What determines the way people respond to an HIV infection? Medical researchers have been asking the question for decades. Genetic studies are now shedding more light on how the virus proliferates (or doesn’t).
One of the newest studies has curious findings, suggesting why certain people of African descent could be more capable of fighting a human immunodeficiency virus infection than their peers. It all boils down to genetic variants.
Genetics Play a Role in Slowing Down HIV Infections
The ground-breaking results of the new study were published in Nature magazine in August 2023.
An international team of researchers discovered genetic variants in people of African descent that seems to slow down the proliferation of the HIV infection after the virus enters the body.
According to the researchers, this finding could explain why some people in African countries have a very low viral load. Their body is simply more capable of slowing down the replication of the virus, which also results in a reduced likelihood of its transmission.
The analysis examined the genetics of 3,900 volunteers living with HIV-1 – the most common type of infection with the human immunodeficiency virus. A collection of 16 genetic variants was identified as a reason for the slower progression of the infection in some volunteers.
“By studying a large sample of people of African ancestry, we’ve been able to identify a new genetic variant that only exists in this population and which is linked to lower HIV viral loads,” Canadian National Microbiology Laboratory for HIV Genetics representative and research scientist Paul McLaren said.
According to McLaren and his colleagues in the international research team, about four to 13 per cent of people from African descent carry the top ranking genetic variant that slows down the progression of the virus, supresses the viral load and prevents its transmission even in the event of a chronic infection.
The study is at the opposite end of the spectrum when it comes to findings in comparison to a previous analysis carried out in Botswana. Carried out in 2021, the study identified genetic variants that seem to make people more susceptible in the event of an infection with the human immunodeficiency virus.
Previous studies on HIV and genetic variants have been conducted on Caucasian volunteers of European descent. This is why the new research is considered such an important breakthrough that could help for the development of newer and more effective antiviral therapies.
The findings are also different from research on the so-called elite controllers. Elite controllers represent fewer than 0.5 per cent of all the individuals in the world infected with HIV. And while they have the HIV genome woven into their chromosomes, elite controllers are capable of achieving undetectable viral load without the use of antiretroviral medications. Some have even managed to completely eliminate the virus from their body, regardless of the fact that they have tested HIV-positive. Studies have been ongoing for over 20 years in hopes of developing a vaccine against HIV. Unfortunately, a lot more work will need to be done and new genetic variant research could speed up the work that needs to be done in order to make this kind of HIV prevention possible.
The Implications
Such findings can have significantly positive impacts on the development of antiviral medications. It’s also important that the study group was of African descent. While many previous analyses focused on Caucasian HIV-positive individuals, the vast majority of infections in the world occurs among people of African ancestry.
The new genetic variant only exists among people of African descent. There is also enough evidence to establish the fact it is linked to a lower HIV viral load. It’s still not clear how genetics impact the proliferation of the virus and that mechanism is probably going to be studied further in the future.
It’s also important to point out that the genetic resistance to the virus also involves a complex interaction between two or more genetic variants. These are intricate mechanisms rather than simple quirks and links have to be understood and established to take the analysis to the next step.
Nearly 39 million people across the globe live with HIV. Since the start of the pandemic, 85.6 million people have been infected and many have died of AIDS-related complications. It’s clear that people don’t respond to the virus in the same way. The job of researchers is to now identify the mechanisms that play a role in the intricate interaction between the virus and the cells of the immune system most impacted by it.
And while a lot more work needs to be done, we already have reliable safeguards in place. HIV testing and treatments like HIV pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP) reduce the risk of an infection significantly.
You can learn more about these opportunities at men’s health facilities like Shim Clinic. Visit Shim Clinic during working hours every day of the week or contact us to have your questions about HIV answered.
Sources:
- McLaren, P. J. (2023). Africa-specific human genetic variation near CHD1L associates with HIV-1 load. Nature. https://doi.org/10.1038/s41586-023-06370-4
- Shevchenko, A., Zhernakova, D. V., Malov, S. V., Komissarov, A., Kolchanova, S. M., Tamazian, G., Antonik, A., Cherkasov, N., Kliver, S., Туренко, А. С., Rotkevich, M., Evsyukov, I., Vlahov, D., Thami, P. K., Gaseitsiwe, S., Novitsky, V., Essex, M., & O’Brien, S. J. (2021). Genome-wide association study reveals genetic variants associated with HIV-1C infection in a Botswana study population. Proceedings of the National Academy of Sciences of the United States of America, 118(47). https://doi.org/10.1073/pnas.2107830118