RESUMEN
Host defense at the mucosal interface requires collaborative interactions between diverse cell lineages. Epithelial cells damaged by microbial invaders release reparative proteins such as the Trefoil factor family (TFF) peptides that functionally restore barrier integrity. However, whether TFF peptides and their receptors also serve instructive roles for immune cell function during infection is incompletely understood. Here, we demonstrate that the intestinal trefoil factor, TFF3, restrains (T cell helper) TH1 cell proliferation and promotes host-protective type 2 immunity against the gastrointestinal parasitic nematode Trichuris muris. Accordingly, T cell-specific deletion of the TFF3 receptor, leucine-rich repeat and immunoglobulin containing nogo receptor 2 (LINGO2), impairs TH2 cell commitment, allows proliferative expansion of interferon (IFN)g+ cluster of differentiation (CD)4+ TH1 cells and blocks normal worm expulsion through an IFNg-dependent mechanism. This study indicates that TFF3, in addition to its known tissue reparative functions, drives anti-helminth immunity by controlling the balance between TH1/TH2 subsets.
Asunto(s)
Enfermedades Transmisibles , Enfermedades Gastrointestinales , Nematodos , Infecciones por Nematodos , Tricuriasis , Animales , Factor Trefoil-3 , Células TH1 , Linfocitos T Colaboradores-InductoresRESUMEN
The impact of the host immune environment on parasite transcription and fitness is currently unknown. It is widely held that hookworm infections have an immunomodulatory impact on the host, but whether the converse is true remains unclear. Immunity against adult-stage hookworms is largely mediated by Type 2 immune responses driven by the transcription factor Signal Transducer and Activator of Transcription 6 (STAT6). This study investigated whether serial passage of the rodent hookworm Nippostrongylus brasiliensis in STAT6-deficient mice (STAT6 KO) caused changes in parasites over time. After adaptation to STAT6 KO hosts, N. brasiliensis increased their reproductive output, feeding capacity, energy content, and body size. Using an improved N. brasiliensis genome, we found that these physiological changes corresponded with a dramatic shift in the transcriptional landscape, including increased expression of gene pathways associated with egg production, but a decrease in genes encoding neuropeptides, proteases, SCP/TAPS proteins, and transthyretin-like proteins; the latter three categories have been repeatedly observed in hookworm excreted/secreted proteins (ESPs) implicated in immunosuppression. Although transcriptional changes started to appear in the first generation of passage in STAT6 KO hosts for both immature and mature adult stages, downregulation of the genes putatively involved in immunosuppression was only observed after multiple generations in this immunodeficient environment. When STAT6 KO-adapted N. brasiliensis were reintroduced to a naive WT host after up to 26 generations, this progressive change in host-adaptation corresponded to increased production of inflammatory cytokines by the WT host. Surprisingly, however, this single exposure of STAT6 KO-adapted N. brasiliensis to WT hosts resulted in worms that were morphologically and transcriptionally indistinguishable from WT-adapted parasites. This work uncovers remarkable plasticity in the ability of hookworms to adapt to their hosts, which may present a general feature of parasitic nematodes.
Asunto(s)
Ancylostomatoidea , Infecciones por Uncinaria , Ratones , Animales , Citocinas , Nippostrongylus , Factor de Transcripción STAT6/genéticaRESUMEN
Skin employs interdependent cellular networks to facilitate barrier integrity and host immunity through ill-defined mechanisms. This study demonstrates that manipulation of itch-sensing neurons bearing the Mas-related G protein-coupled receptor A3 (MrgprA3) drives IL-17+ γδ T cell expansion, epidermal thickening, and resistance to the human pathogen Schistosoma mansoni through mechanisms that require myeloid antigen presenting cells (APC). Activated MrgprA3 neurons instruct myeloid APCs to downregulate interleukin 33 (IL-33) and up-regulate TNFα partially through the neuropeptide calcitonin gene related peptide (CGRP). Strikingly, cell-intrinsic deletion of IL-33 in myeloid APC basally alters chromatin accessibility at inflammatory cytokine loci and promotes IL-17/23-dependent epidermal thickening, keratinocyte hyperplasia, and resistance to helminth infection. Our findings reveal a previously undescribed mechanism of intercellular cross-talk wherein "itch" neuron activation reshapes myeloid cytokine expression patterns to alter skin composition for cutaneous immunity against invasive pathogens.
