H. pylori is a prevalent human pathogen that infects more than 50% of the world’s population. Although the majority of infected individuals do not develop symptoms, a significant number of patients suffer from clinically relevant complications leading to ulceration of the stomach and duodenum, gastritis, lymphoma of the MALT (mucosa associated lymphoid tissue) system and gastric cancer. If not appropriately treated by antibiotics, H. pylori persists in the human stomach lifelong. Dr. Benjamin Hoy identified HtrA as a novel secreted virulence factor of H. pylori. He found that HtrA cleaves the ectodomain of E-cadherin leading to an efficient disruption of the intercellular adhesions of a polarized cell monolayer to abolish the epithelial barrier function. Shedding of the extracellular E-cadherin domain allows the bacterium to enter the intercellular space of the epithelium. Finally, Dr. Hoy showed that this novel bacterial mechanism is not limited to infections with H. pylori, but represents a prevalent microbial strategy of a number of important Gram-negative bacteria.  
Benjamin Hoy started his PhD thesis „Helicobacter pylori-secreted HtrA cleaves E-cadherin – Biochemical characterization, inhibitor screen and implications for gastrointestinal infections“ in the research group of Prof. Dr. Silja Wessler at the Paul-Ehrlich Institute in Langen(Germany) in 2009 and continued his research at the University of Salzburgfrom 2010 to 2012. This work was financed by the Paul-Ehrlich Institute.