RESUMO
While intestinal Th17 cells are critical for maintaining tissue homeostasis, recent studies have implicated their roles in the development of extra-intestinal autoimmune diseases including multiple sclerosis. However, the mechanisms by which tissue Th17 cells mediate these dichotomous functions remain unknown. Here, we characterized the heterogeneity, plasticity, and migratory phenotypes of tissue Th17 cells in vivo by combined fate mapping with profiling of the transcriptomes and TCR clonotypes of over 84,000 Th17 cells at homeostasis and during CNS autoimmune inflammation. Inter- and intra-organ single-cell analyses revealed a homeostatic, stem-like TCF1+ IL-17+ SLAMF6+ population that traffics to the intestine where it is maintained by the microbiota, providing a ready reservoir for the IL-23-driven generation of encephalitogenic GM-CSF+ IFN-γ+ CXCR6+ T cells. Our study defines a direct in vivo relationship between IL-17+ non-pathogenic and GM-CSF+ and IFN-γ+ pathogenic Th17 populations and provides a mechanism by which homeostatic intestinal Th17 cells direct extra-intestinal autoimmune disease.
Assuntos
Autoimunidade , Intestinos/imunologia , Células-Tronco/metabolismo , Células Th17/imunologia , Animais , Movimento Celular , Células Clonais , Encefalomielite Autoimune Experimental/imunologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Homeostase , Humanos , Interferon gama/metabolismo , Interleucina-17/metabolismo , Camundongos Endogâmicos C57BL , Especificidade de Órgãos , RNA/metabolismo , RNA-Seq , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores CXCR6/metabolismo , Receptores de Interleucina/metabolismo , Reprodutibilidade dos Testes , Família de Moléculas de Sinalização da Ativação Linfocitária/metabolismo , Análise de Célula Única , Baço/metabolismoRESUMO
Inflammation is paramount in pancreatic oncogenesis. We identified a uniquely activated γδT cell population, which constituted â¼40% of tumor-infiltrating T cells in human pancreatic ductal adenocarcinoma (PDA). Recruitment and activation of γδT cells was contingent on diverse chemokine signals. Deletion, depletion, or blockade of γδT cell recruitment was protective against PDA and resulted in increased infiltration, activation, and Th1 polarization of αßT cells. Although αßT cells were dispensable to outcome in PDA, they became indispensable mediators of tumor protection upon γδT cell ablation. PDA-infiltrating γδT cells expressed high levels of exhaustion ligands and thereby negated adaptive anti-tumor immunity. Blockade of PD-L1 in γδT cells enhanced CD4(+) and CD8(+) T cell infiltration and immunogenicity and induced tumor protection suggesting that γδT cells are critical sources of immune-suppressive checkpoint ligands in PDA. We describe γδT cells as central regulators of effector T cell activation in cancer via novel cross-talk.
Assuntos
Carcinogênese/imunologia , Carcinoma Ductal Pancreático/imunologia , Carcinoma Ductal Pancreático/fisiopatologia , Ativação Linfocitária/imunologia , Linfócitos T/imunologia , Imunidade Adaptativa , Animais , Carcinogênese/patologia , Células Cultivadas , Quimiocinas/imunologia , Células Epiteliais/fisiologia , Feminino , Humanos , Ligantes , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Transdução de Sinais/imunologia , Microambiente Tumoral/imunologiaRESUMO
The role of B cells in anti-tumour immunity is still debated and, accordingly, immunotherapies have focused on targeting T and natural killer cells to inhibit tumour growth1,2. Here, using high-throughput flow cytometry as well as bulk and single-cell RNA-sequencing and B-cell-receptor-sequencing analysis of B cells temporally during B16F10 melanoma growth, we identified a subset of B cells that expands specifically in the draining lymph node over time in tumour-bearing mice. The expanding B cell subset expresses the cell surface molecule T cell immunoglobulin and mucin domain 1 (TIM-1, encoded by Havcr1) and a unique transcriptional signature, including multiple co-inhibitory molecules such as PD-1, TIM-3, TIGIT and LAG-3. Although conditional deletion of these co-inhibitory molecules on B cells had little or no effect on tumour burden, selective deletion of Havcr1 in B cells both substantially inhibited tumour growth and enhanced effector T cell responses. Loss of TIM-1 enhanced the type 1 interferon response in B cells, which augmented B cell activation and increased antigen presentation and co-stimulation, resulting in increased expansion of tumour-specific effector T cells. Our results demonstrate that manipulation of TIM-1-expressing B cells enables engagement of the second arm of adaptive immunity to promote anti-tumour immunity and inhibit tumour growth.