RESUMEN
The authors have withdrawn this manuscript owing to inaccuracies in the calculation of tuft cell numbers and errors in the selection of immunofluorescence images used to support our claims. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.
RESUMEN
Antigen encounter directs CD4+ T cells to differentiate into T helper or regulatory cells. This process focuses the immune response on the invading pathogen and limits tissue damage. Mechanisms that govern T helper cell versus T regulatory cell fate remain poorly understood. Here, we show that the E3 ubiquitin ligase Cul5 determines fate selection in CD4+ T cells by regulating IL-4 receptor signaling. Mice lacking Cul5 in T cells develop Th2 and Th9 inflammation and show pathophysiological features of atopic asthma. Following T cell activation, Cul5 forms a complex with CIS and pJak1. Cul5 deletion reduces ubiquitination and subsequent degradation of pJak1, leading to an increase in pJak1 and pSTAT6 levels and reducing the threshold of IL-4 receptor signaling. As a consequence, Cul5 deficient CD4+ T cells deviate from Treg to Th9 differentiation in low IL-4 conditions. These data support the notion that Cul5 promotes a tolerogenic T cell fate choice and reduces susceptibility to allergic asthma.
Asunto(s)
Asma , Ubiquitina , Animales , Inflamación , Activación de Linfocitos , Ratones , Receptores de Interleucina-4 , Linfocitos T Colaboradores-Inductores , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismoRESUMEN
Helminth infections, including hookworms and Schistosomes, can cause severe disability and death. Infection management and control would benefit from identification of biomarkers for early detection and prognosis. While animal models suggest that Trefoil Factor Family proteins (TFF2 and TFF3) and interleukin-33 (IL-33) -driven type 2 immune responses are critical mediators of tissue repair and worm clearance in the context of hookworm infection, very little is known about how they are modulated in the context of human helminth infection. We measured TFF2, TFF3, and IL-33 levels in serum from patients in Brazil infected with Hookworm and/or Schistosomes, and compared them to endemic and non-endemic controls. TFF2 was specifically elevated by Hookworm infection in females, not Schistosoma or co-infection. This elevation was correlated with age, but not worm burden. TFF3 was elevated by Schistosoma infection and found to be generally higher in females. IL-33 was not significantly altered by infection. To determine if this might apply more broadly to other species or regions, we measured TFFs and cytokine levels (IFNγ, TNFα, IL-33, IL-13, IL-1ß, IL-17A, IL-22, and IL-10) in both the serum and urine of Nigerian school children infected with S. haematobium. We found that serum levels of TFF2 and 3 were reduced by infection, likely in an age dependent manner. In the serum, only IL-10 and IL-13 were significantly increased, while in urine IFN-γ, TNF-α, IL-13, IL-1ß, IL-22, and IL-10 were significantly increased in by infection. Taken together, these data support a role for TFF proteins in human helminth infection.
Asunto(s)
Helmintiasis/sangre , Helmintos/clasificación , Helmintos/fisiología , Factor Trefoil-2/sangre , Factor Trefoil-3/sangre , Adolescente , Adulto , Factores de Edad , Animales , Brasil , Niño , Estudios de Cohortes , Femenino , Helmintiasis/parasitología , Helmintos/genética , Humanos , Interferón gamma/sangre , Interleucina-10/sangre , Interleucina-33/sangre , Masculino , Persona de Mediana Edad , Especificidad de la Especie , Factor de Necrosis Tumoral alfa/sangre , Adulto JovenRESUMEN
Helminths are distinct from microbial pathogens in both size and complexity, and are the likely evolutionary driving force for type 2 immunity. CD4+ helper T cells can both coordinate worm clearance and prevent immunopathology, but issues of T cell antigen specificity in the context of helminth-induced Th2 and T regulatory cell (Treg) responses have not been addressed. Herein, we generated a novel transgenic line of the gastrointestinal nematode Strongyloides ratti expressing the immunodominant CD4+ T cell epitope 2W1S as a fusion protein with green fluorescent protein (GFP) and FLAG peptide in order to track and study helminth-specific CD4+ T cells. C57BL/6 mice infected with this stable transgenic line (termed Hulk) underwent a dose-dependent expansion of activated CD44hiCD11ahi 2W1S-specific CD4+ T cells, preferentially in the lung parenchyma. Transcriptional profiling of 2W1S-specific CD4+ T cells isolated from mice infected with either Hulk or the enteric bacterial pathogen Salmonella expressing 2W1S revealed that pathogen context exerted a dominant influence over CD4+ T cell phenotype. Interestingly, Hulk-elicited 2W1S-specific CD4+ T cells exhibited both Th2 and Treg phenotypes and expressed high levels of the EGFR ligand amphiregulin, which differed greatly from the phenotype of 2W1S-specific CD4+ T cells elicited by 2W1S-expressing Salmonella. While immunization with 2W1S peptide did not enhance clearance of Hulk infection, immunization did increase total amphiregulin production as well as the number of amphiregulin-expressing CD3+ cells in the lung following Hulk infection. Altogether, this new model system elucidates effector as well as immunosuppressive and wound reparative roles of helminth-specific CD4+ T cells. This report establishes a new resource for studying the nature and function of helminth-specific T cells.
