Biology subjects

Gieseck, R. L.

Publications and source records attributed to Gieseck, R. L..

3 recordsLinked to original sources

bioRxiv2026

TCF21 loss identifies a conserved inflammation-associated fibroblast state across Crohn's disease and ulcerative colitis

Background and Aims: Inflammatory bowel diseases (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), are associated with stromal remodeling; however, the fibroblast states that contribute to chronic inflammation remain incompletely defined. We aimed to identify conserved pathogenic fibroblast programs across CD and UC and determine whether these states are linked to loss of homeostatic stromal regulators. Methods: We integrated publicly available single-cell RNA sequencing datasets from healthy and inflamed intestinal tissues to define stromal populations across CD, UC, and control samples. Fibroblast subsets were annotated using cluster-specific markers and patient-level abundance analyses. Multiplex immunofluorescence of human gastrointestinal tissue microarrays assessed protein expression. Human colonic fibroblasts were stimulated with IL1B and TNF to model inflammation-associated fibroblast polarization, and restoration of homeostatic factors was evaluated using mRNA-loaded lipid nanoparticles (LNPs). Results: A conserved inflammation-associated fibroblast (IAF) population was expanded in both CD and UC and expressed inflammatory chemokines, matrix-remodeling genes, and activation markers including CXCL1, MMP3, FAP, and PDPN. In contrast, a homeostatic ADAMDEC1/TCF21-enriched fibroblast population was reduced in inflamed tissue. TCF21 expression positively correlated with ADAMDEC1 and negatively correlated with activation markers. Multiplex immunofluorescence confirmed depletion of TCF21-positive non-immune, stromal cells in IBD tissue. In vitro, IL1B and TNF induced an IAF-like phenotype and reduced TCF21. TCF21 mRNA-LNP restoration attenuated inflammatory mediators including IL1B and IL6. Conclusions: TCF21 loss identifies a conserved inflammation-associated fibroblast state across CD and UC. Restoring TCF21 partially suppresses inflammatory fibroblast programs, supporting stromal reprogramming as a therapeutic concept in IBD.

immunology↗

bioRxiv2025

L-Cells are the Functional Neuropod Cell in Human Gastrointestinal Tract and are Dysregulated in Inflammatory Bowel Disease (IBD)

Neuropod cells are a newly discovered type of enteroendocrine cell (EEC) that connect the gut and brain functionally into one circuit. In the mouse colon, neuropod cells express various peptide hormones, such as Pyy and Glp1, presynaptic proteins, and make synaptic contacts with sensory neurons. While their function is not fully elucidated, they play a significant role in relaying signals to the brainstem upon sensing nutrients and microbial factors in the gut lumen. Their occurrence in the human gastrointestinal tract is currently not established. In this study, we showed that PYY-expressing cells (L-cells) in the human colon exhibit characteristics of neuropod cells. Utilizing advanced histological methods and confocal microscopy we found that L-cells of the healthy human colon possess distinctive morphology, express synaptic proteins, and exist proximal to sensory neurons. This agrees with our meta-analysis of single-cell RNA sequencing (scRNA-Seq) data that showed that human colonic L-cells express pre- and post-synaptic genes. As inflammatory conditions could affect colonic neuropod cells, we aimed to profile the phenotypic and transcriptional changes of neuropod cells both in human and murine colon in Inflammatory Bowel Disease (IBD) and experimental colitis, respectively. In human IBD, the abundance of neuropod cells and spatial proximity to sensory neurons were decreased in the colon of ulcerative colitis (UC) and Crohns disease (CD) patients. L-cells in IBD patients display genes related to innate and adaptive immunity, including antigen presentation genes suggesting a role in immune regulation. We further confirmed the effects of intestinal inflammation in neuropod cells by utilizing the DSS mouse model of colitis, where we showed that acute DSS colitis induced spatially distinct effects on the abundance of neuropod cells and impaired the synaptic connection with sensory neurons. Overall, these findings extend early murine characterizations to the human system and highlight the complex interactions between colonic neuropod cells and the enteric nervous and immune systems during inflammatory diseases.

cell biology↗

bioRxiv2025

Therapeutic Blockade of Type 2 Cytokines and PD1 Unleashes Anti-Tumor Immunity Through Coordinated Reprogramming of Innate and Adaptive Immune Surveillance

BackgroundCheckpoint inhibitors improve survival in patients with several types of tumors. However, resistance to checkpoint inhibitors creates an opportunity for patients to benefit from novel immunotherapies. The type 2 cytokines IL-4, IL-13 and TSLP have been implicated in suppressing anti-tumor immune responses through T and myeloid cells. Our current study tested whether combined therapeutic blockade of IL-4, IL-13 and TSLP improved anti-tumor immunity alone and in combination with PD1 antagonism. MethodsWe used in vitro experiments with primary cells to identify cell types likely to participate in controlling tumors upon IL-4, IL-13, TSLP and PD1 blockade. Therapeutic blockade in the subcutaneous CT26 model tested in vivo tumor growth inhibition and associated immunological changes. Bioinformatic analysis of human tumor bulk RNA sequencing data probed for survival associations with IL-4/IL-13 and TSLP transcriptional responses. ResultsIn vitro, IL-4 suppressed T cell-mediated tumor growth inhibition and reduced monocyte-derived dendritic cell expression of proteins associated with anti-tumor immunity. In vivo, blocking IL-4, IL-13, TSLP and PD1 improved tumor growth inhibition by creating "hotter" tumors. This was associated with repolarization of CD4 and CD8 T cells and shifts in monocyte, conventional type 1 and type 2 (or monocyte-derived) dendritic cell programs. Transcriptional responses to IL-4/IL-13 and TSLP were associated with poor survival outcomes across patients with several types of cancers. ConclusionTherapeutic blockade of IL-4, IL-13 and TSLP may drive immunological tumor growth inhibition in subsets of cancer patients alone and in combination with checkpoint inhibitors. Improved tumor growth inhibition was likely driven through augmented cytotoxic T cell priming in secondary lymphoid organs and improved reactivation by repolarized monocytes and dendritic cells in tumors.

cancer biology↗