RESUMO
Lung dendritic cells (DCs) bridge innate and adaptive immunity, and depending on context, they also induce a Th1, Th2, or Th17 response to optimally clear infectious threats. Conversely, lung DCs can also mount maladaptive Th2 immune responses to harmless allergens and, in this way, contribute to immunopathology. It is now clear that the various aspects of DC biology can be understood only if we take into account the functional specializations of different DC subsets that are present in the lung in homeostasis or are attracted to the lung as part of the inflammatory response to inhaled noxious stimuli. Lung DCs are heavily influenced by the nearby epithelial cells, and a model is emerging whereby direct communication between DCs and epithelial cells determines the outcome of the pulmonary immune response. Here, we have approached DC biology from the perspective of viral infection and allergy to illustrate these emerging concepts.
Assuntos
Asma/imunologia , Células Dendríticas/imunologia , Influenza Humana/imunologia , Pulmão/imunologia , Imunidade Adaptativa , Alérgenos/imunologia , Animais , Asma/prevenção & controle , Células Dendríticas/metabolismo , Humanos , Pulmão/patologia , Pulmão/virologia , Camundongos , Pneumonia/imunologia , Pneumonia/patologiaRESUMO
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
The antimicrobial functions of neutrophils are facilitated by a defensive armamentarium of proteins stored in granules, and by the formation of neutrophil extracellular traps (NETs). However, the toxic nature of these structures poses a threat to highly vascularized tissues, such as the lungs. Here, we identified a cell-intrinsic program that modified the neutrophil proteome in the circulation and caused the progressive loss of granule content and reduction of the NET-forming capacity. This program was driven by the receptor CXCR2 and by regulators of circadian cycles. As a consequence, lungs were protected from inflammatory injury at times of day or in mouse mutants in which granule content was low. Changes in the proteome, granule content and NET formation also occurred in human neutrophils, and correlated with the incidence and severity of respiratory distress in pneumonia patients. Our findings unveil a 'disarming' strategy of neutrophils that depletes protein stores to reduce the magnitude of inflammation.
Assuntos
Ritmo Circadiano/imunologia , Inflamação/metabolismo , Neutrófilos/metabolismo , Pneumonia/metabolismo , Síndrome do Desconforto Respiratório/metabolismo , Animais , Degranulação Celular/imunologia , Grânulos Citoplasmáticos/imunologia , Grânulos Citoplasmáticos/metabolismo , Armadilhas Extracelulares/imunologia , Armadilhas Extracelulares/metabolismo , Humanos , Inflamação/imunologia , Camundongos , Neutrófilos/imunologia , Pneumonia/complicações , Pneumonia/imunologia , Proteoma/imunologia , Proteoma/metabolismo , Síndrome do Desconforto Respiratório/imunologiaRESUMO
Follicular regulatory T (TFR) cells have specialized roles in modulating follicular helper T (TFH) cell activation of B cells. However, the precise role of TFR cells in controlling antibody responses to foreign antigens and autoantigens in vivo is still unclear due to a lack of specific tools. A TFR cell-deleter mouse was developed that selectively deletes TFR cells, facilitating temporal studies. TFR cells were found to regulate early, but not late, germinal center (GC) responses to control antigen-specific antibody and B cell memory. Deletion of TFR cells also resulted in increased self-reactive immunoglobulin (Ig) G and IgE. The increased IgE levels led us to interrogate the role of TFR cells in house dust mite models. TFR cells were found to control TFH13 cell-induced IgE. In vivo, loss of TFR cells increased house-dust-mite-specific IgE and lung inflammation. Thus, TFR cells control IgG and IgE responses to vaccines, allergens and autoantigens, and exert critical immunoregulatory functions before GC formation.
