The Junior Research Group “Intestinal immune regulation” was established in 2018. Our main focus is the role of antigen-specific Th cells in human immune responses. T helper (Th) cells are central organizers of immune responses. Via their T cell receptor, they are able to recognize a specific antigen. By releasing different effector cytokines, they can initiate a particular immune response appropriate to the antigen. However, inappropriate or too strong immune reactions can lead to immune pathologies, such autoimmunity, chronic inflammation or allergies. A specialized Th cell subpopulation, the regulatory T cells (Tregs) on the other hand, have suppressive properties. This enables them to dampen or even prevent the immune response against a certain antigen.

However, which T cells react against a particular antigen, which antigens are at all recognized and how protective immunity and tolerance is maintained or disrupted is in many clinically situations not known. Using novel approaches to analyse directly ex vivo antigen-reactive Th cells we are conducting studies to understand why in patients with chronic inflammatory diseases, such as inflammatory bowel disease or allergies, tolerance mechanisms fail. Antigen-reactive Th cell analysis can be combined with powerful state-of-the-art analytical technologies, such as multidimensional flow cytometry, (single cell) transcriptomics, TCR sequencing and proteomics, to provide single cell information at high resolution. We aim to elucidate the interaction between environmental factors and microbial and inflammatory processes that lead to dysfunctions and inflammation. The analysis of these fundamental processes directly in cells from the human immune system will significantly advance our understanding of basic mechanisms underlying human immune-mediated diseases and speed up the development of new diagnostic as well as therapeutic strategies for chronic inflammatory diseases, autoimmunity or allergy.