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1.
Front Endocrinol (Lausanne) ; 12: 626842, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33790857

RESUMO

Endogenous oxidized phospholipids are produced during tissue stress and are responsible for sustaining inflammatory responses in immune as well as non-immune cells. Their local and systemic production and accumulation is associated with the etiology and progression of several inflammatory diseases, but the molecular mechanisms that underlie the biological activities of these oxidized phospholipids remain elusive. Increasing evidence highlights the ability of these stress mediators to modulate cellular metabolism and pro-inflammatory signaling in phagocytes, such as macrophages and dendritic cells, and to alter the activation and polarization of these cells. Because these immune cells serve a key role in maintaining tissue homeostasis and organ function, understanding how endogenous oxidized lipids reshape phagocyte biology and function is vital for designing clinical tools and interventions for preventing, slowing down, or resolving chronic inflammatory disorders that are driven by phagocyte dysfunction. Here, we discuss the metabolic and signaling processes elicited by endogenous oxidized lipids and outline new hypotheses and models to elucidate the impact of these lipids on phagocytes and inflammation.


Assuntos
Inflamação/fisiopatologia , Fagócitos/imunologia , Fosfolipídeos/metabolismo , Animais , /fisiopatologia , Humanos , Inflamação/imunologia , Oxirredução
2.
Front Immunol ; 12: 640093, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33717193

RESUMO

COVID-19 (SARS-CoV-2) disease severity and stages varies from asymptomatic, mild flu-like symptoms, moderate, severe, critical, and chronic disease. COVID-19 disease progression include lymphopenia, elevated proinflammatory cytokines and chemokines, accumulation of macrophages and neutrophils in lungs, immune dysregulation, cytokine storms, acute respiratory distress syndrome (ARDS), etc. Development of vaccines to severe acute respiratory syndrome (SARS), Middle East Respiratory Syndrome coronavirus (MERS-CoV), and other coronavirus has been difficult to create due to vaccine induced enhanced disease responses in animal models. Multiple betacoronaviruses including SARS-CoV-2 and SARS-CoV-1 expand cellular tropism by infecting some phagocytic cells (immature macrophages and dendritic cells) via antibody bound Fc receptor uptake of virus. Antibody-dependent enhancement (ADE) may be involved in the clinical observation of increased severity of symptoms associated with early high levels of SARS-CoV-2 antibodies in patients. Infants with multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19 may also have ADE caused by maternally acquired SARS-CoV-2 antibodies bound to mast cells. ADE risks associated with SARS-CoV-2 has implications for COVID-19 and MIS-C treatments, B-cell vaccines, SARS-CoV-2 antibody therapy, and convalescent plasma therapy for patients. SARS-CoV-2 antibodies bound to mast cells may be involved in MIS-C and multisystem inflammatory syndrome in adults (MIS-A) following initial COVID-19 infection. SARS-CoV-2 antibodies bound to Fc receptors on macrophages and mast cells may represent two different mechanisms for ADE in patients. These two different ADE risks have possible implications for SARS-CoV-2 B-cell vaccines for subsets of populations based on age, cross-reactive antibodies, variabilities in antibody levels over time, and pregnancy. These models place increased emphasis on the importance of developing safe SARS-CoV-2 T cell vaccines that are not dependent upon antibodies.


Assuntos
Anticorpos Facilitadores , Mastócitos/imunologia , Coronavírus da Síndrome Respiratória do Oriente Médio/fisiologia , Fagócitos/imunologia , Síndrome de Resposta Inflamatória Sistêmica/imunologia , Animais , Anticorpos Antivirais/metabolismo , Criança , Reações Cruzadas , Feminino , Humanos , Recém-Nascido , Transmissão Vertical de Doença Infecciosa , Modelos Imunológicos , Gravidez , Receptores Fc/metabolismo , Risco , Linfócitos T/imunologia
3.
Nat Commun ; 12(1): 805, 2021 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-33547295

