RESUMEN
T cells are critical effectors of cancer immunotherapies, but little is known about their gene expression programs in diffuse gliomas. Here, we leverage single-cell RNA sequencing (RNA-seq) to chart the gene expression and clonal landscape of tumor-infiltrating T cells across 31 patients with isocitrate dehydrogenase (IDH) wild-type glioblastoma and IDH mutant glioma. We identify potential effectors of anti-tumor immunity in subsets of T cells that co-express cytotoxic programs and several natural killer (NK) cell genes. Analysis of clonally expanded tumor-infiltrating T cells further identifies the NK gene KLRB1 (encoding CD161) as a candidate inhibitory receptor. Accordingly, genetic inactivation of KLRB1 or antibody-mediated CD161 blockade enhances T cell-mediated killing of glioma cells in vitro and their anti-tumor function in vivo. KLRB1 and its associated transcriptional program are also expressed by substantial T cell populations in other human cancers. Our work provides an atlas of T cells in gliomas and highlights CD161 and other NK cell receptors as immunotherapy targets.
Asunto(s)
Glioma/inmunología , Subfamilia B de Receptores Similares a Lectina de Células NK/genética , Linfocitos T/inmunología , Animales , Antígenos de Neoplasias , Modelos Animales de Enfermedad , Perfilación de la Expresión Génica , Glioma/genética , Células Asesinas Naturales/inmunología , Lectinas Tipo C/genética , Linfocitos Infiltrantes de Tumor/inmunología , Ratones , Receptores de Superficie Celular/genética , Análisis de la Célula Individual , Subgrupos de Linfocitos T/inmunología , Linfocitos T/citología , Escape del TumorRESUMEN
The non-pathogenic TH17 subset of helper T cells clears fungal infections, whereas pathogenic TH17 cells cause inflammation and tissue damage; however, the mechanisms controlling these distinct responses remain unclear. Here we found that fungi sensing by the C-type lectin dectin-1 in human dendritic cells (DCs) directed the polarization of non-pathogenic TH17 cells. Dectin-1 signaling triggered transient and intermediate expression of interferon (IFN)-ß in DCs, which was mediated by the opposed activities of transcription factors IRF1 and IRF5. IFN-ß-induced signaling led to integrin αvß8 expression directly and to the release of the active form of the cytokine transforming growth factor (TGF)-ß indirectly. Uncontrolled IFN-ß responses as a result of IRF1 deficiency induced high expression of the IFN-stimulated gene BST2 in DCs and restrained TGF-ß activation. Active TGF-ß was required for polarization of non-pathogenic TH17 cells, whereas pathogenic TH17 cells developed in the absence of active TGF-ß. Thus, dectin-1-mediated modulation of type I IFN responses allowed TGF-ß activation and non-pathogenic TH17 cell development during fungal infections in humans.
Asunto(s)
Células Dendríticas , Interferón Tipo I , Micosis , Humanos , Citocinas/metabolismo , Células Dendríticas/metabolismo , Interferón Tipo I/metabolismo , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Células Th17/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Micosis/inmunologíaRESUMEN
Differentiation of proinflammatory CD4+ conventional T cells (Tconv) is critical for productive antitumor responses yet their elicitation remains poorly understood. We comprehensively characterized myeloid cells in tumor draining lymph nodes (tdLN) of mice and identified two subsets of conventional type-2 dendritic cells (cDC2) that traffic from tumor to tdLN and present tumor-derived antigens to CD4+ Tconv, but then fail to support antitumor CD4+ Tconv differentiation. Regulatory T cell (Treg) depletion enhanced their capacity to elicit strong CD4+ Tconv responses and ensuing antitumor protection. Analogous cDC2 populations were identified in patients, and as in mice, their abundance relative to Treg predicts protective ICOS+ PD-1lo CD4+ Tconv phenotypes and survival. Further, in melanoma patients with low Treg abundance, intratumoral cDC2 density alone correlates with abundant CD4+ Tconv and with responsiveness to anti-PD-1 therapy. Together, this highlights a pathway that restrains cDC2 and whose reversal enhances CD4+ Tconv abundance and controls tumor growth.