising rearranged immunoglobulin sequences, wherein the rearranged immunoglobulin sequences are produced by a method comprising:

providing a transgenic mouse that comprises two human immunoglobulin loci, wherein one human immunoglobulin locus is a human heavy chain locus located on an autonomous transchromosome comprising a fragment of human chromosome 14 having a human chromosome 14 centromere, and the other human immunoglobulin locus is a human light chain locus transgene integrated into the mouse genome, and

obtaining the rearranged immunoglobulin sequences from the transgenic mouse.

3. An isolated nucleic acid encoding the light chain variable region sequence isolated and amplified from cDNA generated from mRNA, wherein the mRNA is isolated and amplified from B lymphocytes comprising rearranged immunoglobulin sequences, wherein the rearranged immunoglobulin sequences are produced by a method comprising:

providing a transgenic mouse that comprises two human immunoglobulin loci, wherein one human immunoglobulin locus is a human heavy chain locus located on an autonomous transchromosome comprising a fragment of human chromosome 14 having a human chromosome 14 centromere, and the other human immunoglobulin locus is a human light chain locus transgene integrated into the mouse genome, and

obtaining the rearranged immunoglobulin sequences from the transgenic mouse.

4. A vector comprising the nucleic acid of claim 1 .

5. An expression vector comprising the nucleic acid of claim 1 in which the heavy and light chain variable regions sequences of the nucleic acid are operatively linked with a regulatory sequence that controls expression of the nucleic acid in a host cell.

6. A host cell comprising the nucleic acid of claim 1 , or progeny of the cell.

7. The host cell of claim 6 , which is a eukaryote.

8. A method of producing a human antibody display library, comprising:

introducing an immunogen into a transgenic mouse, wherein the transgenic mouse comprises two human immunoglobulin loci, wherein one human immunoglobulin locus is a human heavy chain locus located on an autonomous transchromosome comprising a fragment of human chromosome 14 having a human chromosome 14 centromere, and the other human immunoglobulin locus is a human light chain locus transgene integrated into the mouse genome;

isolating a population of nucleic acids encoding human antibody chains from lymphatic cells of the transgenic mouse; and

forming a library of display packages displaying the antibody chains, wherein a library member comprises a nucleic acid encoding an antibody chain displayed from the package.

9. The method of claim 8 , wherein the transgenic mouse lacks a detectable titer to the immunogen when the isolating is performed.

10. The method of claim 8 , wherein the immunogen is encoded by a nucleic acid.

11. The method of claim 10 , wherein the nucleic acid encodes a membrane bound receptor.