Pure intestinal epithelial cells have been difficult to isolate and in situ are relatively unordered/intermixed with regard to the different cell types. Recent development of organoid culture systems, which reflect near physiological growth and differentiation patterns have been a crucial step forward and have stimulated a vast number of mechanistic studies. We have adopted this technology and are currently further refining the approach for dissecting and reconstructing the intestinal barrier with its microbes and underlaying immune cells .
We employ human and murine organoid models generated from tissue resident ISC, as well as iPSC cell lines. Especially for rare genetic diseases like monogenic disorders, iPSC-derived tissue like organoids and immune cells are advanced models to study complex interactions, signals and drug response in specific genotypes.
To better understand the pathogenesis of IBD, studies on the dynamic processes occurring at the host–microbe interface and the mutual interactions between IECs and the cells involved in the maintenance of local immune homeostasis are critical. We utilize 2D-organoid monolayer systems to investigate barrier function, use co-culture systems to examine the crosstalk between IECs, microbes and immune cells and use transplantation of murine organoids, e.g. to assess the malignant potential of mutations. We also aim to identify actionable molecular switches for correcting cellular functions. Various CRISPR/Cas9 strategies (genome editing, transcriptional inhibition [CRISPRi], transcriptionally activating [CRISPRa)], Cas9 guided DNA-methylation are currently established.
The aims of this technology focus are
- To create a resource for genetically characterized stem-cell and organoid-based cellular models for investigating inflammatory responses in IBD
- To systematically and mechanistically dissect fixed inflammatory network states in patient derived cells through genome and epigenome editing technologies.
- To use the cellular model systems for assessing individualized therapeutic targets based on genetic and epigenetic findings (“clinical studies in a dish”)
- Our long-term vision foresees the use of these technologies to pharmacologically and (epi-) genetically modify specific cell types from individual patients, e.g., to achieve therapeutic restoration of normal immune homeostasis.