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Pro-inflammatory CD4+ T cells are major drivers of autoimmune diseases, yet therapies modulating T cell phenotypes to promote an anti-inflammatory state are lacking. Here, we identify T helper 17 (TH17) cell plasticity in the kidneys of patients with antineutrophil cytoplasmic antibody-associated glomerulonephritis on the basis of single-cell (sc) T cell receptor analysis and scRNA velocity. To uncover molecules driving T cell polarization and plasticity, we established an in vivo pooled scCRISPR droplet sequencing (iCROP-seq) screen and applied it to mouse models of glomerulonephritis and colitis. CRISPR-based gene targeting in TH17 cells could be ranked according to the resulting transcriptional perturbations, and polarization biases into T helper 1 (TH1) and regulatory T cells could be quantified. Furthermore, we show that iCROP-seq can facilitate the identification of therapeutic targets by efficient functional stratification of genes and pathways in a disease- and tissue-specific manner. These findings uncover TH17 to TH1 cell plasticity in the human kidney in the context of renal autoimmunity.
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Análisis de la Célula Individual , Células Th17 , Animales , Humanos , Ratones , Células Th17/inmunología , Glomerulonefritis/inmunología , Glomerulonefritis/genética , Plasticidad de la Célula/inmunología , Plasticidad de la Célula/genética , Riñón/inmunología , Riñón/patología , Ratones Endogámicos C57BL , Sistemas CRISPR-Cas , Colitis/inmunología , Colitis/genética , Inflamación/inmunología , Inflamación/genética , Femenino , Masculino , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas/inmunologíaRESUMEN
BACKGROUND: Circulating tumor cells (CTCs) hold immense promise for unraveling tumor heterogeneity and understanding treatment resistance. However, conventional methods, especially in cancers like non-small cell lung cancer (NSCLC), often yield low CTC numbers, hindering comprehensive analyses. This study addresses this limitation by employing diagnostic leukapheresis (DLA) to cancer patients, enabling the screening of larger blood volumes. To leverage DLA's full potential, this study introduces a novel approach for CTC enrichment from DLAs. METHODS: DLA was applied to six advanced stage NSCLC patients. For an unbiased CTC enrichment, a two-step approach based on negative depletion of hematopoietic cells was used. Single-cell (sc) whole-transcriptome sequencing was performed, and CTCs were identified based on gene signatures and inferred copy number variations. RESULTS: Remarkably, this innovative approach led to the identification of unprecedented 3,363 CTC transcriptomes. The extensive heterogeneity among CTCs was unveiled, highlighting distinct phenotypes related to the epithelial-mesenchymal transition (EMT) axis, stemness, immune responsiveness, and metabolism. Comparison with sc transcriptomes from primary NSCLC cells revealed that CTCs encapsulate the heterogeneity of their primary counterparts while maintaining unique CTC-specific phenotypes. CONCLUSIONS: In conclusion, this study pioneers a transformative method for enriching CTCs from DLA, resulting in a substantial increase in CTC numbers. This allowed the creation of the first-ever single-cell whole transcriptome in-depth characterization of the heterogeneity of over 3,300 NSCLC-CTCs. The findings not only confirm the diagnostic value of CTCs in monitoring tumor heterogeneity but also propose a CTC-specific signature that can be exploited for targeted CTC-directed therapies in the future. This comprehensive approach signifies a major leap forward, positioning CTCs as a key player in advancing our understanding of cancer dynamics and paving the way for tailored therapeutic interventions.
