There are a wide variety of viral vectors available for gene therapy. Some common examples include:
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adenoviruses
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adeno-associated viruses (AAV)
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alphaviruses
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flaviviruses
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herpes simplex viruses (HSV)
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measles viruses
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rhabdoviruses, retroviruses
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lentiviruses
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Newcastle disease virus (NDV)
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poxviruses
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picornaviruses
Viral vectors can be single-stranded or double-stranded and DNA- or RNA-based. Among other things, they differ in how large inserts they can carry (from below 4kb to over 30 kb), what cells can be targeted, how they trigger the immune response and their mode of action.
AAV vectors are commonly used for gene therapy as they generate low toxicity and pathogenicity while providing long-term transgene expression. These vectors have shown promising results for a number of diseases and FDA-approved drugs based on AAV vectors are currently on the market. Drawbacks include the immune response that occurs by repeated administration or by previous infection of the wild-type virus in the patient. Another limitation is the small carrying capacity of AAV vectors.
Adenoviruses offer short-term expression of the transgene in a wide range of host cells. Originally, they were generated strong immune responses in patients, but newer generations of the vectors have substantially lower immunogenicity.
Retroviruses are typically randomly integrated into the genome, which can be problematic. However, newer and safer vectors have been developed to partly overcome this problem. This kind of vector can only be used on dividing cells, which has led to more interest in the lentiviral vectors that do not have this limitation.
In conclusion, there are many kinds of vectors available for gene therapy, each with their own advantages and disadvantages. Which one to choose for your project comes down to factors like the size of the transgene, the kind of gene therapy target cells used, how the transgene should be expressed and more.
What we offer?
Svar is in a unique position to offer assistance in any gene therapy project. We have robust platforms suited for all phases of drug development, as well as the experience and knowledge from our diagnostic and bioanalytical services. We are currently developing cell-based assays for immunogenicity and potency testing. Furthermore, we can create custom projects tailored to your specific needs to create truly tailor-made assays. Our Bioanalytical Services offer flexible solutions adapted to your needs and requirements.
Together, we can move the promise of gene therapy to reality.
