RESUMEN
AQP4 is expressed in the endfeet membranes of subpial and perivascular astrocytes and in the ependymal cells that line the ventricular system. The sporadic appearance of obstructive congenital hydrocephalus (OCHC) has been observed in the offspring of AQP4-/- mice (KO) due to stenosis of Silvio's aqueduct. Here, we explore whether the lack of AQP4 expression leads to abnormal development of ependymal cells in the aqueduct of mice. We compared periaqueductal samples from wild-type and KO mice. The microarray-based transcriptome analysis reflected a large number of genes with differential expression (809). Gene sets (GS) associated with ependymal development, ciliary function and the immune system were specially modified qPCR confirmed reduced expression in the KO mice genes: (i) coding for transcription factors for ependymal differentiation (Rfx4 and FoxJ1), (ii) involved in the constitution of the central apparatus of the axoneme (Spag16 and Hydin), (iii) associated with ciliary assembly (Cfap43, Cfap69 and Ccdc170), and (iv) involved in intercellular junction complexes of the ependyma (Cdhr4). By contrast, genes such as Spp1, Gpnmb, Itgax, and Cd68, associated with a Cd11c-positive microglial population, were overexpressed in the KO mice. Electron microscopy and Immunofluorescence of vimentin and γ-tubulin revealed a disorganized ependyma in the KO mice, with changes in the intercellular complex union, unevenly orientated cilia, and variations in the planar cell polarity of the apical membrane. These structural alterations translate into reduced cilia beat frequency, which might alter cerebrospinal fluid movement. The presence of CD11c + microglia cells in the periaqueductal zone of mice during the first postnatal week is a novel finding. In AQP4-/- mice, these cells remain present around the aqueduct for an extended period, showing peak expression at P11. We propose that these cells play an important role in the normal development of the ependyma and that their overexpression in KO mice is crucial to reduce ependyma abnormalities that could otherwise contribute to the development of obstructive hydrocephalus.
Asunto(s)
Acuaporina 4 , Epéndimo , Hidrocefalia , Ratones Noqueados , Microglía , Animales , Epéndimo/metabolismo , Epéndimo/patología , Hidrocefalia/metabolismo , Hidrocefalia/genética , Hidrocefalia/patología , Microglía/metabolismo , Acuaporina 4/metabolismo , Acuaporina 4/genética , Ratones , Acueducto del Mesencéfalo/metabolismo , Acueducto del Mesencéfalo/patología , Antígenos CD11/metabolismo , Antígenos CD11/genética , Ratones Endogámicos C57BLRESUMEN
Hericenone C is one of the most abundant secondary metabolites derived from Hericium erinaceus, under investigation for medicinal properties. Here, we report that Hericenone C inhibits the second phase of formalin-induced nociceptive behavior in mice. As the second phase is involved in inflammation, in a mechanistic analysis on cultured cells targeting NF-κB response element (NRE): luciferase (Luc)-expressing cells, lipopolysaccharide (LPS)-induced NRE::Luc luciferase activity was found to be significantly inhibited by Hericenone C. Phosphorylation of p65, which is involved in the inflammatory responses of the NF-κB signaling pathway, was also induced by LPS and significantly reduced by Hericenone C. Additionally, in mice, the number of CD11c-positive cells increased in the paw during the peak of the second phase of the formalin test, which decreased upon Hericenone C intake. Our findings confirm the possibility of Hericenone C as a novel therapeutic target for pain-associated inflammation.
Asunto(s)
Epidermis , Formaldehído , Animales , Fosforilación/efectos de los fármacos , Ratones , Masculino , Epidermis/metabolismo , Epidermis/efectos de los fármacos , Factor de Transcripción ReIA/metabolismo , Antígenos CD11/metabolismo , Nocicepción/efectos de los fármacos , HumanosRESUMEN
Neuropathic pain is often caused by injury and diseases that affect the somatosensory system. Although pain development has been well studied, pain recovery mechanisms remain largely unknown. Here, we found that CD11c-expressing spinal microglia appear after the development of behavioral pain hypersensitivity following nerve injury. Nerve-injured mice with spinal CD11c+ microglial depletion failed to recover spontaneously from this hypersensitivity. CD11c+ microglia expressed insulin-like growth factor-1 (IGF1), and interference with IGF1 signaling recapitulated the impairment in pain recovery. In pain-recovered mice, the depletion of CD11c+ microglia or the interruption of IGF1 signaling resulted in a relapse in pain hypersensitivity. Our findings reveal a mechanism for the remission and recurrence of neuropathic pain, providing potential targets for therapeutic strategies.
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Dolor Crónico/fisiopatología , Hiperalgesia/fisiopatología , Microglía/fisiología , Neuralgia/fisiopatología , Traumatismos de los Nervios Periféricos/fisiopatología , Médula Espinal/fisiopatología , Animales , Proteínas Bacterianas/genética , Antígenos CD11/genética , Antígenos CD11/metabolismo , Femenino , Proteínas Luminiscentes/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , RecurrenciaRESUMEN
Expression of Itgax (encoding the CD11c surface protein) and Spp1 (encoding osteopontin; OPN) has been associated with activated microglia that can develop in healthy brains and some neuroinflammatory disorders. However, whether CD11c and OPN expression is a consequence of microglial activation or represents a portion of the genetic program expressed by a stable microglial subset is unknown. Here, we show that OPN production in the brain is confined to a small CD11c+ microglial subset that differentiates from CD11c- precursors in perinatal life after uptake of apoptotic neurons. Our analysis suggests that coexpression of OPN and CD11c marks a microglial subset that is expressed at birth and persists into late adult life, independent of environmental activation stimuli. Analysis of the contribution of OPN to the intrinsic functions of this CD11c+ microglial subset indicates that OPN is required for subset stability and the execution of phagocytic and proinflammatory responses, in part through OPN-dependent engagement of the αVß3-integrin receptor. Definition of OPN-producing CD11c+ microglia as a functional microglial subset provides insight into microglial differentiation in health and disease.
