Scientists uses Retrovirus

Given its huge impact on human health worldwide, HIV is at the forefront of retroviral research. In the last decade, the development of effective new drug therapies has helped thousands of people survive an HIV infection, although often at the expense of unpleasant side effects.
Preventing the spread of the virus has proved a more difficult challenge.Despite intensive research, a vaccine against HIV still does not exist, largely because the virus mutates at such a rapid rate.

As a group, however, retroviruses may one day play a more positive role in human health. In gene therapy scientists use genetically altered viruses to insert beneficial genes into human cells.Once in place, these genes can potentially correct inherited disorders, such as cystic fibrosis. Retroviruses make suitable delivery vehicles because they have the chemical apparatus that is needed to splice genes into particular target cells.

Once the genes are inserted, they are copied and handed on each time the recipient cells divide.Gene therapy is still in its experimental stages, and where retroviruses are concerned, there are a number of practical problems to overcome.One of these involves the space where the genetic information of a retrovirus is stored.This space is small, which means that there is a limited amount of storage space for the beneficial genes that are to be transferred.

Another problem is safety, a prime consideration with agents associated with disease. Retroviruses used in gene therapy are genetically engineered to prevent them from replicating. However, there is still a slight possibility that these genetically engineered retroviruses may insert genes in an inappropriate region of DNA, triggering cancer or other problems.

In early 2003, the United States Food and Drug Administration (FDA) halted 27 gene therapy clinical trials that used a retrovirus to ferry genes into blood-producing cells.Two children involved in the trials became ill with a condition resembling leukemia, and the FDA decided it was unsafe to continue using this procedure.

Once safety problems can be overcome, however, the use of retroviruses in gene therapy may become a matter of routine.