An essential part of the Lab activities is the production of high-quality unique biologicals that are not available from commercial sources. During the last year the Unit performed around 50 processes, which include propagation of bacteria, yeast, insect cells, and mammalian cells (in volumes ranging from 2 to 100 liters), and executed initial recovery and purification of biomolecules. The following are examples of processes performed: growth of bacteria such as Escherichia coli, nonpathogenic Bacillus anthracis, and various recombinant yeast strains such as Pichia pastoris. In addition, mammalian cells such as CHO, Hela, PG13 and HEK 293, insect cell such as Sf 9 and Hi five, for transient expression of recombinant proteins were propagated. The various products were needed for several collaborative research projects such as expression of P-glycoprotein (membrane protein transporter) from Pichia pastoris (NCI), peptidoglycan from Bacillus anthraces (NIH clinical center) polysaccharides from E. coli (FDA) and specific antibodies from HEK 293 cells (VRC). Several large-scale growth of Pichia pastoris for production of potential malaria vaccine were performed. The lab continues its project together with the surgery branch of the National Cancer Institute for improving the current method to produce gammaretroviral vectors needed for adoptive T cell therapy. The existing procedure is based on production from adherent packaging cells growing on stationary support which is a rate limiting step for obtaining the proper vector. The modified process is based on growing the adherent cells on microcarriers in a stirred tank bioreactor. Using this methodology, we could produce infective particles in higher yield. The process was optimized and perfusion system which allow us to increase the cell number and the production yield was incorporated. We also continue to work on developing and alternative approach for the production which is based on lentiviral vector from cells growing in suspension.
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