Asunto(s)
Antígenos CD11/metabolismo , Microglía/fisiología , Osteopontina/metabolismo , Animales , Encéfalo/metabolismo , Antígenos CD11/genética , Femenino , Expresión Génica/genética , Regulación de la Expresión Génica/genética , Inflamación/metabolismo , Activación de Macrófagos , Macrófagos/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Neurogénesis , Osteopontina/genética , Fagocitos/metabolismo , Transcriptoma/genéticaRESUMEN
Intestinal eosinophils are implicated in the inflammatory pathology of eosinophilic gastrointestinal diseases and inflammatory bowel diseases. Eosinophils also contribute to intestinal immunologic and tissue homeostasis and host defense. Recent studies in allergic airway disease suggest functional subphenotypes of eosinophils may underly their pathogenic versus protective roles. However, subphenotypes of intestinal eosinophils have not been defined and are complicated by their constitutive expression of the putative eosinophil inflammatory marker CD11c. Here, we propose a framework for subphenotype characterization of intestinal eosinophils based on relative intensity of surface CD11c expression. Using this flow cytometry framework in parallel with histology and BrdU tracing, we characterize intestinal eosinophil subphenotypes and monitor their plasticity at baseline and within the context of acute allergic and chronic systemic inflammation. Data reveal a conserved continuum of CD11c expression amongst intestinal eosinophils in health and acute disease states that overall tracked with other markers of activation. Oral allergen challenge induced recruitment of eosinophils into small intestinal lamina propria surrounding crypts, followed by in situ induction of CD11c expression in parallel with eosinophil redistribution into intestinal villi. Allergen challenge also elicited eosinophil transepithelial migration and the appearance of CD11clo CD11bhi eosinophils in the intestinal lumen. Chronic inflammation driven by overexpression of TNFα led to a qualitative shift in the relative abundance of CD11c-defined eosinophil subphenotypes favoring CD11chi -expressing eosinophils. These findings provide new insights into heterogeneity of intestinal tissue eosinophils and offer a framework for measuring and tracking eosinophil subphenotype versatility in situ in health and disease.
Asunto(s)
Antígenos CD11/metabolismo , Eosinófilos , Hipersensibilidad , Alérgenos , Animales , Biomarcadores/metabolismo , Antígeno CD11c/metabolismo , Eosinófilos/metabolismo , Inflamación/patología , RatonesRESUMEN
Gland macrophages are primed for gland development and functions through interactions within their niche. However, the phenotype, ontogeny, and function of steady-state salivary gland (SG) macrophages remain unclear. We herein identified CD11c+ and CD11c- subsets among CD64+ macrophages in steady-state murine SGs. CD11c- macrophages were predominant in the SGs of embryonic and newborn mice and decreased with advancing age. CD11c+ macrophages were rarely detected in the embryonic period, but rapidly expanded after birth. CD11c+, but not CD11c-, macrophage numbers decreased in mice treated with a CCR2 antagonist, suggesting that CD11c+ macrophages accumulate from bone marrow-derived progenitors in a CCR2-dependent manner, whereas CD11c- macrophages were derived from embryonic progenitors in SGs. CD11c+ and CD11c- macrophages strongly expressed colony-stimulating factor (CSF)-1 receptor, the injection of an anti-CSF-1 receptor blocking antibody markedly reduced both subsets, and SGs strongly expressed CSF-1, indicating the dependency of SG resident macrophage development on CSF-1. The phagocytic activity of SG macrophages was extremely weak; however, the gene expression profile of SG macrophages indicated that SG macrophages regulate gland development and functions in SGs. These results suggest that SG CD11c+ and CD11c- macrophages are developed and instructed to perform SG-specific functions in steady-state SGs.
Asunto(s)
Antígenos CD11/genética , Macrófagos/metabolismo , Glándulas Salivales/metabolismo , Animales , Antígenos CD11/metabolismo , Antígeno CD11c/genética , Antígeno CD11c/metabolismo , Diferenciación Celular , Células Dendríticas/inmunología , Femenino , Expresión Génica/genética , Regulación del Desarrollo de la Expresión Génica/genética , Factor Estimulante de Colonias de Macrófagos/metabolismo , Macrófagos/inmunología , Masculino , Ratones/embriología , Ratones Endogámicos C57BL , Fagocitos/metabolismo , Glándulas Salivales/inmunologíaRESUMEN
Tbet+CD11c+ B cells arise during type 1 pathogen challenge, aging, and autoimmunity in mice and humans. Here, we examined the developmental requirements of this B cell subset. In acute infection, T follicular helper (Tfh) cells, but not Th1 cells, drove Tbet+CD11c+ B cell generation through proximal delivery of help. Tbet+CD11c+ B cells developed prior to germinal center (GC) formation, exhibiting phenotypic and transcriptional profiles distinct from GC B cells. Fate tracking revealed that most Tbet+CD11c+ B cells developed independently of GC entry and cell-intrinsic Bcl6 expression. Tbet+CD11c+ and GC B cells exhibited minimal repertoire overlap, indicating distinct developmental pathways. As the infection resolved, Tbet+CD11c+ B cells localized to the marginal zone where splenic retention depended on integrins LFA-1 and VLA-4, forming a competitive memory subset that contributed to antibody production and secondary GC seeding upon rechallenge. Therefore, Tbet+CD11c+ B cells comprise a GC-independent memory subset capable of rapid and robust recall responses.