Asunto(s)
Epítopos de Linfocito T/genética , Estrongiloidiasis/inmunología , Linfocitos T Reguladores/inmunología , Células Th2/inmunología , Animales , Animales Modificados Genéticamente , Antígenos Helmínticos , Linfocitos T CD4-Positivos/inmunología , Modelos Animales de Enfermedad , Epítopos de Linfocito T/inmunología , Ratones , Ratones Endogámicos C57BL , Strongyloides ratti/inmunologíaRESUMEN
IL-33 is an IL-1 family cytokine that signals through its cognate receptor, ST2, to regulate inflammation. Whether IL-33 serves a pathogenic or protective role during inflammatory bowel disease is controversial. Herein, two different strains of cell-specific conditionally deficient mice were used to compare the role of myeloid- versus intestinal epithelial cell-derived IL-33 during dextran sodium sulfate-induced colitis. Data show that loss of CD11c-restricted IL-33 exacerbated tissue pathology, coinciding with increased tissue Il6 levels and loss of intestinal forkhead box p3+ regulatory T cells. Surprisingly, the lack of intestinal epithelial cell-derived IL-33 had no impact on disease severity or tissue recovery. Thus, we show that myeloid-derived IL-33 functionally restrains colitic disease, whereas intestinal epithelial cell-derived IL-33 is dispensable.
Asunto(s)
Colitis/inmunología , Colitis/patología , Interleucina-33/metabolismo , Células Mieloides/inmunología , Animales , Colitis/inducido químicamente , Sulfato de Dextran/toxicidad , Células Epiteliales/inmunología , Células Epiteliales/metabolismo , Mucosa Intestinal/inmunología , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patología , Ratones , Ratones Noqueados , Células Mieloides/metabolismoRESUMEN
Interleukin-33 (IL-33) is a pleiotropic cytokine that can promote type 2 inflammation but also drives immunoregulation through Foxp3+Treg expansion. How IL-33 is exported from cells to serve this dual role in immunosuppression and inflammation remains unclear. Here, we demonstrate that the biological consequences of IL-33 activity are dictated by its cellular source. Whereas IL-33 derived from epithelial cells stimulates group 2 innate lymphoid cell (ILC2)-driven type 2 immunity and parasite clearance, we report that IL-33 derived from myeloid antigen-presenting cells (APCs) suppresses host-protective inflammatory responses. Conditional deletion of IL-33 in CD11c-expressing cells resulted in lowered numbers of intestinal Foxp3+Treg cells that express the transcription factor GATA3 and the IL-33 receptor ST2, causing elevated IL-5 and IL-13 production and accelerated anti-helminth immunity. We demonstrate that cell-intrinsic IL-33 promoted mouse dendritic cells (DCs) to express the pore-forming protein perforin-2, which may function as a conduit on the plasma membrane facilitating IL-33 export. Lack of perforin-2 in DCs blocked the proliferative expansion of the ST2+Foxp3+Treg subset. We propose that perforin-2 can provide a plasma membrane conduit in DCs that promotes the export of IL-33, contributing to mucosal immunoregulation under steady-state and infectious conditions.
