Avian Bioreactor Systems: A Review

Animal bioreactors are genetically modified animal systems that have the potential to reduce production cost, and improve production efficiency, of pharmaceutically relevant recombinant proteins. Several species including goats, cattle, rabbits, and avians have been genetically modified to secrete target proteins into milk, egg whites, blood, or other bodily fluids. There are several advantages associated with the use of avians as bioreactor systems. Avians have a short generation time, leading to the quick establishment of a transgenic line and high egg production. Transgenic avian systems allow for appropriate post-translational modification, as opposed to prokaryotic cell culture bioreactors, and have higher productivity than mammalian cell culture systems. Furthermore, recombinant proteins can be incorporated into egg whites and easily collected from the sterile environment of the egg. Magnum-specific expression of target genes has been achieved by use of the ovalbumin promoter, leading to a localization of the target protein into the avian egg. In this review, we discuss the current advancements, future potential, and limitations of avian bioreactor systems.