Contact
Director
Univ.-Prof. Dr. rer. nat. Oliver Pabst
phone: +49 241 80-85496
opabstukaachende
AG Pabst (ukaachen.de)
Office:
Betül Aycicek
Tel.: +49 241 80-85686
Fax: +49 241 80-82094
baycicekukaachende
Ebene 5, Gang D, Raum 20
Postdocs
Doctoral candidates
My project:
Intestinal tumors exploit the intricate immune mechanisms responsible for gut homeostasis to ensure their growth and survival. For instance, a common observation in intestinal tumors is the increased frequencies of Regulatory T cells (Tregs), which suppress immune responses. Furthermore, these tumors often give rise to liver metastasis, thus creating a significant challenge for cancer treatment. My goal is to understand how early tumoral changes leads to the accumulation of tumor Tregs in the intestine and their subsequent impact on secondary sites, such as the liver. Using techniques such as high-end spectral flow cytometry, single-cell sequencing, and multiplex immunostaining, I am characterizing the changes in phenotype, function, and localization of gut and liver immune cells during the earliest stages of tumor development. We anticipate that understanding these mechanisms could pave the way for novel therapeutic approaches aimed at mitigating tumor progression.
My project:
Dendritic cells (DCs) are the most important antigen-presenting cells orchestrating both immunogenic and tolerogenic adaptive immune responses. Their key role lies in their ability to sense their environment and migrate from peripheral tissues to lymph nodes, where they present peripherally acquired antigens to T cells. DC migration can be induced by inflammatory stimuli, but there is also a constant migration of DCs that occurs in the absence of overt inflammation and favors the induction of peripheral tolerance. I aim to examine this homeostatic migration of DCs. To this end, I am characterizing in vivo migration kinetics by combining single cell transcriptomic and FACS-based methods with in situ labeling of cells and other approaches to obtain high-resolution spatio-temporal information on DC phenotypes and pool sizes. We expect that a holistic understanding of DC migration will shed new light on how tolerance and immunity are balanced in the intestinal immune system.
Katharina Kunesch
Katharina Kunesch
phone: +49 241 80-37764
Kkuneschukaachende
My project:
Immunoglobulin A (IgA) is a key host factor that regulates the composition and distribution of the gut microbiota and the defence against enteropathogens. IgA is produced by plasma cells in the intestinal lamina propria and is a fundamental element in organising a complex network of interactions between the intestinal epithelium, the microbiota and the immune system. However, despite its importance, the effects of IgA on the integrity and function of the intestinal barrier are poorly understood. Therefore, my aim is to understand the function of IgA on intestinal epithelial cells and the intestinal barrier. To this end, I am investigating epithelial cell function and phenotype in the absence of IgA, as well as the spatio-phenotypic characteristics of plasma cells using a newly established AI-based image analysis pipeline. We anticipate that this knowledge will be critical in developing a comprehensive understanding of the gut barrier and it's defects in human disease.
Hormoz Noormohammadian
Hormoz Noormohammadian
phone: +49 241 80-37623
hnoormohammaukaachende
My project:
In humans, approximately 5 g of immunoglobulin A is produced per day, making IgA the most abundant antibody at all. IgA coats commensal bacteria in the gut and affects their growth, motility, metabolism, bile acid sensitivity and interactions with the host. Surprisingly, however, we know little about the actual targets of IgA at the molecular level. I am developing a systematic approach to better define IgA targets in the intestinal immune system. I combine FACS-based enrichment of transposon mutant libraries stained with IgA and high content identification of transposon insertion sites. We expect that a deeper understanding of IgA targets will ultimately be an important step towards therapeutic manipulation of the gut microbiota.
My project:
Tolerance and immunity in the gut are a balancing act - not only is the gut constantly exposed to foreign material such as food and the microbiota, but the mucosal surface is also a critical site for infection. Secretory antibodies in the gut lumen play a crucial role in this balancing act. They support tolerance and peaceful coexistence between the gut microbiota and the host, but also provide potent immunity against pathogens. A key to understanding how these systems work are the plasma cells that produces the antibodies. Therefore, my goal is to better understand intestinal plasma cells. I use high dimensional flow cytometry and single cell sequencing to define how age, microbiota composition and plasma cell origin affect their functions in the tissue. This knowledge is integrated with an exciting development in the field that considers plasma cells as a dynamic and functionally diverse cell type.