Asunto(s)
Células Dendríticas/inmunología , Interleucina-33/metabolismo , Proteínas de la Membrana/metabolismo , Infecciones por Strongylida/inmunología , Linfocitos T Reguladores/inmunología , Animales , Membrana Celular/metabolismo , Enfermedad Crónica , Células Dendríticas/metabolismo , Modelos Animales de Enfermedad , Femenino , Humanos , Tolerancia Inmunológica , Inmunidad Innata , Inmunidad Mucosa , Interleucina-33/análisis , Interleucina-33/genética , Masculino , Ratones , Ratones Transgénicos , Mucosa Nasal/inmunología , Mucosa Nasal/patología , Pólipos Nasales/inmunología , Pólipos Nasales/patología , Nematospiroides dubius/inmunología , Nippostrongylus/inmunología , Proteínas Citotóxicas Formadoras de Poros , Rinitis/inmunología , Rinitis/patología , Sinusitis/inmunología , Sinusitis/patología , Infecciones por Strongylida/parasitología , Linfocitos T Reguladores/metabolismoRESUMEN
Intestinal epithelial cells (IEC) have important functions in nutrient absorption, barrier integrity, regeneration, pathogen-sensing, and mucus secretion. Goblet cells are a specialized cell type of IEC that secrete Trefoil factor 3 (TFF3) to regulate mucus viscosity and wound healing, but whether TFF3-responsiveness requires a receptor is unclear. Here, we show that leucine rich repeat receptor and nogo-interacting protein 2 (LINGO2) is essential for TFF3-mediated functions. LINGO2 immunoprecipitates with TFF3, co-localizes with TFF3 on the cell membrane of IEC, and allows TFF3 to block apoptosis. We further show that TFF3-LINGO2 interactions disrupt EGFR-LINGO2 complexes resulting in enhanced EGFR signaling. Excessive basal EGFR activation in Lingo2 deficient mice increases disease severity during colitis and augments immunity against helminth infection. Conversely, TFF3 deficiency reduces helminth immunity. Thus, TFF3-LINGO2 interactions de-repress inhibitory LINGO2-EGFR complexes, allowing TFF3 to drive wound healing and immunity.
Asunto(s)
Colitis/inmunología , Receptores ErbB/inmunología , Helmintiasis/inmunología , Mucosa Intestinal/inmunología , Proteínas de la Membrana/metabolismo , Proteínas del Tejido Nervioso/inmunología , Factor Trefoil-3/inmunología , Animales , Línea Celular Tumoral , Colitis/inducido químicamente , Colitis/metabolismo , Sulfato de Dextran , Receptores ErbB/genética , Receptores ErbB/metabolismo , Células Caliciformes/inmunología , Células Caliciformes/metabolismo , Células Caliciformes/parasitología , Células HEK293 , Helmintiasis/metabolismo , Helmintiasis/parasitología , Helmintos/inmunología , Helmintos/fisiología , Humanos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/parasitología , Proteínas de la Membrana/genética , Ratones Endogámicos C57BL , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Organofosfonatos , Factor Trefoil-3/genética , Factor Trefoil-3/metabolismo , Células U937RESUMEN
Whether conventional dendritic cells (cDC) acquire subset identity under direction of Wnt family glycoproteins is unknown. We demonstrate that Wnt4, a ß-catenin-independent Wnt ligand, is produced by both hematopoietic and nonhematopoietic cells and is both necessary and sufficient for preconventional DC1/cDC1 maintenance. Whereas bone marrow cDC precursors undergo phosphoJNK/c-Jun activation upon Wnt4 treatment, loss of cDC Wnt4 in CD11cCreWnt4flox/flox mice impaired differentiation of CD24+, Clec9A+, CD103+ cDC1 compared with CD11cCre controls. Conversely, single-cell RNA sequencing analysis of bone marrow revealed a 2-fold increase in cDC2 gene signature genes, and flow cytometry demonstrated increased numbers of SIRP-α+ cDC2 amid lack of Wnt4. Increased cDC2 numbers due to CD11c-restricted Wnt4 deficiency increased IL-5 production, group 2 innate lymphoid cell expansion, and host resistance to the hookworm parasite Nippostrongylus brasiliensis Collectively, these data uncover a novel and unexpected role for Wnt4 in cDC subset differentiation and type 2 immunity.