Assuntos
Linfócitos B/imunologia , Centro Germinativo/imunologia , Hipersensibilidade/imunologia , Pneumonia/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Reguladores/imunologia , Animais , Antígenos de Dermatophagoides/imunologia , Autoantígenos/imunologia , Deleção Clonal/genética , Modelos Animais de Doenças , Humanos , Tolerância Imunológica , Imunidade Humoral , Imunoglobulina E/metabolismo , Imunoglobulina G/metabolismo , Memória Imunológica , Interleucina-13/metabolismo , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Pyroglyphidae/imunologiaRESUMO
Interleukin (IL)-1R3 is the co-receptor in three signaling pathways that involve six cytokines of the IL-1 family (IL-1α, IL-1ß, IL-33, IL-36α, IL-36ß and IL-36γ). In many diseases, multiple cytokines contribute to disease pathogenesis. For example, in asthma, both IL-33 and IL-1 are of major importance, as are IL-36 and IL-1 in psoriasis. We developed a blocking monoclonal antibody (mAb) to human IL-1R3 (MAB-hR3) and demonstrate here that this antibody specifically inhibits signaling via IL-1, IL-33 and IL-36 in vitro. Also, in three distinct in vivo models of disease (crystal-induced peritonitis, allergic airway inflammation and psoriasis), we found that targeting IL-1R3 with a single mAb to mouse IL-1R3 (MAB-mR3) significantly attenuated heterogeneous cytokine-driven inflammation and disease severity. We conclude that in diseases driven by multiple cytokines, a single antagonistic agent such as a mAb to IL-1R3 is a therapeutic option with considerable translational benefit.
Assuntos
Anticorpos Bloqueadores/farmacologia , Anticorpos Monoclonais/farmacologia , Proteína Acessória do Receptor de Interleucina-1/antagonistas & inibidores , Peritonite/imunologia , Pneumonia/imunologia , Psoríase/imunologia , Células A549 , Animais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Células HEK293 , Humanos , Imiquimode/toxicidade , Inflamação/patologia , Interleucina-1/imunologia , Proteína Acessória do Receptor de Interleucina-1/imunologia , Interleucina-1beta/imunologia , Interleucina-33/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Ovalbumina/toxicidade , Peritonite/tratamento farmacológico , Peritonite/patologia , Pneumonia/tratamento farmacológico , Pneumonia/patologia , Psoríase/tratamento farmacológico , Psoríase/patologia , Transdução de Sinais/imunologia , Ácido Úrico/toxicidadeRESUMO
Immune profiling of COVID-19 patients has identified numerous alterations in both innate and adaptive immunity. However, whether those changes are specific to SARS-CoV-2 or driven by a general inflammatory response shared across severely ill pneumonia patients remains unknown. Here, we compared the immune profile of severe COVID-19 with non-SARS-CoV-2 pneumonia ICU patients using longitudinal, high-dimensional single-cell spectral cytometry and algorithm-guided analysis. COVID-19 and non-SARS-CoV-2 pneumonia both showed increased emergency myelopoiesis and displayed features of adaptive immune paralysis. However, pathological immune signatures suggestive of T cell exhaustion were exclusive to COVID-19. The integration of single-cell profiling with a predicted binding capacity of SARS-CoV-2 peptides to the patients' HLA profile further linked the COVID-19 immunopathology to impaired virus recognition. Toward clinical translation, circulating NKT cell frequency was identified as a predictive biomarker for patient outcome. Our comparative immune map serves to delineate treatment strategies to interfere with the immunopathologic cascade exclusive to severe COVID-19.
Assuntos
COVID-19/imunologia , SARS-CoV-2/patogenicidade , Adulto , Enzima de Conversão de Angiotensina 2/metabolismo , Apresentação de Antígeno , Biomarcadores/sangue , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , COVID-19/patologia , Feminino , Antígenos HLA/genética , Antígenos HLA/imunologia , Humanos , Imunidade Inata , Imunofenotipagem , Masculino , Pessoa de Meia-Idade , Células T Matadoras Naturais/imunologia , Pneumonia/imunologia , Pneumonia/patologia , SARS-CoV-2/imunologia , Índice de Gravidade de Doença , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismoRESUMO
Although master transcription factors (TFs) are key to the development of specific T cell subsets, whether additional transcriptional regulators are induced by the same stimuli that dominantly repress the development of other, non-specific T cell lineages has not been fully elucidated. Through the use of regulatory T cells (Treg cells) induced by transforming growth factor-ß (TGF-ß), we identified the TF musculin (MSC) as being critical for the development of induced Treg cells (iTreg cells) by repression of the T helper type 2 (TH2) transcriptional program. Loss of MSC reduced expression of the Treg cell master TF Foxp3 and induced TH2 differentiation even under iTreg-cell-differentiation conditions. MSC interrupted binding of the TF GATA-3 to the locus encoding TH2-cell-related cytokines and diminished intrachromosomal interactions within that locus. MSC-deficient (Msc-/-) iTreg cells were unable to suppress TH2 responses, and Msc-/- mice spontaneously developed gut and lung inflammation with age. MSC therefore enforced Foxp3 expression and promoted the unidirectional induction of iTreg cells by repressing the TH2 developmental program.