Assuntos
Linfócitos B , Melanoma , Animais , Camundongos , Linfócitos B/citologia , Linfócitos B/imunologia , Linfócitos B/metabolismo , Ativação Linfocitária , Melanoma/imunologia , Melanoma/patologia , Melanoma/prevenção & controle , Linfócitos T/citologia , Linfócitos T/imunologia , Citometria de Fluxo , Melanoma Experimental/imunologia , Melanoma Experimental/patologia , Linfonodos/citologia , Linfonodos/imunologia , Apresentação de Antígeno , Receptores de Antígenos de Linfócitos B/genética , Análise da Expressão Gênica de Célula Única , Carga Tumoral , Interferon Tipo IRESUMO
Dendritic cells (DCs) have a role in the development and activation of self-reactive pathogenic T cells1,2. Genetic variants that are associated with the function of DCs have been linked to autoimmune disorders3,4, and DCs are therefore attractive therapeutic targets for such diseases. However, developing DC-targeted therapies for autoimmunity requires identification of the mechanisms that regulate DC function. Here, using single-cell and bulk transcriptional and metabolic analyses in combination with cell-specific gene perturbation studies, we identify a regulatory loop of negative feedback that operates in DCs to limit immunopathology. Specifically, we find that lactate, produced by activated DCs and other immune cells, boosts the expression of NDUFA4L2 through a mechanism mediated by hypoxia-inducible factor 1α (HIF-1α). NDUFA4L2 limits the production of mitochondrial reactive oxygen species that activate XBP1-driven transcriptional modules in DCs that are involved in the control of pathogenic autoimmune T cells. We also engineer a probiotic that produces lactate and suppresses T cell autoimmunity through the activation of HIF-1α-NDUFA4L2 signalling in DCs. In summary, we identify an immunometabolic pathway that regulates DC function, and develop a synthetic probiotic for its therapeutic activation.
Assuntos
Doenças Autoimunes , Sistema Nervoso Central , Células Dendríticas , Subunidade alfa do Fator 1 Induzível por Hipóxia , Ácido Láctico , Humanos , Doenças Autoimunes/imunologia , Doenças Autoimunes/metabolismo , Doenças Autoimunes/prevenção & controle , Autoimunidade , Sistema Nervoso Central/citologia , Sistema Nervoso Central/imunologia , Sistema Nervoso Central/patologia , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/química , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Ácido Láctico/metabolismo , Probióticos/uso terapêutico , Espécies Reativas de Oxigênio/metabolismo , Linfócitos T/imunologia , Retroalimentação Fisiológica , Lactase/genética , Lactase/metabolismo , Análise de Célula ÚnicaRESUMO
Neoplastic pancreatic epithelial cells are believed to die through caspase 8-dependent apoptotic cell death, and chemotherapy is thought to promote tumour apoptosis. Conversely, cancer cells often disrupt apoptosis to survive. Another type of programmed cell death is necroptosis (programmed necrosis), but its role in pancreatic ductal adenocarcinoma (PDA) is unclear. There are many potential inducers of necroptosis in PDA, including ligation of tumour necrosis factor receptor 1 (TNFR1), CD95, TNF-related apoptosis-inducing ligand (TRAIL) receptors, Toll-like receptors, reactive oxygen species, and chemotherapeutic drugs. Here we report that the principal components of the necrosome, receptor-interacting protein (RIP)1 and RIP3, are highly expressed in PDA and are further upregulated by the chemotherapy drug gemcitabine. Blockade of the necrosome in vitro promoted cancer cell proliferation and induced an aggressive oncogenic phenotype. By contrast, in vivo deletion of RIP3 or inhibition of RIP1 protected against oncogenic progression in mice and was associated with the development of a highly immunogenic myeloid and T cell infiltrate. The immune-suppressive tumour microenvironment associated with intact RIP1/RIP3 signalling depended in part on necroptosis-induced expression of the chemokine attractant CXCL1, and CXCL1 blockade protected against PDA. Moreover, cytoplasmic SAP130 (a subunit of the histone deacetylase complex) was expressed in PDA in a RIP1/RIP3-dependent manner, and Mincle--its cognate receptor--was upregulated in tumour-infiltrating myeloid cells. Ligation of Mincle by SAP130 promoted oncogenesis, whereas deletion of Mincle protected against oncogenesis and phenocopied the immunogenic reprogramming of the tumour microenvironment that was induced by RIP3 deletion. Cellular depletion suggested that whereas inhibitory macrophages promote tumorigenesis in PDA, they lose their immune-suppressive effects when RIP3 or Mincle is deleted. Accordingly, T cells, which are not protective against PDA progression in mice with intact RIP3 or Mincle signalling, are reprogrammed into indispensable mediators of anti-tumour immunity in the absence of RIP3 or Mincle. Our work describes parallel networks of necroptosis-induced CXCL1 and Mincle signalling that promote macrophage-induced adaptive immune suppression and thereby enable PDA progression.