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Células Dendríticas/inmunología , Animales , Antígenos de Neoplasias/inmunología , Linfocitos T CD4-Positivos/citología , Linfocitos T CD4-Positivos/metabolismo , Diferenciación Celular , Línea Celular Tumoral , Citocinas/metabolismo , Células Dendríticas/citología , Células Dendríticas/metabolismo , Toxina Diftérica/inmunología , Factores de Transcripción Forkhead/metabolismo , Humanos , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Ganglios Linfáticos/inmunología , Ganglios Linfáticos/metabolismo , Activación de Linfocitos , Melanoma Experimental/inmunología , Melanoma Experimental/patología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Receptores de Quimiocina/metabolismo , Linfocitos T Reguladores/inmunología , Microambiente TumoralRESUMEN
Type 1 conventional dendritic (cDC1) cells are necessary for cross-presentation of many viral and tumor antigens to CD8+ T cells. cDC1 cells can be identified in mice and humans by high expression of DNGR-1 (also known as CLEC9A), a receptor that binds dead-cell debris and facilitates XP of corpse-associated antigens. Here, we show that DNGR-1 is a dedicated XP receptor that signals upon ligand engagement to promote phagosomal rupture. This allows escape of phagosomal contents into the cytosol, where they access the endogenous major histocompatibility complex class I antigen processing pathway. The activity of DNGR-1 maps to its signaling domain, which activates SYK and NADPH oxidase to cause phagosomal damage even when spliced into a heterologous receptor and expressed in heterologous cells. Our data reveal the existence of innate immune receptors that couple ligand binding to endocytic vesicle damage to permit MHC class I antigen presentation of exogenous antigens and to regulate adaptive immunity.
Asunto(s)
Presentación de Antígeno , Reactividad Cruzada , Células Dendríticas/metabolismo , Lectinas Tipo C/metabolismo , Fagosomas/metabolismo , Receptores Inmunológicos/metabolismo , Receptores Mitogénicos/metabolismo , Linfocitos T/metabolismo , Animales , Muerte Celular , Técnicas de Cocultivo , Células Dendríticas/inmunología , Células HEK293 , Antígenos de Histocompatibilidad Clase I/metabolismo , Humanos , Lectinas Tipo C/genética , Ligandos , Ratones , NADPH Oxidasas/metabolismo , Fagosomas/genética , Fagosomas/inmunología , Fosforilación , Células RAW 264.7 , Especies Reactivas de Oxígeno/metabolismo , Receptores Inmunológicos/genética , Receptores Mitogénicos/genética , Transducción de Señal , Quinasa Syk/metabolismo , Linfocitos T/inmunologíaRESUMEN
Pathologic roles of innate immunity in neurologic disorders are well described, but their beneficial aspects are less understood. Dectin-1, a C-type lectin receptor (CLR), is largely known to induce inflammation. Here, we report that Dectin-1 limited experimental autoimmune encephalomyelitis (EAE), while its downstream signaling molecule, Card9, promoted the disease. Myeloid cells mediated the pro-resolution function of Dectin-1 in EAE with enhanced gene expression of the neuroprotective molecule, Oncostatin M (Osm), through a Card9-independent pathway, mediated by the transcription factor NFAT. Furthermore, we find that the Osm receptor (OsmR) functioned specifically in astrocytes to reduce EAE severity. Notably, Dectin-1 did not respond to heat-killed Mycobacteria, an adjuvant to induce EAE. Instead, endogenous Dectin-1 ligands, including galectin-9, in the central nervous system (CNS) were involved to limit EAE. Our study reveals a mechanism of beneficial myeloid cell-astrocyte crosstalk regulated by a Dectin-1 pathway and identifies potential therapeutic targets for autoimmune neuroinflammation.
