TRANSGENIC APPROACHES FOR MODIFYING THE MAMMARY-GLAND TO PRODUCE THERAPEUTIC PROTEINS

Bioengineering of the mammary gland to produce proteins of therapeutic and industrial value is the result of extensive investigation of the physiology of the mammary gland and the ability to generate transgenic animals. Targeting the expression of heterologous proteins to mammary tissue requires a thorough understanding of the biochemical events th at coordinate growth and differentiation of the mammary gland and of t he hormonal and developmental regulation of expression of milk protein genes. The characterization of mammary-specific promoter regions in m ilk protein genes and knowledge of the mechanisms that confer integrat ion site-independent expression of transgenes have significantly contr ibuted to modifying the mammary gland to produce heterologous proteins of therapeutic interest. The generation of large transgenic farm anim als provides the opportunity for large-scale production of proteins in milk that have a therapeutic value but art naturally present at low c oncentrations in biological fluids. Transgenic mammary epithelial cell s offer a versatile research model in biomedical, environmental health , and neonatal toxicology research.