Asunto(s)
Linfocitos B/inmunología , Antígenos CD11/metabolismo , Subgrupos Linfocitarios/inmunología , Células T Auxiliares Foliculares/inmunología , Proteínas de Dominio T Box/metabolismo , Virosis/inmunología , Animales , Anticuerpos Antivirales/metabolismo , Linfocitos B/metabolismo , Diferenciación Celular/inmunología , Centro Germinal/inmunología , Alphainfluenzavirus/inmunología , Integrinas/metabolismo , Subgrupos Linfocitarios/metabolismo , Virus de la Coriomeningitis Linfocítica/inmunología , Células B de Memoria/inmunología , Células B de Memoria/metabolismo , Ratones , Bazo/inmunologíaRESUMEN
CD11d/CD18 is the most recently discovered and least understood ß2 integrin. Known CD11d adhesive mechanisms contribute to both extravasation and mesenchymal migration - two key aspects for localizing peripheral leukocytes to sites of inflammation. Differential expression of CD11d induces differences in monocyte/macrophage mesenchymal migration including impacts on macrophage sub-set migration. The participation of CD11d/CD18 in leukocyte localization during atherosclerosis and following neurotrauma has sparked interest in the development of CD11d-targeted therapeutic agents. Whereas the adhesive properties of CD11d have undergone investigation, the signalling pathways induced by ligand binding remain largely undefined. Underlining each adhesive and signalling function, CD11d is under unique transcriptional control and expressed on a sub-set of predominately tissue-differentiated innate leukocytes. The following review is the first to capture the nearly three decades of CD11d research and discusses the emerging role of CD11d in leukocyte migration and retention during the progression of a staged immune response.
Asunto(s)
Antígenos CD11/genética , Antígenos CD18/genética , Quimiotaxis de Leucocito/genética , Quimiotaxis de Leucocito/inmunología , Regulación de la Expresión Génica , Cadenas alfa de Integrinas/genética , Leucocitos/fisiología , Animales , Antígenos CD11/química , Antígenos CD11/metabolismo , Antígenos CD18/química , Antígenos CD18/metabolismo , Susceptibilidad a Enfermedades , Desarrollo de Medicamentos , Humanos , Cadenas alfa de Integrinas/química , Cadenas alfa de Integrinas/metabolismo , Linfopoyesis/genética , Terapia Molecular Dirigida , Especificidad de Órganos/genética , Fagocitosis/genética , Fagocitosis/inmunología , Unión Proteica , Dominios y Motivos de Interacción de Proteínas , Procesamiento Proteico-Postraduccional , Relación Estructura-Actividad , Factores de TranscripciónRESUMEN
A wealth of innate and adaptive immune cells and hormones are involved in mounting tolerance towards the fetus, a key aspect of successful reproduction. We could recently show that the specific cross talk between the pregnancy hormone progesterone and dendritic cells (DCs) is significantly engaged in the generation of CD4+ FoxP3+ regulatory T (Treg) cells while a disruption led to placental alterations and intra-uterine growth restriction. Apart from progesterone, also glucocorticoids affect immune cell functions. However, their functional relevance in the context of pregnancy still needs clarification. We developed a mouse line with a selective knockout of the glucocorticoid receptor (GR) on DCs, utilizing the cre/flox system. Reproductive outcome and maternal immune and endocrine adaptation of Balb/c-mated C57Bl/6 GRflox/floxCD11ccre/wt (mutant) females was assessed on gestation days (gd) 13.5 and 18.5. Balb/c-mated C57Bl/6 GRwt/wtCD11ccre/wt (wt) females served as controls. The number of implantation and fetal loss rate did not differ between groups. However, we identified a significant increase in fetal weight in fetuses from mutant dams. While the frequencies of CD11c+ cells remained largely similar, a decreased expression of co-stimulatory molecules was observed on DCs of mutant females on gd 13.5, along with higher frequencies of CD4+ and CD8+ Treg cells. Histomorphological and gene expression analysis revealed an increased placental volume and an improved functional placental capacity in mice lacking the GR on CD11c+ DCs. In summary, we here demonstrate that the disrupted communication between GCs and DCs favors a tolerant immune microenvironment and improves placental function and fetal development.