Assuntos
Carcinogênese , Quimiocina CXCL1/metabolismo , Tolerância Imunológica , Lectinas Tipo C/metabolismo , Proteínas de Membrana/metabolismo , Necrose , Neoplasias Pancreáticas/imunologia , Neoplasias Pancreáticas/patologia , Adenocarcinoma/imunologia , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Animais , Apoptose/efeitos dos fármacos , Carcinogênese/efeitos dos fármacos , Carcinoma Ductal Pancreático/imunologia , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Quimiocina CXCL1/antagonistas & inibidores , Desoxicitidina/análogos & derivados , Desoxicitidina/farmacologia , Progressão da Doença , Feminino , Proteínas Ativadoras de GTPase/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Lectinas Tipo C/imunologia , Masculino , Proteínas de Membrana/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias Pancreáticas/metabolismo , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Transdução de Sinais , Regulação para Cima , GencitabinaRESUMO
BACKGROUND: COVID-19 has resulted in significant morbidity and mortality worldwide. Lateral flow assays can detect anti-Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) antibodies to monitor transmission. However, standardized evaluation of their accuracy and tools to aid in interpreting results are needed. METHODS: We evaluated 20 IgG and IgM assays selected from available tests in April 2020. We evaluated the assays' performance using 56 pre-pandemic negative and 56 SARS-CoV-2-positive plasma samples, collected 10-40 days after symptom onset, confirmed by a molecular test and analyzed by an ultra-sensitive immunoassay. Finally, we developed a user-friendly web app to extrapolate the positive predictive values based on their accuracy and local prevalence. RESULTS: Combined IgG + IgM sensitivities ranged from 33.9 to 94.6%, while combined specificities ranged from 92.6 to 100%. The highest sensitivities were detected in Lumiquick for IgG (98.2%), BioHit for both IgM (96.4%), and combined IgG + IgM sensitivity (94.6%). Furthermore, 11 LFAs and 8 LFAs showed perfect specificity for IgG and IgM, respectively, with 15 LFAs showing perfect combined IgG + IgM specificity. Lumiquick had the lowest estimated limit-of-detection (LOD) (0.1 µg/mL), followed by a similar LOD of 1.5 µg/mL for CareHealth, Cellex, KHB, and Vivachek. CONCLUSION: We provide a public resource of the accuracy of select lateral flow assays with potential for home testing. The cost-effectiveness, scalable manufacturing process, and suitability for self-testing makes LFAs an attractive option for monitoring disease prevalence and assessing vaccine responsiveness. Our web tool provides an easy-to-use interface to demonstrate the impact of prevalence and test accuracy on the positive predictive values.
Assuntos
Anticorpos Antivirais/sangue , Teste Sorológico para COVID-19/métodos , COVID-19/diagnóstico , Imunoglobulina G/sangue , Imunoglobulina M/sangue , SARS-CoV-2/imunologia , Adulto , Idoso , COVID-19/sangue , Feminino , Humanos , Limite de Detecção , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prevalência , Sensibilidade e Especificidade , Design Centrado no Usuário , Interface Usuário-ComputadorRESUMO
Con A hepatitis is regarded as a T cell-mediated model of acute liver injury. Mincle is a C-type lectin receptor that is critical in the immune response to mycobacteria and fungi but does not have a well-defined role in preclinical models of non-pathogen-mediated inflammation. Because Mincle can ligate the cell death ligand SAP130, we postulated that Mincle signaling drives intrahepatic inflammation and liver injury in Con A hepatitis. Acute liver injury was assessed in the murine Con A hepatitis model using C57BL/6, Mincle(-/-), and Dectin-1(-/-) mice. The role of C/EBPß and hypoxia-inducible factor-1α (HIF-1α) signaling was assessed using selective inhibitors. We found that Mincle was highly expressed in hepatic innate inflammatory cells and endothelial cells in both mice and humans. Furthermore, sterile Mincle ligands and Mincle signaling intermediates were increased in the murine liver in Con A hepatitis. Most significantly, Mincle deletion or blockade protected against Con A hepatitis, whereas Mincle ligation exacerbated disease. Bone marrow chimeric and adoptive transfer experiments suggested that Mincle signaling in infiltrating myeloid cells dictates disease phenotype. Conversely, signaling via other C-type lectin receptors did not alter disease course. Mechanistically, we found that Mincle blockade decreased the NF-κß-related signaling intermediates C/EBPß and HIF-1α, both of which are necessary in macrophage-mediated inflammatory responses. Accordingly, Mincle deletion lowered production of nitrites in Con A hepatitis and inhibition of both C/EBPß and HIF-1α reduced the severity of liver disease. Our work implicates a novel innate immune driver of Con A hepatitis and, more broadly, suggests a potential role for Mincle in diseases governed by sterile inflammation.
