The developing biotechnology community may offer solutions and hope for recent world events that have focused attention on the vulnerability of the world’s population. Concerns about new pandemics have been raised by the emergence of new influenza strains and the re-emergence of older and even more highly virulent strains. In addition, there are fears that bioterrorism could involve agents such as anthrax or smallpox, and these threats become even more of a concern when you consider the increased mobility of such organisms via today’s commercial aviation. The ability of the biomedical community to respond rapidly to these shifting threats is more important than ever…
Category: <span>Baculovirus Expression Technology</span>
The baculovirus expression vector system, which is based on infecting insect cells with recombinant Autographa californica nuclear polyhedrosis virus (AcNPV), is one of the most commonly used eukaryotic expression systems aimed at producing functionally active mammalian proteins. It offers advantages such as high-level protein expression and post-translational processing capabilities that are extremely important to the biological activity of certain proteins. This system utilizes a strong promoter of the very late gene, polyhedrin, to drive heterologous protein overexpression. Nevertheless, in order to generate milligram amounts of recombinant proteins, cell culture often needs to be scaled up to as much as 25 liters….
The Baculovirus Expression Vector System (BEVS) is widely used for the production of a broad variety of heterologous proteins that are often secreted into the culture medium as soluble, biologically active, properly glycosylated, and correctly folded. Downstream purification of a secreted protein is considerably easier due to the absence of many contaminating cellular proteins and nucleic acids in the culture supernatant. The BEVS system has also successfully been used for the production of virus-like particles (VLPs) for a broad variety of proteins derived from many different viruses…
G protein-coupled receptors (GPCRs) comprise a “superfamily” of cell surface receptors that play a prominent role in cell signalling and are classified into more than 100 subfamilies according to sequence, ligand structure, and receptor function. They are cell surface receptor proteins with seven transmembrane domains which transduce extracellular signals to the interior of cells through heterotrimeric G proteins. GPCRs’ exposure at the exterior cell surface and strong role in cell regulation has provided a rich target family for small compound therapeutics. Of the estimated 35,000 genes in the human genome, approximately 750 encode for GPCRs; half likely encoding sensory receptors, the remaining half representing potential drug targets. Only about 30 of these potential targets are currently modulated by existing pharmaceuticals with approximately 400 remaining potential pharmaceutical targets for validation…
The Sf-9 insect cell/baculovirus expression system is one of the most commonly used protein expression systems. It is the preferred system for generating large amounts of protein in a short period of time, and it has been successfully used to express several hundreds of different proteins. A representative list of the different proteins made in our laboratory over the past decade with the Sf-9 insect cell/BEVS system is given in Table 1. These proteins are often used in drug screening studies and structure function analysis. Proteins intended for therapeutic purposes are not normally produced using this technology, although a few examples do exist. There is also an unexplored potential for the cells to be used for the production of recombinant viral vectors. Recent reports demonstrating the ability of baculoviruses to express proteins in mammalian cells, with mammalian promoters, indicate that BEVS technology might soon have a major role to play in the field of gene delivery…
The baculovirus-insect cell system consists of a recombinant baculovirus vector and its host, which may be a lepidopteran insect larvae or an established lepidopteran insect cell line. Hundreds of different recombinant proteins have been produced using the baculovirus-insect cell system, facilitating biomedical research on protein structure, function, and the roles of various proteins in disease. In addition, many biotechnology companies are using this system to produce recombinant proteins for potential clinical use as vaccines, therapeutics, or diagnostic reagents…
The insect cell/baculovirus expression system typically results in more rapid expression and higher concentrations of recombinant proteins than what can be achieved with other animal cell culture systems. The lack of complex glycosylation in the proteins produced by this system, however, limits its use in the commercial-scale production of therapeutics. Complex glycosylation is required in many cases for adequate protein activity and pharmokinetic characteristics. In contrast to the protein’s primary structure, which is encoded by the genetic material and is constant regardless of the host utilized, the extent of glycosylation is determined by the host, and by the protein itself. Even cells from different tissues of the same organism provide different glycosylation profiles. In addition, culture conditions and the cellular metabolic state can also influence protein glycosylation…