Mammalian cells autonomously activate hypoxia-inducible transcription factors (HIFs) to ensure survival in low-oxygen environments. We report here that injury-induced hypoxia is insufficient to ...trigger HIF1α in damaged epithelium. Instead, multimodal single-cell and spatial transcriptomics analyses and functional studies reveal that retinoic acid-related orphan receptor γt
(RORγt
) γδ T cell-derived interleukin-17A (IL-17A) is necessary and sufficient to activate HIF1α. Protein kinase B (AKT) and extracellular signal-regulated kinase 1/2 (ERK1/2) signaling proximal of IL-17 receptor C (IL-17RC) activates mammalian target of rapamycin (mTOR) and consequently HIF1α. The IL-17A-HIF1α axis drives glycolysis in wound front epithelia. Epithelial-specific loss of IL-17RC, HIF1α, or blockade of glycolysis derails repair. Our findings underscore the coupling of inflammatory, metabolic, and migratory programs to expedite epithelial healing and illuminate the immune cell-derived inputs in cellular adaptation to hypoxic stress during repair.
Abstract
TCR stimulation triggers Ca
2+
signals that are critical for T cell function and immunity. Several pore-forming α and auxiliary β subunits of voltage-gated Ca
2+
channels (VGCC) were ...reported in T cells, but their mechanism of activation remains elusive and their contribution to Ca
2+
signaling in T cells is controversial. We here identify Ca
V
β1, encoded by
Cacnb1
, as a regulator of T cell function.
Cacnb1
deletion enhances apoptosis and impairs the clonal expansion of T cells after lymphocytic choriomeningitis virus (LCMV) infection. By contrast,
Cacnb1
is dispensable for T cell proliferation, cytokine production and Ca
2+
signaling. Using patch clamp electrophysiology and Ca
2+
recordings, we are unable to detect voltage-gated Ca
2+
currents or Ca
2+
influx in human and mouse T cells upon depolarization with or without prior TCR stimulation. mRNAs of several VGCC α1 subunits are detectable in human (Ca
V
3.3, Ca
V
3.2) and mouse (Ca
V
2.1) T cells, but they lack transcription of many 5’ exons, likely resulting in N-terminally truncated and non-functional proteins. Our findings demonstrate that although Ca
V
β1 regulates T cell function, these effects are independent of VGCC channel activity.
Angiogenesis, the growth of new blood vessels from pre-existing vessels, occurs during development, injury repair, and tumorigenesis to deliver oxygen, immune cells, and nutrients to tissues. Defects ...in angiogenesis occur in cardiovascular and inflammatory diseases, and chronic, non-healing wounds, yet treatment options are limited. Here, we provide a map of the early angiogenic niche by analyzing single-cell RNA sequencing of mouse skin wound healing. Our data implicate Langerhans cells (LCs), phagocytic, skin-resident immune cells, in driving angiogenesis during skin repair. Using lineage-driven reportersw, three-dimensional (3D) microscopy, and mouse genetics, we show that LCs are situated at the endothelial cell leading edge in mouse skin wounds and are necessary for angiogenesis during repair. These data provide additional future avenues for the control of angiogenesis to treat disease and chronic wounds and extend the function of LCs beyond their canonical role in antigen presentation and T cell immunity.
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•scRNA sequencing provides a map of the angiogenic niche during skin repair•Langerhans cells upregulate angiogenic mRNAs after injury•Langerhans cells localize to angiogenic blood vessel tips in wound beds•Langerhans cells are necessary for proper angiogenesis and repair after injury in mice
Angiogenesis repairs blood vessels after injury by creating new blood vessels from pre-existing endothelial cell networks. Using scRNA sequencing, Wasko et al. provide a map of the predicted molecular and cellular cues that drive angiogenesis and identify Langerhans cells as a major regulator of angiogenesis in murine skin wounds.
Angiogenesis, the growth of new blood vessels from pre-existing vessels, occurs during development, injury repair, and tumorigenesis to deliver oxygen, immune cells, and nutrients to tissues. Defects ...in angiogenesis in cardiovascular and inflammatory diseases, and chronic, non-healing wounds, yet treatment options are limited. Here, we provide a map of the early angiogenic niche by analyzing single-cell RNA sequencing of mouse skin wound healing. Our data implicate Langerhans cells (LCs), a phagocytic, skin-resident immune cell, in driving angiogenesis during skin repair. Using lineage-driven reporters, three-dimensional (3D) microscopy, and mouse genetics, we show that LCs are situated at the endothelial cell leading edge in mouse skin wounds and are necessary for angiogenesis during repair. These data provide additional future avenues for the control of angiogenesis to treat disease and chronic wounds and extend the function of LCs beyond their canonical role in antigen presentation and T-cell immunity.
Angiogenesis repairs blood vessels after injury by creating new blood vessels from preexisting endothelial cell networks. Using scRNA sequencing, Wasko et al. provide a map of the predicted molecular and cellular cues that drive angiogenesis and identify Langerhans cells as a major regulator of angiogenesis in murine skin wounds.
