Why We Haven’t Cured HIV Infection: A Major Hurdle To Overcome
dormant state for years and they appear to hide out in parts of our body that still are partly a mystery. These resting T-lymphocytes normally stay in this quiet state until some signal from the immune system stimulates them to wake up and become active. When they become active, they then start to produce HIV virus that has remained quiet. These resting lymphocytes that are infected with HIV but not producing the virus are what we refer to as a cellular reservoir.
Now, if these resting lymphocytes comprising the reservoir become active while the person is taking HIV medicines, the medicines are able to work and suppress the virus. They remain undetectable and it is no big deal. But if a person is undetectable and stops taking medicine, some of these resting cells may wake up and start making new virus and soon there is virus detected in the person’s blood. These infected resting lymphocytes are the source of the virus that rebounds in the blood when an undetectable person stops taking medicine.
So how are scientists dealing with this? First, recall from the previous article that there are people whose immune systems can control the virus on their own (Elite controllers) and also, there are some people who can control the infection after being suppressed on the medicines for a while (Post-treatment controllers). However, these special categories do not represent the vast majority of folk who are infected. Most people will experience a rebound of the virus in the blood if they stop taking their medicines after being suppressed.
So scientists realized that we must somehow stop these resting lymphocytes from being activated and producing virus if we are to have any hope of curing this infection. Even though these resting lymphocytes may be hiding in parts of the body that haven’t been identified yet, we do have some specialized tests that can estimate how big this reservoir is, or how many of these infected resting lymphocytes a person has. In studies where patients were able to control their HIV infection without medicine after successful treatment (post-treatment controllers), having a smaller reservoir was one of the most important factors.
Researchers have developed two main strategies to deal with these lymphocytes. The first approach is called “Kick and kill”. In this approach, we use drugs that are designed to stimulate these resting cells all at the same time, wherever they are hiding in the body. This is done while the patients are taking HIV medicines. Once they become active and start making virus, then either the HIV medicines can get in the cells and shut down virus production or the immune system is now able to recognize these infected cells and kill them. If we are successful in