RESUMO

Efforts to improve the prognosis of steroid-resistant gut acute graft-versus-host-disease (SR-Gut-aGVHD) have suffered from poor understanding of its pathogenesis. Here we show that the pathogenesis of SR-Gut-aGVHD is associated with reduction of IFN-γ+ Th/Tc1 cells and preferential expansion of IL-17-IL-22+ Th/Tc22 cells. The IL-22 from Th/Tc22 cells causes dysbiosis in a Reg3γ-dependent manner. Transplantation of IFN-γ-deficient donor CD8+ T cells in the absence of CD4+ T cells produces a phenocopy of SR-Gut-aGVHD. IFN-γ deficiency in donor CD8+ T cells also leads to a PD-1-dependent depletion of intestinal protective CX3CR1hi mononuclear phagocytes (MNP), which also augments expansion of Tc22 cells. Supporting the dual regulation, simultaneous dysbiosis induction and depletion of CX3CR1hi MNP results in full-blown Gut-aGVHD. Our results thus provide insights into SR-Gut-aGVHD pathogenesis and suggest the potential efficacy of IL-22 antagonists and IFN-γ agonists in SR-Gut-aGVHD therapy.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Disbiose/imunologia , Doença Enxerto-Hospedeiro/imunologia , Interferon gama/imunologia , Interleucinas/imunologia , Fagócitos/imunologia , Animais , Linfócitos T CD8-Positivos/patologia , Linfócitos T CD8-Positivos/transplante , Receptor 1 de Quimiocina CX3C/genética , Receptor 1 de Quimiocina CX3C/imunologia , Modelos Animais de Doenças , Disbiose/genética , Disbiose/microbiologia , Disbiose/patologia , Microbioma Gastrointestinal/imunologia , Regulação da Expressão Gênica , Doença Enxerto-Hospedeiro/genética , Doença Enxerto-Hospedeiro/microbiologia , Doença Enxerto-Hospedeiro/patologia , Interferon gama/deficiência , Interferon gama/genética , Interleucina-17/deficiência , Interleucina-17/genética , Interleucina-17/imunologia , Interleucinas/genética , Intestinos/imunologia , Intestinos/microbiologia , Intestinos/patologia , Depleção Linfocítica , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Associadas a Pancreatite/genética , Proteínas Associadas a Pancreatite/imunologia , Fagócitos/citologia , Receptor de Morte Celular Programada 1/genética , Receptor de Morte Celular Programada 1/imunologia , Transdução de Sinais , Linfócitos T Auxiliares-Indutores , Linfócitos T Reguladores , Irradiação Corporal Total
4.
Int J Mol Sci ; 22(2)2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33451043

RESUMO

Our aim was to investigate the subset distribution and function of circulating monocytes, proinflammatory cytokine levels, gut barrier damage, and bacterial translocation in chronic spinal cord injury (SCI) patients. Thus, 56 SCI patients and 28 healthy donors were studied. The levels of circulating CD14+highCD16-, CD14+highCD16+, and CD14+lowCD16+ monocytes, membrane TLR2, TLR4, and TLR9, phagocytic activity, ROS generation, and intracytoplasmic TNF-α, IL-1, IL-6, and IL-10 after lipopolysaccharide (LPS) stimulation were analyzed by polychromatic flow cytometry. Serum TNF-α, IL-1, IL-6 and IL-10 levels were measured by Luminex and LPS-binding protein (LBP), intestinal fatty acid-binding protein (I-FABP) and zonulin by ELISA. SCI patients had normal monocyte counts and subset distribution. CD14+highCD16- and CD14+highCD16+ monocytes exhibited decreased TLR4, normal TLR2 and increased TLR9 expression. CD14+highCD16- monocytes had increased LPS-induced TNF-α but normal IL-1, IL-6, and IL-10 production. Monocytes exhibited defective phagocytosis but normal ROS production. Patients had enhanced serum TNF-α and IL-6 levels, normal IL-1 and IL-10 levels, and increased circulating LBP, I-FABP, and zonulin levels. Chronic SCI patients displayed impaired circulating monocyte function. These patients exhibited a systemic proinflammatory state characterized by enhanced serum TNF-α and IL-6 levels. These patients also had increased bacterial translocation and gut barrier damage.


Assuntos
Suscetibilidade a Doenças , Inflamação/complicações , Enteropatias/complicações , Traumatismos da Medula Espinal/etiologia , Traumatismos da Medula Espinal/metabolismo , Adulto , Biomarcadores , Estudos de Casos e Controles , Doença Crônica , Citocinas/metabolismo , Feminino , Homeostase , Humanos , Mediadores da Inflamação/metabolismo , Masculino , Monócitos/imunologia , Monócitos/metabolismo , Fagócitos/imunologia , Fagócitos/metabolismo , Fagocitose , Índice de Gravidade de Doença , Traumatismos da Medula Espinal/patologia , Fator de Necrose Tumoral alfa/metabolismo , Adulto Jovem
5.
Science ; 371(6527)2021 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-33479125

RESUMO

The skin confers biophysical and immunological protection through a complex cellular network established early in embryonic development. We profiled the transcriptomes of more than 500,000 single cells from developing human fetal skin, healthy adult skin, and adult skin with atopic dermatitis and psoriasis. We leveraged these datasets to compare cell states across development, homeostasis, and disease. Our analysis revealed an enrichment of innate immune cells in skin during the first trimester and clonal expansion of disease-associated lymphocytes in atopic dermatitis and psoriasis. We uncovered and validated in situ a reemergence of prenatal vascular endothelial cell and macrophage cellular programs in atopic dermatitis and psoriasis lesional skin. These data illustrate the dynamism of cutaneous immunity and provide opportunities for targeting pathological developmental programs in inflammatory skin diseases.


