RESUMO
We describe a human lung disease caused by autosomal recessive, complete deficiency of the monocyte chemokine receptor C-C motif chemokine receptor 2 (CCR2). Nine children from five independent kindreds have pulmonary alveolar proteinosis (PAP), progressive polycystic lung disease, and recurrent infections, including bacillus Calmette Guérin (BCG) disease. The CCR2 variants are homozygous in six patients and compound heterozygous in three, and all are loss-of-expression and loss-of-function. They abolish CCR2-agonist chemokine C-C motif ligand 2 (CCL-2)-stimulated Ca2+ signaling in and migration of monocytic cells. All patients have high blood CCL-2 levels, providing a diagnostic test for screening children with unexplained lung or mycobacterial disease. Blood myeloid and lymphoid subsets and interferon (IFN)-γ- and granulocyte-macrophage colony-stimulating factor (GM-CSF)-mediated immunity are unaffected. CCR2-deficient monocytes and alveolar macrophage-like cells have normal gene expression profiles and functions. By contrast, alveolar macrophage counts are about half. Human complete CCR2 deficiency is a genetic etiology of PAP, polycystic lung disease, and recurrent infections caused by impaired CCL2-dependent monocyte migration to the lungs and infected tissues.
Assuntos
Proteinose Alveolar Pulmonar , Receptores CCR2 , Criança , Humanos , Pulmão/metabolismo , Macrófagos Alveolares/metabolismo , Proteinose Alveolar Pulmonar/genética , Proteinose Alveolar Pulmonar/diagnóstico , Receptores CCR2/deficiência , Receptores CCR2/genética , Receptores CCR2/metabolismo , Reinfecção/metabolismoRESUMO
Alveolar type 2 (AT2) cells are stem cells of the alveolar epithelia. Previous genetic lineage tracing studies reported multiple cellular origins for AT2 cells after injury. However, conventional lineage tracing based on Cre-loxP has the limitation of non-specific labeling. Here, we introduced a dual recombinase-mediated intersectional genetic lineage tracing approach, enabling precise investigation of AT2 cellular origins during lung homeostasis, injury, and repair. We found AT1 cells, being terminally differentiated, did not contribute to AT2 cells after lung injury and repair. Distinctive yet simultaneous labeling of club cells, bronchioalveolar stem cells (BASCs), and existing AT2 cells revealed the exact contribution of each to AT2 cells post-injury. Mechanistically, Notch signaling inhibition promotes BASCs but impairs club cells' ability to generate AT2 cells during lung repair. This intersectional genetic lineage tracing strategy with enhanced precision allowed us to elucidate the physiological role of various epithelial cell types in alveolar regeneration following injury.
Assuntos
Células Epiteliais Alveolares , Pulmão , Células-Tronco , Animais , Camundongos , Células Epiteliais Alveolares/metabolismo , Células Epiteliais Alveolares/citologia , Diferenciação Celular , Linhagem da Célula , Pulmão/citologia , Pulmão/metabolismo , Pulmão/fisiologia , Lesão Pulmonar/patologia , Camundongos Endogâmicos C57BL , Alvéolos Pulmonares/citologia , Alvéolos Pulmonares/metabolismo , Receptores Notch/metabolismo , Regeneração , Transdução de Sinais , Células-Tronco/metabolismo , Células-Tronco/citologiaRESUMO
Most human monoclonal antibodies (mAbs) neutralizing SARS-CoV-2 recognize the spike (S) protein receptor-binding domain and block virus interactions with the cellular receptor angiotensin-converting enzyme 2. We describe a panel of human mAbs binding to diverse epitopes on the N-terminal domain (NTD) of S protein from SARS-CoV-2 convalescent donors and found a minority of these possessed neutralizing activity. Two mAbs (COV2-2676 and COV2-2489) inhibited infection of authentic SARS-CoV-2 and recombinant VSV/SARS-CoV-2 viruses. We mapped their binding epitopes by alanine-scanning mutagenesis and selection of functional SARS-CoV-2 S neutralization escape variants. Mechanistic studies showed that these antibodies neutralize in part by inhibiting a post-attachment step in the infection cycle. COV2-2676 and COV2-2489 offered protection either as prophylaxis or therapy, and Fc effector functions were required for optimal protection. Thus, natural infection induces a subset of potent NTD-specific mAbs that leverage neutralizing and Fc-mediated activities to protect against SARS-CoV-2 infection using multiple functional attributes.
