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1.
Nat Commun ; 11(1): 4697, 2020 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-32943639

RESUMO

Unassisted metastasis through the lymphatic system is a mechanism of dissemination thus far ascribed only to cancer cells. Here, we report that Streptococcus pyogenes also hijack lymphatic vessels to escape a local infection site, transiting through sequential lymph nodes and efferent lymphatic vessels to enter the bloodstream. Contrasting with previously reported mechanisms of intracellular pathogen carriage by phagocytes, we show S. pyogenes remain extracellular during transit, first in afferent and then efferent lymphatics that carry the bacteria through successive draining lymph nodes. We identify streptococcal virulence mechanisms important for bacterial lymphatic dissemination and show that metastatic streptococci within infected lymph nodes resist and subvert clearance by phagocytes, enabling replication that can seed intense bloodstream infection. The findings establish the lymphatic system as both a survival niche and conduit to the bloodstream for S. pyogenes, explaining the phenomenon of occult bacteraemia. This work provides new perspectives in streptococcal pathogenesis with implications for immunity.


Assuntos
Linfonodos/microbiologia , Metástase Linfática , Vasos Linfáticos/microbiologia , Infecções Estreptocócicas/microbiologia , Streptococcus pyogenes/patogenicidade , Animais , Bacteriemia/microbiologia , Bacteriemia/patologia , Modelos Animais de Doenças , Feminino , Interleucina-8/metabolismo , Linfonodos/imunologia , Linfonodos/patologia , Metástase Linfática/patologia , Sistema Linfático , Vasos Linfáticos/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Neutrófilos/microbiologia , Fagocitose , Infecções Estreptocócicas/imunologia , Infecções Estreptocócicas/patologia , Streptococcus pyogenes/genética , Virulência
2.
J Toxicol Sci ; 45(9): 569-579, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32879256

RESUMO

Indoxyl, a derivative of indole originating from tryptophan, may undergo phase-II sulfate-conjugation pathway, thereby forming indoxyl sulfate (IS) in vivo. We previously reported that IS, a well-known uremic toxin, can increase the intracellular oxidation level and decrease the phagocytic activity in a differentiated HL-60 human macrophage cell model. Using the same cell model, the current study aimed to investigate whether indole and indoxyl (the metabolic precursors of indoxyl and IS, respectively) may cause macrophage immune dysfunction. Results obtained indicated that intracellular oxidation level and cytotoxicity markedly increased upon treatment with indole and indoxyl, in comparison with IS. Incubation of the cells with indole and indoxyl also resulted in attenuated phagocytic activity. Human serum albumin (HSA)-binding assay confirmed that tryptophan and IS, but not indole and indoxyl, could selectively bind to the site II in HSA. Collectively, the results indicated that indole and indoxyl may strongly down-regulate the phagocytic immune function of macrophages, whereas IS, formed upon sulfate conjugation of indoxyl, may exhibit enhanced HSA-binding capability, thereby reducing the adverse effects of indoxyl.


Assuntos
Indóis/efeitos adversos , Macrófagos/imunologia , Macrófagos/metabolismo , Oxirredução/efeitos dos fármacos , Fagocitose/efeitos dos fármacos , Fagocitose/imunologia , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Células HL-60 , Humanos , Indicã/metabolismo , Macrófagos/efeitos dos fármacos , Ligação Proteica , Albumina Sérica/metabolismo , Triptofano/metabolismo
3.
Nat Commun ; 11(1): 4591, 2020 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-32929084

RESUMO

Although the efficacy of cancer radiotherapy (RT) can be enhanced by targeted immunotherapy, the immunosuppressive factors induced by radiation on tumor cells remain to be identified. Here, we report that CD47-mediated anti-phagocytosis is concurrently upregulated with HER2 in radioresistant breast cancer (BC) cells and RT-treated mouse syngeneic BC. Co-expression of both receptors is more frequently detected in recurrent BC patients with poor prognosis. CD47 is upregulated preferentially in HER2-expressing cells, and blocking CD47 or HER2 reduces both receptors with diminished clonogenicity and augmented phagocytosis. CRISPR-mediated CD47 and HER2 dual knockouts not only inhibit clonogenicity but also enhance macrophage-mediated attack. Dual antibody of both receptors synergizes with RT in control of syngeneic mouse breast tumor. These results provide the evidence that aggressive behavior of radioresistant BC is caused by CD47-mediated anti-phagocytosis conjugated with HER2-prompted proliferation. Dual blockade of CD47 and HER2 is suggested to eliminate resistant cancer cells in BC radiotherapy.