Asunto(s)
Astrocitos/inmunología , Encéfalo/patología , Proteínas Adaptadoras de Señalización CARD/metabolismo , Encefalomielitis Autoinmune Experimental/inmunología , Lectinas Tipo C/metabolismo , Esclerosis Múltiple/inmunología , Células Mieloides/inmunología , Inflamación Neurogénica/inmunología , Receptores Mitogénicos/metabolismo , Animales , Comunicación Celular , Células Cultivadas , Modelos Animales de Enfermedad , Galectinas/metabolismo , Regulación de la Expresión Génica , Lectinas Tipo C/genética , Ratones Endogámicos C57BL , Ratones Noqueados , Glicoproteína Mielina-Oligodendrócito/inmunología , Oncostatina M/genética , Oncostatina M/metabolismo , Subunidad beta del Receptor de Oncostatina M/metabolismo , Fragmentos de Péptidos/inmunología , Receptores Mitogénicos/genética , Transducción de SeñalAsunto(s)
Lectinas Tipo C , Células TH1 , Lectinas Tipo C/genética , Diferenciación Celular , Células Th17RESUMEN
The immune system monitors the health of cells and is stimulated by necrosis. Here we examined the receptors and ligands driving this response. In a targeted screen of C-type lectin receptors, a Clec2d reporter responded to lysates from necrotic cells. Biochemical purification identified histones, both free and bound to nucleosomes or neutrophil extracellular traps, as Clec2d ligands. Clec2d recognized poly-basic sequences in histone tails and this recognition was sensitive to post-translational modifications of these sequences. As compared with WT mice, Clec2d-/- mice exhibited reduced proinflammatory responses to injected histones, and less tissue damage and improved survival in a hepatotoxic injury model. In macrophages, Clec2d localized to the plasma membrane and endosomes. Histone binding to Clec2d did not stimulate kinase activation or cytokine production. Rather, histone-bound DNA stimulated endosomal Tlr9-dependent responses in a Clec2d-dependent manner. Thus, Clec2d binds to histones released upon necrotic cell death, with functional consequences to inflammation and tissue damage.
Asunto(s)
Histonas/metabolismo , Lectinas Tipo C/inmunología , Lectinas Tipo C/metabolismo , Hígado/lesiones , Necrosis/patología , Receptores de Superficie Celular/inmunología , Receptores de Superficie Celular/metabolismo , Animales , Apoptosis/inmunología , Endosomas/metabolismo , Células HEK293 , Humanos , Células Jurkat , Lectinas Tipo C/genética , Macrófagos/inmunología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Neutrófilos/inmunología , Receptores de Superficie Celular/genética , Receptor Toll-Like 9/inmunologíaRESUMEN
Specialized regulatory T (Treg) cells accumulate and perform homeostatic and regenerative functions in nonlymphoid tissues. Whether common precursors for nonlymphoid-tissue Treg cells exist and how they differentiate remain elusive. Using transcription factor nuclear factor, interleukin 3 regulated (Nfil3) reporter mice and single-cell RNA-sequencing (scRNA-seq), we identified two precursor stages of interleukin 33 (IL-33) receptor ST2-expressing nonlymphoid tissue Treg cells, which resided in the spleen and lymph nodes. Global chromatin profiling of nonlymphoid tissue Treg cells and the two precursor stages revealed a stepwise acquisition of chromatin accessibility and reprogramming toward the nonlymphoid-tissue Treg cell phenotype. Mechanistically, we identified and validated the transcription factor Batf as the driver of the molecular tissue program in the precursors. Understanding this tissue development program will help to harness regenerative properties of tissue Treg cells for therapy.
Asunto(s)
Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Ganglios Linfáticos/inmunología , Bazo/inmunología , Linfocitos T Reguladores/citología , Traslado Adoptivo , Animales , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/deficiencia , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Diferenciación Celular/genética , Cromatina/metabolismo , Factor de Transcripción GATA3/genética , Factor de Transcripción GATA3/metabolismo , Perfilación de la Expresión Génica , Regulación de la Expresión Génica/inmunología , Proteína 1 Similar al Receptor de Interleucina-1/metabolismo , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Ratones , Especificidad de Órganos/inmunología , Receptores Inmunológicos/genética , Receptores Inmunológicos/metabolismo , Linfocitos T Reguladores/metabolismoRESUMEN
Clec16a has been identified as a disease susceptibility gene for type 1 diabetes, multiple sclerosis, and adrenal dysfunction, but its function is unknown. Here we report that Clec16a is a membrane-associated endosomal protein that interacts with E3 ubiquitin ligase Nrdp1. Loss of Clec16a leads to an increase in the Nrdp1 target Parkin, a master regulator of mitophagy. Islets from mice with pancreas-specific deletion of Clec16a have abnormal mitochondria with reduced oxygen consumption and ATP concentration, both of which are required for normal ß cell function. Indeed, pancreatic Clec16a is required for normal glucose-stimulated insulin release. Moreover, patients harboring a diabetogenic SNP in the Clec16a gene have reduced islet Clec16a expression and reduced insulin secretion. Thus, Clec16a controls ß cell function and prevents diabetes by controlling mitophagy. This pathway could be targeted for prevention and control of diabetes and may extend to the pathogenesis of other Clec16a- and Parkin-associated diseases.
