Medieval DNA, Modern Medicine - Archaeology Magazine Archive


Medieval DNA, Modern Medicine	Volume 60 Number 6, November/December 2007
by Heather Pringle

Will a cemetery excavation establish a link between the Black Death and resistance to AIDS?

Beneath Eindhoven's modern skin of brick and asphalt lie the bones of its medieval townspeople. Studying their DNA may reveal the origin of the genetic resistance to AIDS. (Courtesy Laurens Mulkens)

From the start, Nico Arts sensed that the frail remains of a child buried in front of a medieval church altar had an important story to tell. Arts is the municipal archaeologist in Eindhoven, a prosperous industrial city in the southern Netherlands whose medieval streets vanished long ago beneath a modern warren of concrete and steel. In the late winter of 2002, Arts and his team were conducting a test excavation near St. Catherine's Church in the city center, in advance of the development of a new public square. Arts believed he had found someone very important, such as the son or daughter of a former lord of Eindhoven. He persuaded forensic scientists at the University of Louvain in Belgium to test for ancient DNA. The chances of finding it seemed slim because water dissolves DNA, and the repeated pumping of groundwater from underground parking lots over the past decade could have periodically soaked the child's bones. But in 2004, Arts received some unexpected news: one of the child's milk teeth yielded DNA. It was the first time usable amounts of this molecule had been recovered from an ancient body in the Netherlands, and it showed the child was a boy.

This chance discovery of ancient DNA has led to one of the most ambitious archaeological projects ever to come out of the Netherlands--a massive excavation in the St. Catherine's Church cemetery and the establishment of a major ancient human DNA databank. With $3.4 million in funding, Arts and a team of archaeologists and physical anthropologists have now unearthed the skeletons of more than 750 Eindhoven citizens. And over the next two years, University of Leiden geneticist Peter de Knijff will attempt to recover DNA from these remains. "We expect that at least 75 percent of all individuals will have ancient DNA and proteins," says Arts.

Eveline Altena prepares to take a DNA sample from a recently excavated molar. The tooth's pulp cavity seals off DNA from contaminants, making it the best place to look for intact genetic samples. (Courtesy Laurens Mulkens)

For researchers, the Eindhoven DNA bank could prove a major windfall, paving the way for a host of new studies. To unravel the mysteries of human disease, researchers are increasingly studying genetic variations in human populations that increase the risk of illnesses, such as diabetes, or boost resistance to infections such as malaria. By studying the variants over time, researchers hope to advance knowledge of these diseases and gather clues to produce vaccines or new drug treatments. And such medical research is where the Eindhoven DNA bank, which spans 600 years of history, could really shine.

The Dutch team hopes, for example, that their project will reveal the origin and prevalence of a genetic variant that increases resistance to one of the world's most lethal viruses--HIV. Today, nearly 10 percent of people of northern European descent possess this variant, known as the CCR5D32 allele, and the discovery is sparking the development of a new class of AIDS-fighting drugs. Evidence suggests that this mutation first arose 3,100 to 7,800 years ago, but how did it become so prevalent across Europe in an age before the AIDS epidemic? Could this mutation also have boosted resistance to an earlier epidemic, such as smallpox or the Black Death? In search of new data, Knijff and his team will search for this variant in the DNA of Eindhoven's citizens. "There is no doubt that these studies are valuable," says Susan Scott, a University of Liverpool historian who has written extensively on the Black Death and its possible connection to the HIV-resistance variant. "Whilst I don't think [ancient DNA] studies will yield a vaccine for AIDS, they may assist molecular geneticists to develop some gene therapy."

For Arts and many of his colleagues, the bold project has ushered in a new era in archaeological research. "It makes archaeology much more relevant than it ever has been before," says Eveline Altena, a University of Leiden doctoral student in charge of recovering ancient DNA from the Eindhoven burials. "If we can use archaeological samples to answer medical questions, how cool is that?"

Heather Pringle is a freelance science journalist and author of Master Plan: Himmler's Scholars and the Holocaust.