Assuntos
Diferenciação Celular , Inflamação , Mucosa Intestinal/imunologia , Pneumonia/imunologia , Linfócitos T Reguladores/fisiologia , Células Th2/fisiologia , Fatores de Transcrição/metabolismo , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Células Cultivadas , Fatores de Transcrição Forkhead/metabolismo , Fator de Transcrição GATA3/metabolismo , Regulação da Expressão Gênica , Inflamação/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fatores de Transcrição/genética , Transcrição Gênica , Fator de Crescimento Transformador beta/metabolismoRESUMO
Type 3 innate lymphoid cells (ILC3s) are critical for lung defense against bacterial pneumonia in the neonatal period, but the signals that guide pulmonary ILC3 development remain unclear. Here, we demonstrated that pulmonary ILC3s descended from ILC precursors that populated a niche defined by fibroblasts in the developing lung. Alveolar fibroblasts produced insulin-like growth factor 1 (IGF1), which instructed expansion and maturation of pulmonary ILC precursors. Conditional ablation of IGF1 in alveolar fibroblasts or deletion of the IGF-1 receptor from ILC precursors interrupted ILC3 biogenesis and rendered newborn mice susceptible to pneumonia. Premature infants with bronchopulmonary dysplasia, characterized by interrupted postnatal alveolar development and increased morbidity to respiratory infections, had reduced IGF1 concentrations and pulmonary ILC3 numbers. These findings indicate that the newborn period is a critical window in pulmonary immunity development, and disrupted lung development in prematurely born infants may have enduring effects on host resistance to respiratory infections.
Assuntos
Imunidade Inata , Fator de Crescimento Insulin-Like I/metabolismo , Pulmão/imunologia , Linfócitos/citologia , Células Epiteliais Alveolares/metabolismo , Animais , Animais Recém-Nascidos , Displasia Broncopulmonar/imunologia , Diferenciação Celular , Proliferação de Células , Suscetibilidade a Doenças/imunologia , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Fator de Crescimento Insulin-Like I/deficiência , Interleucinas/metabolismo , Pulmão/citologia , Pulmão/crescimento & desenvolvimento , Linfócitos/metabolismo , Camundongos , Pneumonia/imunologia , Proteína com Dedos de Zinco da Leucemia Promielocítica/metabolismo , Receptor IGF Tipo 1/genética , Receptor IGF Tipo 1/metabolismo , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/metabolismo , Transdução de Sinais , Interleucina 22RESUMO
Group 2 innate lymphoid cells (ILC2 cells) are type 2 cytokine-producing cells of the innate immune system with important roles in helminth infection and allergic inflammation. Here we found that tissue-resident ILC2 cells proliferated in situ without migrating during inflammatory responses. Both type I and type II interferons and interleukin 27 (IL-27) suppressed ILC2 function in a manner dependent on the transcription factor STAT1. ILC2-mediated lung inflammation was enhanced in the absence of the interferon-γ (IFN-γ) receptor on ILC2 cells in vivo. IFN-γ effectively suppressed the function of tissue-resident ILC2 cells but not that of inflammatory ILC2 cells, and IL-27 suppressed tissue-resident ILC2 cells but not tissue-resident TH2 cells during lung inflammation induced by Alternaria alternata. Our results demonstrate that suppression mediated by interferon and IL-27 is a negative feedback mechanism for ILC2 function in vivo.
