The science behind 'A Vested Interest' - Genetic Therapy

What exactly is it?

Gene therapy is a technique being developed that uses genes to treat or prevent disease. This technique will allow doctors to treat a disorder by inserting a gene into a patient’s cells instead of using drugs or surgery. To introduce the modifications necessary a 'vector' is used. This can be done in several ways:

• Replacing a mutated gene that causes disease with a healthy copy of the gene. A modified virus is often used to do this. The virus has it's ability to reproduce copies of itself 'knocked out' to prevent it from causing a new disease. Viruses are good at changing our DNA - it's how they infect us.

• Inactivating, or “knocking out,” a mutated gene that is functioning improperly. While this removes damaging effects it also means the gene will not function at all.

• Introducing a new gene into the body to help fight a disease.

Although gene therapy is a promising treatment option for a number of diseases (including inherited disorders, some types of cancer, and certain viral infections), the technique can be risky and as a result was usually only attempted as a last resort in the treatment of diseases that have no other cures.

We already contain in our bodies DNA which probably came from viruses but which proved so useful to our cells that it was incorporated in our DNA. You'll find it in the mitochondria in our cells.

In 'A Vested Interest' the technique used is to change the HIV1 virus (The one that causes Aids) so that it introduces two new genetic sequences to our DNA. One sequence makes the body much more efficient at destroying faulty DNA - on it's own this would lead to early death through old age. The second sequence makes the body replace damaged cells or those destroyed by the first sequence. Again - on it's own this would lead to early death through cancers. The two together lead to immortality.

'A Vested Interest' makes one change. The virus used in this case does not have it's ability to reproduce destroyed. It must target every cell in the body and destroying it's ability to reproduce would prevent this. Our 'life' virus would be very infective and would spread. We suggest modifying it so that it's more easily spread than as a veneral disease. We suggest it could be spread through tears. Try resisting the temptation to touch your eyes for a while. You'll find you do it more often than you think. Everything you touch after wiping your eye would then be contaminated by the virus. Fortunately for us, the current HIV1 virus rapidly dries out and is destroyed but if it's modified...?

Sounds too fantastic? Well there are living things which are already immortal. A good example of this is the humble bacterium which will go on until killed, eaten or poisoned by our antibiotics. There are multicellular organisms which are effectively immortal too. One can even withstand the vacuum of space. If there is food they will grow and divide, if not, they will go into stasis. Somewhere in our past, evolution found that death hastened change and made survival of a species rather than an individual more likely. Today we are at the point where that change could be reversed.

As you go through the books you'll encounter the Dine'é Yá who are experts at gene therapy. They don't use a virus as a vector though - they use nanotechnology.

Is it really possible to use the HIV virus as a vector to 'fix' people? When we started writing the books we didn't know of any research using HIV as a vector but that's not true today.

What would be the implications of immortality?