Assuntos
Anticorpos Monoclonais/farmacologia , Anticorpos Neutralizantes/farmacologia , Substâncias Protetoras/farmacologia , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/imunologia , Animais , Ligação Competitiva , COVID-19/imunologia , COVID-19/virologia , Quimiocinas/metabolismo , Chlorocebus aethiops , Células HEK293 , Humanos , Fragmentos Fab das Imunoglobulinas/metabolismo , Imunoglobulina G/metabolismo , Pulmão/metabolismo , Camundongos Endogâmicos C57BL , Modelos Moleculares , Mutagênese/genética , Testes de Neutralização , Domínios Proteicos , Células VeroRESUMO
Metastasis is the leading cause of cancer-related deaths, and greater knowledge of the metastatic microenvironment is necessary to effectively target this process. Microenvironmental changes occur at distant sites prior to clinically detectable metastatic disease; however, the key niche regulatory signals during metastatic progression remain poorly characterized. Here, we identify a core immune suppression gene signature in pre-metastatic niche formation that is expressed predominantly by myeloid cells. We target this immune suppression program by utilizing genetically engineered myeloid cells (GEMys) to deliver IL-12 to modulate the metastatic microenvironment. Our data demonstrate that IL12-GEMy treatment reverses immune suppression in the pre-metastatic niche by activating antigen presentation and T cell activation, resulting in reduced metastatic and primary tumor burden and improved survival of tumor-bearing mice. We demonstrate that IL12-GEMys can functionally modulate the core program of immune suppression in the pre-metastatic niche to successfully rebalance the dysregulated metastatic microenvironment in cancer.
Assuntos
Terapia de Imunossupressão , Células Mieloides/metabolismo , Imunidade Adaptativa , Animais , Linhagem Celular Tumoral , Engenharia Genética , Humanos , Interleucina-12/genética , Interleucina-12/metabolismo , Pulmão/metabolismo , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Ativação Linfocitária , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Células Mieloides/citologia , Células Mieloides/imunologia , Metástase Neoplásica , Rabdomiossarcoma/metabolismo , Rabdomiossarcoma/patologia , Taxa de Sobrevida , Linfócitos T/imunologia , Linfócitos T/metabolismo , Microambiente TumoralRESUMO
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA generally becomes undetectable in upper airways after a few days or weeks postinfection. Here we used a model of viral infection in macaques to address whether SARS-CoV-2 persists in the body and which mechanisms regulate its persistence. Replication-competent virus was detected in bronchioalveolar lavage (BAL) macrophages beyond 6 months postinfection. Viral propagation in BAL macrophages occurred from cell to cell and was inhibited by interferon-γ (IFN-γ). IFN-γ production was strongest in BAL NKG2r+CD8+ T cells and NKG2Alo natural killer (NK) cells and was further increased in NKG2Alo NK cells after spike protein stimulation. However, IFN-γ production was impaired in NK cells from macaques with persisting virus. Moreover, IFN-γ also enhanced the expression of major histocompatibility complex (MHC)-E on BAL macrophages, possibly inhibiting NK cell-mediated killing. Macaques with less persisting virus mounted adaptive NK cells that escaped the MHC-E-dependent inhibition. Our findings reveal an interplay between NK cells and macrophages that regulated SARS-CoV-2 persistence in macrophages and was mediated by IFN-γ.