Assuntos
Concanavalina A/imunologia , Hepatite/imunologia , Lectinas Tipo C/imunologia , Proteínas de Membrana/imunologia , Transdução de Sinais/imunologia , Animais , Modelos Animais de Doenças , Hepatite/metabolismo , Humanos , Inflamação/imunologia , Lectinas Tipo C/deficiência , Leucócitos Mononucleares , Masculino , Proteínas de Membrana/deficiência , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Nitritos/metabolismoRESUMO
BACKGROUND & AIMS: The role of radiation therapy in the treatment of patients with pancreatic ductal adenocarcinoma (PDA) is controversial. Randomized controlled trials investigating the efficacy of radiation therapy in patients with locally advanced unresectable PDA have reported mixed results, with effects ranging from modest benefit to worse outcomes compared with control therapies. We investigated whether radiation causes inflammatory cells to acquire an immune-suppressive phenotype that limits the therapeutic effects of radiation on invasive PDAs and accelerates progression of preinvasive foci. METHODS: We investigated the effects of radiation therapy in p48(Cre);LSL-Kras(G12D) (KC) and p48(Cre);LSLKras(G12D);LSL-Trp53(R172H) (KPC) mice, as well as in C57BL/6 mice with orthotopic tumors grown from FC1242 cells derived from KPC mice. Some mice were given neutralizing antibodies against macrophage colony-stimulating factor 1 (CSF1 or MCSF) or F4/80. Pancreata were exposed to doses of radiation ranging from 2 to 12 Gy and analyzed by flow cytometry. RESULTS: Pancreata of KC mice exposed to radiation had a higher frequency of advanced pancreatic intraepithelial lesions and more foci of invasive cancer than pancreata of unexposed mice (controls); radiation reduced survival time by more than 6 months. A greater proportion of macrophages from radiation treated invasive and preinvasive pancreatic tumors had an immune-suppressive, M2-like phenotype compared with control mice. Pancreata from mice exposed to radiation had fewer CD8(+) T cells than controls, and greater numbers of CD4(+) T cells of T-helper 2 and T-regulatory cell phenotypes. Adoptive transfer of T cells from irradiated PDA to tumors of control mice accelerated tumor growth. Radiation induced production of MCSF by PDA cells. A neutralizing antibody against MCSF prevented radiation from altering the phenotype of macrophages in tumors, increasing the anti-tumor T-cell response and slowing tumor growth. CONCLUSIONS: Radiation treatment causes macrophages murine PDA to acquire an immune-suppressive phenotype and disabled T-cell-mediated anti-tumor responses. MCSF blockade negates this effect, allowing radiation to have increased efficacy in slowing tumor growth.