Asunto(s)
Diabetes Mellitus Tipo 1/genética , Islotes Pancreáticos/patología , Lectinas Tipo C/metabolismo , Mitofagia , Proteínas de Transporte de Monosacáridos/metabolismo , Secuencia de Aminoácidos , Animales , Proteínas Portadoras/química , Diabetes Mellitus Tipo 1/patología , Predisposición Genética a la Enfermedad , Glucosa/metabolismo , Humanos , Células Secretoras de Insulina/metabolismo , Islotes Pancreáticos/metabolismo , Lectinas Tipo C/química , Lectinas Tipo C/genética , Lisosomas/química , Lisosomas/metabolismo , Proteínas de la Membrana/metabolismo , Ratones , Datos de Secuencia Molecular , Proteínas de Transporte de Monosacáridos/química , Proteínas de Transporte de Monosacáridos/genética , Polimorfismo de Nucleótido Simple , Ubiquitina-Proteína LigasasRESUMEN
The activation marker CD69 is expressed by skin γδ T cells. Here we found that CD69 controlled the aryl hydrocarbon receptor (AhR)-dependent secretion of interleukin 22 (IL-22) by γδ T cells, which contributed to the development of psoriasis induced by IL-23. CD69 associated with the aromatic-amino-acid-transporter complex LAT1-CD98 and regulated its surface expression and uptake of L-tryptophan (L-Trp) and the intracellular quantity of L-Trp-derived activators of AhR. In vivo administration of L-Trp, an inhibitor of AhR or IL-22 abrogated the differences between CD69-deficient mice and wild-type mice in skin inflammation. We also observed LAT1-mediated regulation of AhR activation and IL-22 secretion in circulating Vγ9(+) γδ T cells of psoriatic patients. Thus, CD69 serves as a key mediator of the pathogenesis of psoriasis by controlling LAT1-CD98-mediated metabolic cues.
Asunto(s)
Antígenos CD/metabolismo , Antígenos de Diferenciación de Linfocitos T/metabolismo , Lectinas Tipo C/metabolismo , Psoriasis/inmunología , Piel/inmunología , Subgrupos de Linfocitos T/inmunología , Células Th17/inmunología , Sistema de Transporte de Aminoácidos y+/metabolismo , Sistema de Transporte de Aminoácidos y+L , Animales , Antígenos CD/genética , Antígenos de Diferenciación de Linfocitos T/genética , Células Cultivadas , Endocitosis , Proteína-1 Reguladora de Fusión/metabolismo , Interleucina-23/inmunología , Interleucinas/metabolismo , Lectinas Tipo C/genética , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Receptores de Antígenos de Linfocitos T gamma-delta/metabolismo , Receptores de Hidrocarburo de Aril/metabolismo , Triptófano/metabolismo , Interleucina-22RESUMEN
Production of interleukin-17 (IL-17) and IL-22 by T helper 17 (Th17) cells and group 3 innate lymphoid cells (ILC3s) in response to the gut microbiota ensures maintenance of intestinal barrier function. Here, we examined the mechanisms whereby the immune system detects microbiota in the steady state. A Syk-kinase-coupled signaling pathway in dendritic cells (DCs) was critical for commensal-dependent production of IL-17 and IL-22 by CD4+ T cells. The Syk-coupled C-type lectin receptor Mincle detected mucosal-resident commensals in the Peyer's patches (PPs), triggered IL-6 and IL-23p19 expression, and thereby regulated function of intestinal Th17- and IL-17-secreting ILCs. Mice deficient in Mincle or with selective depletion of Syk in CD11c+ cells had impaired production of intestinal RegIIIγ and IgA and increased systemic translocation of gut microbiota. Consequently, Mincle deficiency led to liver inflammation and deregulated lipid metabolism. Thus, sensing of commensals by Mincle and Syk signaling in CD11c+ cells reinforces intestinal immune barrier and promotes host-microbiota mutualism, preventing systemic inflammation.