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Biomarcadores de Tumor , Carcinoma de Pulmón de Células no Pequeñas , Leucaféresis , Neoplasias Pulmonares , Células Neoplásicas Circulantes , Fenotipo , Células Neoplásicas Circulantes/patología , Células Neoplásicas Circulantes/metabolismo , Humanos , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico , Carcinoma de Pulmón de Células no Pequeñas/patología , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/diagnóstico , Análisis de la Célula Individual/métodos , Transcriptoma , Transición Epitelial-Mesenquimal/genética , Perfilación de la Expresión Génica , Línea Celular TumoralRESUMEN
Macrophages are functionally heterogeneous cells essential for apoptotic cell clearance. Apoptotic cells are defined by homogeneous characteristics, ignoring their original cell lineage identity. We found that in an interleukin-4 (IL-4)-enriched environment, the sensing of apoptotic neutrophils by macrophages triggered their tissue remodeling signature. Engulfment of apoptotic hepatocytes promoted a tolerogenic phenotype, whereas phagocytosis of T cells had little effect on IL-4-induced gene expression. In a mouse model of parasite-induced pathology, the transfer of macrophages conditioned with IL-4 and apoptotic neutrophils promoted parasitic egg clearance. Knockout of phagocytic receptors required for the uptake of apoptotic neutrophils and partially T cells, but not hepatocytes, exacerbated helminth infection. These findings suggest that the identity of apoptotic cells may contribute to the development of distinct IL-4-driven immune programs in macrophages.
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Apoptosis , Interleucina-4 , Macrófagos , Fagocitosis , Esquistosomiasis mansoni , Animales , Ratones , Apoptosis/inmunología , Hepatocitos/inmunología , Interleucina-4/genética , Interleucina-4/metabolismo , Macrófagos/inmunología , Ratones Noqueados , Neutrófilos/inmunología , Fagocitosis/inmunología , Esquistosomiasis mansoni/genética , Esquistosomiasis mansoni/inmunología , Modelos Animales de EnfermedadRESUMEN
BACKGROUND AND AIMS: Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease characterized by biliary inflammation and fibrosis. We showed an elevated interferon γ response in patients with primary sclerosing cholangitis and in multidrug resistance protein 2-deficient ( Mdr2-/- ) mice developing sclerosing cholangitis. Interferon γ induced expression of the cytotoxic molecules granzyme B (GzmB) and TRAIL in hepatic lymphocytes and mediated liver fibrosis in sclerosing cholangitis. APPROACH AND RESULTS: In patient samples and Mdr2-/- mice, we identified lymphocyte clusters with a cytotoxic gene expression profile using single-cell RNA-seq and cellular indexing of transcriptomes and epitopes by sequencing analyses combined with multi-parameter flow cytometry. CD8 + T cells and NK cells showed increased expression of GzmB and TRAIL in sclerosing cholangitis. Depletion of CD8 + T cells ameliorated disease severity in Mdr2-/- mice. By using Mdr2-/- × Gzmb-/- and Mdr2-/- × Tnfsf10-/- mice, we investigated the significance of GzmB and TRAIL for disease progression in sclerosing cholangitis. Interestingly, the lack of GzmB resulted in reduced cholangiocyte apoptosis, liver injury, and fibrosis. In contrast, sclerosing cholangitis was aggravated in the absence of TRAIL. This correlated with elevated GzmB and interferon γ expression by CD8 + T cells and NK cells enhanced T-cell survival, and increased apoptosis and expansion of cholangiocytes. CONCLUSIONS: GzmB induces apoptosis and fibrosis in sclerosing cholangitis, whereas TRAIL regulates inflammatory and cytotoxic immune responses, subsequently leading to reduced liver injury and fibrosis.
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BACKGROUND: Complement may drive the pathology of hypertension through effects on innate and adaptive immune responses. Recently an injurious role for the anaphylatoxin receptors C3aR (complement component 3a receptor) and C5aR1 (complement component 5a receptor) in the development of hypertension was shown through downregulation of Foxp3+ (forkhead box protein 3) regulatory T cells. Here, we deepen our understanding of the therapeutic potential of targeting both receptors in hypertension. METHODS: Data from the European Renal cDNA Bank, single cell sequencing and immunohistochemistry were examined in hypertensive patients. The effect of C3aR or C3aR/C5aR1 double deficiency was assessed in two models of Ang II (angiotensin II)-induced hypertension in knockout mice. RESULTS: We found increased expression of C3aR, C5aR1 and Foxp3 cells in kidney biopsies of patients with hypertensive nephropathy. Expression of both receptors was mainly found in myeloid cells. No differences in blood pressure, renal injury (albuminuria, glomerular filtration rate, glomerular and tubulointerstitial injury, inflammation) or cardiac injury (cardiac fibrosis, heart weight, gene expression) between control and mutant mice was discerned in C3aR-/- as well as C3aR/C5aR1-/- double knockout mice. The number of renal Tregs was not decreased in Ang II as well as in DOCA salt induced hypertension. CONCLUSIONS: Hypertensive nephropathy in mice and men is characterized by an increase of renal regulatory T cells and enhanced expression of anaphylatoxin receptors. Our investigations do not corroborate a role for C3aR/C5aR1 axis in Ang II-induced hypertension hence challenging the concept of anaphylatoxin receptor targeting in the treatment of hypertensive disease.
