August 31st, 2010 - Keele, UK: RecipharmCobra Biologics, the international manufacturer of biopharmaceuticals, today announces that it has been granted European and United States patents for its novel plasmid maintenance system. Classically, genes of interest are inserted into plasmids with antibiotic resistance genes and then inserted into E. coli with antibiotics present. Only those E. coli cells that contain the inserted genes and the antibiotic resistance genes will survive to produce plasmids or proteins. oriSELECT will, on the other hand, enable the production of plasmids or proteins in E. coli without the requirement for antibiotics in the medium or for plasmid selection and maintenance. This will avoid some of the problems associated with the conventional selection method including loss of the plasmid from the cell during cell division (which can reduce product yield), product contamination with antibiotics, and the potential transfer risk of antibiotic resistance genes to pathogens, which could result in the generation of ‘superbugs’. Therefore technologies that prevent the use of antibiotics and their resistance genes could have a significant commercial and regulatory advantage.
The invention of oriSELECT puts RecipharmCobra in the unique position of owning the only two plasmid maintenance systems, including ORT (Operator-Repressor Titration), that are free of the burden of expressed selectable marker genes.
Simon Saxby, Vice President, Biologics commented: “RecipharmCobra is continually looking at the application of state-of-the-art genetic engineering methods in order to improve regulatory compliance, which is continually becoming more stringent, and to ensure maximum efficiencies and cost benefits for our customers. Antibiotic resistance gene transfer is an area of concern where oriSELECT and ORT can provide a state-of-the-art solution.”
Plasmids are autonomously replicating, circular DNA molecules that are naturally found in microoganisms. The plasmids based on the pMB1 (ColEI-type) origin of replication from E. coli are used widely in molecular biology, and enable several hundred plasmids to be produced per cell. Genes of interest are inserted into plasmids to produce proteins, and plasmids are also designed for therapeutic applications.
Whilst there are other antibiotic free plasmid maintenance systems available, oriSELECT requires no selectable marker genes on the plasmid, thereby allowing smaller plasmids to be produced (known to improve transfection and DNA immunisation), and reducing the metabolic burden associated with selectable marker gene expression. The key to oriSELECT is that the pMB1 plasmid origin of replication, which is essential for plasmid replication and is found on virtually all plasmids used in the biotechnology industry, acts as the selectable marker. This means that no further modifications are needed to the plasmid, and existing plasmids can have their antibiotic resistance genes excised for use in the oriSELECT system.
The pMB1 origin of replication produces two RNA molecules, which regulate plasmid replication. The oriSELECT E. coli strain is modified such that an essential gene is controlled by one of these RNA molecules, and is switched off in the absence of a plasmid, preventing cell growth. Insertion of a plasmid enables the essential gene to be expressed, thus permitting cell growth and plasmid maintenance.
About ORT Technology:
Is a way of creating totally stable genetically engineered strains of micro-organisms without the use of antibiotics or antibiotic genes. Other technologies rely on either integrating the synthetic gene(s) into the bacterial chromosome or using antibiotics and antibiotic resistance genes to amplify plasmids containing the new genes. In the vaccine field it has been known for 10 years that the former approach leads to poor strain productivity and the latter to strain instability. Use of antibiotics also creates the risk of passing on the antibiotic resistance genes to pathogens in the environment. Such events have occurred naturally to create MRSA super bug strains so ORT strains are inherently safer for patients. ORT technology avoids these problems.
About RecipharmCobra Biologics:
RecipharmCobra Biologics has a proven track record in the development and manufacture of monoclonal antibodies, recombinant therapeutic proteins, viruses and DNA as well as cell based vaccines and therapies for clinical trials and regulatory approvals. RecipharmCobra Biologics has two GMP approved production facilities, from which a comprehensive service is provided; including cell line development, process and analytical development, GMP manufacture, coordination of formulation and fill/finish activities, and release to clinic.
RecipharmCobra is the specialist biologics division of Recipharm AB.
Recipharm AB is a leading contract development and manufacturing organisation based in Sweden with 2,000 employees. The company operates 11 development and manufacturing facilities in Sweden, France, the UK, and Germany and is headquartered near Stockholm. We supply the global pharmaceuticals market with hundreds of different products in most dosage forms, including solid dose, granulates, powders, sterile liquids and lyophilisates, semisolids, beta-lactams, hormones, and inhalers.
Vice President of Biologics +44 (0) 1782 714 181
De Facto Communications
330 High Holborn
London WC1V 7QD
Telephone: +44 (0)207 861 3838
Direct: +44 (0)207 861 3043
Fax: +44 (0)207 861 3839