Assuntos
Dermatite Atópica/embriologia , Dermatite Atópica/patologia , Psoríase/embriologia , Psoríase/patologia , Pele/embriologia , Animais , Atlas como Assunto , Movimento Celular , Conjuntos de Dados como Assunto , Células Dendríticas/imunologia , Dermatite Atópica/imunologia , Fármacos Dermatológicos/farmacologia , Humanos , Imunidade Inata/genética , Metotrexato/farmacologia , Camundongos , Fagócitos/imunologia , Psoríase/imunologia , Análise de Célula Única , Pele/citologia , Pele/imunologia , Linfócitos T/imunologia , Transcriptoma
6.
Mol Immunol ; 131: 68-77, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33358569

RESUMO

Phagocytic cells are critical to host defense against Pseudomonas aeruginosa, a Gram-negative bacterium that is an opportunistic pathogen. Accordingly, susceptible individuals frequently have impaired innate immune responses, including those with cystic fibrosis or neutropenia. Previous studies identified that the downregulation, or loss, of bacterial flagellar motility enables bacteria to evade interactions with phagocytic cells that result in phagocytic uptake of the bacteria. However, the mechanistic bases for motility-dependent interactions between P. aeruginosa and host cell surfaces that lead to phagocytic uptake of the bacteria are poorly understood. A recent insight is that exogenous addition of a negatively charged phospholipid, phosphatidylinositol-(3,4,5)-triphosphate (PIP3), promotes the engagement of non-motile strains of P. aeruginosa with phagocytes leading to uptake of the bacteria. Thus, we hypothesized that the engagement of P. aeruginosa by phagocytic cells is mediated by motility-dependent interactions with cell-surface polyanions. Here we report that endogenous polyanionic N-linked glycans and heparan sulfate mediate bacterial binding of P. aeruginosa by human monocytic cells. These specific interactions resulted in P. aeruginosa phagocytosis, bacterial type 3 secretion system (T3SS)-mediated cellular intoxication and the IL-1ß response of host innate immune cells. Importantly, the bacterial interactions with the glycans were motility-dependent and could be recapitulated with purified, immobilized glycans. Therefore, this work describes novel interactions of P. aeruginosa with specific phagocyte cell-surface glycans that modulate relevant host innate immune responses to the bacteria, including phagocytosis, inflammation and cytotoxicity.


Assuntos
Fagócitos/imunologia , Polissacarídeos/imunologia , Infecções por Pseudomonas/imunologia , Pseudomonas aeruginosa/imunologia , Linhagem Celular Tumoral , Células Cultivadas , Células HL-60 , Heparitina Sulfato/imunologia , Humanos , Imunidade Inata/imunologia , Interleucina-1beta/imunologia , Monócitos/imunologia , Fagocitose/imunologia , Células THP-1
7.
Methods Mol Biol ; 2183: 559-574, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32959268

RESUMO

Antibodies against Streptococcus pneumoniae (pneumococcus) following vaccination are crucial for host protection against invasive pneumococcal infections. The antibodies induced by pneumococcal vaccines act as opsonins to mediate bacterial uptake and killing by host phagocytic cells, especially polymorphonuclear leukocytes (PMNs) also called neutrophils. Therefore, it is important to measure not only the levels of antibodies induced by a pneumococcal vaccine candidate but their actual functional capacity in mediating bacterial opsonization and killing by PMNs. Here, we describe a protocol to demonstrate effective deposition of vaccine-induced antibodies on the surface of S. pneumoniae by flow cytometry and subsequent opsonophagocytic killing (OPH) by murine bone-marrow derived PMNs.


Assuntos
Anticorpos Antibacterianos/imunologia , Neutrófilos/imunologia , Infecções Pneumocócicas/imunologia , Vacinas Pneumocócicas/imunologia , Streptococcus pneumoniae/imunologia , Animais , Biomarcadores , Células da Medula Óssea/imunologia , Células da Medula Óssea/metabolismo , Citometria de Fluxo , Soros Imunes/imunologia , Camundongos , Neutrófilos/metabolismo , Fagócitos/imunologia , Fagócitos/metabolismo , Infecções Pneumocócicas/metabolismo , Infecções Pneumocócicas/microbiologia
8.
PLoS Pathog ; 16(8): e1008414, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32776983