Assuntos
Neoplasias da Mama/metabolismo , Antígeno CD47/metabolismo , Tolerância a Radiação , Receptor ErbB-2/metabolismo , Animais , Neoplasias da Mama/patologia , Antígeno CD47/genética , Proliferação de Células , Células Clonais , Feminino , Humanos , Células MCF-7 , Macrófagos/metabolismo , Camundongos , Modelos Biológicos , NF-kappa B/metabolismo , Fagocitose , Transdução de Sinais , Transcrição Genética , Carga Tumoral
4.
Science ; 369(6503): 530-537, 2020 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-32732419

RESUMO

Microglia, immune cells of the central nervous system (CNS), are important for tissue development and maintenance and are implicated in CNS disease, but we lack understanding of human fetal microglia development. Single-cell gene expression and bulk chromatin profiles of microglia at 9 to 18 gestational weeks (GWs) of human fetal development were generated. Microglia were heterogeneous at all studied GWs. Microglia start to mature during this developmental period and increasingly resemble adult microglia with CNS-surveilling properties. Chromatin accessibility increases during development with associated transcriptional networks reflective of adult microglia. Thus, during early fetal development, microglia progress toward a more mature, immune-sensing competent phenotype, and this might render the developing human CNS vulnerable to environmental perturbations during early pregnancy.


Assuntos
Encéfalo/embriologia , Desenvolvimento Embrionário/imunologia , Feto/imunologia , Microglia/imunologia , Fagocitose/imunologia , Encéfalo/citologia , Separação Celular , Células Cultivadas , Desenvolvimento Embrionário/genética , Redes Reguladoras de Genes , Humanos , Fagocitose/genética , Transcriptoma
5.
Acta Neuropathol Commun ; 8(1): 147, 2020 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-32847628

RESUMO

We document the neuropathologic findings of a 73-year old man who died from acute cerebellar hemorrhage in the context of relatively mild SARS-CoV2 infection. The patient developed sudden onset of headache, nausea, and vomiting, immediately followed by loss of consciousness on the day of admission. Emergency medical services found him severely hypoxemic at home, and the patient suffered a cardiac arrest during transport to the emergency department. The emergency team achieved return of spontaneous circulation after over 17 min of resuscitation. A chest radiograph revealed hazy bilateral opacities; and real-time-PCR for SARS-CoV-2 on the nasopharyngeal swab was positive. Computed tomography of the head showed a large right cerebellar hemorrhage, with tonsillar herniation and intraventricular hemorrhage. One day after presentation, he was transitioned to comfort care and died shortly after palliative extubation. Autopsy performed 3 h after death showed cerebellar hemorrhage and acute infarcts in the dorsal pons and medulla. Remarkably, there were microglial nodules and neuronophagia bilaterally in the inferior olives and multifocally in the cerebellar dentate nuclei. This constellation of findings has not been reported thus far in the context of SARS-CoV-2 infection.


Assuntos
Infartos do Tronco Encefálico/patologia , Doenças Cerebelares/patologia , Infecções por Coronavirus/patologia , Hemorragias Intracranianas/patologia , Microglia/patologia , Neurônios/patologia , Fagocitose , Pneumonia Viral/patologia , Idoso , Betacoronavirus , Infartos do Tronco Encefálico/complicações , Infartos do Tronco Encefálico/diagnóstico por imagem , Doenças Cerebelares/complicações , Doenças Cerebelares/diagnóstico por imagem , Núcleos Cerebelares/patologia , Infecções por Coronavirus/complicações , Infecções por Coronavirus/diagnóstico , Cefaleia/etiologia , Parada Cardíaca/etiologia , Humanos , Hipóxia/etiologia , Hemorragias Intracranianas/complicações , Hemorragias Intracranianas/diagnóstico por imagem , Masculino , Bulbo/diagnóstico por imagem , Bulbo/patologia , Núcleo Olivar/patologia , Pandemias , Pneumonia Viral/complicações , Pneumonia Viral/diagnóstico , Tegmento Pontino/diagnóstico por imagem , Tegmento Pontino/patologia , Tomografia Computadorizada por Raios X
6.
Int J Nanomedicine ; 15: 4919-4932, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32764925