Assuntos
Adenoma/imunologia , Carcinoma Ductal Pancreático/imunologia , Macrófagos/efeitos da radiação , Neoplasias Pancreáticas/imunologia , Linfócitos T/imunologia , Adenoma/radioterapia , Animais , Carcinoma Ductal Pancreático/radioterapia , Modelos Animais de Doenças , Camundongos , Camundongos Endogâmicos C57BL , Pâncreas/imunologia , Pâncreas/efeitos da radiação , Neoplasias Pancreáticas/radioterapia , Linfócitos T/efeitos da radiaçãoRESUMO
BACKGROUND & AIMS: Subsets of leukocytes synergize with regenerative growth factors to promote hepatic regeneration. γδT cells are early responders to inflammation-induced injury in a number of contexts. We investigated the role of γδT cells in hepatic regeneration using mice with disruptions in Tcrd (encodes the T-cell receptor δ chain) and Clec7a (encodes C-type lectin domain family 7 member a, also known as DECTIN1). METHODS: We performed partial hepatectomies on wild-type C57BL/6, CD45.1, Tcrd(-/-), or Clec7a(-/-) mice. Cells were isolated from livers of patients and mice via mechanical and enzymatic digestion. γδT cells were purified by fluorescence-activated cell sorting. RESULTS: In mice, partial hepatectomy up-regulated expression of CCL20 and ligands of Dectin-1, which was associated with recruitment and activation of γδT cells and their increased production of interleukin (IL)-17 family cytokines. Recruited γδT cells induced production of IL-6 by antigen-presenting cells and suppressed expression of interferon gamma by natural killer T cells, promoting hepatocyte proliferation. Absence of IL-17-producing γδT cells or deletion of Dectin-1 prevented development of regenerative phenotypes in subsets of innate immune cells. This slowed liver regeneration and was associated with reduced expression of regenerative growth factors and cell cycle regulators. Conversely, exogenous administration of IL-17 family cytokines or Dectin-1 ligands promoted regeneration. More broadly, we found that γδT cells are required for inflammatory responses mediated by IL-17 and Dectin-1. CONCLUSIONS: γδT cells regulate hepatic regeneration by producing IL-22 and IL-17, which have direct mitogenic effects on hepatocytes and promote a regenerative phenotype in hepatic leukocytes, respectively. Dectin-1 ligation is required for γδT cells to promote hepatic regeneration.
Assuntos
Proliferação de Células , Hepatócitos/metabolismo , Mediadores da Inflamação/metabolismo , Interleucina-17/metabolismo , Regeneração Hepática , Fígado/metabolismo , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Linfócitos T/metabolismo , Animais , Células Cultivadas , Quimiocina CCL20/metabolismo , Genótipo , Hepatectomia , Hepatócitos/imunologia , Humanos , Interferon gama/metabolismo , Interleucina-6/metabolismo , Interleucinas/metabolismo , Lectinas Tipo C/deficiência , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Fígado/imunologia , Fígado/cirurgia , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fenótipo , Receptores de Antígenos de Linfócitos T gama-delta/deficiência , Receptores de Antígenos de Linfócitos T gama-delta/genética , Transdução de Sinais , Linfócitos T/imunologia , Fatores de Tempo , Interleucina 22RESUMO
Dendritic cells (DC) are professional APCs that regulate innate and adaptive immunity. The role of fatty-acid synthesis in DC development and function is uncertain. We found that blockade of fatty-acid synthesis markedly decreases dendropoiesis in the liver and in primary and secondary lymphoid organs in mice. Human DC development from PBMC precursors was also diminished by blockade of fatty-acid synthesis. This was associated with higher rates of apoptosis in precursor cells and increased expression of cleaved caspase-3 and BCL-xL and downregulation of cyclin B1. Further, blockade of fatty-acid synthesis decreased DC expression of MHC class II, ICAM-1, B7-1, and B7-2 but increased their production of selected proinflammatory cytokines including IL-12 and MCP-1. Accordingly, inhibition of fatty-acid synthesis enhanced DC capacity to activate allogeneic as well as Ag-restricted CD4(+) and CD8(+) T cells and induce CTL responses. Further, blockade of fatty-acid synthesis increased DC expression of Notch ligands and enhanced their ability to activate NK cell immune phenotype and IFN-γ production. Because endoplasmic reticulum (ER) stress can augment the immunogenic function of APC, we postulated that this may account for the higher DC immunogenicity. We found that inhibition of fatty-acid synthesis resulted in elevated expression of numerous markers of ER stress in humans and mice and was associated with increased MAPK and Akt signaling. Further, lowering ER stress by 4-phenylbutyrate mitigated the enhanced immune stimulation associated with fatty-acid synthesis blockade. Our findings elucidate the role of fatty-acid synthesis in DC development and function and have implications to the design of DC vaccines for immunotherapy.
