Christiana Lyn Scheib, Associate Professor of Ancient Biomolecules at the University of Tartu, is working on an innovative methodology to find answers to questions about the development of the human immune system. The European Research Council (ERC) supports her research with a Starting Grant of nearly €1.5 million.
Infectious diseases were the leading cause of death in the world before the advent of antibiotics and have played a major role in the evolution of the human immune system. However, due to a lack of sufficient data, it has not been possible to accurately assess the impact of infectious diseases on human populations, nor to identify the causes of the most common diseases, including the reasons for child mortality, as many of them are viruses that are chemically unstable at the DNA level. There are no records for many ancient periods, so we lack a clear understanding of why people became ill and died.
According to the recipient of the grant, Associate Professor of Ancient Biomolecules at the University of Tartu Christiana Lyn Scheib, we have become pretty good at studying how the immune system of living humans fights infections but have no capacity to do so for long-dead populations. "The immunity of modern populations has been shaped by our past. To understand our immune system and better account for inherited differences in disease prevention and treatment, it is necessary to understand how they evolved. For that, we need to study how human immune responses have changed over time and the pathogens against which these changes have occurred," said Scheib.
When a person comes into contact with a pathogen, antibodies are produced in the body that remember the disease for the future. The antibodies stay in the bloodstream for life and thus retain information about all infections a person has been exposed to. When the person dies, the proteins and DNA from the bloodstream stick to the teeth and can remain there for hundreds of thousands of years.
"With all this in mind, I came to the idea of how we might gain unprecedented insight into the history of diseases that have affected humans. The plan is to combine the methods of palaeoproteomics, ancient DNA and immunologicaresearch to match ancient antibodies with their corresponding pathogens and identify ancient viruses such as measles, mumps and influenza from skeletal remains. As a result, we also hope to find out whether exposure to diseases increased or decreased the chances of survival for ancient humans and how plague waves have affected the humankind," Scheib explained.
According to Kristjan Vassil, Vice Rector for Research at the University of Tartu, receiving an ERC grant is a great achievement. "Around one tenth of the research projects submitted have a chance of winning an ERC grant. University of Tartu researchers have received this grant on seven occasions in the past, but for the Institute of Genomics, this is the first time. This confirms that the University of Tartu has created a good environment for researchers to carry out cutting-edge research here," said Vassil.
Professor Mait Metspalu, Director of the Institute of Genomics, emphasised the innovative nature of Christiana Lyn Scheib's project. "This project has the ambition expected from ERC grants. For example, while so far, we have studied the spread of medieval and earlier diseases by extracting old pathogen DNA from human remains, in this project, Christiana looks at the immune response of humans to infectious diseases they have suffered during their lifetime. If successful, this will give a much broader picture of the diseases prevalent in ancient populations."
Metspalu added that the Institute of Genomics has a dedicated laboratory for working with ancient biomolecules, be they DNA or proteins, which allows the study of hereditary material from precious archaeological material, as well as antibodies, in ultra-pure conditions where samples are protected from contamination by modern material.
ERC grants are among the largest and most prestigious individual research grants in the world. Five types of grants are awarded and the main evaluation criterion is scientific excellence. The Starting Grants are awarded to early-stage researchers, with 408 outstanding researchers receiving this grant this year in a total amount of €636 million.