Assuntos
Helmintíase Animal/imunologia , Imunidade Inata/imunologia , Interferons/imunologia , Interleucinas/imunologia , Linfócitos/imunologia , Transferência Adotiva , Animais , Modelos Animais de Doenças , Citometria de Fluxo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pneumonia/imunologia , Reação em Cadeia da Polimerase em Tempo RealRESUMO
Group 2 innate lymphoid cells (ILC2s) regulate tissue inflammation and repair after activation by cell-extrinsic factors such as host-derived cytokines. However, the cell-intrinsic metabolic pathways that control ILC2 function are undefined. Here we demonstrate that expression of the enzyme arginase-1 (Arg1) during acute or chronic lung inflammation is a conserved trait of mouse and human ILC2s. Deletion of mouse ILC-intrinsic Arg1 abrogated type 2 lung inflammation by restraining ILC2 proliferation and dampening cytokine production. Mechanistically, inhibition of Arg1 enzymatic activity disrupted multiple components of ILC2 metabolic programming by altering arginine catabolism, impairing polyamine biosynthesis and reducing aerobic glycolysis. These data identify Arg1 as a key regulator of ILC2 bioenergetics that controls proliferative capacity and proinflammatory functions promoting type 2 inflammation.
Assuntos
Arginase/metabolismo , Linfócitos/fisiologia , Pneumonia/imunologia , Animais , Arginase/genética , Proliferação de Células/genética , Células Cultivadas , Citocinas/metabolismo , Glicólise/genética , Humanos , Imunidade Inata , Ativação Linfocitária/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Poliaminas/metabolismo , Células Th2/imunologiaRESUMO
Group 2 innate lymphoid cells (ILC2s) secrete type 2 cytokines, which protect against parasites but can also contribute to a variety of inflammatory airway diseases. We report here that interleukin 1ß (IL-1ß) directly activated human ILC2s and that IL-12 induced the conversion of these activated ILC2s into interferon-γ (IFN-γ)-producing ILC1s, which was reversed by IL-4. The plasticity of ILCs was manifested in diseased tissues of patients with severe chronic obstructive pulmonary disease (COPD) or chronic rhinosinusitis with nasal polyps (CRSwNP), which displayed IL-12 or IL-4 signatures and the accumulation of ILC1s or ILC2s, respectively. Eosinophils were a major cellular source of IL-4, which revealed cross-talk between IL-5-producing ILC2s and IL-4-producing eosinophils. We propose that IL-12 and IL-4 govern ILC2 functional identity and that their imbalance results in the perpetuation of type 1 or type 2 inflammation.
Assuntos
Plasticidade Celular , Eosinófilos/imunologia , Imunidade Inata , Interleucina-12/metabolismo , Interleucina-1beta/metabolismo , Interleucina-4/metabolismo , Linfócitos/imunologia , Pólipos Nasais/imunologia , Pneumonia/imunologia , Doença Pulmonar Obstrutiva Crônica/imunologia , Rinite/imunologia , Sinusite/imunologia , Animais , Diferenciação Celular , Células Cultivadas , Feminino , Humanos , Interferon gama/metabolismo , Ativação Linfocitária , Camundongos , Camundongos SCID , Células Th1/imunologia , Equilíbrio Th1-Th2 , Células Th2/imunologiaRESUMO
CD4+ T helper (Th) differentiation is regulated by diverse inputs, including the vitamin A metabolite retinoic acid (RA). RA acts through its receptor RARα to repress transcription of inflammatory cytokines, but is also essential for Th-mediated immunity, indicating complex effects of RA on Th specification and the outcome of the immune response. We examined the impact of RA on the genome-wide transcriptional response during Th differentiation to multiple subsets. RA effects were subset-selective and were most significant in Th9 cells. RA globally antagonized Th9-promoting transcription factors and inhibited Th9 differentiation. RA directly targeted the extended Il9 locus and broadly modified the Th9 epigenome through RARα. RA-RARα activity limited murine Th9-associated pulmonary inflammation, and human allergic inflammation was associated with reduced expression of RA target genes. Thus, repression of the Th9 program is a major function of RA-RARα signaling in Th differentiation, arguing for a role for RA in interleukin 9 (IL-9) related diseases.