Assuntos
Diferenciação Celular/imunologia , Células Dendríticas/imunologia , Ácidos Graxos/biossíntese , Animais , Apoptose/imunologia , Antígeno B7-1/imunologia , Antígeno B7-1/metabolismo , Antígeno B7-2/imunologia , Antígeno B7-2/metabolismo , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Caspase 3/imunologia , Caspase 3/metabolismo , Quimiocina CCL2/imunologia , Quimiocina CCL2/metabolismo , Ciclina B1/imunologia , Ciclina B1/metabolismo , Células Dendríticas/citologia , Células Dendríticas/metabolismo , Retículo Endoplasmático/imunologia , Retículo Endoplasmático/metabolismo , Ácidos Graxos/imunologia , Ácidos Graxos/metabolismo , Genes MHC da Classe II/imunologia , Humanos , Molécula 1 de Adesão Intercelular/imunologia , Molécula 1 de Adesão Intercelular/metabolismo , Interferon gama/imunologia , Interferon gama/metabolismo , Interleucina-12/imunologia , Interleucina-12/metabolismo , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Fígado/imunologia , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Quinases de Proteína Quinase Ativadas por Mitógeno/imunologia , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , PPAR gama/imunologia , PPAR gama/metabolismo , Proteínas Proto-Oncogênicas c-akt/imunologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/metabolismo , Proteína bcl-X/imunologia , Proteína bcl-X/metabolismoRESUMO
UNLABELLED: Nonalcoholic steatohepatitis (NASH) is the most common etiology of chronic liver dysfunction in the United States and can progress to cirrhosis and liver failure. Inflammatory insult resulting from fatty infiltration of the liver is central to disease pathogenesis. Dendritic cells (DCs) are antigen-presenting cells with an emerging role in hepatic inflammation. We postulated that DCs are important in the progression of NASH. We found that intrahepatic DCs expand and mature in NASH liver and assume an activated immune phenotype. However, rather than mitigating the severity of NASH, DC depletion markedly exacerbated intrahepatic fibroinflammation. Our mechanistic studies support a regulatory role for DCs in NASH by limiting sterile inflammation through their role in the clearance of apoptotic cells and necrotic debris. We found that DCs limit CD8(+) T-cell expansion and restrict Toll-like receptor expression and cytokine production in innate immune effector cells in NASH, including Kupffer cells, neutrophils, and inflammatory monocytes. Consistent with their regulatory role in NASH, during the recovery phase of disease, ablation of DC populations results in delayed resolution of intrahepatic inflammation and fibroplasia. CONCLUSION: Our findings support a role for DCs in modulating NASH. Targeting DC functional properties may hold promise for therapeutic intervention in NASH.
Assuntos
Comunicação Celular/fisiologia , Células Dendríticas/fisiologia , Progressão da Doença , Fígado Gorduroso/fisiopatologia , Fígado/fisiopatologia , Animais , Apoptose/fisiologia , Linfócitos T CD8-Positivos/patologia , Células Cultivadas , Células Dendríticas/patologia , Modelos Animais de Doenças , Fígado Gorduroso/patologia , Células de Kupffer/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Necrose/fisiopatologia , Neutrófilos/patologia , Receptores Toll-Like/fisiologiaRESUMO
BACKGROUND & AIMS: Immune cells of the liver must be able to recognize and react to pathogens yet remain tolerant to food molecules and other nonpathogens. Dendritic cells (DCs) are believed to contribute to hepatic tolerance. Lipids have been implicated in dysfunction of DCs in cancer. Therefore, we investigated whether high lipid content in liver DCs affects induction of tolerance. METHODS: Mouse and human hepatic nonparenchymal cells were isolated by mechanical and enzymatic digestion. DCs were purified by fluorescence-activated cell sorting or with immunomagnetic beads. DC lipid content was assessed by flow cytometry, immune fluorescence, and electron microscopy and by measuring intracellular component lipids. DC activation was determined from surface phenotype and cytokine profile. DC function was assessed in T-cell, natural killer (NK) cell, and NKT cell coculture assays as well as in vivo. RESULTS: We observed 2 distinct populations of hepatic DCs in mice and humans based on their lipid content and expression of markers associated with adipogenesis and lipid metabolism. This lipid-based dichotomy in DCs was unique to the liver and specific to DCs compared with other hepatic immune cells. However, rather than mediate tolerance, the liver DC population with high concentrations of lipid was immunogenic in multiple models; they activated T cells, NK cells, and NKT cells. Conversely, liver DCs with low levels of lipid induced regulatory T cells, anergy to cancer, and oral tolerance. The immunogenicity of lipid-rich liver DCs required their secretion of tumor necrosis factor α and was directly related to their high lipid content; blocking DC synthesis of fatty acids or inhibiting adipogenesis (by reducing endoplasmic reticular stress) reduced DC immunogenicity. CONCLUSIONS: Human and mouse hepatic DCs are composed of distinct populations that contain different concentrations of lipid, which regulates immunogenic versus tolerogenic responses in the liver.
