Ancient DNA may provide key to origins of TB

Skeleton of a child from the middle bronze age, excavated in Beit Shean, whose bones will be included in this project. (Photo: Mark Spigelman)Joshua fought the battle at Jericho but then, as now, the real enemy in the region known …

Skeleton of a child from the middle bronze age, excavated in Beit Shean, whose bones will be included in this project. (Photo: Mark Spigelman)Joshua fought the battle at Jericho but then, as now, the real enemy in the region known as the Fertile Crescent was disease. Tuberculosis (TB) was well known in ancient Mesopotamia and Egypt, and research has already discovered mummified vertebrae with lesions characteristic of TB. Now, a joint Israeli-Palestinian-German research group will use DNA research on 6,000-year-old bones excavated in Jericho in hopes of finding data to help combat TB today.

TB is a deadly infectious bacterial disease that usually attacks the lungs. A disease of crowds, it is transmitted from human to human living in close contact. One-third of the world’s current population has been infected by tuberculosis, resulting, in recent years, in approximately three million deaths per year.

Team leader Prof. Mark Spigelman of the Kuvin Center for the Study of Infectious and Tropical Diseases at the Hebrew University of Jerusalem is known for his pioneering studies of ancient diseases (palaeoepidemiology) found on mummified bodies and human remains from Hungary and Korea to Sudan.

Disease evolution

His research tracks the development of diseases affecting humans today, such as tuberculosis, hepatitis and malaria. Knowing how a disease developed in the Middle Bronze era, Spigelman believes, enables understanding of what it will do as it continues to evolve, and can ultimately help to alter public health policies.

While examining mummies at Sydney University’s Nicholson Museum, Spigelman came across the bones, which were excavated at Jericho by Dr. Kathleen Kenyon between 50 and 70 years ago and brought to Australia by an anthropologist who had worked with Kenyon. He immediately recognized the significance of the cache.

“Here we had a population that had never really been exposed to TB, and we had bugs that had never been exposed to human systems. And we have an opportunity to see how the bacteria changed as our immune systems changed,” said Spigelman.

While the origins of tuberculosis and its evolution remain unclear, it is thought it came from the first villages and small towns in the Fertile Crescent region about 9-10,000 years ago. Jericho is one of the earliest towns on earth, dating back to 9,000 B.C.

The Sydney Jericho bones, some of which are now in Israel, will be studied along with other bones from Jericho that were contributed by the Duckworth Collection at Cambridge University. The team will also examine bones from other sites, such as Tel Beit She’an, Qumran and the 8,000 year-old village of Atlit Yam, which is now undersea.

“This is the sort of material we’re going to look at, particularly the huge Duckworth collection,” Spigelman said with excitement. Another source of DNA material is a body from a Second Temple era tomb. “The person died of TB but suffered from leprosy. We expect to get good results because the DNA is preserved,” he added.

Crowds and Cows

Examining human and animal bones will give the researchers insight into the first people living in a crowded situation and how they developed crowd diseases; the nature of human-animal interaction; the MTB strains that were present in founder populations, the changes in the DNA of both microbes and people and how those changes affected the disease’s development.

“We may have an opportunity to identify the real bugs that harmed humankind,” said Dr. Andreas Nerlich of Ludwig-Maximilians University, Munich. The bones will be tested for tuberculosis, leprosy, leishmania and malaria, however, the primary focus in the first funding period will be mycobacterium tuberculosis complex (MTBC).

The most significant results, the researchers say, will come from comparing data for humans and corresponding animal remains. Initial results already contained one surprise, Nerlich said. “We did not find mycobacterium bovis. We tend to think that [diseases] come from cows to humans, but it could have been the other way around.”

Spigelman adds that Atlit Yam is one of the first villages in which a large number of cow bones were found, indicating domestication of the animal. “And yet the TB strain is modern TB and not bovis. So the theory is that we gave TB to the cows,” he said.

Borders and Bacteria

The research is sponsored by a grant from the German Science Foundation, Deutsche Forschungsgemeinschaft (DFG), and will be conducted by the Hebrew University, Al Quds University and the Ludwig-Maximilians University, Munich. In Israel, Ph.D. and master’s students from both Al-Quds and Hebrew University will devote their time exclusively to this project. An ancient DNA lab is planned to be set up at Al Quds University.

The challenge of regional cooperation was touched on at the project launch in Jerusalem, particularly the immense political and emotional hurdles to be met.

“Do not underestimate the complexity of collaboration in conflict areas,” warned Prof. Ziad Abdeen of Al-Quds University. “Remember, there’s more history than geography in this area. There’s a lack of trust”

Colleague Prof. Hillel Bercovier, chairman of the Research Authority at Hebrew University noted: “When you do scientific cooperation, it has to be based on trust.”

Bacteria and mosquitoes don’t care about borders, and that hoary old cliché, said Bercovier, was a primary motivation on the part of both Hebrew University and Al-Quds University to soldier on with their collaboration, despite the obstacles.

Bringing in international third parties is one key to a successful outcome, Bercovier says. “We celebrated 10 years of trilateral cooperation at Hebrew University and our mission is to continue with that.”

The Jericho bones DNA research is one of 11 trilateral research projects at the Hebrew University involving Palestinian, Israeli and German cooperation. In addition, the university has just closed funding with the Dutch government for trilateral cooperation and Bercovier said other governments were invited to get on the bandwagon “and be remembered in the future as peace builders.”

About Rachel Neiman

A veteran media professional who has lived in Israel since 1984, Rachel has been part of the ISRAEL21c organization since 2008. Prior to that, she served as managing editor of Globes Online, the English-language edition of Israel’s leading business daily, and before that, at The Jerusalem Post, as a business reporter, feature writer, and consumer columnist. Rachel began writing about Israeli technology companies at LINK Israel’s Business and Technology Magazine and is a professional Hebrew to English translator. In her spare time, she is an active member of the Havurat Tel Aviv congregation, and the Holyland Hash House Harriers, part of an international running and drinking disorganization.