Projects
Inhibition of the activity of α-hemolysin of Staphylococcus aureus
α-hemolysin is one of the proteins of S. aureus that is secreted by the bacteria and leads to damage of human cells by forming pores in the membrane of the cells. In humans, it particularly attacks cells of the immune system and epithelial and endothelial cells and is the decisive virulence factor in pneumonia and skin infections caused by S. aureus. For a screening campaign at the Lead Discovery Center (LDC) in Dortmund with 180,000 substances, we developed the screening test with the recombinant protein and provided test substances. To validate the activity of the inhibitors found, we established infection models in which the lung epithelial cell A549 was specifically infected with S. aureus. Using this model, we were also able to characterize the pathogenic properties of more than 100 isolates from patients. The added inhibitors were able to prevent damage to the cells by α-hemolysin and also the formation of inflammatory markers (cytokines). Special cell culture models in which infection occurs at the boundary layer between air and cell culture (air-liquid interface cultures) are being established for even more extensive investigations under conditions close to infection. We are also establishing diagnostic methods to quantify α-hemolysin in patient samples, as the presence of significant α-hemolysin concentrations cannot be inferred from the presence of S. aureus alone when inhibitors are used prophylactically.
Duration: since 2015
Funded by: Helmholtz Validation Fund, Pre4D program, CARB-X, DZIF
Antiviral agents
Chikungunya - Virus
The chikungunya virus is transmitted by mosquitoes, causes severe muscle and joint pain and headaches and is accompanied by a high fever. Newborns, the elderly and people with chronic illnesses are at risk of severe cases. Originally, the virus was mainly found in South East Asia and Africa, but has been spreading worldwide for some time, including to Europe, in line with the spread of mosquitoes. There is currently no specific treatment.
In collaboration with Prof. J. Diez, Barcelona and funded by the European Commission, we screened the EU-OPENSCREEN substance library of approx. 100,000 substances for substances that inhibit the replication of the Chikungunya virus. We were able to use a reporter virus that contained luciferase in the genome so that the luciferase activity was a measure of the number of virus particles. We were also able to quantify the cytopathic effects caused by the virus.
To achieve a sufficiently high substance throughput and to minimize substance consumption, 384well microtiter plates were used for the assay. The substance plates were prepared by transferring 100 nL of the substance solutions through the Echo®550 acoustic dispenser. The actual infection assay was performed in the S3** laboratory. The same protocol was also used to investigate the anti-Chikungunya activity of natural products or other chemically synthesized substances. Some very promising substances were identified, which were further investigated in a medicinal chemistry project (funded by EU-OPENSCREEN).
Metabolome studies were carried out to investigate the interaction between the virus and host cells in more detail, and CRISPR-Cas9 technology was established. The aim is to identify new targets for active substances that can be addressed by specific tests.
Duration of the project: since 2020
Funded by: European Commission through a demonstration project of the EU-OPENSCREEN research infrastructure and through a cooperation project within the framework of cooperation with Southeast Asia;
Fellowship from the Alexander von Humboldt Foundation
SARS-CoV-2
The outbreak of the Covid-19 pandemic triggered global efforts to find active substances to treat this disease, as most of the known antiviral drugs did not have a satisfactory effect against SARS-CoV-2. We used the EU-OPENSCREEN substance library (approx. 100,000 substances) in screening campaigns.
In cooperation with Prof. E. Kierzek, Polish Academy of Sciences, Poznan and funded by the European consortium of research infrastructures ISIDORe, a test was established that can be used to search for intercalators in conserved RNA secondary structures in a largely automated manner. After determining the effective concentration ranges (IC50 values), the activity of the substances is checked in the infection assay with SARS-CoV-2. An automated test facility is also available in the S3 laboratory for this purpose.
Duration: 2020 - 2025
Funded by: European Commission through the European Research Infrastructures Network ISIDORe
Preparing for future pandemics: COMBINE
The Marburg virus will be used to develop strategies for the prevention and treatment of future viral infections. The project is coordinated by Prof. Christian Sieben (HZI). The task of the COPS working group / CBIO department is to search for inhibitors of interactions between phosphatidylserine, viral glycoproteins and viral proteins with their respective receptors on the surface of host cells. These inhibitors are intended to prevent the uptake of virus particles into cells and thus the infection of the cells. The EU-OPENSCREEN library as well as natural products and target-specific libraries are used as substance libraries. In order to achieve a sufficient throughput of substances, the aim is to automate the tests as far as possible. Further information can be found at www.combine-MARV.eu.
Duration: 2025 - 2029
Funded by: European Commission
