There has been some interesting news recently in the fight
against HIV. Scientists have managed to genetically engineer HIV resistant
cells. Although there are current treatments that work well at suppressing the
HIV virus, these medications have many side effects and need to be taken daily
for the rest of that person’s life.The reason the drugs have to be taken indefinitely is that the HIV virus is very
clever and can mutate and become resistant to the treatments, even if just a few
doses are missed. The other reason is that even though the drug suppresses the
HIV to undetectable levels in most patients, there is a so-called ‘viral
reservoir’, which can make new HIV as soon as the medication is stopped. This is
why we still have no cure for the virus.

HIV infects the T-cells (immune cells) and destroys them, so over
time the person’s immunity will fail and AIDS will develop. To enter these
T-cells the virus uses 2 entry points or genes, CXR4 and CCR5. Current drugs
help to block these sites so that the virus cannot gain entry.

Gene Therapy for HIV

Recently, however, scientists have been looking at ways to alter
these entry points, so that the T- cells become immune to HIV. If the virus
cannot enter the cells, then it cannot replicate, and they have now had some
success with this method. The researchers at Stanford have managed to alter the
sites by using ‘molecular scissors to cut and paste resistant genes, into
these areas of entry. They inactivated one of the receptors (entry points) and
also added new genes in a process called stacking. This in effect means that
these genetically modified cells would be immune to HIV
infection.

Although this is great news, the procedure needs to undergo human
testing and will take some time before we know if it works in the real world. If
it does however, it doesn’t mean the person would be cured of HIV, just that the
there would be a set of T-cells that are protected from infection, which in turn
can replenish the immune system, allowing people to come off their
medication.

Step by step we are getting there.