Lena Ostermann has been a researcher at Hannover Medical School (MHH) since 2019 in the working group led by Prof. Ulrich Maus, working in particular on the causes and possible therapeutic approaches for pneumonia. In her award-winning project, “S100A9 is indispensable for survival of pneumococcal pneumonia in mice”, the basic researcher investigated how specific proteins affect the course and severity of pneumoccal pneumonia. Worldwide, a great many people fall ill with bacterial pneumonia, which then leads to a high death rate. A characteristic of bacterial pneumonia is the normally massive pulmonary recruitment of neutrophilic granulocytes which releases, alongside many other inflammatory mediators, in particular specific proteins of the S100 family, namely S100A8 and S100A9, at the inflammation site. S100A8 and S100A9 belong to the family of calcium-binding proteins. Due to their capacity as complex chelating agents, S100A8/A9 proteins are able to regulate the availability of various metal ions at the inflammation site and thus inhibit the growth of bacterial pathogens. In her study, Lena Ostermann was able to show that S100A9 in the bronchoalveolar lavage of patients with bacterial, but not viral pneumonia, is significantly increased. From this, the working group concludes that S100A9 represents a highly promising biomarker for differentiation of patients with bacterial versus viral pneumonia. In addition, they were able to show in a preclinical model that S100A8/A9 strongly reduces the bacterial growth both in the mouse as well as in the cell culture by binding important metal ions. Furthermore, the reduced microbial load in the lungs of wild-type mice was accompanied by a reduced activation of inflammatory cells, which in turn protected the lungs of the mice from infection-related damage to the pulmonary tissue and thus significantly improved their chance of survival.

In short, Lena Ostermann was able to show that S100A8/A9 proteins are important anti-bacterial effector proteins, which substantially weaken the course and severity of  pneumococcal pneumonia. „With these results, we have been able to lay the foundation for therapy options for patients with bacterial pneumonia. We will continue to build on this knowledge and to work towards reducing the morbidity and lethality of bacterial pneumonias“ says Ms Ostermann.

We congratulate Ms Ostermann on her successful project and the highly promising results and we are already looking forward to her poster at the next DZL  Annual Meeting.

Text: BREATH/UM, AB

Photo: Michael Haggenmüller