Recombinant Human Serum Albumin for Use in Cell Culture

DESCRIPTION (provided by applicant): Plasma-derived human serum albumin (pHSA) or bovine serum albumin are commonly added to cell culture media used in cell culture-based vaccine and therapeutic production, because it enhances cell growth and increases protein productivity. However, the use of pHSA carries the risk of transmission of viruses and emerging infectious pathogens, particularly for those for which no tests are available. Because millions of people are immunized annually with cell culture- based vaccines and millions more require cell culture-based therapeutics for the treatment of various disorders, regulatory agencies have called for a replacement of pHSA in vaccine and therapeutic production with recombinant HSA (rHSA). In Phase I feasibility study, we showed that rHSA from rice can not only be used to replace pHSA but also outperform pHSA by 51% in cell growth enhancement and by 50% in antibody production. In phase II, we will extend the studies in phase I to test the effect of rHSA on cell growth and productivity of hybridoma, CHO and Vero cells in larger scale cell culture with commercial media. We will also attempt to identify which factor(s) is (are) responsible for the superior performance of our rHSA preparation from rice. We will initiate a breeding program to improve the grain yield so to further reduce cost rHSA production. We anticipate that at the end of phase II studies, our project will have addressed the call by regulatory agencies for a safe alternative to pHSA in vaccine and therapeutic production by providing to the market rHSA with superior performance. Public Health Relevance: Safety concerns regarding human-to-human transmission of emerging infectious pathogens from the use of plasma-derived human serum albumin (pHSA) and blood products as an ingredient in cell culture media for cell-based vaccine and therapeutic production exist. Regulatory agencies have called for the replacement of pHSA with recombinant HSA. In response, an inexpensive source of recombinant HSA produced in rice would not only assure a safe alternative to pHSA, but would also allow cost- effective production of cell-based vaccine and therapeutics.