Asunto(s)
Antígenos CD11/metabolismo , Células Dendríticas/metabolismo , Desarrollo Fetal , Feto/metabolismo , Glucocorticoides/metabolismo , Receptores de Glucocorticoides/metabolismo , Linfocitos T Reguladores/metabolismo , Animales , Antígenos CD11/genética , Células Dendríticas/inmunología , Femenino , Peso Fetal , Feto/inmunología , Edad Gestacional , Histocompatibilidad Materno-Fetal , Tolerancia Inmunológica , Masculino , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Fenotipo , Placentación , Embarazo , Progesterona/metabolismo , Receptores de Glucocorticoides/genética , Transducción de Señal , Linfocitos T Reguladores/inmunologíaRESUMEN
Neutrophils are key players in innate immunity and originate from the bone marrow of the adult mammalian organism. In mammals, mature neutrophils are released from the bone marrow into the peripheral blood where they circulate until their recruitment to sites of inflammation in a multistep adhesion cascade. Here, adhesion molecules of the ß2 integrin family (CD11/CD18) are critically required for the initial neutrophil adhesion to the inflamed endothelium and several post-adhesion steps allowing their extravasation into the inflamed tissue. Within the mammalian tissue, interstitial neutrophil migration can occur widely independent of ß2 integrins. This is in sharp contrast to neutrophil recruitment in zebrafish larvae (Danio rerio) where neutrophils originate from the caudal hematopoietic tissue and mainly migrate interstitially to sites of lesion upon the early onset of inflammation. However, neutrophils extravasate from the circulation to the inflamed tissue in zebrafish larvae at later-time points. Although zebrafish larvae are a widely accepted model system to analyze neutrophil trafficking in vivo, the functional impact of ß2 integrins for neutrophil trafficking during acute inflammation is completely unknown in this model. In this study, we generated zebrafish with a genetic deletion of CD18, the ß subunit of ß2 integrins, using CRISPR/Cas9 technology. Sequence alignments demonstrated a high similarity of the amino acid sequences between zebrafish and human CD18 especially in the functionally relevant I-like domain. In addition, the cytoplasmic domain of CD18 harbors two highly conserved NXXF motifs suggesting that zebrafish CD18 may share functional properties of human CD18. Accordingly, CD18 knock-out (KO) zebrafish larvae displayed the key symptoms of patients suffering from leukocyte adhesion deficiency (LAD) type I due to defects in ITGB2, the gene for CD18. Importantly, CD18 KO zebrafish larvae showed reduced neutrophil trafficking to sites of sterile inflammation despite the fact that an increased number of neutrophils was detectable in the circulation. By demonstrating the functional importance of CD18 for neutrophil trafficking in zebrafish larvae, our findings shed new light on neutrophil biology in vertebrates and introduce a new model organism for studying LAD type I.
Asunto(s)
Antígenos CD18/metabolismo , Adhesión Celular/genética , Movimiento Celular/genética , Infiltración Neutrófila/genética , Neutrófilos/inmunología , Pez Cebra/genética , Pez Cebra/inmunología , Secuencia de Aminoácidos , Animales , Animales Modificados Genéticamente , Antígenos CD11/química , Antígenos CD11/genética , Antígenos CD11/metabolismo , Antígenos CD18/química , Antígenos CD18/genética , Adhesión Celular/inmunología , Movimiento Celular/inmunología , Modelos Animales de Enfermedad , Eliminación de Gen , Técnicas de Inactivación de Genes , Inflamación/genética , Inflamación/inmunología , Integrinas/metabolismo , Larva/genética , Larva/inmunología , Síndrome de Deficiencia de Adhesión del Leucocito/inmunología , Infiltración Neutrófila/inmunologíaRESUMEN
Understanding mechanisms of immune regulation is key to developing immunotherapies for autoimmunity and cancer. We examined the role of mononuclear phagocytes during peripheral T cell regulation in type 1 diabetes and melanoma. MERTK expression and activity in mononuclear phagocytes in the pancreatic islets promoted islet T cell regulation, resulting in reduced sensitivity of T cell scanning for cognate antigen in prediabetic islets. MERTK-dependent regulation led to reduced T cell activation and effector function at the disease site in islets and prevented rapid progression of type 1 diabetes. In human islets, MERTK-expressing cells were increased in remaining insulin-containing islets of type 1 diabetic patients, suggesting that MERTK protects islets from autoimmune destruction. MERTK also regulated T cell arrest in melanoma tumors. These data indicate that MERTK signaling in mononuclear phagocytes drives T cell regulation at inflammatory disease sites in peripheral tissues through a mechanism that reduces the sensitivity of scanning for antigen leading to reduced responsiveness to antigen.
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Autoinmunidad/fisiología , Islotes Pancreáticos/enzimología , Fagocitos/fisiología , Linfocitos T/inmunología , Tirosina Quinasa c-Mer/inmunología , Adenina/análogos & derivados , Adenina/farmacología , Animales , Células Presentadoras de Antígenos/inmunología , Antígenos/inmunología , Antígenos/metabolismo , Antígenos CD11/metabolismo , Diabetes Mellitus Experimental/enzimología , Diabetes Mellitus Experimental/inmunología , Diabetes Mellitus Tipo 1/enzimología , Diabetes Mellitus Tipo 1/patología , Femenino , Humanos , Islotes Pancreáticos/inmunología , Ratones Endogámicos C57BL , Ratones Endogámicos NOD , Ratones Transgénicos , Neoplasias Experimentales/enzimología , Neoplasias Experimentales/inmunología , Fagocitos/inmunología , Piperazinas/farmacología , Tirosina Quinasa c-Mer/genética , Tirosina Quinasa c-Mer/metabolismoRESUMEN
In this study, we detail a novel approach that combines bacterial fitness fluorescent reporter strains with scRNA-seq to simultaneously acquire the host transcriptome, surface marker expression, and bacterial phenotype for each infected cell. This approach facilitates the dissection of the functional heterogeneity of M. tuberculosis-infected alveolar (AMs) and interstitial macrophages (IMs) in vivo. We identify clusters of pro-inflammatory AMs associated with stressed bacteria, in addition to three different populations of IMs with heterogeneous bacterial phenotypes. Finally, we show that the main macrophage populations in the lung are epigenetically constrained in their response to infection, while inter-species comparison reveals that most AMs subsets are conserved between mice and humans. This conceptual approach is readily transferable to other infectious disease agents with the potential for an increased understanding of the roles that different host cell populations play during the course of an infection.