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Complemento C3a , Hipertensión , Animales , Humanos , Ratones , Anafilatoxinas , Angiotensina II , Complemento C3a/metabolismo , Complemento C5a/metabolismo , Factores de Transcripción Forkhead , Hipertensión/genética , Ratones Noqueados , Receptor de Anafilatoxina C5a/genética , Receptores de Complemento/genética , Receptores de Complemento/metabolismoRESUMEN
INTRODUCTION: The chemokine receptor CCR4 is expressed by diverse CD4+ T cell subsets including regulatory T cells (Tregs) but its functional importance for leukocyte recruitment and the relevance of its two corresponding chemokines CCL17 and CCL22 have not been studied in immune-mediated crescentic glomerulonephritis (cGN). METHODS: Utilizing the single-cell RNA sequencing (scRNAseq) data in analyzing leukocytes isolated from both human and murine nephritic kidneys, we identified CCL17 as a potential therapeutic target in immune-mediated renal disease. Using a mouse model of murine cGN, we then delineated the effects of targeting CCL17 by neutralizing antibodies and in Ccl17 gene-deficient mice. RESULTS: Unsupervised scRNAseq analyses identified the CCL17-CCR4 axis as a mechanism potentially involved in renal T-cell migration. Analyses of functional kidney impairment and histopathological kidney damage revealed an attenuation of crescentic GN in anti-CCL17 antibody-treated mice which was corroborated using in Ccl17 gene-deficient mice. Immunohistochemical analyses revealed that these changes were accompanied by an affected renal Treg recruitment in both experimental approaches. CONCLUSION: The chemokine receptor CCR4 and its corresponding chemokine CCL17 are expressed in human and murine cGN and targeting the CCR4-CCL17 axis by neutralizing antibodies as well as Ccl17 gene deficiency led to increased renal Treg recruitment and reduced histological and functional kidney damage in murine cGN.
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Quimiocina CCL17 , Glomerulonefritis , Animales , Humanos , Ratones , Anticuerpos Neutralizantes/farmacología , Anticuerpos Neutralizantes/uso terapéutico , Riñón , Monocitos , Receptores CCR4 , Receptores de Quimiocina , Linfocitos T ReguladoresRESUMEN
Type I interferons (IFN-I) are important mediators of antiviral immunity and autoimmune diseases. Female plasmacytoid dendritic cells (pDCs) exert an elevated capacity to produce IFN-I upon toll-like receptor 7 (TLR7) activation compared to male pDCs, and both sex hormones and X-encoded genes have been implicated in these sex-specific differences. Using longitudinal samples from a trans men cohort receiving gender-affirming hormone therapy (GAHT), the impact of testosterone injections on TLR7-mediated IFN-I production by pDCs was assessed. Single-cell RNA analyses of pDCs showed downregulation of IFN-I-related gene expression signatures but also revealed transcriptional inter-donor heterogeneity. Longitudinal quantification showed continuous reduction of IFN-I protein production by pDCs and reduced expression of IFN-I-stimulated genes in peripheral blood mononuclear cells (PBMCs). These studies in trans men demonstrate that testosterone administration reduces IFN-I production by pDCs over time and provide insights into the immune-modulatory role of testosterone in sex-specific IFN-I-mediated immune responses.
