Biology subjects

Clausen, B. E.

Publications and source records attributed to Clausen, B. E..

4 recordsLinked to original sources

bioRxiv2026

E-cadherin maintains oral Langerhans cell barrier surveillance to preserve microbiota-dependent immune homeostasis

Langerhans cells (LC) are specialized antigen-presenting cells that form a dense immune surveillance network within the oral epithelium. There, they continuously interact with epithelial cells and the resident microbiota to maintain mucosal homeostasis. A defining feature of LC is their highly dendritic morphology, which enables efficient sampling of the environment at barrier surfaces. Although E-cadherin-mediated adhesion has been implicated in LC-epithelial cell interactions, its role in oral LC biology and periodontal immune homeostasis remains elusive. Here, we investigated the function of E-cadherin on oral LC using CD11c-specific E-cadherin-deficient (CD11c-EcadDEL) mice. Loss of E-cadherin profoundly altered LC morphology throughout the oral mucosa, resulting in reduced dendrite formation and impaired dendrite extension towards the epithelial surface, thereby disrupting interaction with the oral microbiota. While the total number of LC remained unchanged, E-cadherin deficiency significantly altered the relative distribution of LC subsets, characterized by reduced LC1 and increased LC2 populations. E-cadherin-deficiency was associated with pronounced oral dysbiosis, characterized by increased bacterial burden and microbial diversity, as well as a shift away from the commensal-dominated community, particularly through the loss of protective lactobacilli. Transcriptome analysis of gingival tissue revealed inflammatory reprogramming marked by enrichment of NF-{kappa}B, TNF, IL-17, Toll-like receptor, and MAPK signaling pathways. Consistently, CD11c-EcadDEL mice exhibited increased IL-17A production in the gingiva, expansion of {beta} and {gamma}{delta} T cells, spontaneous age-dependent alveolar bone loss, and exacerbated inflammatory bone destruction in a model of ligature-induced periodontitis. In summary, our findings reveal that E-cadherin preserves oral LC dendrite organization and microbiota-dependent immune homeostasis, thereby limiting dysbiosis-driven inflammation and periodontal bone loss.

immunology↗

bioRxiv2025

Langerhans Cells Regulate Tongue Intraepithelial Innervation in a Microbiota- and Age-Dependent Manner

Oral Langerhans cells (LCs) are well recognized for their immunological roles, but their involvement in other physiological processes remains poorly understood. This study identifies a novel function of oral LCs in regulating tongue epithelial innervation. Postnatal LC development coincides with the establishment of local innervation, and LC depletion impairs innervation and alters nociceptive responses, underscoring their neuroimmune function. This function is driven by LC-derived IL-1{beta}, which stimulates basal epithelial cells to produce nerve growth factor (NGF), thereby promoting sensory nerve growth. Transcriptomic analyses revealed neuronal-related pathways enriched in LCs. Aging reduces LC frequency, NGF expression, and epithelial innervation, linking neuroimmune regulation to epithelial aging. While LC frequencies in the tongue remain unaffected in germ-free mice, the microbiota is essential for optimal LC function and NGF production. These findings expand our understanding of oral LCs, revealing their pivotal role in epithelial innervation beyond immune surveillance.

immunology↗

bioRxiv2022

Epidermal maintenance of Langerhans cells relies on autophagy-regulated lipid metabolism

Macroautophagy (often-named autophagy), a catabolic process involving autophagy-related (Atg) genes, prevents accumulation of harmful cytoplasmic components and mobilizes energy reserves in long-lived and self-renewing cells. Autophagy deficiency affects antigen presentation in conventional dendritic cells (DCs) without impacting their survival. However, previous studies did not address epidermal Langerhans cells (LCs). Here, we demonstrate that deletion of either Atg5 or Atg7 in LCs leads to their gradual depletion. ATG5-deficient LCs showed metabolic dysregulation and accumulated neutral lipids. Despite increased mitochondrial respiratory capacity, they were unable to process lipids, eventually leading them to ferroptosis. Finally, metabolically impaired LCs upregulated proinflammatory transcripts and showed decreased expression of neuronal interaction receptors. Altogether, autophagy represents a critical regulator of lipid storage and metabolism in LCs, allowing their maintenance in the epidermis.

immunology↗

bioRxiv2021

Specialized subsets of innate-like T cells and dendritic cells protect from lethal pneumococcal infection in the lung

Innate-like T cells, including invariant natural killer T (iNKT) cells, mucosal-associated invariant T (MAIT) cells and {gamma}{delta} T cells, are present in various barrier tissues, including the lung. They carry out protective responses during infections, but the mechanisms for protection are not completely understood. Here, we investigated their roles during pulmonary infection with Streptococcus pneumoniae. Following infection, innate-like T cells rapidly increased in lung tissue, in part through recruitment, but TCR activation and cytokine production occurred mostly in IL-17-producing NKT17 and {gamma}{delta} T cells. NKT17 cells were preferentially located outside the vasculature prior to infection, as were CD103+ dendritic cells (cDC1), which were important both for antigen presentation to NKT17 cells and {gamma}{delta} T cell activation. Whereas IL-17A-producing {gamma}{delta} T cells also were numerous, GM-CSF was exclusive to NKT17 cells and contributed to iNKT cell-mediated protection. These studies demonstrate how particular cellular interactions and responses of functional subsets of innate-like T cells contribute to protection from pathogenic lung infection.

immunology↗