Asunto(s)
Macrófagos Alveolares/microbiología , Mycobacterium tuberculosis/efectos de los fármacos , Mycobacterium tuberculosis/genética , Tuberculosis Pulmonar/patología , Animales , Antituberculosos/farmacología , Líquido del Lavado Bronquioalveolar/microbiología , Antígenos CD11/inmunología , Antígenos CD11/metabolismo , Epigénesis Genética , Regulación Bacteriana de la Expresión Génica , Hemo/metabolismo , Interacciones Huésped-Patógeno , Humanos , Pulmón/microbiología , Pulmón/patología , Macrófagos Alveolares/inmunología , Macrófagos Alveolares/patología , Ratones Endogámicos C57BL , Microorganismos Modificados Genéticamente , Mycobacterium tuberculosis/inmunología , Mycobacterium tuberculosis/patogenicidad , Análisis de Secuencia de ARN , Análisis de la Célula Individual , Tuberculosis Pulmonar/genética , Tuberculosis Pulmonar/microbiologíaRESUMEN
BACKGROUND: Tumor metastasis is the major cause of death of colorectal cancer (CRC), and metastatic CRC remains incurable in many cases despite great advances in genetic and molecular profiling, and clinical development of numerous drugs, including immune checkpoint inhibitors. Thus, more effective treatments are urgently needed for the patients in clinical settings. METHODS: We used mouse CRC metastasis models that murine Colon26 cells were subcutaneously and intravenously implanted and attempted to elucidate the tumor biological and immunological mechanisms underlying cancer metastasis. Then, we evaluated in vivo antitumor efficacy induced by agents targeting the identified molecular mechanisms using the mouse models. We validated the clinical relevancy of the findings using peripheral blood mononuclear cells obtained from stage IV metastatic CRC patients. RESULTS: CD11b+CTLA4+ myeloid cells were systemically expanded in the metastatic settings and facilitated tumor progression and metastasis directly via generating lipid droplets in tumor cells and indirectly via inducing immune exhaustion. These events were mediated by IL1B produced via the CTLA4 signaling from the increased myeloid cells. Blocking CTLA4 and IL1B with the specific mAbs significantly suppressed tumor progression and metastasis in the mouse models resistant to anti-PD1 therapy, and the therapeutic efficacy was optimized by blocking cyclooxygenases with aspirin. CONCLUSIONS: The CD11b+CTLA4+ cells are a key driver of tumor evasion, and targeting the CTLA4-IL1B axis could be a promising strategy for treating metastatic CRC. The triple combination regimen with anti-CTLA4/IL1B mAbs and aspirin may be useful in clinical settings.
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Antígenos CD11/metabolismo , Antígeno CTLA-4/metabolismo , Neoplasias Colorrectales/genética , Anciano , Animales , Neoplasias Colorrectales/patología , Femenino , Humanos , Ratones , Ratones Desnudos , Persona de Mediana Edad , Células MieloidesRESUMEN
Alveolar macrophages (AMs) are pivotal for maintaining lung immune homeostasis. We demonstrated that deletion of liver kinase b1 (Lkb1) in CD11c+ cells led to greatly reduced AM abundance in the lung due to the impaired self-renewal of AMs but not the impeded pre-AM differentiation. Mice with Lkb1-deficient AMs exhibited deteriorated diseases during airway Staphylococcus aureus (S. aureus) infection and allergic inflammation, with excessive accumulation of neutrophils and more severe lung pathology. Drug-mediated AM depletion experiments in wild type mice indicated a cause for AM reduction in aggravated diseases in Lkb1 conditional knockout mice. Transcriptomic sequencing also revealed that Lkb1 inhibited proinflammatory pathways, including IL-17 signaling and neutrophil migration, which might also contribute to the protective function of Lkb1 in AMs. We thus identified Lkb1 as a pivotal regulator that maintains the self-renewal and immune function of AMs.
