Tag: <span>BEVS</span>

Baculoviruses are large rod-shaped DNA-viruses which specifically infect only arthropods, mostly lepidopteran species. Among the over 600 known species, Autographa californica multiple nucleopolyhedrovirus (AcMNPV) is the most characterized and widely used. The baculovirus genome is poorly transcribed and does not replicate in non-target cells. Thus, baculoviruses are harmless for vertebrates even though they can be found everywhere and we eat them daily on our vegetables. Baculoviruses have been applied in biotechnology for almost a century now, first as biopesticides (since the 1920s), then for recombinant protein production (since the early 1980s), and most recently for gene delivery into vertebrate cells (since the mid-1990s)…

Baculovirus Expression Technology

ImmBio’s lead development candidate is an influenza vaccine based on the ImmunoBody® platform technology. An ImmunoBody is a fusion of a selected immuno-dominant antigen with a cell-binding domain — the Fc fragment of human IgG1. The use of recombinant Fc fusion proteins is well documented where it can help solubilize hydrophobic proteins, provide a handle for easy detection and purification, as well as improve half-life…

Baculovirus Expression Technology Biologics Production

The biologics market, although difficult to estimate, is currently thought to be in excess of $20 billion. In recent years, the growth in the novel therapeutics market has continued to exceed all but the most optimistic of expectations. The number of products in early stage trials may already be over 1,000, with an estimated 40 or so additional products in the process of finally being released to the market. The biologics market is led by relatively few “blockbuster” drugs, but the breadth of novel products continues to expand. This has resulted in exciting times for clinicians but has resulted in concern related to the bottleneck of production capacities for these drugs, as well as the pressure from healthcare agencies to reduce the cost of goods…

Baculovirus Expression Technology Biologics Production

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…

Baculovirus Expression Technology Biologics Production

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….

Baculovirus Expression Technology

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…

Baculovirus Expression Technology

Recombinant protein expression using the Baculovirus Expression Vector System (BEVS) is a powerful tool for the production of therapeutics, diagnostics, and reagents. To maximize efficiency of protein production, and thereby reduce costs, it is important to optimize the production parameters. A crucial step in optimization is determining the best multiplicity of infection (MOI) for the system in use. Factors that can affect the MOI include the recombinant baculovirus itself as well as cell line type and media composition. Typically the titer of a viral stock is determined in a standard manner, and then that titer is applied to each and every parameter tested; for instance, titering the virus on a Spodoptera cell line in a serum-containing media, and then using those data to determine the MOI used to infect Trichoplusia cells in a serum-free media formulation. The results may suggest that either the Trichoplusia cell line or the media formulation is inadequate for protein expression when, in fact, the MOI was incorrect for that particular combination…

Baculovirus Expression Technology Biologics Production

Variation of viral titre and recombinant product yields reported for the baculovirus expression vector system have been attributed to many specific infection variables. These include multiplicity of infection (MOI) and cell density at time of infection and time of harvest, as well as virus bank quality and efficiency. The MOI is defined as the number of plaque forming units (pfu) per cell that are added at the time of infection. Virus titre (pfu/ml) is determined by the plaque assay method. The MOI parameter is easily manipulated and may be important in optimising recombinant protein yields. Other sources of variation during both cell growth and viral infection phases may be responsible for the range of reported yields. Past studies in our laboratory compared the behaviour of cells infected with high and low MOI values, specifically regarding nutrient limitation and deprivation. In addition to these aspects, the quality of the virus bank may be an important factor which influences heterologous protein yields in the insect cell baculovirus system. Thus, production yields may be correlated to virus efficiency…

Baculovirus Expression Technology Biologics Production

In general, the industry has gone through another of its realignment periods, where much was learned, but a lot of restructuring and refocusing took place. Driven by the need to keep the doors open, small to medium sized firms had to do some severe belt tightening, or completely redefine themselves as to technologies, products, and personnel. Many of the larger firms reevaluated their product pipelines, and then made the changes they felt were necessary to assure future revenues, or to make themselves attractive merger partners. Numerous large mergers took place with some that were the largest the biopharmaceutical industry has ever seen. In addition, several medium-sized companies merged, or otherwise found strategic alliances that energized their product pipelines, or simply provided the cash they needed to keep going. Antibody products did very well with a number of blockbusters receiving license approval in 2003…

Biologics Production

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…

Baculovirus Expression Technology Research