Gene therapy is a promising new technique for treating cancer and genetic disorders by introducing foreign genomic materials into host cells to elicit a therapeutic benefit. The key to success of gene therapy is to create safe and efficient gene delivery vehicles. Viral vehicles are the most commonly used carriers for delivering DNA because of their high efficiency and safety. Creative Biolabs provides comprehensive viral vectors and cutting-edge viral vector technology for basic research and preclinical applications, including the design and construction of suitable viral vectors and small to large-scale production of viral vectors.
Viral vectors not only have the ability to effectively infect cells, but also transfer DNA to the host without causing an immune response. Viral vectors are designed to be safe by making them incapable of replication. Genes transferred by viral vectors have dominated the clinical trials in gene therapy because they are more efficient and specific than physical and chemical methods. Viral vectors can be divided into two types: Integrating and non-integrating viral vectors. Integrated viral vectors can be integrated into the human genome, including lentiviral, adeno-associated virus and retroviral vectors; non-integrating vectors, like adenoviral vectors, remain in the nucleus without being integrated into the chromosomal DNA, thus the transgene is apt to lose during cell division and the expression of foreign genes is transient.
Fig.1 Viral vectors for gene therapy
Lentiviruses are a special group of retroviruses. The envelope protein gene can be replaced by genes from another viral Genome, so as to expand the spectrum of target cells. Creative Biolabs can offer the lentiviral transfer system that ensures long-term expression and efficient transfer without causing inflammatory response.
The adenovirus is a virus that carries its genetic material in the form of double-stranded DNA. The adenoviral vector has advantages of being able to make most cells susceptible to infection and has a relatively high titer, thus it is widely used for treating cancer and adenovirus-based gene therapy products have been approved.
The herpes simplex virus (HSV) is a human neurotropic virus that has the greatest potential for gene delivery to the nervous system and tumor cells. The large size, continuous expression of genes and broad-spectrum effects make HSV an important virus candidate for gene delivery.
The vaccinia (VACV or VV) is a large and complex enveloped virus belonging to the poxvirus family. The absence of viral integration into the host cellular genome and the excellent immune stimulation make the vaccinia virus an attractive immunotherapy for cancer treatment.
The adeno-associated virus (AAV) is a small virus that displays low immunogenicity and apparent lack of pathogenicity. Creative Biolabs provides AAV vectors characterized by molecular engineering and directed evolution to generate powerful delivery vectors with enhanced properties for the treatment of human diseases.
The baculovirus is a type of double-stranded circular DNA virus that specifically infects arthropods. It has been successfully applied to the delivery of foreign genes into mammalian cells without any viral replication, and it also has the effect of stimulating the host antiviral immune responses and providing protection from lethal viral infection.
Creative Biolabs also provides alphavirus vectors, flavivirus vectors, measles virus vectors, foamy virus vectors, helper-dependent adenoviral vectors and hybrid adenoviral vectors, etc.
Fig.2 Viral vectors applied to gene therapy
Besides the design, construction and cloning of customized plasmids for viral vector production, Creative Biolabs uses a number of technologies and scientific talent to provide comprehensive consultation services about the selection of viral vectors for gene therapy. For more information, please feel free to contact us.
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