Tallinn University of Technology

TTÜ junior researcher of the year 2017 Pirjo Spuul, a cell biologist with an international background, is a senior researcher in the Department of Chemistry and Biotechnology, Division of Gene Technology and her research is focused on the impact of Helicobacter pylori (H. pylori) on human liver.

The field of H. pylori research started in the 1980s when two Australian scientists, Barry Marshall and Robin Warren discovered this bacteria and demonstrated its important role in chronic gastritis and peptic ulcer disease in the human stomach. Due to the efficient treatment against H. pylori at the end of the 1990s the infection rate decreased and the scientific interest started to fade as well. Today, the H. pylori studies are gaining popularity again but the research is not so much bacteria-centered, instead the interest is now in the microbiome studies and extragastric diseases caused by H. pylori.

Pirjo Spuul: “The focus of our research group is to investigate the interactions between H. pylori and liver cells to understand which hepatocyte functions and cellular targets of liver cells are altered upon infection with different strains of H. pylori and how these alterations lead to the development of cancer cells.”

Most of the H. pylori research has been carried out in the gastric model whereas the effect of the bacteria in the liver has been studied much less. The novelty of the work carried out by the helicobacter research team in TTÜ lies in the analysis of the mechanisms how H. pylori could damage the liver.

Already during her postdoctoral studies in the University of Bordeaux in 2011 Pirjo Spuul focused on the host pathogen interactions and specially its impact on the signaling pathways that can lead to alterations in the actin cytoskeleton. During this time she started to collaborate with the scientists from Bordeaux hospital. The joint collaboration project demonstrated that the infection of H. pylori is inducing actin rich structures called invadosomes in liver cells. These relatively unknown structures assemble in the cell in response to different signals and cells are using invadosomes to sense and also degrade the surrounding environment. The research carried out by Pirjo Spuul has shown that different H. pylori strains, with distinct pathogenic outcomes, affect liver cells differently. Studies carried out in Estonia (mainly by professor Heidi-Ingrid Maaroos) indicate that there are very pathogenic strains of H. pylori circulating in Estonia.

“Our aim is to clarify the mechanisms behind helicobacter-induced carcinogenesis in the liver. Revealing the cellular targets of H. pylori and correlating these findings with the changes in the liver cells would open a possibility for the development of novel drugs with reduced risks for emergence of drug resistance. Currently a combined eradication therapy (triple therapy including antibiotics) is used against H. pylori infection but increased resistance of the bacteria to certain antibiotics resulting a treatment failure are becoming an increasing problem,” Pirjo Spuul explains.

H. pylori has been associated with humans for many thousands of years. As the infection is usually acquired in childhood, the hygiene at home and in the kindergarten/school is very important. Our immune system is not able to remove the H. pylori and without the treatment the infection lasts for life. However, it is relatively unlikely to get H. pylori infection in adulthood. Due to better hygiene and eradication treatment the infections of H. pylori are decreasing. Nevertheless, H. pylori has been classified as class-I carcinogen and salty food and smoking have been shown to increase the risk for damage.

Pirjo Spuul is worried about the statics in Estonia – more than 80% of adult population is infected with H. pylori (the average infection rate in the world is 50%). Therefore this research has a very practical outcome – besides the studies carried out in the laboratory, it aims to increase the knowledge level of people about H. pylori by introducing its specificities and potential threats.

Kersti Vähi, TTÜ Research Administration Office