Making recombinant proteins in animals – different systems, different applications

Oviduct-specific expression of two therapeutic proteins in transgenic hens

“…The basic strategy used has been to target expression of a therapeutic protein to a protein secretory tissue, often the mammary gland, using the regulatory sequences of one of the native proteins synthesized in that tissue. The production of therapeutic proteins has now been demonstrated in transgenic mammals, including sheep, goats, cattle, rabbits (1,2), and chickens (3)(4)(5). The use of transgenic chickens as bioreactors to synthesize therapeutic proteins, as a component of egg yolk or white, may have several advantages over mammalian expression systems, including a shorter timescale for setup and ease of scaleup to a transgenic flock, lower costs associated with husbandry, the potential to produce proteins that are toxic to mammalian cells, beneficial glycosylation profile, and reduced immunogenicity of the purified product (reviewed in ref.…”

The contribution of farm animals to human health

“…These attractive perspectives led to the development of the 'gene pharming' concept, which has been advanced to the level of commercial application [5]. The most promising site for production of recombinant proteins is the mammary gland, but other body fluids including blood, urine and seminal fluid have also been explored [6]. The mammary gland is the preferred production site mainly because of the quantities of protein that can be produced and the ease of extraction or purification of the respective protein.…”

Spermatogonial Stem Cells and Animal Transgenesis

“…This last application is especially important for species in which embryonic stem cell lines have not been established and other transgenic techniques present limited efficiency. Transgenic animals have huge applications from basic science such as the creation of animal models for human diseases, like Parkinson´s (Crabtree & Zhang, 2011) to production of recombinant pharmaceutic proteins in the animal's fluid: blood, milk (Houdebine, 2000a,b andHoudebine, 2002), egg white (Zhu et al, 2005;van de Lavoir et al, 2006 andLillico et al, 2007) and seminal plasma (Dyck et al, 2003). Ever since the generation of the first transgenic animal, in 1980, through pronuclei microinjection in an embryo's pronuclei (Houdebine, 2009), this method has been used in other prolific species as rat, rabbit and pig (Houdebine, 2000a,b).…”