Assuntos
COVID-19 , Interferon gama , Animais , Interferon gama/metabolismo , SARS-CoV-2/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Macrófagos Alveolares/metabolismo , Células Matadoras Naturais/metabolismo , Pulmão/metabolismo , Macaca/metabolismoRESUMO
Chronic obstructive pulmonary disease (COPD) is a progressive condition of chronic bronchitis, small airway obstruction, and emphysema that represents a leading cause of death worldwide. While inflammation, fibrosis, mucus hypersecretion, and metaplastic epithelial lesions are hallmarks of this disease, their origins and dependent relationships remain unclear. Here we apply single-cell cloning technologies to lung tissue of patients with and without COPD. Unlike control lungs, which were dominated by normal distal airway progenitor cells, COPD lungs were inundated by three variant progenitors epigenetically committed to distinct metaplastic lesions. When transplanted to immunodeficient mice, these variant clones induced pathology akin to the mucous and squamous metaplasia, neutrophilic inflammation, and fibrosis seen in COPD. Remarkably, similar variants pre-exist as minor constituents of control and fetal lung and conceivably act in normal processes of immune surveillance. However, these same variants likely catalyze the pathologic and progressive features of COPD when expanded to high numbers.
Assuntos
Pulmão/patologia , Doença Pulmonar Obstrutiva Crônica/genética , Doença Pulmonar Obstrutiva Crônica/metabolismo , Adulto , Idoso , Animais , Feminino , Fibrose/fisiopatologia , Humanos , Inflamação/patologia , Pulmão/metabolismo , Masculino , Metaplasia/fisiopatologia , Camundongos , Pessoa de Meia-Idade , Neutrófilos/imunologia , Pneumonia/patologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Análise de Célula Única/métodos , Células-Tronco/metabolismoRESUMO
During respiration, humans breathe in more than 10,000 liters of non-sterile air daily, allowing some pathogens access to alveoli. Interestingly, alveoli outnumber alveolar macrophages (AMs), which favors alveoli devoid of AMs. If AMs, like most tissue macrophages, are sessile, then this numerical advantage would be exploited by pathogens unless neutrophils from the blood stream intervened. However, this would translate to omnipresent persistent inflammation. Developing in vivo real-time intravital imaging of alveoli revealed AMs crawling in and between alveoli using the pores of Kohn. Importantly, these macrophages sensed, chemotaxed, and, with high efficiency, phagocytosed inhaled bacterial pathogens such as P. aeruginosa and S. aureus, cloaking the bacteria from neutrophils. Impairing AM chemotaxis toward bacteria induced superfluous neutrophil recruitment, leading to inappropriate inflammation and injury. In a disease context, influenza A virus infection impaired AM crawling via the type II interferon signaling pathway, and this greatly increased secondary bacterial co-infection.
Assuntos
Bactérias/imunologia , Macrófagos Alveolares/imunologia , Macrófagos Alveolares/metabolismo , Animais , Feminino , Homeostase , Humanos , Pulmão/imunologia , Pulmão/metabolismo , Macrófagos/imunologia , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Infiltração de Neutrófilos , Neutrófilos/imunologia , Fagocitose/imunologia , Pseudomonas aeruginosa/imunologia , Pseudomonas aeruginosa/patogenicidade , Alvéolos Pulmonares , Transdução de Sinais , Staphylococcus aureus/imunologia , Staphylococcus aureus/patogenicidadeRESUMO
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a pandemic with millions of human infections. One limitation to the evaluation of potential therapies and vaccines to inhibit SARS-CoV-2 infection and ameliorate disease is the lack of susceptible small animals in large numbers. Commercially available laboratory strains of mice are not readily infected by SARS-CoV-2 because of species-specific differences in their angiotensin-converting enzyme 2 (ACE2) receptors. Here, we transduced replication-defective adenoviruses encoding human ACE2 via intranasal administration into BALB/c mice and established receptor expression in lung tissues. hACE2-transduced mice were productively infected with SARS-CoV-2, and this resulted in high viral titers in the lung, lung pathology, and weight loss. Passive transfer of a neutralizing monoclonal antibody reduced viral burden in the lung and mitigated inflammation and weight loss. The development of an accessible mouse model of SARS-CoV-2 infection and pathogenesis will expedite the testing and deployment of therapeutics and vaccines.