Asunto(s)
Células Dendríticas/inmunología , Microbioma Gastrointestinal/inmunología , Interleucina-17/inmunología , Interleucinas/inmunología , Lectinas Tipo C/inmunología , Proteínas de la Membrana/inmunología , Quinasa Syk/inmunología , Animales , Células Dendríticas/metabolismo , Microbioma Gastrointestinal/fisiología , Humanos , Interleucina-17/metabolismo , Interleucinas/metabolismo , Mucosa Intestinal/inmunología , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiología , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones Endogámicos C57BL , Ratones Noqueados , Ganglios Linfáticos Agregados/inmunología , Ganglios Linfáticos Agregados/metabolismo , Ganglios Linfáticos Agregados/microbiología , Transducción de Señal/inmunología , Quinasa Syk/genética , Quinasa Syk/metabolismo , Células Th17/inmunología , Células Th17/metabolismo , Interleucina-22RESUMEN
Mononuclear phagocytes are classified as macrophages or dendritic cells (DCs) based on cell morphology, phenotype, or select functional properties. However, these attributes are not absolute and often overlap, leading to difficulties in cell-type identification. To circumvent this issue, we describe a mouse model to define DCs based on their ontogenetic descendence from a committed precursor. We show that precursors of mouse conventional DCs, but not other leukocytes, are marked by expression of DNGR-1. Genetic tracing of DNGR-1 expression history specifically marks cells traditionally ascribed to the DC lineage, and this restriction is maintained after inflammation. Notably, in some tissues, cells previously thought to be monocytes/macrophages are in fact descendants from DC precursors. These studies provide an in vivo model for fate mapping of DCs, distinguishing them from other leukocyte lineages, and thus help to unravel the functional complexity of the mononuclear phagocyte system.
Asunto(s)
Linaje de la Célula , Células Dendríticas/citología , Lectinas Tipo C/metabolismo , Receptores Inmunológicos/metabolismo , Animales , Células Dendríticas/metabolismo , Hematopoyesis , Inflamación/patología , Riñón/citología , Lectinas Tipo C/genética , Células Progenitoras Linfoides/metabolismo , Macrófagos/citología , Ratones , Ratones Endogámicos C57BL , Fagocitos/citología , Receptores de IgG/metabolismo , Receptores Inmunológicos/genéticaRESUMEN
Fungal infection stimulates the canonical C-type lectin receptor (CLR) signaling pathway via activation of the tyrosine kinase Syk. Here we identify a crucial role for the tyrosine phosphatase SHP-2 in mediating CLR-induced activation of Syk. Ablation of the gene encoding SHP-2 (Ptpn11; called 'Shp-2' here) in dendritic cells (DCs) and macrophages impaired Syk-mediated signaling and abrogated the expression of genes encoding pro-inflammatory molecules following fungal stimulation. Mechanistically, SHP-2 operated as a scaffold, facilitating the recruitment of Syk to the CLR dectin-1 or the adaptor FcRγ, through its N-SH2 domain and a previously unrecognized carboxy-terminal immunoreceptor tyrosine-based activation motif (ITAM). We found that DC-derived SHP-2 was crucial for the induction of interleukin 1ß (IL-1ß), IL-6 and IL-23 and anti-fungal responses of the TH17 subset of helper T cells in controlling infection with Candida albicans. Together our data reveal a mechanism by which SHP-2 mediates the activation of Syk in response to fungal infection.