RESUMO

The host innate immune system has developed elegant processes for the detection and clearance of invasive fungal pathogens. These strategies may also aid in the spread of pathogens in vivo, although technical limitations have previously hindered our ability to view the host innate immune and endothelial cells to probe their roles in spreading disease. Here, we have leveraged zebrafish larvae as a model to view the interactions of these host processes with the fungal pathogen Candida albicans in vivo. We examined three potential host-mediated mechanisms of fungal spread: movement inside phagocytes in a "Trojan Horse" mechanism, inflammation-assisted spread, and endothelial barrier passage. Utilizing both chemical and genetic tools, we systematically tested the loss of neutrophils and macrophages and the loss of blood flow on yeast cell spread. Both neutrophils and macrophages respond to yeast-locked and wild type C. albicans in our model and time-lapse imaging revealed that macrophages can support yeast spread in a "Trojan Horse" mechanism. Surprisingly, loss of immune cells or inflammation does not alter dissemination dynamics. On the other hand, when blood flow is blocked, yeast can cross into blood vessels but they are limited in how far they travel. Blockade of both phagocytes and circulation reduces rates of dissemination and significantly limits the distance of fungal spread from the infection site. Together, this data suggests a redundant two-step process whereby (1) yeast cross the endothelium inside phagocytes or via direct uptake, and then (2) they utilize blood flow or phagocytes to travel to distant sites.


Assuntos
Candida albicans/imunologia , Candidíase/imunologia , Células Endoteliais/imunologia , Interações Hospedeiro-Patógeno/imunologia , Neutrófilos/imunologia , Fagócitos/imunologia , Peixe-Zebra/microbiologia , Animais , Candidíase/microbiologia , Larva , Macrófagos/imunologia , Macrófagos/microbiologia , Neutrófilos/microbiologia , Fagócitos/microbiologia
9.
J Vis Exp ; (160)2020 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-32628177

RESUMO

The innate immune system plays important roles in ocular pathophysiology including uveitis, diabetic retinopathy, and age-related macular degeneration. Innate immune cells, specifically mononuclear phagocytes, express overlapping cell surface markers, which makes identifying these populations a challenge. Multi-parameter flow cytometry allows for the simultaneous, quantitative analysis of multiple cell surface markers in order to differentiate monocytes, macrophages, microglia, and dendritic cells in mouse eyes. This protocol describes the enucleation of whole mouse eyes, ocular dissection, digestion into a single cell suspension, and staining of the single cell suspension for myeloid cell markers. Additionally, we explain the proper methods for determining voltages using single color controls and for delineating positive gates using fluorescence minus one controls. The major limitation of multi-parameter flow cytometry is the absence of tissue architecture. This limitation can be overcome by multi-parameter flow cytometry of individual ocular compartments or complimentary immunofluorescence staining. However, immunofluorescence is limited by its lack of quantitative analysis and reduced number of fluorophores on most microscopes. We describe the use of multi-parametric flow cytometry to provide highly quantitative analysis of mononuclear phagocytes in laser-induced choroidal neovascularization. Additionally, multi-parameter flow cytometry can be used for the identification of macrophage subsets, fate mapping, and cell sorting for transcriptomic or proteomic studies.


Assuntos
Olho/citologia , Olho/diagnóstico por imagem , Citometria de Fluxo , Fagócitos/citologia , Animais , Anticorpos/metabolismo , Células Dendríticas/citologia , Feminino , Corantes Fluorescentes/metabolismo , Lasers , Macrófagos/citologia , Masculino , Camundongos Endogâmicos C57BL , Microglia/citologia , Monócitos/citologia , Fagócitos/imunologia
10.
ACS Chem Neurosci ; 11(15): 2149-2151, 2020 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-32662981

RESUMO

Acanthamoeba and macrophages exhibit significant parallels in biochemical, physiological, cellular, and functional aspects. Given the ability of Acanthamoeba to contribute to the evolutionary gain of pathogenicity of a variety of microbial pathogens, here we propose the use of Acanthamoeba as a paradigm to study SARS-CoV-2 pathogenicity, infectivity, and evasion of cellular immune defenses.