Assuntos
Anticorpos Monoclonais/uso terapêutico , Anticorpos Neutralizantes/uso terapêutico , Anticorpos Antivirais/uso terapêutico , Betacoronavirus/imunologia , Infecções por Coronavirus/terapia , Modelos Animais de Doenças , Pneumonia Viral/terapia , Enzima de Conversão de Angiotensina 2 , Animais , COVID-19 , Chlorocebus aethiops , Infecções por Coronavirus/virologia , Feminino , Células HEK293 , Humanos , Imunização Passiva/métodos , Pulmão/metabolismo , Pulmão/virologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Knockout , Pandemias , Peptidil Dipeptidase A/genética , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/virologia , SARS-CoV-2 , Transdução Genética , Células Vero , Carga Viral/imunologiaRESUMO
The emergence of SARS-CoV-2 led to pandemic spread of coronavirus disease 2019 (COVID-19), manifesting with respiratory symptoms and multi-organ dysfunction. Detailed characterization of virus-neutralizing antibodies and target epitopes is needed to understand COVID-19 pathophysiology and guide immunization strategies. Among 598 human monoclonal antibodies (mAbs) from 10 COVID-19 patients, we identified 40 strongly neutralizing mAbs. The most potent mAb, CV07-209, neutralized authentic SARS-CoV-2 with an IC50 value of 3.1 ng/mL. Crystal structures of two mAbs in complex with the SARS-CoV-2 receptor-binding domain at 2.55 and 2.70 Å revealed a direct block of ACE2 attachment. Interestingly, some of the near-germline SARS-CoV-2-neutralizing mAbs reacted with mammalian self-antigens. Prophylactic and therapeutic application of CV07-209 protected hamsters from SARS-CoV-2 infection, weight loss, and lung pathology. Our results show that non-self-reactive virus-neutralizing mAbs elicited during SARS-CoV-2 infection are a promising therapeutic strategy.
Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/imunologia , Betacoronavirus/metabolismo , Infecções por Coronavirus/patologia , Pneumonia Viral/patologia , Enzima de Conversão de Angiotensina 2 , Animais , Anticorpos Monoclonais/uso terapêutico , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/uso terapêutico , Reações Antígeno-Anticorpo , Betacoronavirus/imunologia , Betacoronavirus/patogenicidade , Sítios de Ligação , COVID-19 , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/virologia , Cricetinae , Cristalografia por Raios X , Modelos Animais de Doenças , Humanos , Cinética , Pulmão/imunologia , Pulmão/metabolismo , Pulmão/patologia , Camundongos , Camundongos Endogâmicos C57BL , Simulação de Dinâmica Molecular , Pandemias , Peptidil Dipeptidase A/química , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/virologia , Ligação Proteica , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/metabolismoRESUMO
We show that SARS-CoV-2 spike protein interacts with both cellular heparan sulfate and angiotensin-converting enzyme 2 (ACE2) through its receptor-binding domain (RBD). Docking studies suggest a heparin/heparan sulfate-binding site adjacent to the ACE2-binding site. Both ACE2 and heparin can bind independently to spike protein in vitro, and a ternary complex can be generated using heparin as a scaffold. Electron micrographs of spike protein suggests that heparin enhances the open conformation of the RBD that binds ACE2. On cells, spike protein binding depends on both heparan sulfate and ACE2. Unfractionated heparin, non-anticoagulant heparin, heparin lyases, and lung heparan sulfate potently block spike protein binding and/or infection by pseudotyped virus and authentic SARS-CoV-2 virus. We suggest a model in which viral attachment and infection involves heparan sulfate-dependent enhancement of binding to ACE2. Manipulation of heparan sulfate or inhibition of viral adhesion by exogenous heparin presents new therapeutic opportunities.
