Tag: <span>retroviral vector</span>

Biopharmaceutical companies are constantly evaluating new methods for mammalian cell line development that provide benefits such as shorter timelines, improved consistency, higher production, better genetic stability, and increased flexibility. Each of these advantages extends a large cost benefit to companies as their recombinant protein products are moved from development into the clinic and finally to commercial launch. A versatile system has been developed that is capable of transferring genes of interest into a wide variety of mammalian host cells and offers a number of the above advantages over other methods. The system, which is referred to as GPEx™ (an acronym for “gene product expression”), utilizes replication-defective retroviral vectors, derived from Moloney murine leukemia virus (MLV) and pseudotyped with vesicular stomatitis virus G protein (VSV-G), to stably insert single copies of genes into dividing cells…

Biologics Production Viral Vectors

The Lentiviral Vector Reference Working Group (LVRWG) was created at the conclusion of a meeting organized by The Williamsburg BioProcessing Foundation in June 2002, in conjunction with the American Society of Gene Therapy (ASGT) annual conference. The meeting participants were gathered to evaluate the need for developing reference material to ensure comparability of lentiviral and retroviral vectors, in a similar spirit to the Adenovirus Reference Material program that had just been completed. The concensus at the conclusion of this meeting was that the diversity in the lentiviral vector field, which includes vectors derived from different parental viruses and with various designs, does not allow for identification of a single reference material that would benefit more than a single or very few investigators…

Viral Reference Materials Viral Vectors

The Good Manufacturing Practices (GMPs) are becoming more and more familiar in biotechnology, and concepts such as quality assurance or validation are now part of the background of clinicians and researchers involved in clinical trials. A recent European Community directive (2001/20/CE) states that GMPs should also be applied to investigational medicinal products and not only to products on the market. Vector supernatant is a so-called Active Pharmaceutical Ingredient (API) and is subject to the same guidelines as traditional drugs produced by the pharmaceutical industry. This has a deep impact in the field of gene therapy because clinical trials are often run by small biotech companies or, at least in the first phases, by academic centers. The field is continuously developing and, according to the progress of the clinical studies, new processes are necessary to produce large-scale amounts of vector supernatant in a safe and reproducible way…

Manufacturing Viral Vectors

Gene therapy is a promising medical technology that has the ability to treat inherited diseases. However, efficient and economical large-scale production of vectors is necessary to meet the potential patient demand. Several approaches have been evaluated for the mass production of retroviral vectors, including fixed-bed bioreactors, suspension cultures, and microcarrier cultures. In this article, we report on the use of a Cytopilot fluidized-bed bioreactor for the production of retroviral vectors from the human packaging cell line TEFLYRD…

Cell & Gene Therapy Viral Vectors

More than 70 percent of all prospective gene transfer/gene therapy protocols are designed to treat metastatic cancer. A large number of such protocols involve strategies to attempt cancer immunization via cell-based gene transfer of cytokines or tumor antigens, while others involve the delivery of oncolytic viruses or vectors bearing prodrugs, chemoprotective agents, antisense constructs, or tumor suppressor genes. However, a major unresolved problem that has impeded the progress of cancer gene therapy to the clinic is that of inefficient gene delivery to target cells in vivo. In this regard, the advent of pathotropic targeting launches a new paradigm in cancer gene therapy. By targeting the histopathology of the cancerous lesion — rather than the cancer cells per se — to effectively concentrate the gene vector within primary and metastatic tumors, the safety and efficacy of intravenously administered vector nanoparticles were increased significantly in animal models of cancer. This article describes the development of the pathotropic Targeted Delivery System (TDS) that now serves as the guidance system for “smart” nanoparticles bearing designer killer genes for cancer gene therapy…

Cell & Gene Therapy