An Expression System for Protein Production in Eggs

DESCRIPTION (provided by applicant): The recent and impending approval of monoclonal antibodies for therapeutic application challenges the capacity of conventional cell culture-based production systems to deliver adequate amount of these proteins. Origen Therapeutics' embryonic stem cell-mediated transgenesis technology offers an alternative production system. The protein can be specifically expressed in the oviduct and deposited into egg white. Large quantities of protein can be easily purified from egg white in a timely fashion. The aim of this research is to develop an oviduct-specific expression system for the ultimate goal of producing pharmaceutical proteins including monoclonal antibodies in eggs of transgenic chickens using Origen Theapeutics' technology. Specifically, monoclonal antibody expression vectors with regulatory sequences of the ovalbumin gene will be introduced into chicken ES cells for making high-grade chimeras and transgenic chickens that deposit monoclonal antibodies in egg white. The expression of the transgene will be determined in terms of tissue specificity and the levels of protein deposited in eggs. Methods for purification of monoclonal antibodies from eggs will be developed. The purified proteins will be subjected to detailed analysis to characterize posttranslational modification and biological activity. The end point of this research is a truly tissue-specific and yet high yield expression system that facilitates production of new pharmaceutical proteins. The system is scalable, rapid and will produce proteins with minimum expense.