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Mucosal-associated invariant T (MAIT) cells have been implicated in various inflammatory diseases of barrier organs, but so far, their role in kidney disease is unclear. Here we report that MAIT cells that recognize their prototypical ligand, the vitamin B2 intermediate 5-OP-RU presented by MR1, reside in human and mouse kidneys. Single cell RNAseq analysis reveals several intrarenal MAIT subsets, and one, carrying the genetic fingerprint of tissue-resident MAIT17 cells, is activated and expanded in a murine model of crescentic glomerulonephritis (cGN). An equivalent subset is also present in kidney biopsies of patients with anti-neutrophil cytoplasmatic antibody (ANCA)-associated cGN. MAIT cell-deficient MR1 mice show aggravated disease, whereas B6-MAITCAST mice, harboring higher MAIT cell numbers, are protected from cGN. The expanded MAIT17 cells express anti-inflammatory mediators known to suppress cGN, such as CTLA-4, PD-1, and TGF-ß. Interactome analysis predicts CXCR6 - CXCL16-mediated cross-talk with renal mononuclear phagocytes, known to drive cGN progression. In line, we find that cGN is aggravated upon CXCL16 blockade. Finally, we present an optimized 5-OP-RU synthesis method which we apply to attenuating cGN in mice. In summary, we propose that CXCR6+ MAIT cells might play a protective role in cGN, implicating them as a potential target for anti-inflammatory therapies.
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Enfermedades Renales , Células T Invariantes Asociadas a Mucosa , Humanos , Animales , Ratones , Células Mieloides/metabolismo , Enfermedades Renales/metabolismo , Antiinflamatorios/metabolismo , Antígenos de Histocompatibilidad Clase I/metabolismoRESUMEN
T regulatory type 1 (Tr1) cells, which are defined by their regulatory function, lack of Foxp3, and high expression of IL-10, CD49b, and LAG-3, are known to be able to suppress Th1 and Th17 in the intestine. Th1 and Th17 cells are also the main drivers of crescentic glomerulonephritis (GN), the most severe form of renal autoimmune disease. However, whether Tr1 cells emerge in renal inflammation and, moreover, whether they exhibit regulatory function during GN have not been thoroughly investigated yet. To address these questions, we used a mouse model of experimental crescentic GN and double Foxp3mRFP IL-10eGFP reporter mice. We found that Foxp3neg IL-10-producing CD4+ T cells infiltrate the kidneys during GN progression. Using single-cell RNA sequencing, we could show that these cells express the core transcriptional factors characteristic of Tr1 cells. In line with this, Tr1 cells showed a strong suppressive activity ex vivo and were protective in experimental crescentic GN in vivo. Finally, we could also identify Tr1 cells in the kidneys of patients with antineutrophil cytoplasmic autoantibody-associated GN and define their transcriptional profile. Tr1 cells are currently used in several immune-mediated inflammatory diseases, such as T-cell therapy. Thus, our study provides proof of concept for Tr1 cell-based therapies in experimental GN.
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Glomerulonefritis , Linfocitos T Reguladores , Humanos , Ratones , Animales , Interleucina-10/metabolismo , Células Th17 , Riñón/metabolismo , Factores de Transcripción/metabolismo , Células TH1RESUMEN
Adaptation of immune cells to tissue-specific microenvironments is a crucial process in homeostasis and inflammation. Here, we show that murine effector type 2 innate lymphoid cells (ILC2s) from various organs are equally effective in repopulating ILC2 niches in other anatomical locations where they adapt tissue-specific phenotypes of target organs. Single-cell transcriptomics of ILC2 populations revealed upregulation of retinoic acid (RA) signaling in ILC2s during adaptation to the small intestinal microenvironment, and RA signaling mediated reprogramming of kidney effector ILC2s toward the small intestinal phenotype in vitro and in vivo. Inhibition of intestinal ILC2 adaptation by blocking RA signaling impaired worm expulsion during Strongyloides ratti infection, indicating functional importance of ILC2 tissue imprinting. In conclusion, this study highlights that effector ILC2s retain the ability to adapt to changing tissue-specific microenvironments, enabling them to exert tissue-specific functions, such as promoting control of intestinal helminth infections.