Assuntos
Betacoronavirus/fisiologia , Heparitina Sulfato/metabolismo , Peptidil Dipeptidase A/metabolismo , Glicoproteína da Espícula de Coronavírus/metabolismo , Sequência de Aminoácidos , Enzima de Conversão de Angiotensina 2 , Betacoronavirus/isolamento & purificação , Sítios de Ligação , COVID-19 , Linhagem Celular , Infecções por Coronavirus/patologia , Infecções por Coronavirus/virologia , Heparina/química , Heparina/metabolismo , Heparitina Sulfato/química , Humanos , Rim/metabolismo , Pulmão/metabolismo , Simulação de Dinâmica Molecular , Pandemias , Peptidil Dipeptidase A/química , Pneumonia Viral/patologia , Pneumonia Viral/virologia , Ligação Proteica , Domínios Proteicos , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Internalização do VírusRESUMO
The mode of acquisition and causes for the variable clinical spectrum of coronavirus disease 2019 (COVID-19) remain unknown. We utilized a reverse genetics system to generate a GFP reporter virus to explore severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pathogenesis and a luciferase reporter virus to demonstrate sera collected from SARS and COVID-19 patients exhibited limited cross-CoV neutralization. High-sensitivity RNA in situ mapping revealed the highest angiotensin-converting enzyme 2 (ACE2) expression in the nose with decreasing expression throughout the lower respiratory tract, paralleled by a striking gradient of SARS-CoV-2 infection in proximal (high) versus distal (low) pulmonary epithelial cultures. COVID-19 autopsied lung studies identified focal disease and, congruent with culture data, SARS-CoV-2-infected ciliated and type 2 pneumocyte cells in airway and alveolar regions, respectively. These findings highlight the nasal susceptibility to SARS-CoV-2 with likely subsequent aspiration-mediated virus seeding to the lung in SARS-CoV-2 pathogenesis. These reagents provide a foundation for investigations into virus-host interactions in protective immunity, host susceptibility, and virus pathogenesis.
Assuntos
Betacoronavirus/genética , Infecções por Coronavirus/patologia , Infecções por Coronavirus/virologia , Pneumonia Viral/patologia , Pneumonia Viral/virologia , Sistema Respiratório/virologia , Genética Reversa/métodos , Idoso , Enzima de Conversão de Angiotensina 2 , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Betacoronavirus/imunologia , Betacoronavirus/patogenicidade , COVID-19 , Linhagem Celular , Células Cultivadas , Chlorocebus aethiops , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/terapia , Fibrose Cística/patologia , DNA Recombinante , Feminino , Furina/metabolismo , Humanos , Imunização Passiva , Pulmão/metabolismo , Pulmão/patologia , Pulmão/virologia , Masculino , Pessoa de Meia-Idade , Mucosa Nasal/metabolismo , Mucosa Nasal/patologia , Mucosa Nasal/virologia , Pandemias , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/imunologia , Sistema Respiratório/patologia , SARS-CoV-2 , Serina Endopeptidases/metabolismo , Células Vero , Virulência , Replicação Viral , Soroterapia para COVID-19RESUMO
The brain is a site of relative immune privilege. Although CD4 T cells have been reported in the central nervous system, their presence in the healthy brain remains controversial, and their function remains largely unknown. We used a combination of imaging, single cell, and surgical approaches to identify a CD69+ CD4 T cell population in both the mouse and human brain, distinct from circulating CD4 T cells. The brain-resident population was derived through in situ differentiation from activated circulatory cells and was shaped by self-antigen and the peripheral microbiome. Single-cell sequencing revealed that in the absence of murine CD4 T cells, resident microglia remained suspended between the fetal and adult states. This maturation defect resulted in excess immature neuronal synapses and behavioral abnormalities. These results illuminate a role for CD4 T cells in brain development and a potential interconnected dynamic between the evolution of the immunological and neurological systems. VIDEO ABSTRACT.
