For years researchers and doctors have struggled to successfully treat or prevent HIV/AIDS. The virus can rapidly mutate and become resistant to many of the therapies we have thrown its way. Currently, the standard treatment involves the use of drugs called anti-retrovirals that act to stop the virus from creating copies of itself or stop it from entering your cells. The problem with these therapies is threefold.
First, they must be used in combination (often called HAART treatment) and can produce troublesome side effects. These can include headaches, fatigue, pain or nerve problems, movement of fat from face to the abdomen, diabetes, and loss of bone density. While these side effects are unpleasant, they are certainly better than the problems associated with AIDS.
The second problem is drug resistance, which like antibiotic resistance is a huge problem and can render your treatment ineffective.
The final problem with these therapies is that they are only taken after a person is infected with HIV and are not useful for preventing infection in the first place. This is why researchers have been working hard towards the development of vaccines for HIV, but with limited success so far.
The problem that researchers have encountered so far in creating a vaccine for HIV is that HIV is really unlike most viruses we encounter. It can mutate fast, similar to the flu virus, but it can do so within the same person a number of times, unlike the flu virus. This means the virus you get infected with initially may look completely different in 10 years. This makes treating it very difficult. The HIV virus also is never truly cleared by the immune system. The immune system can get rid of most virus it encounters in the body, but HIV has a trick, it is able to hide itself within the DNA of its host immune cells so it cannot be attacked by the immune system. Once the immune system stops hunting it, the HIV virus can re-emerge and continue its assault on the patient. The HIV virus is also able to kill the cells in the immune system that are most important in making antibodies to fight infections. Over time your immune system gets weaker and cannot fight the virus anymore. There has been some promising work being done on HIV vaccines and researchers are not giving up the fight but new research, published in Nature, suggests there may be different way to treat and possibly prevent HIV infections.
The researchers noted that HIV needs the help of two proteins found on immune cells (CD4 cells called T-helper cells) to enter the cell. These two proteins, called CD4 and CCR5, act like docking points for the virus similar to how a boat uses ropes to tether itself to a dock. People who have mutated CCR5 have actually been shown to be resistant to HIV infections because the virus cannot attach properly. The researchers thought that maybe they could make a decoy molecule that had characteristics of both the required docking points for the virus. In this way, the virus would bind this decoy molecule and would not be able to infect immune cells. They developed this molecule, an antibody with bits of CCR5 and CD4 on its ends, and injected it into monkeys in such a way that the monkey’s muscles would make the molecule. The researchers then infected the monkeys with the monkey form of HIV (called SIV). What they saw was quite remarkable. The monkeys with the anti HIV molecule remained completely uninfected for at least 8 months even when the researchers tried to give them 4 times the normal amount of the virus or tried to infect them twice over the eight months. This of course meant that the monkeys survived for the 8 months where there infected counterparts did not. The molecule works because it mops of the virus before it can bind to cells. The researchers were able to show that it worked on different forms of the virus, even normally hard to stop variants.
Of course, this research is still in its infancy. We still need to figure out how to deliver the drug effectively in humans and whether there would be any side effects or if the virus could mutate to it. It should be harder for the virus to mutate to this drug because it needs the CD4 and CCR5 proteins to enter the cell, but we still need to know if it is possible. It would also be important to know if this drug can act to prevent HIV infection in people or even be developed into a vaccine rather than just treat current infections. It is a promising time for AIDS patients with lots of good research occurring. It is safe to say that we may even see a cure or vaccine to this terrible disease in our lifetime.