At the bottom of the study I linked above is the following statement:
“The authors thank the Regeneron Pharmaceuticals’ Velocigene team for generating human IL-6 knock-in mice“
Go to Regeneron’s website and read about the use of the VelociGene and Velocimmune technology. Hint: Mice are literally humanized with cells and tissues obtain from aborted children. The info is all there for you to see and speaks for itself.
Challenge accepted, FRacebooker.
VelociGene technologyRegeneron has created a more efficient platform for the discovery of antibody therapeutics through the use of VelociGene technology, a proprietary, high-throughput process using automated systems to make virtually any genetic modification in mouse Embryonic Stem (ES) cells. The speed and precision of VelociGene technology permits the direct exchange of large (100-200 kilobase) genomic DNA sequences in situ, allowing the manipulation of complex genomic loci in murine (mouse) ES cells.
Scientists at Regeneron recognised that antibodies are an active participant in the humoral response, which require efficient signalling through the B-cell receptor, accurate regulation by positive and negative coreceptors, and, perhaps most importantly, productive interactions with Fc receptors and similar constant region recognition elements. Therefore, use of human constant regions, as in the HuMab approaches, may yield less efficient humoral responses to some antigens. Furthermore, the use of YAC or human chromosomal fragments in murine cells may have the added risk of inaccurate gene regulation through human enhancers or locus control regions and instability in transmission.
The Regeneron solution to these issues was the direct and precise replacement of the unrearranged genomic DNA encoding in the variable regions of the mouse heavy and kappa light chain loci with the equivalent human genomic sequences (ed. note: Not human "parts", FRacebooker, but the human genomic code, which was fully sequenced in 2003).
Therefore, the resulting Ig loci encode antibodies possessing fully-human variable regions linked to murine constant regions utilising the genuine murine expression control mechanisms. This approach overcomes the issues presented by HuMab mouse platforms while taking advantage of the superiority of a natural humoral response for the production of antibody therapeutics."
Not only are VelociGene mice not human-adjunct-created, but their very creation resided on Regeneron's specific criticisms that human-adjunct-created HuMab mice had far too many drawbacks!
Instead VelociGene modifies mouse embryonic stem cells (the horror!) to achieve the desired result.