Assuntos
Encéfalo/citologia , Linfócitos T CD4-Positivos/metabolismo , Feto/citologia , Microglia/citologia , Microglia/metabolismo , Sinapses/metabolismo , Adulto , Animais , Antígenos CD/metabolismo , Antígenos de Diferenciação de Linfócitos T/metabolismo , Escala de Avaliação Comportamental , Células Sanguíneas/citologia , Células Sanguíneas/metabolismo , Encéfalo/embriologia , Encéfalo/metabolismo , Criança , Feminino , Feto/embriologia , Humanos , Lectinas Tipo C/metabolismo , Pulmão/citologia , Pulmão/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Neurogênese/genética , Parabiose , Células Piramidais/metabolismo , Células Piramidais/fisiologia , Análise de Célula Única , Baço/citologia , Baço/metabolismo , Sinapses/imunologia , TranscriptomaRESUMO
Alveolar macrophages (AMs) are lung tissue-resident macrophages that can be expanded in culture, but it is unknown to what extent culture affects their in vivo identity. Here we show that mouse long-term ex vivo expanded AMs (exAMs) maintained a core AM gene expression program, but showed culture adaptations related to adhesion, metabolism and proliferation. Upon transplantation into the lung, exAMs reacquired full transcriptional and epigenetic AM identity, even after several months in culture and could self-maintain long-term in the alveolar niche. Changes in open chromatin regions observed in culture were fully reversible in transplanted exAMs and resulted in a gene expression profile indistinguishable from resident AMs. Our results indicate that long-term proliferation of AMs in culture did not compromise cellular identity in vivo. The robustness of exAM identity provides new opportunities for mechanistic analysis and highlights the therapeutic potential of exAMs.
Assuntos
Pulmão , Macrófagos Alveolares , Animais , Cromatina/metabolismo , Epigênese Genética , Epigenômica , Pulmão/metabolismo , Macrófagos Alveolares/metabolismo , CamundongosRESUMO
Here, we describe a novel pathogenic entity, the activated PMN (polymorphonuclear leukocyte, i.e., neutrophil)-derived exosome. These CD63+/CD66b+ nanovesicles acquire surface-bound neutrophil elastase (NE) during PMN degranulation, NE being oriented in a configuration resistant to α1-antitrypsin (α1AT). These exosomes bind and degrade extracellular matrix (ECM) via the integrin Mac-1 and NE, respectively, causing the hallmarks of chronic obstructive pulmonary disease (COPD). Due to both ECM targeting and α1AT resistance, exosomal NE is far more potent than free NE. Importantly, such PMN-derived exosomes exist in clinical specimens from subjects with COPD but not healthy controls and are capable of transferring a COPD-like phenotype from humans to mice in an NE-driven manner. Similar findings were observed for another neutrophil-driven disease of ECM remodeling (bronchopulmonary dysplasia [BPD]). These findings reveal an unappreciated role for exosomes in the pathogenesis of disorders of ECM homeostasis such as COPD and BPD, providing a critical mechanism for proteolytic damage.
Assuntos
Exossomos/fisiologia , Neutrófilos/metabolismo , Animais , Líquido da Lavagem Broncoalveolar/citologia , Células Cultivadas , Matriz Extracelular/metabolismo , Feminino , Humanos , Inflamação , Integrinas , Elastase de Leucócito/metabolismo , Pulmão/metabolismo , Pulmão/fisiopatologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neutrófilos/fisiologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , alfa 1-Antitripsina/metabolismoRESUMO
Adaptive immunity provides life-long protection by generating central and effector memory T cells and the most recently described tissue resident memory T (TRM) cells. However, the cellular origin of CD4 TRM cells and their contribution to host defense remain elusive. Using IL-17A tracking-fate mouse models, we found that a significant fraction of lung CD4 TRM cells derive from IL-17A-producing effector (TH17) cells following immunization with heat-killed Klebsiella pneumonia (Kp). These exTH17 TRM cells are maintained in the lung by IL-7, produced by lymphatic endothelial cells. During a memory response, neither antibodies, γδ T cells, nor circulatory T cells are sufficient for the rapid host defense required to eliminate Kp. Conversely, using parabiosis and depletion studies, we demonstrated that exTH17 TRM cells play an important role in bacterial clearance. Thus, we delineate the origin and function of airway CD4 TRM cells during bacterial infection, offering novel strategies for targeted vaccine design.