Asunto(s)
Células Dendríticas/inmunología , Inmunidad Innata/inmunología , Proteína Wnt4/inmunología , Animales , Antígenos CD/inmunología , Antígeno CD11c/inmunología , Antígeno CD24/inmunología , Diferenciación Celular/inmunología , Citometría de Flujo/métodos , Cadenas alfa de Integrinas/inmunología , Linfocitos/inmunología , Ratones , Transducción de Señal/inmunología , beta Catenina/inmunologíaRESUMEN
Coordinated efforts between macrophages and epithelia are considered essential for wound healing, but the macrophage-derived molecules responsible for repair are poorly defined. This work demonstrates that lung macrophages rely upon Trefoil factor 2 to promote epithelial proliferation following damage caused by sterile wounding, Nippostrongylus brasiliensis or Bleomycin sulfate. Unexpectedly, the presence of T, B, or ILC populations was not essential for macrophage-driven repair. Instead, conditional deletion of TFF2 in myeloid-restricted CD11cCre TFF2 flox mice exacerbated lung pathology and reduced the proliferative expansion of CD45- EpCAM+ pro-SPC+ alveolar type 2 cells. TFF2 deficient macrophages had reduced expression of the Wnt genes Wnt4 and Wnt16 and reconstitution of hookworm-infected CD11cCre TFF2flox mice with rWnt4 and rWnt16 restored the proliferative defect in lung epithelia post-injury. These data reveal a previously unrecognized mechanism wherein lung myeloid phagocytes utilize a TFF2/Wnt axis as a mechanism that drives epithelial proliferation following lung injury.
Asunto(s)
Lesión Pulmonar/inmunología , Pulmón/inmunología , Macrófagos/fisiología , Nippostrongylus/inmunología , Mucosa Respiratoria/fisiología , Infecciones por Strongylida/inmunología , Factor Trefoil-2/metabolismo , Animales , Bleomicina , Antígeno CD11c/metabolismo , Comunicación Celular , Proliferación Celular , Células Cultivadas , Humanos , Pulmón/patología , Lesión Pulmonar/inducido químicamente , Lesión Pulmonar/parasitología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Factor Trefoil-2/genética , Cicatrización de HeridasRESUMEN
BACKGROUND: IL-25 can function as an early signal for the respiratory type 2 response characteristic of allergic asthma and chronic rhinosinusitis with nasal polyps (CRSwNP). In the mouse gut, tuft cells are the epithelial source of IL-25. However, the source of human airway epithelial IL-25 has remained elusive. OBJECTIVE: In this study we sought to determine whether the solitary chemosensory cell (SCC) is the predominant source of IL-25 in the sinonasal epithelium. METHOD: Flow cytometry and immunofluorescence for SCCs and IL-25 were used to interrogate polyp and turbinate tissue from patients with CRSwNP. Mucus was collected during acute inflammatory exacerbations from patients with CRSwNP or chronic rhinosinusitis without nasal polyps and IL-25 levels determined by using ELISA. Lastly, sinonasal epithelial cultures derived from polyp and turbinate tissue were stimulated with IL-13 and analyzed for SCC proliferation and IL-25 production. RESULTS: This study demonstrates that a discrete cell type, likely an SCC, characterized by expression of the taste-associated G protein gustducin and the intestinal tuft cell marker doublecortin-like kinase 1, is the predominant source of IL-25 in the human upper airway. Additionally, we show that patients with CRSwNP have increased numbers of SCCs in nasal polyp tissue and that in vitro IL-13 exposure both increased proliferation and induced apical secretion of IL-25 into the mucosal layer. CONCLUSIONS: Inflammatory sinus polyps but not adjacent turbinate tissue show expansion of the SCC population, which is the source of epithelial IL-25.
