Interfakultäres Institut für Mikrobiologie und Infektionsmedizin

Research Interests

Mucosal Immunity and Microbiome

In recent years, the intestinal microbiota and its influence on the host has gained more and more attention. Not only by microbiologists but also by immunologists, clinicians or even i.e. neurologists. The fact that the intestinal microbiota does not only help its host organism to metabolize nutrients, but also influences generalized body functions such as the immune system, reveals the impact of the gut and its residents on the well-being of the host.

It is known that the composition of the intestinal microbiota greatly influences the outcome and progress of a variety of pathologies. Among these pathologies, our group focuses on various autoimmune diseases. Although generalized effects of the intestinal microbiota on disease outcome are known, underlying molecular mechanisms of the interplay between the gut microbiota and the host immune system are less well understood. However, this understanding is crucial for a prospective microbiota-related therapy of gut-microbiota associated pathologies. We therefore do not focus on pathogens, but rather on commensal bacteria. Although being commensal, which means that they usually belong to a common and “healthy” microbiota, these microbes may provide differential effects on the host organism and this observation makes intestinal commensals important for the understanding of host-microbiota-interactions.

The aim to use microbiota-derived components as therapeuticals or to identifiy novel drug targets in the host, leads to several questions our group addresses to: (1) which bacterial components are the most potent immune system regulators? (2) could these bacterial components be used as potential drugs for inflammatory disorders? (3) what happens inside the host organism after encounter with specific commensals on a molecular level and (4) do these molecular insights help to identify novel drug targets for the treatment of inflammatory disorders?

Therefore, a deeper understanding in how certain gut commensal bacteria adapt to their host is of equal importance as the detailed effects on the immune system of the host.

Current Projects

Work on strategies of symbiotic and pathobiontic commensals to colonize the gut and how they survive in the healthy and inflamed intestine.

Dr. rer. nat. Anna Lange

Pathobionts like E. coli colonize the gut in very low amounts and symbiotic commensals in high abundance the must use different metabolic pathways to grow and reside in the gut ecosystem. Based on genome sequencing certain pathways are investigated.

 

Immunomodulatory properties of E. coli Nissle flagella

Thomas Hagemann, PhD student and Lena Michaelis, PhD Student

E. coli Nissle is a probiotic bacterial strain which is known to promote intestinal homeostasis. As many other bacteria, this strain contains a flagellum, making it a motile bacterium. The flagellum is built up of the FliC protein and we are interested how the E. coli Nissle flagella in general, and FliC in specific, help to promote E.coli Nissle mediated intestinal homeostasis. Answering this question might allow to elucidate future therapeutic approaches using isolated FliC protein in patients with Inflammatory Bowel Diseases.

 

 

Commensals and their impact on Th17 immune responses

Lena Michaelis, PhD student

Th17 immune responses are known to contribute to the progress auf autoimmune diseases. We therefore have a closer look, how distinct commensal bacteria differentially promote or prevent Th17 responses on the host, on a systemic and molecular level.

 

Immune signaling during infection in a novel animal model: Galleria melonella

Dr. rer. nat. Anna Lange

Due to strict regulations concerning animal grants and for ethical reasons we seek to establish an substitute invertebrate host model, which can be used to analyze the effect of certain microbes both commensals and pathogens on the innate immune system of Galleria mellonella. As the innate immune system is highly conversed among mammals and insects such substitute models can be used prior to experiments with mammals.