Assuntos
Infecções por Klebsiella/imunologia , Células Th17/imunologia , Animais , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Toxina Diftérica/farmacologia , Modelos Animais de Doenças , Feminino , Memória Imunológica , Interleucina-17/genética , Interleucina-17/metabolismo , Infecções por Klebsiella/patologia , Klebsiella pneumoniae/imunologia , Klebsiella pneumoniae/patogenicidade , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Células Th17/citologia , Células Th17/metabolismoRESUMO
A hallmark feature of inflammation is the orchestrated recruitment of neutrophils from the bloodstream into inflamed tissue. Although selectins and integrins mediate recruitment in many tissues, they have a minimal role in the lungs and liver. Exploiting an unbiased in vivo functional screen, we identified a lung and liver homing peptide that functionally abrogates neutrophil recruitment to these organs. Using biochemical, genetic, and confocal intravital imaging approaches, we identified dipeptidase-1 (DPEP1) as the target and established its role as a physical adhesion receptor for neutrophil sequestration independent of its enzymatic activity. Importantly, genetic ablation or functional peptide blocking of DPEP1 significantly reduced neutrophil recruitment to the lungs and liver and provided improved survival in models of endotoxemia. Our data establish DPEP1 as a major adhesion receptor on the lung and liver endothelium and identify a therapeutic target for neutrophil-driven inflammatory diseases of the lungs.
Assuntos
Dipeptidases/metabolismo , Neutrófilos/fisiologia , Complexo Glicoproteico GPIb-IX de Plaquetas/metabolismo , Animais , Cilastatina/farmacologia , Cilastatina/uso terapêutico , Dipeptidases/antagonistas & inibidores , Dipeptidases/genética , Modelos Animais de Doenças , Endotoxemia/mortalidade , Endotoxemia/patologia , Endotoxemia/prevenção & controle , Proteínas Ligadas por GPI/antagonistas & inibidores , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/metabolismo , Humanos , Lipopolissacarídeos/farmacologia , Fígado/efeitos dos fármacos , Fígado/imunologia , Fígado/metabolismo , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Pulmão/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos SCID , Infiltração de Neutrófilos/efeitos dos fármacos , Peptídeos/síntese química , Peptídeos/química , Peptídeos/farmacologia , Taxa de SobrevidaRESUMO
Macrophages have long been considered as particularly plastic cells. However, recent work combining fate mapping, single-cell transcriptomics and epigenetics has undermined the macrophage plasticity dogma. Here, we discuss recent studies that have carefully dissected the response of individual macrophage subsets to pulmonary insults and call for an adjustment of the macrophage plasticity concept. We hypothesize that prolonged tissue residency shuts down much of the plasticity of macrophages and propose that the restricted plasticity of resident macrophages has been favored by evolution to safeguard tissue homeostasis. Recruited monocytes are more plastic and their differentiation into resident macrophages during inflammation can result in a dual imprinting from both the ongoing inflammation and the macrophage niche. This results in inflammation-imprinted resident macrophages, and we speculate that rewired niche circuits could maintain this inflammatory state. We believe that this revisited plasticity model offers opportunities to reset the macrophage pool after a severe inflammatory episode.
Assuntos
Plasticidade Celular , Pulmão/imunologia , Macrófagos Alveolares/imunologia , Pneumonia/imunologia , Animais , Microambiente Celular , Epigênese Genética , Humanos , Mediadores da Inflamação/metabolismo , Pulmão/metabolismo , Macrófagos Alveolares/metabolismo , Fenótipo , Pneumonia/genética , Pneumonia/metabolismo , Transdução de SinaisRESUMO
The constituents of the gut microbiome are determined by the local habitat, which itself is shaped by immunological pressures, such as mucosal IgA. Using a mouse model of restricted antibody repertoire, we identified a role for antibody-microbe interactions in shaping a community of bacteria with an enhanced capacity to metabolize L-tyrosine. This model led to increased concentrations of p-cresol sulfate (PCS), which protected the host against allergic airway inflammation. PCS selectively reduced CCL20 production by airway epithelial cells due to an uncoupling of epidermal growth factor receptor (EGFR) and Toll-like receptor 4 (TLR4) signaling. Together, these data reveal a gut microbe-derived metabolite pathway that acts distally on the airway epithelium to reduce allergic airway responses, such as those underpinning asthma.
