Adeno-Associated Virus for Gene Therapy
Human Gene therapy can be described as the delivery of genetic material to patients’ cells with a therapeutic purpose. Two distinctive classes of vectors mediate the transfer of these materials which include non-viral and viral. (1) Non-Viral Vectors Non-viral methods may be divided into three categories; inorganic particles, synthetic/natural biodegradable particles, and physical methods. These methods have become ubiquitous because of their ability to transfer large genes, their relative safety, and site-specificity. However, they may be restricted by their relatively poor transgene expression, and low transfection efficiency. (2) Viral Vectors Viruses have advanced to become quite efficient at the transfer of genetic material to particular cell types or tissues resulting in the expression of therapeutic genes while averting immunosurveillance by an infected host. These characteristics make viruses appealing vectors, for gene therapy. A number of factors must be considered regarding any viral vector including the capability to attach and enter the target cell, successful transfer to the nucleus, the extent of expression inside the nucleus for a sustained period of time, and a general lack of toxicity.
Adeno-Associated Virus (AAV) was discovered during the 1960s and since then, it has become a revolutionary viral vector in gene therapy and gene delivery. AAV is a non-enveloped virus that can be engineered to deliver DNA to target cells, and has attracted a significant amount of attention in the field. The ability to generate recombinant AAV particles lacking any viral genes and containing DNA sequences of interest for various therapeutic applications has thus far proven to be one of the safest strategies for gene therapies.