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Inmunidad Innata , Tretinoina , Ratones , Animales , Tretinoina/farmacología , Linfocitos , Intestinos , Inflamación , CitocinasRESUMEN
SIGNIFICANCE STATEMENT: T-cell infiltration is a hallmark of crescentic GN (cGN), often caused by ANCA-associated vasculitis. Pathogenic T-cell subsets, their clonality, and downstream effector mechanisms leading to kidney injury remain to be fully elucidated. Single-cell RNA sequencing and T-cell receptor sequencing revealed activated, clonally expanded cytotoxic CD4 + and CD8 + T cells in kidneys from patients with ANCA-associated cGN. In experimental cGN, kidney-infiltrating CD8 + T cells expressed the cytotoxic molecule, granzyme B (GzmB), which induced apoptosis in renal tissue cells by activation of procaspase-3, and aggravated disease pathology. These findings describe a pathogenic function of (clonally expanded) cytotoxic T cells in cGN and identify GzmB as a mediator and potential therapeutic target in immune-mediated kidney disease. BACKGROUND: Crescentic GN (cGN) is an aggressive form of immune-mediated kidney disease that is an important cause of end stage renal failure. Antineutrophilic cytoplasmic antibody (ANCA)-associated vasculitis is a common cause. T cells infiltrate the kidney in cGN, but their precise role in autoimmunity is not known. METHODS: Combined single-cell RNA sequencing and single-cell T-cell receptor sequencing were conducted on CD3 + T cells isolated from renal biopsies and blood of patients with ANCA-associated cGN and from kidneys of mice with experimental cGN. Functional and histopathological analyses were performed with Cd8a-/- and GzmB-/- mice. RESULTS: Single-cell analyses identified activated, clonally expanded CD8 + and CD4 + T cells with a cytotoxic gene expression profile in the kidneys of patients with ANCA-associated cGN. Clonally expanded CD8 + T cells expressed the cytotoxic molecule, granzyme B (GzmB), in the mouse model of cGN. Deficiency of CD8 + T cells or GzmB ameliorated the course of cGN. CD8 + T cells promoted macrophage infiltration and GzmB activated procaspase-3 in renal tissue cells, thereby increasing kidney injury. CONCLUSIONS: Clonally expanded cytotoxic T cells have a pathogenic function in immune-mediated kidney disease.
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Vasculitis Asociada a Anticuerpos Citoplasmáticos Antineutrófilos , Glomerulonefritis Membranoproliferativa , Glomerulonefritis , Animales , Ratones , Caspasa 3 , Granzimas , Linfocitos T Citotóxicos/metabolismo , Linfocitos T Citotóxicos/patología , Anticuerpos Anticitoplasma de Neutrófilos , Glomerulonefritis Membranoproliferativa/complicaciones , Vasculitis Asociada a Anticuerpos Citoplasmáticos Antineutrófilos/complicaciones , Enfermedad AgudaRESUMEN
GM-CSF in glomerulonephritisDespite glomerulonephritis being an immune-mediated disease, the contributions of individual immune cell types are not clear. To address this gap in knowledge, Paust et al. characterized pathological immune cells in samples from patients with glomerulonephritis and in samples from mice with the disease. The authors found that CD4+ T cells producing granulocyte-macrophage colony-stimulating factor (GM-CSF) licensed monocytes to promote disease by producing matrix metalloproteinase 12 and disrupting the glomerular basement membrane. Targeting GM-CSF to inhibit this axis reduced disease severity in mice, implicating this cytokine as a potential therapeutic target for patients with glomerulonephritis. -CM.
