Neuroimmunology of the gastrointestinal system: from embryo to clinical application
In the last decade, major scientific advances have been made in the field of neuroimmunology and researchers have managed to decipher how immune cells in the gastrointestinal tract communicate with the gut nervous system (Muller et al, 2014; Gabanyi et al, 2016). Studies investigating the so-called gut-brain axis, or more generally the microbiome-gut-brain axis, have multiplied in recent years, shedding light on the molecular dialogue between gut flora, muscularis macrophages and the enteric nervous system (ENS) (Schepper et al, 2018). Inflammatory bowel diseases, such as ulcerative colitis and Crohn’s disease, impose a heavy burden on healthcare systems (450 million patients worldwide). These patients also often complain of long-term motility disorders (diarrhea, constipation) between acute episodes. The molecular milieu and signalling pathways involved in mucosal immunity and the inflammatory response have been largely characterized, but how mucosal inflammation affects ENS and motility in the long term is still poorly understood.
The goal of the Macrophage Research Group of the Stem Cell and Experimental Embryology Laboratory is to complement the scientific consensus in the field of gastrointestinal neuroimmunology with clinical, pathophysiological perspectives on IBD. Using our strong background in microscopic techniques (fluorescence and electron microscopy) and morphology, as well as molecular and functional studies, we could gain detailed insights into how mucosal inflammation affects ENS at the morphological and molecular level.
Given our laboratory’s strong research background in lymphoid organ and intestinal development, we have the opportunity to use vertebrate embryological models to map the origin of myeloid cells in the intestinal wall. Thus, in parallel with the study of adult mammalian and human models, we would like to explore the developmental aspects of gut immunology.
Techniques used:
- Basic organ isolation techniques and surgical interventions in mice and chicken embryos: colon removal, whole-mount preparation; retroorbital blood sampling, tail vein injection; chicken embryo isolation from egg, chorioallantoic membrane culture, simple embryo-manipulation techniques
- Routine histology techniques: fixation, frozen gelatin block preparation, paraffin-embedding, frozen sections with cryostat, use of microtome
- Immunohistochemistry and immunofluorescence on frozen and paraffin sections
- Preparation of samples for electron microscopy, preparation of ultra-thin sections from LR-white and frozen blocks. Pre- and postembedding immuno-electron microscopy
- RNAscope dual-labeling, IHC-RNAscope multiplexing
- RNA isolation from organs, qRT-PCR
- Fluorescence and confocal microscopy, software morphometry, cell counting and image analysis with ZEN and ImageJ software
- Basic statistical visualisations and bioinformatics data processing in R software environment (Volcano-plot, ggplot2 – heatmap generation, fGSEA, String-map generation)
Collaboration partners:
- Krisztina Kovács and Szilamér Ferenczi: Institute of Experimental Medicine, Molecular Neuroendocrinology Group: DSS-colitis induction, qRT-PCR.
- Zoltán Varga: Semmelweis University, Department of Pharmacology and Pharmacotherapy, Cardiovascular and metabolic research group: RNAscope
- Semmelweis University, 1st Department of Surgery and Interventional Gastroenterology: human gut biopsies
Muller, P. A., Koscsó, B., Rajani, G. M., Stevanovic, K., Berres, M. L., Hashimoto, D., … Bogunovic, M. (2014). Crosstalk between muscularis macrophages and enteric neurons regulates gastrointestinal motility. Cell, 158(2), 300–313. https://doi.org/10.1016/j.cell.2014.04.050
Gabanyi, I., Muller, P. A., Feighery, L., Oliveira, T. Y., Costa-Pinto, F. A., & Mucida, D. (2016). Neuro-immune Interactions Drive Tissue Programming in Intestinal Macrophages. Cell, 164(3), 378–391. https://doi.org/10.1016/j.cell.2015.12.023
De Schepper, S., Verheijden, S., Aguilera-Lizarraga, J., Viola, M. F., Boesmans, W., Stakenborg, N., … Boeckxstaens, G. (2018). Self-Maintaining Gut Macrophages Are Essential for Intestinal Homeostasis. Cell, 175(2), 400-415.e13. https://doi.org/10.1016/j.cell.2018.07.048