Assuntos
Acanthamoeba/imunologia , Betacoronavirus , Infecções por Coronavirus/imunologia , Imunidade Celular/imunologia , Fagócitos/imunologia , Pneumonia Viral/imunologia , Animais , Infecções por Coronavirus/patologia , Infecções por Coronavirus/transmissão , Humanos , Pandemias , Fagócitos/patologia , Fagocitose/imunologia , Pneumonia Viral/patologia , Pneumonia Viral/transmissão
11.
Nat Immunol ; 21(7): 746-755, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32514064

RESUMO

Plasma membranes of animal cells are enriched for cholesterol. Cholesterol-dependent cytolysins (CDCs) are pore-forming toxins secreted by bacteria that target membrane cholesterol for their effector function. Phagocytes are essential for clearance of CDC-producing bacteria; however, the mechanisms by which these cells evade the deleterious effects of CDCs are largely unknown. Here, we report that interferon (IFN) signals convey resistance to CDC-induced pores on macrophages and neutrophils. We traced IFN-mediated resistance to CDCs to the rapid modulation of a specific pool of cholesterol in the plasma membrane of macrophages without changes to total cholesterol levels. Resistance to CDC-induced pore formation requires the production of the oxysterol 25-hydroxycholesterol (25HC), inhibition of cholesterol synthesis and redistribution of cholesterol to an esterified cholesterol pool. Accordingly, blocking the ability of IFN to reprogram cholesterol metabolism abrogates cellular protection and renders mice more susceptible to CDC-induced tissue damage. These studies illuminate targeted regulation of membrane cholesterol content as a host defense strategy.


Assuntos
Infecções Bacterianas/imunologia , Toxinas Bacterianas/imunologia , Hidroxicolesteróis/metabolismo , Interferons/isolamento & purificação , Fagócitos/imunologia , Estreptolisinas/imunologia , Animais , Bactérias/imunologia , Bactérias/metabolismo , Proteínas de Bactérias/administração & dosagem , Proteínas de Bactérias/imunologia , Proteínas de Bactérias/metabolismo , Toxinas Bacterianas/metabolismo , Membrana Celular/metabolismo , Permeabilidade da Membrana Celular/imunologia , Células Cultivadas , Modelos Animais de Doenças , Suscetibilidade a Doenças/imunologia , Feminino , Interações entre Hospedeiro e Microrganismos/imunologia , Humanos , Microscopia Intravital , Masculino , Camundongos , Camundongos Transgênicos , Fagócitos/citologia , Fagócitos/metabolismo , Cultura Primária de Células , Esteroide Hidroxilases/genética , Esteroide Hidroxilases/metabolismo , Estreptolisinas/administração & dosagem , Estreptolisinas/metabolismo
12.
Nat Commun ; 11(1): 2739, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32483165

RESUMO

Synthetic biology is a powerful tool to create therapeutics which can be rationally designed to enable unique and combinatorial functionalities. Here we utilize non-pathogenic E coli Nissle as a versatile platform for the development of a living biotherapeutic for the treatment of cancer. The engineered bacterial strain, referred to as SYNB1891, targets STING-activation to phagocytic antigen-presenting cells (APCs) in the tumor and activates complementary innate immune pathways. SYNB1891 treatment results in efficacious antitumor immunity with the formation of immunological memory in murine tumor models and robust activation of human APCs. SYNB1891 is designed to meet manufacturability and regulatory requirements with built in biocontainment features which do not compromise its efficacy. This work provides a roadmap for the development of future therapeutics and demonstrates the transformative potential of synthetic biology for the treatment of human disease when drug development criteria are incorporated into the design process for a living medicine.


Assuntos
Escherichia coli/imunologia , Imunoterapia/métodos , Proteínas de Membrana/imunologia , Neoplasias/terapia , Transdução de Sinais/imunologia , Animais , Células Apresentadoras de Antígenos/imunologia , Células Apresentadoras de Antígenos/metabolismo , Linhagem Celular Tumoral , Escherichia coli/genética , Escherichia coli/metabolismo , Engenharia Genética/métodos , Humanos , Interferon Tipo I/imunologia , Interferon Tipo I/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neoplasias/genética , Neoplasias/imunologia , Fagócitos/imunologia , Fagócitos/metabolismo , Transdução de Sinais/genética , Biologia Sintética/métodos , Biologia Sintética/tendências
13.
Sci Rep ; 10(1): 1617, 2020 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-32005898

RESUMO

Zinc oxide nanoparticles (ZnO NPs) are used in many applications; however, their interactions with cells, immune cells in particular, and potential health risk(s) are not fully known. In this manuscript, we have demonstrated the potential of ZnO NPs to cross the gut barrier in an invertebrate model, Bombyx mori, and that they can reach the hemolymph where they interact with and/or are taken up by immune-competent cells resulting in various toxic responses like decline in hemocyte viability, ROS generation, morphological alterations, apoptotic cell death, etc. Exposure to these NPs also resulted in alteration of hemocyte dynamics including an immediate increase in THC, possibly due to the release of these hemocytes either from enhanced rate of cell divisions or from attached hemocyte populations, and decline in percentage of prohemocytes and increase in percentage of two professional phagocytes, i.e., granulocytes and plasmatocytes, possibly due to the differentiation of prohemocytes into phagocytes in response to a perceived immune challenge posed by these NPs. Taken together, our data suggest that ZnO NPs have the potential to cross gut barrier and cause various toxic effects that could reverse and the insects could return to normal physiological states as there is restoration and repair of various systems and their affected pathways following the clearance of these NPs from the insect body. Our study also indicates that B. mori has the potential to serve as an effective alternate animal model for biosafety, environmental monitoring and screening of NPs, particularly to evaluate their interactions with invertebrate immune system.