Inflammatory epithelial diseases are spurred by the concomitant dysregulation of immune and epithelial cells. How these two dysregulated cellular compartments simultaneously sustain their heightened ...metabolic demands is unclear. Single-cell and spatial transcriptomics (ST), along with immunofluorescence, revealed that hypoxia-inducible factor 1α (HIF1α), downstream of IL-17 signaling, drove psoriatic epithelial remodeling. Blocking HIF1α in human psoriatic lesions ex vivo impaired glycolysis and phenocopied anti-IL-17 therapy. In a murine model of skin inflammation, epidermal-specific loss of HIF1α or its target gene, glucose transporter 1, ameliorated epidermal, immune, vascular, and neuronal pathology. Mechanistically, glycolysis autonomously fueled epithelial pathology and enhanced lactate production, which augmented the γδ T17 cell response. RORγt-driven genetic deletion or pharmacological inhibition of either lactate-producing enzymes or lactate transporters attenuated epithelial pathology and IL-17A expression in vivo. Our findings identify a metabolic hierarchy between epithelial and immune compartments and the consequent coordination of metabolic processes that sustain inflammatory disease.
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•HIF1α is activated in psoriatic epidermis and associated with IL-17A•Ablating epithelial HIF1α curbs vascular, nervous, and immune skin pathology•HIF1α-induced epithelial glycolysis directs multisystemic skin pathology•Lactate, a glycolysis byproduct, potentiates the underlying γδ T17 response
How immune and epithelial cells simultaneously fuel their dysfunction in chronic skin diseases is unclear. Subudhi and Konieczny et al. find that IL-17-induced epithelial HIF1α activates glycolysis, which potentiates the γδ T17 response via lactate. This metabolic circuit drives multisystems pathology and can be targeted in inflammatory disease.
Whereas the cellular and molecular features of human inflammatory skin diseases are well characterized, their tissue context and systemic impact remain poorly understood. We thus profiled human ...psoriasis (PsO) as a prototypic immune-mediated condition with a high predilection for extracutaneous involvement. Spatial transcriptomics (ST) analyses of 25 healthy, active lesion, and clinically uninvolved skin biopsies and integration with public single-cell transcriptomics data revealed marked differences in immune microniches between healthy and inflamed skin. Tissue-scale cartography further identified core disease features across all active lesions, including the emergence of an inflamed suprabasal epidermal state and the presence of B lymphocytes in lesional skin. Both lesional and distal nonlesional samples were stratified by skin disease severity and not by the presence of systemic disease. This segregation was driven by macrophage-, fibroblast-, and lymphatic-enriched spatial regions with gene signatures associated with metabolic dysfunction. Together, these findings suggest that mild and severe forms of PsO have distinct molecular features and that severe PsO may profoundly alter the cellular and metabolic composition of distal unaffected skin sites. In addition, our study provides a valuable resource for the research community to study spatial gene organization of healthy and inflamed human skin.
T cell activation and function depend on Ca
signals mediated by store-operated Ca
entry (SOCE) through Ca
release-activated Ca
(CRAC) channels formed by ORAI1 proteins. We here investigated how SOCE ...controls T cell function in pulmonary inflammation during a T helper 1 (T
1) cell-mediated response to influenza A virus (IAV) infection and T
2 cell-mediated allergic airway inflammation. T cell-specific deletion of
did not exacerbate pulmonary inflammation and viral burdens following IAV infection but protected mice from house dust mite-induced allergic airway inflammation. ORAI1 controlled the expression of genes including p53 and E2F transcription factors that regulate the cell cycle in T
2 cells in response to allergen stimulation and the expression of transcription factors and cytokines that regulate T
2 cell function. Systemic application of a CRAC channel blocker suppressed allergic airway inflammation without compromising immunity to IAV infection, suggesting that inhibition of SOCE is a potential treatment for allergic airway disease.
TCR stimulation triggers Ca
signals that are critical for T cell function and immunity. Several pore-forming α and auxiliary β subunits of voltage-gated Ca
channels (VGCC) were reported in T cells, ...but their mechanism of activation remains elusive and their contribution to Ca
signaling in T cells is controversial. We here identify Ca
β1, encoded by Cacnb1, as a regulator of T cell function. Cacnb1 deletion enhances apoptosis and impairs the clonal expansion of T cells after lymphocytic choriomeningitis virus (LCMV) infection. By contrast, Cacnb1 is dispensable for T cell proliferation, cytokine production and Ca
signaling. Using patch clamp electrophysiology and Ca
recordings, we are unable to detect voltage-gated Ca
currents or Ca
influx in human and mouse T cells upon depolarization with or without prior TCR stimulation. mRNAs of several VGCC α1 subunits are detectable in human (Ca
3.3, Ca
3.2) and mouse (Ca
2.1) T cells, but they lack transcription of many 5' exons, likely resulting in N-terminally truncated and non-functional proteins. Our findings demonstrate that although Ca
β1 regulates T cell function, these effects are independent of VGCC channel activity.