Assuntos
Anticorpos/metabolismo , Bactérias/metabolismo , Cresóis/metabolismo , Microbioma Gastrointestinal , Intestinos/microbiologia , Pulmão/metabolismo , Pneumonia/prevenção & controle , Hipersensibilidade Respiratória/prevenção & controle , Ésteres do Ácido Sulfúrico/metabolismo , Tirosina/metabolismo , Administração Oral , Alérgenos , Animais , Anticorpos/imunologia , Diversidade de Anticorpos , Bactérias/imunologia , Células Cultivadas , Quimiocina CCL20/metabolismo , Técnicas de Cocultura , Cresóis/administração & dosagem , Modelos Animais de Doenças , Receptores ErbB/metabolismo , Feminino , Interações Hospedeiro-Patógeno , Injeções Intravenosas , Pulmão/imunologia , Pulmão/patologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Pneumonia/imunologia , Pneumonia/metabolismo , Pneumonia/microbiologia , Hipersensibilidade Respiratória/imunologia , Hipersensibilidade Respiratória/metabolismo , Hipersensibilidade Respiratória/microbiologia , Transdução de Sinais , Ésteres do Ácido Sulfúrico/administração & dosagem , Receptor 4 Toll-Like/metabolismo , Tirosina/administração & dosagemRESUMO
Severe asthma and sinus disease are consequences of type 2 inflammation (T2I), mediated by interleukin (IL)-33 signaling through its membrane-bound receptor, ST2. Soluble (s)ST2 reduces available IL-33 and limits T2I, but little is known about its regulation. We demonstrate that prostaglandin E2 (PGE2) drives production of sST2 to limit features of lung T2I. PGE2-deficient mice display diminished sST2. In humans with severe respiratory T2I, urinary PGE2 metabolites correlate with serum sST2. In mice, PGE2 enhanced sST2 secretion by mast cells (MCs). Mice lacking MCs, ST2 expression by MCs, or E prostanoid (EP)2 receptors by MCs showed reduced sST2 lung concentrations and strong T2I. Recombinant sST2 reduced T2I in mice lacking PGE2 or ST2 expression by MCs back to control levels. PGE2 deficiency also reversed the hyperinflammatory phenotype in mice lacking ST2 expression by MCs. PGE2 thus suppresses T2I through MC-derived sST2, explaining the severe T2I observed in low PGE2 states.
Assuntos
Dinoprostona , Proteína 1 Semelhante a Receptor de Interleucina-1 , Interleucina-33 , Pulmão , Mastócitos , Camundongos Knockout , Animais , Proteína 1 Semelhante a Receptor de Interleucina-1/metabolismo , Proteína 1 Semelhante a Receptor de Interleucina-1/genética , Mastócitos/imunologia , Mastócitos/metabolismo , Dinoprostona/metabolismo , Camundongos , Interleucina-33/metabolismo , Humanos , Pulmão/imunologia , Pulmão/metabolismo , Pulmão/patologia , Asma/imunologia , Asma/metabolismo , Receptores de Prostaglandina E Subtipo EP2/metabolismo , Camundongos Endogâmicos C57BL , Inflamação/imunologia , Feminino , Masculino , Transdução de Sinais , Pneumonia/imunologia , Pneumonia/metabolismoRESUMO
Type 2 cytokine responses promote parasitic immunity and initiate tissue repair; however, they can also result in immunopathologies when not properly restricted. Although basophilia is recognized as a common feature of type 2 inflammation, the roles basophils play in regulating these responses are unknown. Here, we demonstrate that helminth-induced group 2 innate lymphoid cell (ILC2) responses are exaggerated in the absence of basophils, resulting in increased inflammation and diminished lung function. Additionally, we show that ILC2s from basophil-depleted mice express reduced amounts of the receptor for the neuropeptide neuromedin B (NMB). Critically, NMB stimulation inhibited ILC2 responses from control but not basophil-depleted mice, and basophils were sufficient to directly enhance NMB receptor expression on ILC2s. These studies suggest that basophils prime ILC2s to respond to neuron-derived signals necessary to maintain tissue integrity. Further, these data provide mechanistic insight into the functions of basophils and identify NMB as a potent inhibitor of type 2 inflammation.