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Glomerulonefritis , Factor Estimulante de Colonias de Granulocitos y Macrófagos , Ratones , Animales , Factor Estimulante de Colonias de Granulocitos y Macrófagos/farmacología , Monocitos/metabolismo , Metaloproteinasa 12 de la Matriz/metabolismo , Linfocitos T CD4-Positivos , Glomerulonefritis/metabolismoRESUMEN
Previous studies have identified a unique Treg population, which expresses the Th17 characteristic transcription factor RORγt. These RORγt+ Tregs possess enhanced immunosuppressive capacity, which endows them with great therapeutic potential. However, as a caveat, they are also capable of secreting pro-inflammatory IL-17A. Since the sum function of RORγt+ Tregs in glomerulonephritis (GN) remains unknown, we studied the effects of their absence. Purified CD4+ T cell populations, containing or lacking RORγt+ Tregs, were transferred into immunocompromised RAG1 knockout mice and the nephrotoxic nephritis model of GN was induced. Absence of RORγt+ Tregs significantly aggravated kidney injury, demonstrating overall kidney-protective properties. Analyses of immune responses showed that RORγt+ Tregs were broadly immunosuppressive with no preference for a particular type of T cell response. Further characterization revealed a distinct functional and transcriptional profile, including enhanced production of IL-10. Expression of the chemokine receptor CCR6 marked a particularly potent subset, whose absence significantly worsened GN. As an underlying mechanism, we found that chemokine CCL20 acting through receptor CCR6 signaling mediated expansion and activation of RORγt+ Tregs. Finally, we also detected an increase of CCR6+ Tregs in kidney biopsies, as well as enhanced secretion of chemokine CCL20 in 21 patients with anti-neutrophil cytoplasmic antibody associated GN compared to that of 31 healthy living donors, indicating clinical relevance. Thus, our data characterize RORγt+ Tregs as anti-inflammatory mediators of GN and identify them as promising target for Treg directed therapies.
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Glomerulonefritis , Miembro 3 del Grupo F de la Subfamilia 1 de Receptores Nucleares , Ratones , Animales , Miembro 3 del Grupo F de la Subfamilia 1 de Receptores Nucleares/genética , Miembro 3 del Grupo F de la Subfamilia 1 de Receptores Nucleares/metabolismo , Linfocitos T Reguladores , Quimiocina CCL20/genética , Quimiocina CCL20/metabolismo , Riñón/patología , Ratones Noqueados , Células Th17 , Receptores CCR6/genética , Receptores CCR6/metabolismoRESUMEN
BACKGROUND: Emerging case series described a temporal association between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination and de novo or relapsing kidney diseases. We aimed to further understand vaccination- and coronavirus disease 2019 (COVID-19)-associated kidney diseases. METHODS: We present findings from native kidney biopsies of patients recently vaccinated against SARS-CoV-2 ( n =27) and those with COVID-19 ( n =15), reviewed at a single German center. Diagnoses were compared among all native kidney biopsies ( n =10,206) obtained between the prepandemic (2019), pandemic (2020), and vaccination periods (2021) to determine whether there was an increase in kidney diseases in the observed periods. RESULTS: Biopsy indication was increased serum creatinine and/or new-onset proteinuria. Glomerulopathies (20/27, 74%) were more common than tubulointerstitial diseases in postvaccination patients, with necrotizing GN (8/27, 30%) and primary podocytopathies and other GN types (6/27, 22% each) the most common forms. Acute tubular injury was the most common kidney disease in patients with COVID-19, followed by thrombotic microangiopathy (TMA) and necrotizing GN. The postvaccination and COVID-19 infection groups had similar kidney function recovery rates (69% and 73%, respectively). Furthermore, the frequencies of necrotizing GN, pauci-immune GN, TMA, or primary podocytopathies at our center did not increase between 2019 and 2021. CONCLUSIONS: We observed differences in entity frequencies between the SARS-CoV-2 vaccination or COVID-19 groups, with glomerulopathies being more common in patients after vaccination and tubulointerstitial diseases in patients with COVID-19. Cases of TMA were observed only in the COVID-19 group. We detected no increase in the frequency of necrotizing GN, TMA, or podocytopathies between 2019 and 2021. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: Kidney Histopathology After COVID-19 and SARS-CoV-2 Vaccination, NCT05043168.