Assuntos
Hipersensibilidade/imunologia , Pulmão/fisiologia , Pneumonia/imunologia , Receptor alfa de Ácido Retinoico/metabolismo , Linfócitos T Auxiliares-Indutores/fisiologia , Animais , Repressão Epigenética , Células HEK293 , Humanos , Hipersensibilidade/genética , Interleucina-9/metabolismo , Pulmão/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pneumonia/genética , Receptor alfa de Ácido Retinoico/genética , Transdução de Sinais , Transcrição Gênica , Tretinoína/metabolismoRESUMO
COVID-19, which is caused by infection with SARS-CoV-2, is characterized by lung pathology and extrapulmonary complications1,2. Type I interferons (IFNs) have an essential role in the pathogenesis of COVID-19 (refs 3-5). Although rapid induction of type I IFNs limits virus propagation, a sustained increase in the levels of type I IFNs in the late phase of the infection is associated with aberrant inflammation and poor clinical outcome5-17. Here we show that the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway, which controls immunity to cytosolic DNA, is a critical driver of aberrant type I IFN responses in COVID-19 (ref. 18). Profiling COVID-19 skin manifestations, we uncover a STING-dependent type I IFN signature that is primarily mediated by macrophages adjacent to areas of endothelial cell damage. Moreover, cGAS-STING activity was detected in lung samples from patients with COVID-19 with prominent tissue destruction, and was associated with type I IFN responses. A lung-on-chip model revealed that, in addition to macrophages, infection with SARS-CoV-2 activates cGAS-STING signalling in endothelial cells through mitochondrial DNA release, which leads to cell death and type I IFN production. In mice, pharmacological inhibition of STING reduces severe lung inflammation induced by SARS-CoV-2 and improves disease outcome. Collectively, our study establishes a mechanistic basis of pathological type I IFN responses in COVID-19 and reveals a principle for the development of host-directed therapeutics.
Assuntos
COVID-19/imunologia , COVID-19/patologia , Interferon Tipo I/imunologia , Proteínas de Membrana/metabolismo , Nucleotidiltransferases/metabolismo , SARS-CoV-2/imunologia , Animais , COVID-19/metabolismo , COVID-19/virologia , Células Cultivadas , DNA Mitocondrial/metabolismo , Modelos Animais de Doenças , Progressão da Doença , Células Endoteliais/patologia , Feminino , Regulação da Expressão Gênica/imunologia , Humanos , Imunidade Inata , Pulmão/imunologia , Pulmão/metabolismo , Pulmão/patologia , Pulmão/virologia , Macrófagos/imunologia , Proteínas de Membrana/antagonistas & inibidores , Camundongos , Camundongos Endogâmicos C57BL , Pneumonia/imunologia , Pneumonia/metabolismo , Pneumonia/patologia , Pneumonia/virologia , SARS-CoV-2/patogenicidade , Transdução de Sinais , Pele/imunologia , Pele/metabolismo , Pele/patologiaRESUMO
Immune responses are tightly regulated to ensure efficient pathogen clearance while avoiding tissue damage. Here we report that Setdb2 was the only protein lysine methyltransferase induced during infection with influenza virus. Setdb2 expression depended on signaling via type I interferons, and Setdb2 repressed expression of the gene encoding the neutrophil attractant CXCL1 and other genes that are targets of the transcription factor NF-κB. This coincided with occupancy by Setdb2 at the Cxcl1 promoter, which in the absence of Setdb2 displayed diminished trimethylation of histone H3 Lys9 (H3K9me3). Mice with a hypomorphic gene-trap construct of Setdb2 exhibited increased infiltration of neutrophils during sterile lung inflammation and were less sensitive to bacterial superinfection after infection with influenza virus. This suggested that a Setdb2-mediated regulatory crosstalk between the type I interferons and NF-κB pathways represents an important mechanism for virus-induced susceptibility to bacterial superinfection.