Asunto(s)
Asma/enzimología , Autorrenovación de las Células , Pulmón/enzimología , Macrófagos Alveolares/enzimología , Neumonía Bacteriana/enzimología , Proteínas Serina-Treonina Quinasas/metabolismo , Infecciones Estafilocócicas/enzimología , Proteínas Quinasas Activadas por AMP , Animales , Asma/genética , Asma/inmunología , Antígenos CD11/genética , Antígenos CD11/metabolismo , Modelos Animales de Enfermedad , Homeostasis , Interleucina-17/genética , Interleucina-17/metabolismo , Pulmón/inmunología , Pulmón/microbiología , Macrófagos Alveolares/inmunología , Macrófagos Alveolares/microbiología , Ratones Endogámicos C57BL , Ratones Noqueados , Infiltración Neutrófila , Neumonía Bacteriana/genética , Neumonía Bacteriana/inmunología , Neumonía Bacteriana/microbiología , Proteínas Serina-Treonina Quinasas/genética , Transducción de Señal , Infecciones Estafilocócicas/genética , Infecciones Estafilocócicas/inmunología , Infecciones Estafilocócicas/microbiología , TranscriptomaRESUMEN
Liver fibrosis is a critical complication of obesity-induced fatty liver disease. Wnt1 inducible signaling pathway protein 1 (WISP1/CCN4), a novel adipokine associated with visceral obesity and insulin resistance, also contributes to lung and kidney fibrosis. The aim of the present study was to investigate the role of CCN4 in liver fibrosis in severe obesity. For this, human liver biopsies were collected from 35 severely obese humans (BMI 42.5 ± 0.7 kg/m2, age 46.7 ± 1.8 y, 25.7% males) during bariatric surgery and examined for the expression of CCN4, fibrosis, and inflammation markers. Hepatic stellate LX-2 cells were treated with human recombinant CCN4 alone or in combination with LPS or transforming growth factor beta (TGF-ß) and examined for fibrosis and inflammation markers. CCN4 mRNA expression in the liver positively correlated with BMI and expression of fibrosis markers COL1A1, COL3A1, COL6A1, αSMA, TGFB1, extracellular matrix turnover enzymes TIMP1 and MMP9, and the inflammatory marker ITGAX/CD11c. In LX-2 cells, the exposure to recombinant CCN4 caused dose-dependent induction of MMP9 and MCP1. CCN4 potentiated the TGF-ß-mediated induction of COL3A1, TIMP1, and MCP1 but showed no interaction with LPS treatment. Our results suggest a potential contribution of CCN4 to the early pathogenesis of obesity-associated liver fibrosis.
Asunto(s)
Proteínas CCN de Señalización Intercelular/metabolismo , Cirrosis Hepática/metabolismo , Hígado/metabolismo , Obesidad Mórbida/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Adulto , Proteínas CCN de Señalización Intercelular/genética , Antígenos CD11/genética , Antígenos CD11/metabolismo , Línea Celular , Quimiocina CCL2/genética , Quimiocina CCL2/metabolismo , Colágeno/genética , Colágeno/metabolismo , Femenino , Humanos , Hígado/patología , Cirrosis Hepática/etiología , Masculino , Metaloproteinasa 9 de la Matriz/genética , Metaloproteinasa 9 de la Matriz/metabolismo , Persona de Mediana Edad , Obesidad Mórbida/complicaciones , Proteínas Proto-Oncogénicas/genética , Inhibidor Tisular de Metaloproteinasa-1/genética , Inhibidor Tisular de Metaloproteinasa-1/metabolismo , Factor de Crecimiento Transformador beta/genética , Factor de Crecimiento Transformador beta/metabolismoRESUMEN
BACKGROUND & AIMS: Helicobacter pylori has been reported to modulate local immune responses to colonize persistently in gastric mucosa. Although the induced expression of programmed cell death ligand 1 (PD-L1) has been suggested as an immune modulatory mechanism for persistent infection of H pylori, the main immune cells expressing PD-L1 and their functions in Helicobacter-induced gastritis still remain to be elucidated. METHODS: The blockades of PD-L1 with antibody or PD-L1-deficient bone marrow transplantation were performed in Helicobacter-infected mice. The main immune cells expressing PD-L1 in Helicobacter-infected stomach were determined by flow cytometry and immunofluorescence staining. Helicobacter felis or H pylori-infected dendritic cell (DC)-deficient mouse models including Flt3-/-, Zbtb46-diphtheria toxin receptor, and BDCA2-diphtheria toxin receptor mice were analyzed for pathologic changes and colonization levels. Finally, the location of PD-L1-expressing DCs and the correlation with H pylori infection were analyzed in human gastric tissues using multiplexed immunohistochemistry. RESULTS: Genetic or antibody-mediated blockade of PD-L1 aggravated Helicobacter-induced gastritis with mucosal metaplasia. Gastric classical DCs expressed considerably higher levels of PD-L1 than other immune cells and co-localized with T cells in gastritis lesions from Helicobacter-infected mice and human beings. H felis- or H pylori-infected Flt3-/- or classical DC-depleted mice showed aggravated gastritis with severe T-cell and neutrophil accumulation with low bacterial loads compared with that in control mice. Finally, PD-L1-expressing DCs were co-localized with T cells and showed a positive correlation with H pylori infection in human subjects. CONCLUSIONS: The PD-1/PD-L1 pathway may be responsible for the immune modulatory function of gastric DCs that protects the gastric mucosa from Helicobacter-induced inflammation, but allows persistent Helicobacter colonization.
