Dependovirus - Gene Therapy

Gene Therapy

The Dependovirus is not a large enough virus to trigger an immune response; this makes it a good virus to use as a gene therapy tool. Gene therapy is a possible treatment for a variety of disorders and diseases that are genetic in origin. Viral vectors are currently being developed to transport genes into human cells. Since this virus does not stimulate an immune response it can be used multiple times effectively without being neutralized before infection. Another reason these viruses are reliable vectors is the known insertion point for the genome. This virus always inserts its contents into the same place on chromosome 19. This predictability can cut down on the chances of inserting into an important area that might disrupt normal gene function or increase the risk of developing cancer. At this time, one challenge using this virus as a therapy tool is the fact that the genome is fairly small. With less than 5kb in the genome the amount of genetic material that can fit into the capsid is limited. Work is currently being done to increase the amount of information this vector can deliver. This may be accomplished by the LTRs found at both the 5’ and 3’ end of the genome. Since the LTRs have the same sequence they will leave complementary strands exposed if they are removed. The complementary strands can undergo recombination and join two 5kb inserted fragments together.