Asunto(s)
Candidiasis/inmunología , Células Dendríticas/fisiología , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Macrófagos/fisiología , Proteína Tirosina Fosfatasa no Receptora Tipo 11/metabolismo , Proteínas Tirosina Quinasas/metabolismo , Linfocitos T Colaboradores-Inductores/inmunología , Células Th17/inmunología , Secuencias de Aminoácidos/genética , Animales , Antígenos Fúngicos/inmunología , Células Cultivadas , Citocinas/metabolismo , Activación Enzimática , Mediadores de Inflamación/metabolismo , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Activación de Linfocitos , Proteínas de la Membrana/genética , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Mutación/genética , Proteína Tirosina Fosfatasa no Receptora Tipo 11/genética , Receptores de IgE/genética , Receptores de IgE/metabolismo , Transducción de Señal , Quinasa SykRESUMEN
Although chitin in fungal cell walls is associated with allergic airway inflammation, the precise mechanism underlying this association has yet to be elucidated. Here, we investigated the involvement of fungal chitin-binding protein and chitin in allergic airway inflammation. Recombinant Aspergillus fumigatus LdpA (rLdpA) expressed in Pichia pastoris was shown to be an O-linked glycoprotein containing terminal α-mannose residues recognized by the host C-type lectin receptor, Dectin-2. Chitin particles were shown to induce acute neutrophilic airway inflammation mediated release of interleukin-1α (IL-1α) associated with cell death. Furthermore, rLdpA-Dectin-2 interaction was shown to promote phagocytosis of rLdpA-chitin complex and activation of mouse bone marrow-derived dendritic cells (BMDCs). Moreover, we showed that rLdpA potently induced T helper 2 (Th2)-driven allergic airway inflammation synergistically with chitin, and Dectin-2 deficiency attenuated the rLdpA-chitin complex-induced immune response in vivo. In addition, we showed that serum LdpA-specific immunoglobulin levels were elevated in patients with pulmonary aspergillosis.
Asunto(s)
Quitina , Lectinas Tipo C , Humanos , Animales , Ratones , Quitina/metabolismo , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Aspergillus fumigatus , Inflamación , Fagocitosis , Glicoproteínas/metabolismoRESUMEN
Neutrophils are critical for antifungal defense, but the mechanisms that clear hyphae and other pathogens that are too large to be phagocytosed remain unknown. We found that neutrophils sensed microbe size and selectively released neutrophil extracellular traps (NETs) in response to large pathogens, such as Candida albicans hyphae and extracellular aggregates of Mycobacterium bovis, but not in response to small yeast or single bacteria. NETs were fundamental in countering large pathogens in vivo. Phagocytosis via dectin-1 acted as a sensor of microbe size and prevented NET release by downregulating the translocation of neutrophil elastase (NE) to the nucleus. Dectin-1 deficiency led to aberrant NET release and NET-mediated tissue damage during infection. Size-tailored neutrophil responses cleared large microbes and minimized pathology when microbes were small enough to be phagocytosed.
Asunto(s)
Trampas Extracelulares/inmunología , Lectinas Tipo C/inmunología , Activación Neutrófila/inmunología , Neutrófilos/inmunología , Neutrófilos/microbiología , Fagocitosis/inmunología , Transporte Activo de Núcleo Celular/inmunología , Aspergillus fumigatus/inmunología , Candida albicans/inmunología , Escherichia coli/inmunología , Humanos , Hifa/inmunología , Klebsiella pneumoniae/inmunología , Lectinas Tipo C/genética , Elastasa de Leucocito/metabolismo , Mycobacterium bovis/inmunologíaRESUMEN
Here we identified a population of bone marrow neutrophils that constitutively expressed the transcription factor RORγt and produced and responded to interleukin 17A (IL-17A (IL-17)). IL-6, IL-23 and RORγt, but not T cells or natural killer (NK) cells, were required for IL-17 production in neutrophils. IL-6 and IL-23 induced expression of the receptors IL-17RC and dectin-2 on neutrophils, and IL-17RC expression was augmented by activation of dectin-2. Autocrine activity of IL-17A and its receptor induced the production of reactive oxygen species (ROS), and increased fungal killing in vitro and in a model of Aspergillus-induced keratitis. Human neutrophils also expressed RORγt and induced the expression of IL-17A, IL-17RC and dectin-2 following stimulation with IL-6 and IL-23. Our findings identify a population of human and mouse neutrophils with autocrine IL-17 activity that probably contribute to the etiology of microbial and inflammatory diseases.
