Antibody producing non-human mammals
Described are transgenic, non-human animals comprising a nucleic acid encoding an immunoglobulin light chain, whereby the immunoglobulin light chain is human, human-like, or humanized. The nucleic acid is provided with a means that renders it resistant to DNA rearrangements and/or somatic hypermutations. In one embodiment, the nucleic acid comprises an expression cassette for the expression of a desired molecule in cells during a certain stage of development in cells developing into mature B cells. Further provided is methods for producing an immunoglobulin from the transgenic, non-human animal.
1. A transgenic mouse whose genome comprises a transgene comprising a human immunoglobulin light chain germline IGκV1-39 gene segment joined to a human immunoglobulin light chain germline J gene segment, such that there is no mutation due to said joining, wherein the joined IGκV1-39/J gene segments encode a rearranged human immunoglobulin light chain variable region, wherein the transgene is inserted by site-specific integration in the murine Rosa26-locus or said transgene lacks a MoEκi enhancer or comprises a truncated 3′ kappa enhancer or combination of these, wherein said transgene is resistant to somatic hypermutation, and wherein the transgene comprises a murine light chain constant region gene segment or is operatively linked to a mouse light chain constant region gene segment,
wherein the transgenic mouse, in response to an antigen, produces antigen specific antibodies comprising the rearranged human light chain variable region and a murine light chain constant region, paired with a diversity of immunoglobulin heavy chains encoded by rearranged and somatically hypermutated heavy chain genes, and wherein the endogenous κ light chain locus of the transgenic mouse is functionally silenced.
2. The transgenic mouse of claim 1 , wherein the joined IGκV1-39/J gene segments encode a rearranged human immunoglobulin light chain variable region comprising the amino acid sequence of the Vκ1-39 region of SEQ ID NO:85.
3. The transgenic mouse of claim 1 , wherein the expression of the rearranged human immunoglobulin light chain variable region is under the control of a B cell specific promoter selected from the group consisting of CD19, CD20, μHC, VpreB1, VpreB2, VpreB3, λ5, Igα, Igβ, κLC, λLC and BSAP (Pax5).
4. The transgenic mouse of claim 1 , wherein the transgene comprises, in a 5′ to 3′ direction,
a promoter selected from the group consisting of CD19, CD20, μHC, VpreB1, VpreB2, VpreB3, λ5, Igα, Igβ, κLC, λLC and BSAP (Pax5),
a human or mouse leader, and
a nucleic acid encoding the rearranged human immunoglobulin light chain variable region.
5. The transgenic mouse of claim 1 , wherein the murine immunoglobulin light chain constant region is a rat immunoglobulin light chain constant region.