Assuntos
Histona-Lisina N-Metiltransferase/imunologia , NF-kappa B/imunologia , Infecções por Orthomyxoviridae/imunologia , Orthomyxoviridae/imunologia , Pneumonia/imunologia , Superinfecção/imunologia , Animais , Quimiocina CXCL1/imunologia , Suscetibilidade a Doenças , Feminino , Interferon Tipo I/imunologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Análise de Sequência com Séries de Oligonucleotídeos , Infecções por Orthomyxoviridae/enzimologia , Infecções por Orthomyxoviridae/virologia , Pneumonia/enzimologia , Pneumonia/virologia , RNA/química , RNA/genética , Reação em Cadeia da Polimerase em Tempo Real , Organismos Livres de Patógenos Específicos , Superinfecção/enzimologia , Superinfecção/microbiologiaRESUMO
Pseudomonas aeruginosa is a complex nosocomial infectious agent responsible for numerous illnesses, with its growing resistance variations complicating treatment development. Studies have emphasized the importance of virulence factors OprE and OprF in pathogenesis, highlighting their potential as vaccine candidates. In this study, B-cell, MHC-I, and MHC-II epitopes were identified, and molecular linkers were active to join these epitopes with an appropriate adjuvant to construct a vaccine. Computational tools were employed to forecast the tertiary framework, characteristics, and also to confirm the vaccine's composition. The potency was weighed through population coverage analysis and immune simulation. This project aims to create a multi-epitope vaccine to reduce P. aeruginosa-related illness and mortality using immunoinformatics resources. The ultimate complex has been determined to be stable, soluble, antigenic, and non-allergenic upon inspection of its physicochemical and immunological properties. Additionally, the protein exhibited acidic and hydrophilic characteristics. The Ramachandran plot, ProSA-web, ERRAT, and Verify3D were employed to ensure the final model's authenticity once the protein's three-dimensional structure had been established and refined. The vaccine model showed a significant binding score and stability when interacting with MHC receptors. Population coverage analysis indicated a global coverage rate of 83.40%, with the USA having the highest coverage rate, exceeding 90%. Moreover, the vaccine sequence underwent codon optimization before being cloned into the Escherichia coli plasmid vector pET-28a (+) at the EcoRI and EcoRV restriction sites. Our research has developed a vaccine against P. aeruginosa that has strong binding affinity and worldwide coverage, offering an acceptable way to mitigate nosocomial infections.
Assuntos
Biologia Computacional , Infecções por Pseudomonas , Pseudomonas aeruginosa , Sepse , Pseudomonas aeruginosa/imunologia , Pseudomonas aeruginosa/genética , Humanos , Infecções por Pseudomonas/prevenção & controle , Infecções por Pseudomonas/imunologia , Infecções por Pseudomonas/microbiologia , Sepse/prevenção & controle , Sepse/imunologia , Sepse/microbiologia , Biologia Computacional/métodos , Epitopos/imunologia , Epitopos/química , Pneumonia/prevenção & controle , Pneumonia/imunologia , Pneumonia/microbiologia , Vacinas contra Pseudomonas/imunologia , Vacinas Bacterianas/imunologia , Proteínas de Bactérias/imunologia , Proteínas de Bactérias/genéticaRESUMO
COVID-19 has affected more than half a billion people worldwide, with more than 6.3 million deaths, but the pathophysiological mechanisms involved in lethal cases and the host determinants that determine the different clinical outcomes are still unclear. In this study, we assessed lung autopsies of 47 COVID-19 patients and examined the inflammatory profiles, viral loads, and inflammasome activation. Additionally, we correlated these factors with the patient's clinical and histopathological conditions. Robust inflammasome activation was detected in the lungs of lethal cases of SARS-CoV-2. Experiments conducted on transgenic mice expressing hACE2 and infected with SARS-CoV-2 showed that Nlrp3-/- mice were protected from disease development and lethality compared to Nlrp3+/+ littermate mice, supporting the involvement of this inflammasome in disease exacerbation. An analysis of gene expression allowed for the classification of COVID-19 patients into two different clusters. Cluster 1 died with higher viral loads and exhibited a reduced inflammatory profile than Cluster 2. Illness time, mechanical ventilation time, pulmonary fibrosis, respiratory functions, histopathological status, thrombosis, viral loads, and inflammasome activation significantly differed between the two clusters. Our data demonstrated two distinct profiles in lethal cases of COVID-19, thus indicating that the balance of viral replication and inflammasome-mediated pulmonary inflammation led to different clinical outcomes. We provide important information to understand clinical variations in severe COVID-19, a process that is critical for decisions between immune-mediated or antiviral-mediated therapies for the treatment of critical cases of COVID-19.