Asunto(s)
Aspergilosis/inmunología , Aspergillus/inmunología , Interleucina-17/metabolismo , Queratitis/inmunología , Neutrófilos/inmunología , Receptores de Interleucina/metabolismo , Animales , Aspergilosis/complicaciones , Comunicación Autocrina , Células de la Médula Ósea/inmunología , Degranulación de la Célula , Células Cultivadas , Citotoxicidad Inmunológica/genética , Modelos Animales de Enfermedad , Humanos , Interleucina-17/genética , Interleucina-17/inmunología , Interleucina-23/inmunología , Interleucina-6/inmunología , Queratitis/etiología , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , 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 , Especies Reactivas de Oxígeno/metabolismoRESUMEN
IFN regulatory factor 7 (IRF7) exerts anti-infective effects by promoting the production of IFNs in various bacterial and viral infections, but its role in highly morbid and fatal Candida albicans infections is unknown. We unexpectedly found that Irf7 gene expression levels were significantly upregulated in tissues or cells after C. albicans infection in humans and mice and that IRF7 actually exacerbates C. albicans infection in mice independent of its classical function in inducing IFNs production. Compared to controls, Irf7-/- mice showed stronger phagocytosis of fungus, upregulation of C-type lectin receptor CD209 expression, and enhanced P53-AMPK-mTOR-mediated autophagic signaling in macrophages after C. albicans infection. The administration of the CD209-neutralizing Ab significantly hindered the phagocytosis of Irf7-/- mouse macrophages, whereas the inhibition of p53 or autophagy impaired the killing function of these macrophages. Thus, IRF7 exacerbates C. albicans infection by compromising the phagocytosis and killing capacity of macrophages via regulating CD209 expression and p53-AMPK-mTOR-mediated autophagy, respectively. This finding reveals a novel function of IRF7 independent of its canonical IFNs production and its unexpected role in enhancing fungal infections, thus providing more specific and effective targets for antifungal therapy.
Asunto(s)
Autofagia , Candida albicans , Candidiasis , Factor 7 Regulador del Interferón , Lectinas Tipo C , Macrófagos , Ratones Noqueados , Fagocitosis , Receptores de Superficie Celular , Serina-Treonina Quinasas TOR , Animales , Ratones , Fagocitosis/inmunología , Autofagia/inmunología , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Candidiasis/inmunología , Candida albicans/inmunología , Candida albicans/fisiología , Factor 7 Regulador del Interferón/genética , Factor 7 Regulador del Interferón/metabolismo , Factor 7 Regulador del Interferón/inmunología , Macrófagos/inmunología , Humanos , Receptores de Superficie Celular/genética , Receptores de Superficie Celular/metabolismo , Serina-Treonina Quinasas TOR/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Proteína p53 Supresora de Tumor/genética , Ratones Endogámicos C57BL , Moléculas de Adhesión Celular/genética , Moléculas de Adhesión Celular/metabolismo , Transducción de Señal/inmunologíaRESUMEN
DEC205 (CD205) is one of the major endocytic receptors on dendritic cells and has been widely used as a receptor target in immune therapies. It has been shown that DEC205 can recognize dead cells through keratins in a pH-dependent manner. However, the mechanism underlying the interaction between DEC205 and keratins remains unclear. Here we determine the crystal structures of an N-terminal fragment of human DEC205 (CysRâ¼CTLD3). The structural data show that DEC205 shares similar overall features with the other mannose receptor family members such as the mannose receptor and Endo180, but the individual domains of DEC205 in the crystal structure exhibit distinct structural features that may lead to specific ligand binding properties of the molecule. Among them, CTLD3 of DEC205 adopts a unique fold of CTLD, which may correlate with the binding of keratins. Furthermore, we examine the interaction of DEC205 with keratins by mutagenesis and biochemical assays based on the structural information and identify an XGGGX motif on keratins that can be recognized by DEC205, thereby providing insights into the interaction between DEC205 and keratins. Overall, these findings not only improve the understanding of the diverse ligand specificities of the mannose receptor family members at the molecular level but may also give clues for the interactions of keratins with their binding partners in the corresponding pathways.
