Modern HIV medicine is based on a common genetic mutation. Now, the researchers have tracked where and when the mutation arose, and how it protected our ancestors from ancient diseases.
What do a human millenary of the Black Sea region and modern HIV medicine have in common?
Quite, it is, according to a new research from the University of Copenhagen.
18-25 percent of the Danish population entails a genetic mutation that can make them resistant or even HIV immune. This knowledge is used to develop modern treatments for the virus.
Until now, it was unknown where, when or why the mutation occurred. But through the use of advanced DNA technology, researchers have now solved this genetic mystery.
“It turns out that the variant emerged in an individual who lived in an area near the Black Sea between 6,700 and 9,000 years,” says Professor Simon Rasmussen from the center of the Novo Nordisk Foundation for basic metabolic research (CBMR) at the University of Copenhagen, corresponding author of a new study that maps the mutation. Add:
“HIV is a relatively new disease, of less than 100 years, so it is almost coincident and very fascinating that a genetic variation that emerged thousands of years ago also protects against a modern virus like HIV.”
Analyzed 900 Skeletons
To determine where and when the mutation arose, the researchers first map by analyzing the genetic material of 2,000 people lives worldwide. Then they developed a new method based on AI to identify the mutation in the old DNA of old bones.
The researchers examined data from more than 900 skeletons dating from the early stone age to the Viking era.
“When observing this great set of data, we can determine where and when the mutation arose. For a period, the mutation is completely absent, but then suddenly appears and spreads incredibly fast. When we combine this with our knowledge of human migration at that time, we can also identify the region where the mutation originated,” explains the first author Kirstine Ravn, a senior researcher in CBMR.
Therefore, the researchers were able to locate the mutation in a person in the Black Sea region up to 9,000 years, an individual from whom all the bearers of the mutation descend.
It was an advantage at that time
But why do so many Danes carry a genetic mutation of millennia that protect against a disease that did not exist at that time?
The researchers believe that the mutation arose and spread rapidly because it gave our ancestors an advantage:
“People with this mutation were better to survive, probably because it cushioned the immune system for a time when humans were exposed to new pathogens,” explains Leonardo Cobuccio, co-first author and postdoc on CBMR. He and Kirstine Ravn elaborate:
“The fascinating thing is that the variation interrupts an immune gene. It sounds negative, but it was probably beneficial. An immune system too aggressive can be deadly: think of allergic reactions or severe cases of viral infections such as COVID-19, where the immune system often causes patients to kill patients. And a more balanced immune system may have been advantageous.”
Read the study “tracing the evolutionary history of the CCR5Delta32 deletion through ancient and modern genomes.”