Assuntos
COVID-19 , Pulmão , SARS-CoV-2 , Carga Viral , Replicação Viral , COVID-19/virologia , COVID-19/mortalidade , COVID-19/imunologia , COVID-19/patologia , Animais , Humanos , Camundongos , Feminino , Masculino , Pulmão/virologia , Pulmão/patologia , Pulmão/imunologia , Pessoa de Meia-Idade , Inflamassomos/imunologia , Inflamassomos/metabolismo , Idoso , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Camundongos Transgênicos , Pneumonia/virologia , Pneumonia/mortalidade , Pneumonia/imunologia , Pneumonia/patologia , Enzima de Conversão de Angiotensina 2/metabolismo , Enzima de Conversão de Angiotensina 2/genética , Camundongos Knockout , AdultoRESUMO
CD96, CD226 (DNAM-1) and TIGIT belong to an emerging family of receptors that interact with nectin and nectin-like proteins. CD226 activates natural killer (NK) cell-mediated cytotoxicity, whereas TIGIT reportedly counterbalances CD226. In contrast, the role of CD96, which shares the ligand CD155 with CD226 and TIGIT, has remained unclear. In this study we found that CD96 competed with CD226 for CD155 binding and limited NK cell function by direct inhibition. As a result, Cd96(-/-) mice displayed hyperinflammatory responses to the bacterial product lipopolysaccharide (LPS) and resistance to carcinogenesis and experimental lung metastases. Our data provide the first description, to our knowledge, of the ability of CD96 to negatively control cytokine responses by NK cells. Blocking CD96 may have applications in pathologies in which NK cells are important.
Assuntos
Antígenos CD/metabolismo , Antígenos de Diferenciação de Linfócitos T/metabolismo , Células Matadoras Naturais/imunologia , Receptores Imunológicos/metabolismo , Animais , Antígenos CD/genética , Antígenos de Diferenciação de Linfócitos T/genética , Moléculas de Adesão Celular/metabolismo , Células Cultivadas , Citotoxicidade Imunológica/genética , Lipopolissacarídeos/imunologia , Neoplasias Pulmonares/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Nectinas , Metástase Neoplásica , Neoplasias Experimentais/imunologia , Pneumonia/imunologia , Ligação Proteica/genética , Receptores Virais/metabolismoRESUMO
Lung infections cause prolonged immune alterations and elevated susceptibility to secondary pneumonia. We found that, after resolution of primary viral or bacterial pneumonia, dendritic cells (DC), and macrophages exhibited poor antigen-presentation capacity and secretion of immunogenic cytokines. Development of these "paralyzed" DCs and macrophages depended on the immunosuppressive microenvironment established upon resolution of primary infection, which involved regulatory T (Treg) cells and the cytokine TGF-ß. Paralyzed DCs secreted TGF-ß and induced local Treg cell accumulation. They also expressed lower amounts of IRF4, a transcription factor associated with increased antigen-presentation capacity, and higher amounts of Blimp1, a transcription factor associated with tolerogenic functions, than DCs present during primary infection. Blimp1 expression in DC of humans suffering sepsis or trauma correlated with severity and complicated outcomes. Our findings describe mechanisms underlying sepsis- and trauma-induced immunosuppression, reveal prognostic markers of susceptibility to secondary infections and identify potential targets for therapeutic intervention.