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Antígeno B7-H1/metabolismo , Células Dendríticas/metabolismo , Gastritis/metabolismo , Gastritis/microbiología , Infecciones por Helicobacter/microbiología , Helicobacter pylori/fisiología , Animales , Anticuerpos/farmacología , Células de la Médula Ósea/efectos de los fármacos , Células de la Médula Ósea/metabolismo , Trasplante de Médula Ósea , Antígenos CD11/metabolismo , Linfocitos T CD8-positivos/efectos de los fármacos , Linfocitos T CD8-positivos/inmunología , Mucosa Gástrica/efectos de los fármacos , Mucosa Gástrica/patología , Gastritis/patología , Infecciones por Helicobacter/patología , Helicobacter pylori/efectos de los fármacos , Inflamación/patología , Masculino , Metaplasia , Ratones Endogámicos C57BL , Linfocitos T/inmunología , Tirosina Quinasa 3 Similar a fms/deficiencia , Tirosina Quinasa 3 Similar a fms/metabolismoRESUMEN
Dendritic cells (DCs) are indispensable for defense against pathogens but may also contribute to immunopathology. Activation of DCs upon the sensing of pathogens by Toll-like receptors (TLRs) is largely mediated by pattern recognition receptor/nuclear factor-κB (NF-κB) signaling and depends on the appropriate ubiquitination of the respective signaling molecules. However, the ubiquitinating and deubiquitinating enzymes involved and their interactions are only incompletely understood. Here, we reveal that the deubiquitinase OTU domain, ubiquitin aldehyde binding 1 (OTUB1) is upregulated in DCs upon murine Toxoplasma gondii infection and lipopolysaccharide challenge. Stimulation of DCs with the TLR11/12 ligand T. gondii profilin and the TLR4 ligand lipopolysaccharide induced an increase in NF-κB activation in OTUB1-competent cells, resulting in elevated interleukin-6 (IL-6), IL-12, and tumor necrosis factor (TNF) production, which was also observed upon the specific stimulation of TLR2, TLR3, TLR7, and TLR9. Mechanistically, OTUB1 promoted NF-κB activity in DCs by K48-linked deubiquitination and stabilization of the E2-conjugating enzyme UBC13, resulting in increased K63-linked ubiquitination of IRAK1 (IL-1 receptor-associated kinase 1) and TRAF6 (TNF receptor-associated factor 6). Consequently, DC-specific deletion of OTUB1 impaired the production of cytokines, in particular IL-12, by DCs over the first 2 days of T. gondii infection, resulting in the diminished production of protective interferon-γ (IFN-γ) by natural killer cells, impaired control of parasite replication, and, finally, death from chronic T. encephalitis, all of which could be prevented by low-dose IL-12 treatment in the first 3 days of infection. In contrast, impaired OTUB1-deficient DC activation and cytokine production by OTUB1-deficient DCs protected mice from lipopolysaccharide-induced immunopathology. Collectively, these findings identify OTUB1 as a potent novel regulator of DCs during infectious and inflammatory diseases.
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Cisteína Endopeptidasas/metabolismo , Células Dendríticas/inmunología , Inmunidad , Inflamación/inmunología , FN-kappa B/metabolismo , Enzimas Ubiquitina-Conjugadoras/metabolismo , Animales , Antígenos CD11/metabolismo , Células Dendríticas/parasitología , Eliminación de Gen , Interferón gamma/metabolismo , Interleucina-12/farmacología , Lipopolisacáridos , Lisina/metabolismo , Ratones Endogámicos C57BL , Ratones Transgénicos , Poliubiquitina/metabolismo , Estabilidad Proteica , Sepsis/inmunología , Sepsis/patología , Toxoplasma/fisiología , Toxoplasmosis/inmunología , Toxoplasmosis/patología , Ubiquitinación , Regulación hacia ArribaRESUMEN
Increasing evidence suggests that in hosts infected with parasites of the Leishmania donovani complex, transmission of infection to the sand fly vector is linked to parasite repositories in the host skin. However, a detailed understanding of the dispersal (the mechanism of spread) and dispersion (the observed state of spread) of these obligatory-intracellular parasites and their host phagocytes in the skin is lacking. Using endogenously fluorescent parasites as a proxy, we apply image analysis combined with spatial point pattern models borrowed from ecology to characterize dispersion of parasitized myeloid cells (including ManR+ and CD11c+ cells) and predict dispersal mechanisms in a previously described immunodeficient model of L. donovani infection. Our results suggest that after initial seeding of infection in the skin, heavily parasite-infected myeloid cells are found in patches that resemble innate granulomas. Spread of parasites from these initial patches subsequently occurs through infection of recruited myeloid cells, ultimately leading to self-propagating networks of patch clusters. This combination of imaging and ecological pattern analysis to identify mechanisms driving the skin parasite landscape offers new perspectives on myeloid cell behavior following parasitism by L. donovani and may also be applicable to elucidating the behavior of other intracellular tissue-resident pathogens and their host cells.