Assuntos
Antígenos CD/metabolismo , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Lipídeos/análise , Fígado/imunologia , Fígado/metabolismo , Adipogenia , Animais , Antígenos CD1d/metabolismo , Apoptose , Antígeno B7-1/metabolismo , Antígeno B7-2/metabolismo , Antígeno CD11b/metabolismo , Antígenos CD40/metabolismo , Células Cultivadas , Células Dendríticas/química , Humanos , Tolerância Imunológica , Molécula 1 de Adesão Intercelular/metabolismo , Células Matadoras Naturais/fisiologia , Antígenos Comuns de Leucócito/metabolismo , Metabolismo dos Lipídeos , Fígado/química , Ativação Linfocitária , Camundongos , Células T Matadoras Naturais/fisiologia , Fenótipo , Linfócitos T/fisiologia , Linfócitos T Reguladores/fisiologia , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Dendritic cells (DCs) control the generation of self-reactive pathogenic T cells. Thus, DCs are considered attractive therapeutic targets for autoimmune diseases. Using single-cell and bulk transcriptional and metabolic analyses in combination with cell-specific gene perturbation studies we identified a negative feedback regulatory pathway that operates in DCs to limit immunopathology. Specifically, we found that lactate, produced by activated DCs and other immune cells, boosts NDUFA4L2 expression through a mechanism mediated by HIF-1α. NDUFA4L2 limits the production of mitochondrial reactive oxygen species that activate XBP1-driven transcriptional modules in DCs involved in the control of pathogenic autoimmune T cells. Moreover, we engineered a probiotic that produces lactate and suppresses T-cell autoimmunity in the central nervous system via the activation of HIF-1α/NDUFA4L2 signaling in DCs. In summary, we identified an immunometabolic pathway that regulates DC function, and developed a synthetic probiotic for its therapeutic activation.
RESUMO
BACKGROUND & AIMS: The cellular mediators of acute pancreatitis are incompletely understood. Dendritic cells (DCs) can promote or suppress inflammation, depending on their subtype and context. We investigated the roles of DC in development of acute pancreatitis. METHODS: Acute pancreatitis was induced in CD11c.DTR mice using caerulein or L-arginine; DCs were depleted by administration of diphtheria toxin. Survival was analyzed using Kaplan-Meier method. RESULTS: Numbers of major histocompatibility complex II(+)CD11c(+) DCs increased 100-fold in pancreata of mice with acute pancreatitis to account for nearly 15% of intrapancreatic leukocytes. Intrapancreatic DCs acquired a distinct immune phenotype in mice with acute pancreatitis; they expressed higher levels of major histocompatibility complex II and CD86 and increased production of interleukin-6, membrane cofactor protein-1, and tumor necrosis factor-α. However, rather than inducing an organ-destructive inflammatory process, DCs were required for pancreatic viability; the exocrine pancreas died in mice that were depleted of DCs and challenged with caerulein or L-arginine. All mice with pancreatitis that were depleted of DCs died from acinar cell death within 4 days. Depletion of DCs from mice with pancreatitis resulted in neutrophil infiltration and increased levels of systemic markers of inflammation. However, the organ necrosis associated with depletion of DCs did not require infiltrating neutrophils, activation of nuclear factor-κB, or signaling by mitogen-activated protein kinase or tumor necrosis factor-α. CONCLUSIONS: DCs are required for pancreatic viability in mice with acute pancreatitis and might protect organs against cell stress.
Assuntos
Células Dendríticas/fisiologia , Pâncreas/patologia , Pâncreas/fisiopatologia , Pancreatite/patologia , Pancreatite/fisiopatologia , Sobrevivência de Tecidos/fisiologia , Doença Aguda , Animais , Arginina/efeitos adversos , Ceruletídeo/efeitos adversos , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/metabolismo , Células Dendríticas/patologia , Toxina Diftérica/farmacologia , Modelos Animais de Doenças , Proteína 1 de Resposta de Crescimento Precoce/metabolismo , Interleucina-6/metabolismo , Estimativa de Kaplan-Meier , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pancreatite/induzido quimicamente , Fenótipo , Fatores de TempoRESUMO
The drivers and the specification of CD4+ T cell differentiation in the tumor microenvironment and their contributions to tumor immunity or tolerance are incompletely understood. Using models of pancreatic ductal adenocarcinoma (PDA), we show that a distinct subset of tumor-infiltrating dendritic cells (DC) promotes PDA growth by directing a unique TH-program. Specifically, CD11b+CD103- DC predominate in PDA, express high IL-23 and TGF-ß, and induce FoxP3neg tumor-promoting IL-10+IL-17+IFNγ+ regulatory CD4+ T cells. The balance between this distinctive TH program and canonical FoxP3+ TREGS is unaffected by pattern recognition receptor ligation and is modulated by DC expression of retinoic acid. This TH-signature is mimicked in human PDA where it is associated with immune-tolerance and diminished patient survival. Our data suggest that CD11b+CD103- DC promote CD4+ T cell tolerance in PDA which may underscore its resistance to immunotherapy.