Asunto(s)
Células Quimiorreceptoras/fisiología , Interleucina-17/metabolismo , Pólipos Nasales/inmunología , Senos Paranasales/patología , Mucosa Respiratoria/fisiología , Rinitis/inmunología , Sinusitis/inmunología , Animales , Células Cultivadas , Enfermedad Crónica , Quinasas Similares a Doblecortina , Citometría de Flujo , Humanos , Interleucina-13/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Ratones , Proteínas Serina-Treonina Quinasas/metabolismo , Gusto/fisiología , Transducina/metabolismoRESUMEN
Trefoil factors (TFFs) are small secreted proteins that regulate tissue integrity and repair at mucosal surfaces, particularly in the gastrointestinal tract. However, their relative contribution(s) to controlling baseline lung function or the extent of infection-induced lung injury are unknown issues. With the use of irradiation bone marrow chimeras, we found that TFF2 produced from both hematopoietic- and nonhematopoietic-derived cells is essential for host protection, proliferation of alveolar type 2 cells, and restoration of pulmonary gas exchange after infection with the hookworm parasite Nippostrongylus brasiliensis. In the absence of TFF2, lung epithelia were unable to proliferate and expressed reduced lung mRNA transcript levels for type 2 response-inducing IL-25 and IL-33 after infectious injury. Strikingly, even in the absence of infection or irradiation, TFF2 deficiency compromised lung structure and function, as characterized by distended alveoli and reduced blood oxygen levels relative to wild-type control mice. Taken together, we show a previously unappreciated role for TFF2, produced by either hematopoietic or nonhematopoietic sources, as a pro-proliferative factor for lung epithelial cells under steady-state and infectious injury conditions.
Asunto(s)
Células Epiteliales/metabolismo , Pulmón/metabolismo , Alveolos Pulmonares/metabolismo , Infecciones por Strongylida/metabolismo , Factor Trefoil-2/metabolismo , Animales , Proliferación Celular , Células Epiteliales/parasitología , Células Epiteliales/patología , Pulmón/parasitología , Pulmón/patología , Ratones , Ratones Transgénicos , Nippostrongylus , Alveolos Pulmonares/parasitología , Alveolos Pulmonares/patología , Infecciones por Strongylida/inmunología , Infecciones por Strongylida/patologíaRESUMEN
How the metabolic demand of parasitism affects immune-mediated resistance is poorly understood. Immunity against parasitic helminths requires M2 cells and IL-13, secreted by CD4(+) Th2 and group 2 innate lymphoid cells (ILC2), but whether certain metabolic enzymes control disease outcome has not been addressed. This study demonstrates that AMP-activated protein kinase (AMPK), a key driver of cellular energy, regulates type 2 immunity and restricts lung injury following hookworm infection. Mice with a selective deficiency in the AMPK catalytic α1 subunit in alveolar macrophages and conventional dendritic cells produced less IL-13 and CCL17 and had impaired expansion of ILC2 in damaged lung tissue compared with wild-type controls. Defective type 2 responses were marked by increased intestinal worm burdens, exacerbated lung injury, and increased production of IL-12/23p40, which, when neutralized, restored IL-13 production and improved lung recovery. Taken together, these data indicate that defective AMPK activity in myeloid cells negatively impacts type 2 responses through increased IL-12/23p40 production. These data support an emerging concept that myeloid cells and ILC2 can coordinately regulate tissue damage at mucosal sites through mechanisms dependent on metabolic enzyme function.
Asunto(s)
Proteínas Quinasas Activadas por AMP/inmunología , Infecciones por Uncinaria/inmunología , Inmunidad Innata/inmunología , Interleucina-12/inmunología , Interleucina-23/inmunología , Lesión Pulmonar/inmunología , Células Mieloides/inmunología , Proteínas Quinasas Activadas por AMP/metabolismo , Animales , Infecciones por Uncinaria/metabolismo , Lesión Pulmonar/metabolismo , Ratones , Ratones Endogámicos C57BL , Células Mieloides/metabolismoRESUMEN
Statins are widely used to prevent cardiovascular disease. In addition to their inhibitory effects on cholesterol synthesis, statins have beneficial effects in patients with sepsis and pneumonia, although molecular mechanisms have mostly remained unclear. Using human airway epithelial cells as a proper in vitro model, we show that prior exposure to physiological nanomolar serum concentrations of simvastatin (ranging from 10-1,000 nM) confers significant cellular resistance to the cytotoxicity of pneumolysin, a pore-forming toxin and the main virulence factor of Streptococcus pneumoniae. This protection could be demonstrated with a different statin, pravastatin, or on a different toxin, α-hemolysin. Furthermore, through the use of gene silencing, pharmacological inhibitors, immunofluorescence microscopy, and biochemical and metabolic rescue approaches, we demonstrate that the mechanism of protection conferred by simvastatin at physiological nanomolar concentrations could be different from the canonical mevalonate pathways seen in most other mechanistic studies conducted with statins at micromolar levels. All of these data are integrated into a protein synthesis-dependent, calcium-dependent model showing the interconnected pathways used by statins in airway epithelial cells to elicit an increased resistance to pore-forming toxins. This research fills large gaps in our understanding of how statins may confer host cellular protection against bacterial infections in the context of airway epithelial cells without the confounding effect from the presence of immune cells. In addition, our discovery could be potentially developed into a host-centric strategy for the adjuvant treatment of pore-forming toxin associated bacterial infections.
