Non-human mammals for the production of chimeric antibodies
The invention provides knock-in non-human cells and mammals having a genome encoding chimeric antibodies and methods of producing knock-in cells and mammals. Certain aspects of the invention include chimeric antibodies, humanized antibodies, pharmaceutical compositions and kits. Certain aspects of the invention also relate to diagnostic and treatment methods using the antibodies of the invention.
1. A non-human mammalian cell whose genome comprises an immunoglobulin (Ig) heavy chain locus comprising a transgene comprising a portion of a syngeneic Ig heavy chain locus, said portion comprising all or part of constant region genes encoding a chimeric Ig heavy chain, the transgene comprising a DNA fragment comprising in operable linkage from 5′ to 3′ a DNA sequence of a human variable heavy (VH) segment gene operably linked to a constant region gene comprising a human CH1, human C upper hinge , human C middle hinge , syngeneic mammalian non-human CH2 and syngeneic mammalian non-human CH3 exons, wherein the human CH1 exon is selected from the group consisting of a human mu constant region (Cμ), a human delta constant region (Cδ), a human gamma-1 constant region (Cγ1), a human gamma-2 constant region (Cγ2) and a human gamma-4 constant region (Cγ4), wherein the transgene comprising said human VH segment gene and said syngeneic Ig heavy chain locus replaces all or a portion of the endogenous Ig heavy chain locus, thereby said non-human mammalian cell comprises a genome encoding the chimeric Ig heavy chain.
2. A method of producing the non-human mammalian cell of claim 1 , comprising the steps of:
producing one or more recombination vectors comprising the desired Ig transgene to be introduced into the endogenous Ig heavy chain locus, the transgene comprising a portion of a syngeneic Ig heavy chain locus, said portion comprising all or part of constant region genes encoding a chimeric Ig heavy chain, the transgene comprising a DNA fragment comprising in operable linkage from 5′ to 3′ a DNA sequence of a human variable heavy (VH) segment gene operably linked to a constant region gene comprising a human CH1, human C upper hinge , human C middle hinge , syngeneic mammalian non-human CH2 and syngeneic mammalian non-human CH3 exons, wherein the human CH1 exon is selected from the group consisting of a human Cμ, a human Cδ, a human Cγ1, a human Cγ2 and a human Cγ4, and
introducing said one or more recombination vectors into the non-human mammalian cell and integrating, in operable linkage, said transgene into the genome of the non-human mammalian cell, wherein the transgene comprising said human VH segment gene and said syngeneic Ig heavy chain locus replaces all or a portion of the endogenous Ig heavy chain locus, thereby said non-human mammalian cell comprising a genome encoding the chimeric Ig heavy chain.
3. The cell according to claim 1 , wherein the transgene further comprises a diversity heavy (DH) segment gene 3′ of the human VH segment gene and 5′ of the human CH1 segment gene, wherein the DH segment gene is selected from the group consisting of human, non-human primate, rabbit, sheep, rat, hamster, and mouse.
4. The cell according to claim 3 , wherein the DH segment gene is human.
5. The non-human mammalian cell according to claim 1 , wherein the human upper and middle hinge exons are IgG4 sequences.
6. The non-human mammalian cell according to claim 1 , wherein the chimeric Ig heavy chain binds an endogenous Fc receptor.
7. The non-human mammalian cell according to claim 1 , wherein the cell is an embryonic stem cell.
8. The non-human mammalian cell according to claim 1 , wherein the cell is a mouse cell.
9. The non-human mammalian cell according to claim 1 , wherein the transgene further comprises a human joining heavy (JH) segment gene 3′ of the human VH segment gene and 5′ of the human CH1 segment gene.
10. A non-human mammalian B cell whose genome comprises an immunoglobulin (Ig) heavy chain locus comprising a transgene encoding a chimeric Ig heavy chain, the transgene comprising a portion of a syngeneic Ig heavy chain locus, said portion comprising all or part of constant region genes encoding a chimeric Ig heavy chain, the transgene comprising a DNA fragment comprising in operable linkage from 5′ to 3′ a DNA sequence of a human variable heavy (VH) segment gene operably linked to a constant region gene comprising a human CH1, human C upper hinge , syngeneic mammalian non-human CH2 and syngeneic mammalian non-human CH3 exons, wherein the human CH1 exon is selected from the group consisting of a human Cμ, a human Cδ, a human Cγ1, a human Cγ2 and a human Cγ4, wherein the transgene comprising said human VH segment gene and said syngeneic Ig heavy chain locus replaces all or a portion of the endogenous Ig heavy chain locus, thereby said non-human B cell comprising a genome encoding the chimeric Ig heavy chain.
11. A non-human mammalian hybridoma cell whose genome comprises an immunoglobulin (Ig) heavy chain locus comprising a transgene encoding a chimeric Ig heavy chain, the transgene comprising a portion of a syngeneic Ig heavy chain locus, said portion comprising all or part of constant region genes, the transgene comprising a DNA fragment comprising in operable linkage from 5′ to 3′ a DNA sequence of a human variable heavy (VH) segment gene operably linked to a constant region gene comprising a human CH1, human C upper hinge , syngeneic mammalian non-human CH2 and syngeneic mammalian non-human CH3 exons, wherein the human CH1 exon is selected from the group consisting of a human Cμ, a human Cδ, a human Cγ1, a human Cγ2 and a human Cγ4, wherein the transgene comprising said human VH segment gene and said syngeneic Ig heavy chain locus replaces all or a portion of the endogenous Ig heavy chain locus, thereby said non-human hybridoma cell comprising a genome encoding the chimeric Ig heavy chain.