Assuntos
Células Dendríticas/imunologia , Interleucina-10/metabolismo , Interleucina-17/metabolismo , Neoplasias Pancreáticas/imunologia , Linfócitos T Reguladores/imunologia , Adenocarcinoma/genética , Adenocarcinoma/imunologia , Adenocarcinoma/patologia , Animais , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/imunologia , Carcinoma Ductal Pancreático/patologia , Diferenciação Celular , Progressão da Doença , Fatores de Transcrição Forkhead , Regulação Neoplásica da Expressão Gênica , Humanos , Lectinas Tipo C/metabolismo , Camundongos Endogâmicos C57BL , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Fenótipo , Transdução de Sinais , Células Th17/imunologia , Receptor 2 Toll-Like/metabolismo , Tretinoína/metabolismo , Neoplasias PancreáticasRESUMO
The progression of pancreatic oncogenesis requires immune-suppressive inflammation in cooperation with oncogenic mutations. However, the drivers of intratumoral immune tolerance are uncertain. Dectin 1 is an innate immune receptor crucial for anti-fungal immunity, but its role in sterile inflammation and oncogenesis has not been well defined. Furthermore, non-pathogen-derived ligands for dectin 1 have not been characterized. We found that dectin 1 is highly expressed on macrophages in pancreatic ductal adenocarcinoma (PDA). Dectin 1 ligation accelerated the progression of PDA in mice, whereas deletion of Clec7a-the gene encoding dectin 1-or blockade of dectin 1 downstream signaling was protective. We found that dectin 1 can ligate the lectin galectin 9 in mouse and human PDA, which results in tolerogenic macrophage programming and adaptive immune suppression. Upon disruption of the dectin 1-galectin 9 axis, CD4+ and CD8+ T cells, which are dispensable for PDA progression in hosts with an intact signaling axis, become reprogrammed into indispensable mediators of anti-tumor immunity. These data suggest that targeting dectin 1 signaling is an attractive strategy for developing an immunotherapy for PDA.
Assuntos
Carcinoma Ductal Pancreático/genética , Galectinas/metabolismo , Lectinas Tipo C/genética , Neoplasias Pancreáticas/genética , Evasão Tumoral/genética , Animais , Western Blotting , Carcinogênese/genética , Carcinoma Ductal Pancreático/imunologia , Carcinoma Ductal Pancreático/metabolismo , Células Epiteliais/metabolismo , Citometria de Fluxo , Técnicas de Silenciamento de Genes , Humanos , Tolerância Imunológica/genética , Imuno-Histoquímica , Imunoprecipitação , Lectinas Tipo C/imunologia , Lectinas Tipo C/metabolismo , Espectrometria de Massas , Camundongos , Camundongos Knockout , Ductos Pancreáticos/citologia , Neoplasias Pancreáticas/imunologia , Neoplasias Pancreáticas/metabolismo , Quinase Syk/genética , Quinase Syk/metabolismo , Evasão Tumoral/imunologiaRESUMO
Regulation of Toll-like receptor responses is critical for limiting tissue injury and autoimmunity in both sepsis and sterile inflammation. We found that Mincle, a C-type lectin receptor, regulates proinflammatory Toll-like receptor 4 signaling. Specifically, Mincle ligation diminishes Toll-like receptor 4-mediated inflammation, whereas Mincle deletion or knockdown results in marked hyperresponsiveness to lipopolysaccharide in vitro, as well as overwhelming lipopolysaccharide-mediated inflammation in vivo. Mechanistically, Mincle deletion does not up-regulate Toll-like receptor 4 expression or reduce interleukin 10 production after Toll-like receptor 4 ligation; however, Mincle deletion decreases production of the p38 mitogen-activated protein kinase-dependent inhibitory intermediate suppressor of cytokine signaling 1, A20, and ABIN3 and increases expression of the Toll-like receptor 4 coreceptor CD14. Blockade of CD14 mitigates the increased sensitivity of Mincle(-/-) leukocytes to Toll-like receptor 4 ligation. Collectively, we describe a major role for Mincle in suppressing Toll-like receptor 4 responses and implicate its importance in nonmycobacterial models of inflammation.