Asunto(s)
Queratinas , Lectinas Tipo C , Modelos Moleculares , Humanos , Células Dendríticas/metabolismo , Lectinas Tipo C/química , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Ligandos , Receptor de Manosa/química , Mutagénesis , Unión Proteica , Pliegue de Proteína , Estructura Terciaria de Proteína , Dominios y Motivos de Interacción de Proteínas , Cristalografía por Rayos XRESUMEN
Receptor-mediated cellular uptake of specific ligands constitutes an important step in the dynamic regulation of individual protein levels in extracellular fluids. With a focus on the inflammatory lung, we here performed a proteomics-based search for novel ligands regulated by the mannose receptor (MR), a macrophage-expressed endocytic receptor. WT and MR-deficient mice were exposed to lipopolysaccharide, after which the protein content in their lung epithelial lining fluid was compared by tandem mass tag-based mass spectrometry. More than 1200 proteins were identified in the epithelial lining fluid using this unbiased approach, but only six showed a statistically different abundance. Among these, an unexpected potential new ligand, thrombospondin-4 (TSP-4), displayed a striking 17-fold increased abundance in the MR-deficient mice. Experiments using exogenous addition of TSP-4 to MR-transfected CHO cells or MR-positive alveolar macrophages confirmed that TSP-4 is a ligand for MR-dependent endocytosis. Similar studies revealed that the molecular interaction with TSP-4 depends on both the lectin activity and the fibronectin type-II domain of MR and that a closely related member of the TSP family, TSP-5, is also efficiently internalized by the receptor. This was unlike the other members of this protein family, including TSPs -1 and -2, which are ligands for a close MR homologue known as urokinase plasminogen activator receptor-associated protein. Our study shows that MR takes part in the regulation of TSP-4, an important inflammatory component in the injured lung, and that two closely related endocytic receptors, expressed on different cell types, undertake the selective endocytosis of distinct members of the TSP family.
Asunto(s)
Lectinas Tipo C , Lesión Pulmonar , Receptor de Manosa , Lectinas de Unión a Manosa , Proteómica , Receptores de Superficie Celular , Trombospondinas , Animales , Ratones , Células CHO , Cricetulus , Endocitosis , Lectinas Tipo C/metabolismo , Lectinas Tipo C/genética , Ligandos , Lipopolisacáridos/toxicidad , Pulmón/metabolismo , Pulmón/patología , Lesión Pulmonar/metabolismo , Lesión Pulmonar/patología , Macrófagos Alveolares/metabolismo , Macrófagos Alveolares/patología , Lectinas de Unión a Manosa/metabolismo , Lectinas de Unión a Manosa/genética , Ratones Noqueados , Proteómica/métodos , Receptores de Superficie Celular/metabolismo , Receptores de Superficie Celular/genética , Trombospondinas/metabolismo , Trombospondinas/genéticaRESUMEN
Incorporation of microbiome data has recently become important for prevention, diagnosis, and treatment of colorectal cancer, and several species of bacteria were shown to be associated with carcinogenesis. However, the role of commensal fungi in colon cancer remains poorly understood. Here, we report that mice lacking the c-type lectin Dectin-3 (Dectin-3-/- ) show increased tumorigenesis and Candida albicans burden upon chemical induction. Elevated C. albicans load triggered glycolysis in macrophages and interleukin-7 (IL-7) secretion. IL-7 induced IL-22 production in RORγt+ (group 3) innate lymphoid cells (ILC3s) via aryl hydrocarbon receptor and STAT3. Consistently, IL-22 frequency in tumor tissues of colon cancer patients positively correlated with fungal burden, indicating the relevance of this regulatory axis in human disease. These results establish a C. albicans-driven crosstalk between macrophages and innate lymphoid cells in the intestine and expand our understanding on how commensal mycobiota regulate host immunity and promote tumorigenesis.