Asunto(s)
Toxinas Bacterianas/antagonistas & inhibidores , Células Epiteliales/efectos de los fármacos , Proteínas Hemolisinas/antagonistas & inhibidores , Inhibidores de Hidroximetilglutaril-CoA Reductasas/farmacología , Inmunidad Innata/efectos de los fármacos , Simvastatina/farmacología , Estreptolisinas/antagonistas & inhibidores , Animales , Proteínas Bacterianas/antagonistas & inhibidores , Proteínas Bacterianas/toxicidad , Toxinas Bacterianas/toxicidad , Línea Celular Transformada , Células Epiteliales/inmunología , Células Epiteliales/patología , Proteínas Hemolisinas/toxicidad , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/inmunología , Inyecciones Intraperitoneales , Pulmón/efectos de los fármacos , Pulmón/inmunología , Pulmón/patología , Ratones , Ratones Endogámicos C57BL , Pravastatina/inmunología , Pravastatina/farmacología , Cultivo Primario de Células , Mucosa Respiratoria/efectos de los fármacos , Mucosa Respiratoria/inmunología , Mucosa Respiratoria/patología , Simvastatina/inmunología , Staphylococcus aureus/química , Streptococcus pneumoniae/química , Estreptolisinas/toxicidadRESUMEN
Airway epithelial cells are the first line of defense against viral infections and are instrumental in coordinating the inflammatory response. In this study, we demonstrate the synergistic stimulation of CXCL10 mRNA and protein, a key chemokine responsible for the early immune response to viral infection, following treatment of airway epithelial cells with IFN γ and influenza virus. The synergism also occurred when the cells were treated with IFN γ and a viral replication mimicker (dsRNA) both in vitro and in vivo. Despite the requirement of type I interferon (IFNAR) signaling in dsRNA-induced CXCL10, the synergism was independent of the IFNAR pathway since it wasn't affected by the addition of a neutralizing IFNAR antibody or the complete lack of IFNAR expression. Furthermore, the same synergistic effect was also observed when a CXCL10 promoter reporter was examined. Although the responsive promoter region contains both ISRE and NFκB sites, western blot analysis indicated that the combined treatment of IFN γ and dsRNA significantly augmented NFκB but not STAT1 activation as compared to the single treatment. Therefore, we conclude that IFN γ and dsRNA act in concert to potentiate CXCL10 expression in airway epithelial cells via an NFκB-dependent but IFNAR-STAT independent pathway and it is at least partly regulated at the transcriptional level.
Asunto(s)
Quimiocina CXCL10/inmunología , Virus de la Influenza A/inmunología , Gripe Humana/inmunología , Interferón gamma/inmunología , Mucosa Respiratoria/inmunología , Animales , Células Cultivadas , Quimiocina CXCL10/biosíntesis , Quimiocina CXCL10/genética , Activación Enzimática , Células Epiteliales/citología , Células Epiteliales/inmunología , Células Epiteliales/virología , Humanos , Gripe Humana/virología , Interferón Tipo I/inmunología , Ratones , Ratones Endogámicos BALB C , FN-kappa B/metabolismo , Regiones Promotoras Genéticas/genética , ARN Bicatenario/inmunología , ARN Mensajero/biosíntesis , Mucosa Respiratoria/citología , Mucosa Respiratoria/virología , Factor de Transcripción STAT1/metabolismo , Transducción de Señal/inmunología , Regulación hacia ArribaRESUMEN
The significance of Th17 cells and interleukin- (IL-)17A signaling in host defense and disease development has been demonstrated in various infection and autoimmune models. Numerous studies have indicated that Th17 cells and its signature cytokine IL-17A are critical to the airway's immune response against various bacteria and fungal infection. Cytokines such as IL-23, which are involved in Th17 differentiation, play a critical role in controlling Klebsiella pneumonia (K. pneumonia) infection. IL-17A acts on nonimmune cells in infected tissues to strengthen innate immunity by inducing the expression of antimicrobial proteins, cytokines, and chemokines. Mice deficient in IL-17 receptor (IL-17R) expression are susceptible to infection by various pathogens. In this review, we summarize the recent advances in unraveling the mechanism behind Th17 cell differentiation, IL-17A/IL-17R signaling, and also the importance of IL-17A in pulmonary infection.