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Procesamiento de Imagen Asistido por Computador , Leishmania donovani/patogenicidad , Leishmaniasis Visceral/parasitología , Microscopía Confocal , Microscopía Fluorescente , Células Mieloides/parasitología , Piel/parasitología , Análisis Espacial , Animales , Antígenos CD11/metabolismo , Análisis por Conglomerados , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Modelos Animales de Enfermedad , Interacciones Huésped-Parásitos , Insectos Vectores/parasitología , Leishmania donovani/inmunología , Leishmaniasis Visceral/inmunología , Leishmaniasis Visceral/metabolismo , Leishmaniasis Visceral/transmisión , Receptor de Manosa/metabolismo , Ratones Endogámicos C57BL , Ratones Noqueados , Modelos Teóricos , Células Mieloides/inmunología , Células Mieloides/metabolismo , Phlebotomus/parasitología , Piel/inmunología , Piel/metabolismoRESUMEN
PURPOSE: The establishment of a preclinical model of the abscopal effect on hepatocellular carcinoma (HCC) and evaluation of whether the hypofractionated radiation therapy (RT) multitumor Hepa1-6 mouse HCC model could be used to suppress nonradiated tumor mass was performed in this study. METHODS AND MATERIALS: Hepa1-6 mouse liver cancer cell lines were used to form tumors. Immunogenicity was analyzed using ELISpot and immune cell labeled antibody. Interferon (IFN) ß expression was confirmed through polymerase chain reaction. RESULTS: After investigation, the intratumoral transcription of type â IFN increased by 2-fold. The antitumor immune response to Hepa 1-6 cells induced by radiation was increased. Moreover, the influx of activated CD8+ T cells was increased in nonirradiated tumors. The number of dendritic cells and activation status were evaluated by flow cytometry on the second day after irradiation. Flow cytometry revealed a significantly increased dendritic cell population expressing the CD11c molecule in tumor-draining lymph nodes. Furthermore, because irradiation leads to adaptation of immune resistance of tumor cells against RT, we sought to elucidate a potent tool to overcome the resistance and confirm the ability of PD-L1 antibody to survive late RT resistance. CONCLUSIONS: The immunologic mechanism of the abscopal effect was revealed and the application of PD-L1 inhibitor successfully performed as a breakthrough in late RT resistance in the Hepa1-6 tumor model.
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Carcinoma Hepatocelular/terapia , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Neoplasias Hepáticas/terapia , Tolerancia a Radiación/inmunología , Radiocirugia/métodos , Animales , Antineoplásicos , Antígeno B7-H1/administración & dosificación , Antígeno B7-H1/antagonistas & inhibidores , Antígeno B7-H1/metabolismo , Antígenos CD11/metabolismo , Linfocitos T CD8-positivos/citología , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/efectos de la radiación , Carcinoma Hepatocelular/inmunología , Carcinoma Hepatocelular/patología , Línea Celular Tumoral , Terapia Combinada/métodos , Células Dendríticas/citología , Células Dendríticas/inmunología , Células Dendríticas/efectos de la radiación , Modelos Animales de Enfermedad , Ensayo de Inmunoadsorción Enzimática , Femenino , Citometría de Flujo , Interferón Tipo I/metabolismo , Interferón beta/metabolismo , Interferón gamma/inmunología , Interferón gamma/metabolismo , Neoplasias Hepáticas/inmunología , Neoplasias Hepáticas/patología , Ganglios Linfáticos/metabolismo , Linfocitos Infiltrantes de Tumor/citología , Linfocitos Infiltrantes de Tumor/inmunología , Linfocitos Infiltrantes de Tumor/efectos de la radiación , Ratones , Ratones Endogámicos C57BL , Trasplante de Neoplasias , Hipofraccionamiento de la Dosis de Radiación , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Carga Tumoral/efectos de la radiaciónRESUMEN
BACKGROUND: Liver sinusoidal endothelial cells (LSECs) and Kupffer cells (KCs; liver resident macrophages) form the body's most effective scavenger cell system for the removal of harmful blood-borne substances, ranging from modified self-proteins to pathogens and xenobiotics. Controversies in the literature regarding the LSEC phenotype pose a challenge when determining distinct functionalities of KCs and LSECs. This may be due to overlapping functions of the two cells, insufficient purification and/or identification of the cells, rapid dedifferentiation of LSECs in vitro, or species differences. We therefore characterized and quantitatively compared expressed gene products of freshly isolated, highly pure LSECs (fenestrated SE-1/FcγRIIb2+) and KCs (CD11b/c+) from Sprague Dawley, Crl:CD (SD), male rats using high throughput mRNA-sequencing and label-free proteomics. RESULTS: We observed a robust correlation between the proteomes and transcriptomes of the two cell types. Integrative analysis of the global molecular profile demonstrated the immunological aspects of LSECs. The constitutive expression of several immune genes and corresponding proteins of LSECs bore some resemblance with the expression in macrophages. LSECs and KCs both expressed high levels of scavenger receptors (SR) and C-type lectins. Equivalent expression of SR-A1 (Msr1), mannose receptor (Mrc1), SR-B1 (Scarb1), and SR-B3 (Scarb2) suggested functional similarity between the two cell types, while functional distinction between the cells was evidenced by LSEC-specific expression of the SRs stabilin-1 (Stab1) and stabilin-2 (Stab2), and the C-type lectins LSECtin (Clec4g) and DC-SIGNR (Clec4m). Many immune regulatory factors were differentially expressed in LSECs and KCs, with one cell predominantly expressing a specific cytokine/chemokine and the other cell the cognate receptor, illustrating the complex cytokine milieu of the sinusoids. Both cells expressed genes and proteins involved in antigen processing and presentation, and lymphocyte co-stimulation. CONCLUSIONS: Our findings support complementary and partly overlapping scavenging and immune functions of LSECs and KCs. This highlights the importance of including LSECs in studies of liver immunity, and liver clearance and toxicity of large molecule drugs and nano-formulations.