Lentiviral Vector Design for Regulated Integration and Expression
Gene therapy relies on the delivery of therapeutic genes into patients' cells. Lentiviral vectors are very efficient in transducing cells, which makes them highly useful tools for gene therapy. As a leader in the field of lentiviral vectors, Creative Biolabs provides comprehensive technologies to meet the diverse requirements of our customers. With our professional experience and advanced lentiviral vector design platform, we are therefore confident in offering the best lentiviral vector design service to make your project success.
Design of Lentiviral Vectors
Gene therapy has been widely used in a number of disease treatment, such as tumors, as well as autoimmune diseases. In general, gene therapy is conducted by transferring therapeutic genes into specific cellular targets. Gene transfer based on lentiviral vector has been proven with great effectiveness, specificity, and stability for treating colon cancer, breast cancer, and diabetes. Lentiviral vectors were originally designed as replication-defective, hybrid viral particles made from the core proteins and enzymes of HIV-1, and the envelope of a different virus, most often the vesicular stomatitis virus(VSV). The packaging functions are provided by at least two separate expression plasmids that use transcriptional signals unrelated to those of the virus. One or more core packaging constructs, derived from the lentiviral genome, express the viral proteins but not the env gene that has been deleted. A separate construct expresses a heterologous envelope that is incorporated into the vector particles and allows entry into a wide spectrum of target cells.
Figure 1. A typical lentiviral vector particle.
The Service of Lentiviral Vector Design for Regulated Integration and Expression
In a range of human trials, lentiviral vectors have emerged as safe and effective delivery vehicles for clinical gene therapy, particularly for monogenic recessive disorders, and there has reported some early work on idiopathic diseases. Therefore, Creative Biolabs now offers a number of lentiviral vector design services covering the integration-deficient lentiviral vector (IDLV) service, site-directed IDLV, self-deleting lentiviral vector, inducible vector systems design for lentiviral vector, including but not limited to:
It has been demonstrated that IDLVs generate high levels of replicating episomes in transduced cells and mediate efficient transduction. IDLVs have a greatly reduced risk of causing insertional mutagenesis and a lower risk of generating replication-competent recombinants (RCRs). Integration-deficient HIV-1 vectors typically have mutations in the IN gene that amplify the formation of episomal genomes in the nucleus, with minimal vector integration. Integration can be reduced up to 104-fold with an integration-deficient HIV-1 vector.
-
Site-Directed IDLV Service
IDLVs mediated site-directed gene addition permits the design of a platform that can target the insertion of transgenes into a pre-determined genomic site. This system achieves high levels of site-directed gene addition in a panel of human cell lines, including embryonic stem cells, allowing rapid selection-free isolation of clonogenic cells with the desired genetic modification.
Self-deleting lentiviral vectors have been developed on the basis of the Cre/loxP system. Self-deletion is achieved by expression of the Cre recombinase from vectors with a loxP site into the U3 region of the 3'-LTR. Duplication of the U3 region of the 3'-LTR during reverse transcription generates a proviral DNA with one loxP site in both LTRs. After integration and subsequent Cre expression, Cre-mediated recombination of these two loxP sites deletes most of the integrated vector genome with the exception of the flanking U sequences and one loxP site.
Lentiviral vectors can be used for externally controllable transgene expression. Among several inducible systems, the rtTA (reverse tetracyclin-controlled transactivator)-regulated system has been widely used for inducible gene expression. This system uses a chimeric transcription factor tTA transactivator, a fusion protein between the bacterial TetR with the activating domain of herpes simplex virus VP16, or its derivative rtTA protein, along with a TetO-binding-sites-containing promoter for tetracycline-induced gene silencing (Tet-Off) or activation (Tet-On) respectively. The Tet-On/Tet-Off systems have been studied extensively in the context of lentiviral vectors, in which the Tet-regulated system is incorporated into a single lentiviral vector.
Equipped with high-end technologies and Ph.D. level scientists, Creative Biolabs has focused on the development of gene therapies for years. We have accumulated extensive experience from the accomplishment projects and are very proud of our high-quality, omnidirectional lentiviral vector design services to meet any special need of your research. If you are interested in our services, please contact us or send us an inquiry.
