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Stange, E.-L.

Publications and source records attributed to Stange, E.-L..

5 recordsLinked to original sources

Swimming motility in the gut microbiota is diverse and increased in inflammation.

Swimming motility has long been studied as a virulence mechanism of enteric pathogens, while the resident microbiota's motility has only been inferred from proxies or explored through a few model species. This study presents a direct, functional analysis of gut bacterial motility in health and inflammation. Using phase-contrast microscopy and high-throughput 3D tracking, we quantified motile bacteria and characterized their swimming behaviours directly in diluted fresh gut content. In healthy mice, fewer than 3% of bacteria were motile along the digestive tract, and their swimming patterns were dominated not by the run-tumble behavior of model gut species but by diverse behaviours rich in reverses. In five mouse models with intestinal inflammation (spanning chemical, genetic, dietary and infectious etiologies) the motile fraction rose by at least 4-fold, correlating with elevated Lipocalin-2 where measured. Reverse-rich patterns remained prevalent in these inflamed conditions, with the notable exception of Salmonella infection. Paired metagenomics and metatranscriptomics showed enrichment of flagellar genes, while communities transferred into cecal water from inflamed mice raised their motile fraction within an hour, indicating that the rise reflects both enrichment of motile taxa and rapid modulation within existing populations. In vitro assays with human-derived isolates confirmed motility across several phyla, with variability down to strain level, and identified oxygen and viscosity as key modulators. These findings support increased motility as a hallmark of the inflamed gut and challenge established assumptions about gut bacterial motility.

microbiology↗

Neonatal liver niches program T cell tolerance

After birth, the immune system must learn to tolerate a rapidly changing milieu of commensals and self while remaining ready for pathogens. Here we characterize the neonatal liver as a central hub in this process: In postnatal week 1-2, the liver hosts a developmentally encoded, microbiota-independent expansion of regulatory T cells (Tregs) that coexists with microbiota-tuned conventional wave of activated CD4 T cells (Tconvs). Mechanistically, the Treg expansion is governed by MHCII-mediated antigen presentation by CCR7+ cDC1s, which establish tolerogenic DC:T cell clusters in the liver parenchyma, allowing for local expansion and control via PD-L1 checkpoints that selectively increase Tregs without unleashing Tconvs. Importantly, this transient, neonatal program predisposes hepatotropic viral infections to progress toward chronic disease but also protects the adult liver from steatotic disease. These data position the neonatal liver as a unique site of early life T-cell education with timing-sensitive implications for early-life interventions.

immunology↗

Cross-species analyses reveal RORγt-expressing dendritic cells are a lineage of antigen presenting cells conserved across tissues

Conventional dendritic cells (cDCs) are potent antigen presenting cells (APCs) that exhibit tissue and age-specific diversity allowing them to direct situation-adapted immunity. Thereby they harbor great potential for being targeted in vaccination and cancer. Here, we resolve conflicting data about expression of retinoic acid receptor-related orphan receptor-{gamma}t (ROR{psi}t) in cDCs. We show that ROR{psi}t+ DCs exist in murine lymphoid and non-lymphoid tissues across age. Fate mapping, functional assays and single cell multiomic profiling reveal these cells as ontogenetically and transcriptionally distinct from other well characterized cDC subtypes, as well as from ROR{psi}t+ type 3 innate lymphocytes (ILC3s). We show that ROR{psi}t+ DCs can migrate to lymph nodes and activate naive CD4+ T cells in response to inflammatory triggers. Comparative and cross-species transcriptomics revealed homologous populations in human spleen, lymph nodes and intestines. Further, integrated meta-analyses aligned ROR{psi}t+ DCs identified here with other emerging populations of ROR{psi}t+APCs, including R-DC-like cells, Janus cells/extrathymic Aire expressing cells (eTACs) and subtypes of Thetis cells. While ROR{psi}t+APCs have primarily been linked to T cell tolerance, our work establishes ROR{psi}t+ DCs as unique lineage of immune sentinel cells conserved across tissues and species that expands the functional repertoire of ROR{psi}t+ APCs beyond promoting tolerance. One sentence summaryROR{gamma}t+ DC exhibit versatile APC functions and are a distinct immune lineage conserved across age, tissues and species that entails Thetis cells, Janus cells/ROR{gamma}t+ eTACs and R-DC-like cells.

immunology↗

Neonatal Peyer's patch cDC activation as a pacemaker of postnatal immune maturation

Marked differences exist between the mucosal immune system of the neonate and adult host. The pronounced influence of the enteric microbiota in adults suggests a causal relationship between postnatal colonization and immune maturation. However, using metagenomic, metaproteomic, and functional immunological analyses we demonstrate an early presence of bacteria and immunogenic microbial antigens preceding immune maturation in the small intestine, the primary inductive site of intestinal immunity. Instead, transcriptomic, flow cytometric and histological analysis indicated neonatal Peyers patch (PP) mononuclear phagocytes (MNP) as rate limiting factor of postnatal immune maturation. Despite the early presence of MNPs, conventional dendritic cells (cDC) of type 1, 2a and 2b exhibited significant age-dependent differences in tissue distribution and cellular composition. Single cell transcriptional profiling and functional assays revealed decreased antimicrobial and antigen processing/presentation capacity, an overall retarded cell maturation and reduced antigen uptake. In cDC2a this resulted in a reduced proportion of CCR7+ migratory cells and a consequent defect in CD4 T cell priming. Interestingly, transcriptional profiling of neonatal DC subsets identified reduced expression of type I interferon (IFN)-stimulated genes (ISG). Type I IFN induction by oral administration of the TLR7 agonist R848 accelerated MNP maturation and enhanced cognate antigen CD4 T cell priming. However, humoral responses to oral vaccination in the presence of R848 were significantly reduced. Together, our results identify PP MNP maturation as pacemaker of postnatal mucosal immune priming, indicate the biological role of delayed maturation and demonstrate that targeted interventional strategies allow manipulation of mucosal responses in early life.

immunology↗

Staphylococcus aureus activates the Aryl Hydrocarbon Receptor in Human Keratinocytes

Staphylococcus (S.) aureus is an important pathogen causing various infections including - as most frequently isolated bacterium - cutaneous infections. Keratinocytes as the first barrier cells of the skin respond to S. aureus by the release of defense molecules such as cytokines and antimicrobial peptides. Although several pattern recognition receptors expressed in keratinocytes such as Toll-like and NOD-like receptors have been reported to detect the presence of S. aureus, the mechanisms underlying the interplay between S. aureus and keratinocytes are still emerging. Here we report that S. aureus induced gene expression of CYP1A1 and CYP1B1, responsive genes of the aryl hydrocarbon receptor (AhR). AhR activation by S. aureus was further confirmed by AhR gene reporter assays. AhR activation was mediated by factor(s) < 2 kDa secreted by S. aureus. Whole transcriptome analyses and real-time PCR analyses identified IL-24, IL-6 and IL-1beta as cytokines induced in an AhR-dependent manner in S. aureus-treated keratinocytes. AhR inhibition in a 3D organotypic skin equivalent confirmed the crucial role of the AhR in mediating the induction of IL-24, IL-6 and IL-1beta upon stimulation with living S. aureus. Taken together, we further highlight the important role of the AhR in cutaneous innate defense and identified the AhR as a novel receptor mediating the sensing of the important skin pathogen S. aureus in keratinocytes.

immunology↗