Assuntos
Transporte Biológico/imunologia , Bombyx/imunologia , Sistema Imunitário/imunologia , Invertebrados/imunologia , Nanopartículas Metálicas/administração & dosagem , Óxido de Zinco/imunologia , Animais , Apoptose/imunologia , Diferenciação Celular/imunologia , Divisão Celular/imunologia , Hemócitos/imunologia , Hemolinfa/imunologia , Nanopartículas , Fagócitos/imunologia , Espécies Reativas de Oxigênio/imunologia
14.
PLoS One ; 15(2): e0228893, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32074628

RESUMO

BACKGROUND: The immune system of echinoderm sea urchins is characterised by a high degree of complexity that is not completely understood. The Mediterranean sea urchin Paracentrotus lividus coelomocytes mediate immune responses through phagocytosis, encapsulation of non-self particles, and production of diffusible factors including antimicrobial molecules. Details of these processes, and molecular pathways driving these mechanisms, are still to be fully elucidated. PRINCIPAL FINDINGS: In the present study we treated the sea urchin P. lividus with the bacterial lipopolysaccharide (LPS) and collected coelomocytes at different time-points (1, 3, 6 and 24 hours). We have shown, using label-free quantitative mass spectrometry, how LPS is able to modulate the coelomocyte proteome and to effect cellular pathways, such as endocytosis and phagocytosis, as soon as the immunomodulating agent is injected. The present study has also shown that treatment can modulate various cellular processes such as cytoskeleton reorganisation, and stress and energetic homeostasis. CONCLUSIONS: Our data demonstrates, through mass spectrometry and the following functional annotation bioinformatics analysis, how the bacterial wall constituent is sufficient to set off an immune response inducing cytoskeleton reorganisation, the appearance of clusters of heat shock proteins (Hsp) and histone proteins and the activation of the endocytic and phagocytic pathways. Data are available via ProteomeXchange with identifier PXD008439.


Assuntos
Paracentrotus/genética , Paracentrotus/imunologia , Animais , Sistema Imunitário/imunologia , Lipopolissacarídeos/farmacologia , Sistema Linfático/imunologia , Paracentrotus/metabolismo , Fagócitos/imunologia , Fagocitose/genética , Fagocitose/imunologia , Proteoma/genética , Ouriços-do-Mar/imunologia
15.
Cell Mol Life Sci ; 77(5): 781-788, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31897541

RESUMO

Age-related macular degeneration (AMD) is a leading cause of visual impairment of the elderly population. Since AMD is a multifactorial age-related disease with various genetic risk factors, the understanding of its complex pathophysiology is still limited. However, animal experiments, genome-wide association data and the molecular profiling of AMD patient samples have highlighted a key role of systemic and local immune processes that contribute to this chronic eye disease. In this overview article, we concentrate on the role of lymphocytes and mononuclear phagocytes and their interplay in triggering a persistent immune response in the AMD retina. We preferentially review findings from human immune cell analyses and complement these with related findings in experimental models. We conclude that both immune cell types as their signaling network may be a rich source to identify novel molecular targets for immunomodulation in AMD.


Assuntos
Linfócitos B/imunologia , Linfócitos T CD8-Positivos/imunologia , Degeneração Macular/imunologia , Fagócitos/imunologia , Células Th1/imunologia , Células Th17/imunologia , Idoso de 80 Anos ou mais , Proteínas do Sistema Complemento/imunologia , Humanos , Imunomodulação/fisiologia , Degeneração Macular/patologia , Retina/imunologia , Retina/patologia , Transtornos da Visão/imunologia
16.
Stroke ; 51(3): 958-966, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31914884

