What are the viral vectors used in gene therapy?
Nearly all gene therapies currently available use one of three vector types: adeno-associated-virus (AAV) vectors, adenovirus vectors, or lentivirus vectors (Exhibit 1).
What are the advantages of viral vectors if used in gene therapy?
Benefits and advantages of using the Adeno-Associated Virus as the vector in gene therapy trials include integration into host genome, no viral genes, able to transduce cells not actively dividing, wide range of host cells, and they are non-inflammatory and non-pathogenic.
What are the advantages and disadvantages of using viral vectors?
|Efficient and stable gene transfer Transduction rates of up to 40% of HSCs in non-human primates||Low rates of expression One or fewer copies of provirus per cell Sensitive to chromosomal position effects Sensitive to DNA repeats, introns|
What are the two main types of vectors used in gene therapy?
The two major classes of methods are those that use recombinant viruses (sometimes called biological nanoparticles or viral vectors) and those that use naked DNA or DNA complexes (non-viral methods).
Which type of viral vector is most commonly used for clinical gene therapy trials?
Commonly used viral vectors. In gene therapy clinical trials the most commonly used gene delivery systems have been based on adenovirus (Ad), retrovirus, poxvirus, adeno-associated virus (AAV) and herpes simplex virus (HSV), which were cumulatively used in more than 66% of all clinical trials to date .
Is a viral vector a biologic?
Viral vectors are produced in a similar manner to other biologics. Viruses containing the gene of interest are allowed to infect cultured cells. The cells then produce and shed additional copies of the virus into the culture media, which is harvested for purification.
What are 2 advantages of viral vectors?
In general, the advantages of viral vectors are as follows: (a) high efficiency gene transduction; (b) highly specific delivery of genes to target cells; and (c) induction of robust immune responses, and increased cellular immunity.
Why are viruses useful in gene therapy?
Viruses, for example, have a natural ability to deliver genetic material into cells, and therefore, can be used as vectors. Before a virus can be used to carry therapeutic genes into human cells, however, it is modified to remove its ability to cause an infectious disease.
What are some disadvantages of viral vectors?
The disadvantages of retroviral vectors include: the random insertion into the host genome, which could possibly cause oncogene activation or tumour-suppressor gene inactivation; the limited insert capacity (8 kb); the low titres; their inactivation by human complement; the inability to transduce non-dividing cells and …
What are the types of viral vectors?
There are several types of viral vectors that can be used to deliver nucleic acids into the genetic makeup of cells, including retrovirus, lentivirus, adenovirus, adeno-associated virus and herpes simplex virus. Each of these has unique advantages and disadvantages for specific applications, as outlined below.
What are the most common vectors used in gene therapy?
The most typical vector for gene therapy is viruses, owing to their inherent adaptability and efficiency of gene delivery.