In an effort to cure HIV/AIDS, researchers have investigated the possibility of creating designer immunotherapies that would specifically use the body’s own immune response to eliminate the HIV virus. This research comes at a particularly critical time in the development of the HIV/AIDS pandemic because of how many people currently live with the virus in a controlled, but still uncured, condition. The successful use of designer immunotherapy would allow the body of an HIV-positive patient to effectively cure itself entirely of the infection.
Acquired Immunodeficiency Syndrome (AIDS) remains one of the leading causes of death in the world. This is particularly true in sub-Saharan Africa and other developing countries. In 2011 it was estimated that 34 million people were living with HIV, which makes finding a cure for this disease a high priority.
Treatment of HIV-infected patients has come a long way. Antiretroviral therapy, also known as ART, has increased the longevity and quality of life for HIV-infected patients. While access to ART and medical care remains a challenge for some, for the first time in years the number of deaths from HIV/AIDS has declined in many parts of the developing world because of advances in proper disease management.
However, ART is not a cure for HIV/AIDS. ART acts by suppressing viral replication and thus slowing the rate at which a person’s immune system succumbs to the virus. This means that some virus still remains in the infected person’s body even if their viral loads remain low and they seem healthy. Thus, while ART can control the infection, it is still not considered a cure.
To cure HIV entirely, researchers are exploring different potential therapies that would take the final step to eliminate the last of the HIV infection from the body of a person that is already taking ART. The advantage of treating these people is that their viral loads are already quite low and thus theoretically easier to address with an end-game therapy.
In particular, a number of studies are investigating the possibility of using designer immunotherapies to help the body cure itself of an HIV infection. In one promising study, researchers sought to recruit a patient’s own dendritic cells to induce the body to hunt out and eliminate the last of the HIV infection.
Within the body, dendritic cells (seen in the picture above) act by snatching up particles of HIV virus or other antigens and presenting them to other cell types within the immune system. To generate a designer HIV therapy, researchers sought to cure their infected patients by priming each individual’s dendritic cells with known HIV antigens. These primed dendritic cells were injected back into the respective patients during four sessions that were spaced over the course of about four months.
In response to the treatment, more than seven out of the nine patients experienced an increase in their levels of CD8+ T cells. During an HIV infection, CD8+ T-cells seek out and destroy other cells in which the HIV virus hides and lies dormant. Thus, increasing the number of CD8+ T-cells is one way in which the body can fight off the last of the lingering HIV infection.
Though only a pilot study, the success of this project provided the proof-of-concept that has encouraged researchers to continue pursuing designer HIV immunotherapies as a potential HIV cure.
By Sarah Takushi