RESUMO

Background and Purpose- Phagocytic cells, such as microglia and blood-derived macrophages, are a key biological modality responsible for phagocytosis-mediated clearance of damaged, dead, or displaced cells that are compromised during senescence or pathological processes, including after stroke. This process of clearance is essential to eliminate the source of inflammation and to allow for optimal brain repair and functional recovery. Transcription factor, RXR (retinoic-X-receptor) is strongly implicated in phagocytic functions regulation, and as such could represent a novel target for brain recovery after stroke. Methods- Primary cultured microglia and bone marrow macrophages were used for phagocytic study. Mice with deleted RXR-α in myeloid phagocytes (Mac-RXR-α-/-) were subjected to transient middle cerebral artery occlusion to mimic ischemic stroke and then treated with RXR agonist bexarotene. RNA-sequencing and long-term recovery were evaluated. Results- Using cultured microglia, we demonstrated that the RXR-α promotes the phagocytic functions of microglia toward apoptotic neurons. Using mice with deleted RXR-α in myeloid phagocytes (Mac-RXR-α-/-), we have shown that despite behaving similarly to the control at early time points (up to 3 days, damage established histologically and behaviorally), these Mac-RXR-α-/- mice demonstrated worsened late functional recovery and developed brain atrophy that was larger in size than that seen in control mice. The RXR-α deficiency was associated with reduced expression of genes known to be under control of the prominent transcriptional RXR partner, PPAR (peroxisome proliferator-activated receptor)-γ, as well as genes encoding for scavenger receptors and genes that signify microglia/macrophages polarization to a reparative phenotype. Finally, we demonstrated that the RXR agonist, bexarotene, administered as late as 1 day after middle cerebral artery occlusion, improved neurological recovery, and reduced the atrophy volume as assessed 28 days after stroke. Bexarotene did not improve outcome in Mac-RXR-α-/- mice. Conclusions- Altogether, these data suggest that phagocytic cells control poststroke recovery and that RXR in these cells represents an attractive target with exceptionally long therapeutic window.


Assuntos
Isquemia Encefálica/imunologia , Encéfalo/imunologia , Regulação da Expressão Gênica/imunologia , Fagócitos/imunologia , Fagocitose , Receptor X Retinoide alfa/imunologia , Acidente Vascular Cerebral/imunologia , Animais , Bexaroteno/farmacologia , Encéfalo/patologia , Isquemia Encefálica/genética , Isquemia Encefálica/patologia , Regulação da Expressão Gênica/efeitos dos fármacos , Camundongos , Camundongos Knockout , Fagócitos/patologia , Receptor X Retinoide alfa/genética , Acidente Vascular Cerebral/genética , Acidente Vascular Cerebral/patologia
17.
mBio ; 11(1)2020 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-31992625

RESUMO

Activation of cyclic GMP-AMP (cGAMP) synthase (cGAS) plays a critical role in antiviral responses to many DNA viruses. Sensing of cytosolic DNA by cGAS results in synthesis of the endogenous second messenger cGAMP that activates stimulator of interferon genes (STING) in infected cells. Critically, cGAMP can also propagate antiviral responses to uninfected cells through intercellular transfer, although the modalities of this transfer between epithelial and immune cells remain poorly defined. We demonstrate here that cGAMP-producing epithelial cells can transactivate STING in cocultured macrophages through direct cGAMP transfer. cGAMP transfer was reliant upon connexin expression by epithelial cells and pharmacological inhibition of connexins blunted STING-dependent transactivation of the macrophage compartment. Macrophage transactivation by cGAMP contributed to a positive-feedback loop amplifying antiviral responses, significantly protecting uninfected epithelial cells against viral infection. Collectively, our findings constitute the first direct evidence of a connexin-dependent cGAMP transfer to macrophages by epithelial cells, to amplify antiviral responses.IMPORTANCE Recent studies suggest that extracellular cGAMP can be taken up by macrophages to engage STING through several mechanisms. Our work demonstrates that connexin-dependent communication between epithelial cells and macrophages plays a significant role in the amplification of antiviral responses mediated by cGAMP and suggests that pharmacological strategies aimed at modulating connexins may have therapeutic applications to control antiviral responses in humans.


Assuntos
Conexinas/metabolismo , Interações Hospedeiro-Patógeno , Nucleotídeos Cíclicos/metabolismo , Fagócitos/imunologia , Fagócitos/metabolismo , Viroses/etiologia , Viroses/metabolismo , Animais , Biomarcadores , Células Cultivadas , Interações Hospedeiro-Patógeno/imunologia , Humanos , Imunomodulação , Camundongos
18.
Dev Comp Immunol ; 103: 103530, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31669308

RESUMO

In the present work, we investigated, in the colonial ascidian Botryllus schlosseri, the role of complement C3 (BsC3) in phagocytosis. We studied the modulation of BsC3 transcription in the course of the colonial blastogenetic cycle, with particular reference to the takeover, when apoptotic cells in the tissues of old zooids are cleared by circulating phagocytes. In situ hybridisation with BsC3 riboprobes labelled only morula cells, the most abundant haemocytes. Anti-hC3 antibody recognised morula cells and also phagocytes when haemocytes were previously incubated with zymosan. The inhibition of C3 activation prevented the labelling of phagocytes. In phagocytosis assays with haemocytes from colonies injected with anti-hC3 antibody or bsc3 iRNA, the capability to ingest target cells was significantly (p < 0.001) reduced. Therefore, our results strongly support a key role of BsC3 in phagocytosis and open to new investigations on the nature of the receptors of the products of BsC3 activation.


