Origen Therapeutics today announced the first published scientific report of fully functional, human sequence monoclonal antibodies (mAbs) produced in chickens. The antibodies were expressed solely in the chicken oviduct and deposited into egg white in concentrations of 1-3 milligrams per egg. Moreover, antibodies produced in this manner demonstrated 10-100 fold greater cell-killing ability (ADCC) compared to therapeutic antibodies produced by conventional cell culture methods.
The new report was published in the September issue of Nature Biotechnology by researchers from Origen Therapeutics and their collaborators at Medarex, Texas A&M University and the University of California, Los Angeles. A research brief commenting on the potential impact of this development for the production of human therapeutic proteins was also published in the September issue of Nature Medicine.
"This work demonstrates the potential for producing therapeutic proteins with enhanced properties in the eggs of chickens as an alternative to established mammalian cell culture systems," said Robert J. Etches, Ph.D., D. Sc., Origen Therapeutics vice president, research. "Antibodies produced by this method had very similar physical and biological characteristics to those produced in CHO cells, including nearly identical binding curves, similar affinities, and an equal ability to be internalized by antigen on prostate cancer cells. At the same time, chicken-produced antibodies lacked the sugar residue, fucose, which greatly increases their cell-killing activity compared to CHO-produced antibodies."
To create the antibody-producing chickens, the researchers first inserted into chicken embryonic stem cells the genes encoding the antibody and the regulatory sequences restricting its deposition to egg white. The stem cells were then introduced into
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Source:emm4@pacbell.net