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BACKGROUND: Diabetic nephropathy (DN) is the leading cause of end-stage renal disease, and histopathologic glomerular lesions are among the earliest structural alterations of DN. However, the signaling pathways that initiate these glomerular alterations are incompletely understood. METHODS: To delineate the cellular and molecular basis for DN initiation, we performed single-cell and bulk RNA sequencing of renal cells from type 2 diabetes mice (BTBR ob/ob) at the early stage of DN. RESULTS: Analysis of differentially expressed genes revealed glucose-independent responses in glomerular cell types. The gene regulatory network upstream of glomerular cell programs suggested the activation of mechanosensitive transcriptional pathway MRTF-SRF predominantly taking place in mesangial cells. Importantly, activation of MRTF-SRF transcriptional pathway was also identified in DN glomeruli in independent patient cohort datasets. Furthermore, ex vivo kidney perfusion suggested that the regulation of MRTF-SRF is a common mechanism in response to glomerular hyperfiltration. CONCLUSIONS: Overall, our study presents a comprehensive single-cell transcriptomic landscape of early DN, highlighting mechanosensitive signaling pathways as novel targets of diabetic glomerulopathy.
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Diabetes Mellitus Tipo 2 , Nefropatías Diabéticas , Ratones , Animales , Nefropatías Diabéticas/genética , Nefropatías Diabéticas/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Transcriptoma , Glomérulos Renales/metabolismo , Glomérulos Renales/patología , Transducción de SeñalRESUMEN
γδ T cells are involved in the control of Staphylococcus aureus infection, but their importance in protection compared to other T cells is unclear. We used a mouse model of systemic S. aureus infection associated with high bacterial load and persistence in the kidney. Infection caused fulminant accumulation of γδ T cells in the kidney. Renal γδ T cells acquired tissue residency and were maintained in high numbers during chronic infection. At day 7, up to 50% of renal γδ T cells produced IL-17A in situ and a large fraction of renal γδ T cells remained IL-17A+ during chronic infection. Controlled depletion revealed that γδ T cells restricted renal S. aureus replication in the acute infection and provided protection during chronic renal infection and upon reinfection. Our results demonstrate that kidney-resident γδ T cells are nonredundant in limiting local S. aureus growth during chronic infection and provide enhanced protection against reinfection.
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Interleucina-17 , Infecciones Estafilocócicas , Ratones , Animales , Staphylococcus aureus , Receptores de Antígenos de Linfocitos T gamma-delta , Infección Persistente , Reinfección , Riñón , Ratones Endogámicos C57BLRESUMEN
Glucocorticoids remain a cornerstone of therapeutic regimes for autoimmune and chronic inflammatory diseases - for example, in different forms of crescentic glomerulonephritis - because of their rapid antiinflammatory effects, low cost, and wide availability. Despite their routine use for decades, the underlying cellular mechanisms by which steroids exert their therapeutic effects need to be fully elucidated. Here, we demonstrate that high-dose steroid treatment rapidly reduced the number of proinflammatory CXCR3+CD4+ T cells in the kidney by combining high-dimensional single-cell and morphological analyses of kidney biopsies from patients with antineutrophil cytoplasmic antibody-associated (ANCA-associated) crescentic glomerulonephritis. Using an experimental model of crescentic glomerulonephritis, we show that the steroid-induced decrease in renal CD4+ T cells is a consequence of reduced T cell recruitment, which is associated with an ameliorated disease course. Mechanistic in vivo and in vitro studies revealed that steroids act directly on renal tissue cells, such as tubular epithelial cells, but not on T cells, which resulted in an abolished renal expression of CXCL9 and CXCL10 as well as in the prevention of CXCR3+CD4+ T cell recruitment to the inflamed kidneys. Thus, we identified the CXCL9/CXCL10-CXCR3 axis as a previously unrecognized cellular and molecular target of glucocorticoids providing protection from immune-mediated pathology.