Asunto(s)
Interleucina-17/metabolismo , Neumonía/inmunología , Neumonía/metabolismo , Células Th17/inmunología , Células Th17/metabolismo , Animales , Diferenciación Celular , Regulación de la Expresión Génica , Humanos , Inmunidad Innata , Neumonía/genética , Neumonía/microbiología , Receptores de Interleucina-17/metabolismo , Mucosa Respiratoria/inmunología , Mucosa Respiratoria/metabolismo , Transducción de Señal , Células Th17/citologíaRESUMEN
Parasitic helminths are a major cause of chronic human disease, affecting more than 3 billion people worldwide. Host protection against most parasitic helminths relies upon Type 2 cytokine production, but the mechanisms that regulate interleukin (IL) 4 and 13 production from CD4(+) T helper 2 cells (T(H)2) and innate lymphoid type 2 cells (ILC2s) remain incompletely understood. The epithelial cell-derived cytokines IL-25 and IL-33 promote Type 2 responses, but the extent of functional redundancy between these cytokines is unclear and whether Type 2 memory relies upon either IL-25 or IL-33 is unknown. Herein, we demonstrate a pivotal role for IL-33 in driving primary and anamnestic immunity against the rodent hookworm Nippostrongylus brasiliensis. IL-33-deficient mice have a selective defect in ILC2-derived IL-13 during both primary and secondary challenge infections but generate stronger canonical CD4(+) T helper 2 cells responses (IL-4, IgE, mast cells, and basophils) than WT controls. Lack of IL-13 production in IL-33-deficient mice impairs resistin-like molecule beta (RELMß) expression and eosinophil recruitment, which are two mechanisms that eliminate N. brasiliensis parasites from infected hosts. Thus, IL-33 is requisite for IL-13 but not IL-4-driven Type 2 responses during hookworm infection.
Asunto(s)
Infecciones por Uncinaria/inmunología , Interleucina-13/inmunología , Interleucinas/inmunología , Nippostrongylus/inmunología , Células Th2/inmunología , Análisis de Varianza , Animales , Eosinófilos/inmunología , Citometría de Flujo , Hormonas Ectópicas/inmunología , Péptidos y Proteínas de Señalización Intercelular , Interleucina-33 , Interleucinas/deficiencia , Ratones , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
A major pathological feature of chronic airway diseases is the elevated expression of gel-forming mucins. NF-κB activation in airway epithelial cells has been shown to play a proinflammatory role in chronic airway diseases; however, the specific role of NF-κB in mucin gene expression has not been characterized. In this study, we show that the proinflammatory cytokines, IL-1ß and IL-17A, both of which use the NF-κB pathway, are potent inducers of MUC5B mRNA expression in both well differentiated primary normal human bronchial epithelial cells and the human bronchial epithelial cell line, HBE1. MUC5B induction by these cytokines was both time- and dose-dependent, and was attenuated by the small molecule inhibitor, NF-κB inhibitor III, as well as p65 small interfering RNA, suggesting that the regulation of MUC5B expression by these cytokines is via an NF-κB-based transcriptional mechanism. Deletion analysis of the MUC5B promoter demonstrated that IL-1ß- and IL-17A-induced promoter activity resides within the -4.17-kb to -2.56-kb region relative to the transcriptional start site. This region contains three putative κB-binding sites (NF-κB-1, -3,786/-3,774; NF-κB-2, -3,173/-3,161; and NF-κB-3, -2,921/-2,909). Chromatin immunoprecipitation analysis confirmed enhanced binding of the p50 NF-κB subunit to the NF-κB-3 site after cytokine stimulation. We conclude that an NF-κB-based transcriptional mechanism is involved in MUC5B regulation by IL-1ß and IL-17A in airway epithelium. This is the first demonstration of the participation of NF-κB and its specific binding site in cytokine-mediated airway MUC5B expression.