Assuntos
Complemento C3/imunologia , Hemócitos/imunologia , Fagocitose/imunologia , Urocordados/imunologia , Animais , Fagócitos/imunologia
19.
Med Mycol ; 58(2): 227-239, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31095342

RESUMO

Current antifungal drugs present poor effectiveness and there is no available vaccine for fungal infections. Thus, novel strategies to treat or prevent invasive mycosis, such as cryptococcosis, are highly desirable. One strategy is the use of immunomodulators of polysaccharide nature isolated from mushrooms. The purpose of the present work was to evaluate the immunostimulatory activity of ß-(1,3)-glucan-containing exopolysaccharides (EPS) from the edible mushrooms Auricularia auricula in phagocytes and mice infected with Cryptococcus neoformans. EPS triggered macrophages and dendritic cell activation upon binding to Dectin-1, a pattern recognition receptor of the C-type lectin receptor family. Engagement of Dectin-1 culminated in pro-inflammatory cytokine production and cell maturation via its canonical Syk-dependent pathway signaling. Furthermore, upon EPS treatment, M2-like phenotype macrophages, known to support intracellular survival and replication of C. neoformans, repolarize to M1 macrophage pattern associated with enhanced production of the microbicidal molecule nitric oxide that results in efficient killing of C. neoformans. Treatment with EPS also upregulated transcript levels of genes encoding products associated with host protection against C. neoformans and Dectin-1 mediated signaling in macrophages. Finally, orally administrated ß-glucan-containing EPS from A. auricular enhanced the survival of mice infected with C. neoformans. In conclusion, the results demonstrate that EPS from A. auricula exert immunostimulatory activity in phagocytes and induce host protection against C. neoformans, suggesting that polysaccharides from this mushroom may be promising as an adjuvant for vaccines or antifungal therapy.


Assuntos
Agaricales/química , Criptococose/prevenção & controle , Polissacarídeos Fúngicos/imunologia , Fagócitos/efeitos dos fármacos , Fagócitos/imunologia , beta-Glucanas/imunologia , Animais , Criptococose/imunologia , Cryptococcus neoformans/imunologia , Citocinas/imunologia , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Células Dendríticas/microbiologia , Fatores Imunológicos/farmacologia , Lectinas Tipo C/imunologia , Pneumopatias Fúngicas , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Fagócitos/microbiologia , Transdução de Sinais , beta-Glucanas/farmacologia
20.
Sci Rep ; 9(1): 16267, 2019 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-31700127

RESUMO

Invasion and persistence of bacteria within host cells requires that they adapt to life in an intracellular environment. This adaptation induces bacterial stress through events such as phagocytosis and enhanced nutrient-restriction. During stress, bacteria synthesize a family of proteins known as heat shock proteins (HSPs) to facilitate adaptation and survival. Previously, we determined the Staphylococcus aureus HSP ClpC temporally alters bacterial metabolism and persistence. This led us to hypothesize that ClpC might alter intracellular survival. Inactivation of clpC in S. aureus strain DSM20231 significantly enhanced long-term intracellular survival in human epithelial (HaCaT) and endothelial (EA.hy926) cell lines, without markedly affecting adhesion or invasion. This phenotype was similar across a genetically diverse collection of S. aureus isolates, and was influenced by the toxin/antitoxin encoding locus mazEF. Importantly, MazEF alters mRNA synthesis and/or stability of S. aureus virulence determinants, indicating ClpC may act through the mRNA modulatory activity of MazEF. Transcriptional analyses of total RNAs isolated from intracellular DSM20231 and isogenic clpC mutant cells identified alterations in transcription of α-toxin (hla), protein A (spa), and RNAIII, consistent with the hypothesis that ClpC negatively affects the intracellular survival of S. aureus in non-professional phagocytic cells, via modulation of MazEF and Agr.


Assuntos
Proteínas de Bactérias/genética , Proteínas de Choque Térmico/genética , Interações Hospedeiro-Patógeno , Fagócitos/imunologia , Fagócitos/microbiologia , Infecções Estafilocócicas/genética , Infecções Estafilocócicas/imunologia , Staphylococcus aureus/fisiologia , Aderência Bacteriana , Proteínas de Bactérias/metabolismo , Citotoxicidade Imunológica , Proteínas de Choque Térmico/metabolismo , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Humanos , Viabilidade Microbiana/imunologia , Mutação , Fagócitos/metabolismo , Infecções Estafilocócicas/microbiologia , Ativação Transcricional , Virulência
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