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Glomerulonefritis , Glucocorticoides , Humanos , Glucocorticoides/farmacología , Riñón/patología , Linfocitos T CD4-Positivos , Quimiocina CXCL9 , Quimiocina CXCL10/metabolismo , Receptores CXCR3/metabolismoRESUMEN
Since the re-classification of membranoproliferative glomerulonephritis the new disease entity C3 glomerulopathy is diagnosed if C3 deposition is clearly dominant over immunoglobulins in immunohistochemistry or immunofluorescence. Although this new definition is more orientated at the pathophysiology as mediated by activity of the alternative complement pathway C3 glomerulopathy remains a heterogenous group of disorders. Genetic or autoimmune causes are associated in several but not in all patients with this disease. However, prognosis is poorly predictable, and clinicians cannot directly identify patients that might benefit from therapy. Moreover, therapy may range from supportive care alone, unspecific immune suppression, plasma treatment, or plasma exchange to complement inhibition. The current biopsy based diagnostic approaches sometimes combined with complement profiling are not sufficient to guide clinicians neither (i) whether to treat an individual patient, nor (ii) to choose the best therapy. With this perspective, we propose an interdisciplinary diagnostic approach, including detailed analysis of the kidney biopsy for morphological alterations and immunohistochemical staining, for genetic analyses of complement genes, complement activation patterning in plasma, and furthermore for applying novel approaches for convertase typing and complement profiling directly in renal tissue. Such a combined diagnostic approach was used here for a 42-year-old female patient with a novel mutation in the Factor H gene, C3 glomerulopathy and signs of chronic endothelial damage. We present here an approach that might in future help to guide therapy of renal diseases with relevant complement activation, especially since diverse new anti-complement agents are under clinical investigation.
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Complemento C3 , Glomerulonefritis Membranoproliferativa , Adulto , Activación de Complemento , Vía Alternativa del Complemento/genética , Femenino , Glomerulonefritis Membranoproliferativa/diagnóstico , Glomerulonefritis Membranoproliferativa/terapia , Humanos , Inmunoglobulinas/uso terapéuticoRESUMEN
Staphylococcus aureus is frequently detected in patients with sepsis and thus represents a major health burden worldwide. CD4+ T helper cells are involved in the immune response to S. aureus by supporting antibody production and phagocytosis. In particular, Th1 and Th17 cells secreting IFN-γ and IL-17A, are involved in the control of systemic S. aureus infections in humans and mice. To investigate the role of T cells in severe S. aureus infections, we established a mouse sepsis model in which the kidney was identified to be the organ with the highest bacterial load and abundance of Th17 cells. In this model, IL-17A but not IFN-γ was required for bacterial control. Using Il17aCre × R26YFP mice we could show that Th17 fate cells produce Th17 and Th1 cytokines, indicating a high degree of Th17 cell plasticity. Single cell RNA-sequencing of renal Th17 fate cells uncovered their heterogeneity and identified a cluster with a Th1 expression profile within the Th17 cell population, which was absent in mice with T-bet/Tbx21-deficiency in Th17 cells (Il17aCre x R26eYFP x Tbx21-flox). Blocking Th17 to Th1 transdifferentiation in Th17 fate cells in these mice resulted in increased S. aureus tissue loads. In summary, we highlight the impact of Th17 cells in controlling systemic S. aureus infections and show that T-bet expression by Th17 cells is required for bacterial clearance. While targeting the Th17 cell immune response is an important therapeutic option in autoimmunity, silencing Th17 cells might have detrimental effects in bacterial infections.
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Sepsis , Infecciones Estafilocócicas , Proteínas de Dominio T Box/metabolismo , Animales , Plasticidad de la Célula , Humanos , Interleucina-17 , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Fenotipo , Staphylococcus aureus , Células TH1 , Células Th17RESUMEN
Acute and chronic kidney diseases are major contributors to morbidity and mortality in the global population. Many nephropathies are considered to be immune-mediated with dysregulated immune responses playing an important role in the pathogenesis. At present, targeted approaches for many kidney diseases are still lacking, as the underlying mechanisms remain insufficiently understood. With the recent development of organoids-a three-dimensional, multicellular culture system, which recapitulates important aspects of human tissues-new opportunities to investigate interactions between renal cells and immune cells in the pathogenesis of kidney diseases arise. To date, kidney organoid systems, which reflect the structure and closer resemble critical aspects of the organ, have been established. Here, we highlight the recent advances in the development of kidney organoid models, including pluripotent stem cell-derived kidney organoids and primary epithelial cell-based tubuloids. The employment and further required advances of current organoid models are discussed to investigate the role of the immune system in renal tissue development, regeneration, and inflammation to identify targets for the development of novel therapeutic approaches of immune-mediated kidney diseases.