RESUMO

Background: Alzheimer's disease (AD) is a progressive neurodegenerative disorder and the most common cause of dementia. Diagnosing AD before symptoms arise will facilitate earlier intervention. The early diagnostic approaches are thus urgently needed. Methods: The multifunctional nanoparticles W20/XD4-SPIONs were constructed by the conjugation of oligomer-specific scFv antibody W20 and class A scavenger receptor (SR-A) activator XD4 onto superparamagnetic iron oxide nanoparticles (SPIONs). The SPIONs' stability and uniformity in size were measured by dynamic light scattering and transmission electron microscopy. The ability of W20/XD4-SPIONs for recognizing Aß oligomers (AßOs) and promoting AßOs phagocytosis was assessed by immunocytochemistry and flow cytometry analysis. The blood-brain barrier permeability of W20/XD4-SPIONs was determined by a co-culture transwell model. The in vivo probe distribution of W20/XD4-SPIONs in AD mouse brains was detected by magnetic resonance imaging (MRI). Results: W20/XD4-SPIONs, as an AßOs-targeted molecular MRI contrast probe, readily reached pathological AßOs regions in brains and distinguished AD transgenic mice from WT controls. W20/XD4-SPIONs retained the property of XD4 for SR-A activation and significantly promoted microglial phagocytosis of AßOs. Moreover, W20/XD4-SPIONs exhibited the properties of good biocompatibility, high stability and low cytotoxicity. Conclusion: Compared with W20-SPIONs or XD4-SPIONs, W20/XD4-SPIONs show the highest efficiency for AßOs-targeting and significantly enhance AßOs uptake by microglia. As a molecular probe, W20/XD4-SPIONs also specifically and sensitively bind to AßOs in AD brains to provide an MRI signal, demonstrating that W20/XD4-SPIONs are promising diagnostic agents for early-stage AD. Due to the beneficial effect of W20 and XD4 on neuropathology, W20/XD4-SPIONs may also have therapeutic potential for AD .


Assuntos
Doença de Alzheimer/diagnóstico , Peptídeos beta-Amiloides/imunologia , Imunoconjugados/química , Nanopartículas de Magnetita/química , Receptores Depuradores/metabolismo , Anticorpos de Cadeia Única/química , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Animais , Especificidade de Anticorpos , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Diagnóstico Precoce , Imunoconjugados/farmacologia , Imagem por Ressonância Magnética , Camundongos , Camundongos Transgênicos , Microglia/efeitos dos fármacos , Microglia/patologia , Nanopartículas Multifuncionais/química , Fagocitose/efeitos dos fármacos , Anticorpos de Cadeia Única/imunologia
7.
Nat Commun ; 11(1): 4027, 2020 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-32788676

RESUMO

Programmed cell death or apoptosis is a central biological process that is dysregulated in many diseases, including inflammatory conditions and cancer. The detection and quantification of apoptotic cells in vivo is hampered by the need for fixatives or washing steps for non-fluorogenic reagents, and by the low levels of free calcium in diseased tissues that restrict the use of annexins. In this manuscript, we report the rational design of a highly stable fluorogenic peptide (termed Apo-15) that selectively stains apoptotic cells in vitro and in vivo in a calcium-independent manner and under wash-free conditions. Furthermore, using a combination of chemical and biophysical methods, we identify phosphatidylserine as a molecular target of Apo-15. We demonstrate that Apo-15 can be used for the quantification and imaging of drug-induced apoptosis in preclinical mouse models, thus creating opportunities for assessing the in vivo efficacy of anti-inflammatory and anti-cancer therapeutics.


Assuntos
Apoptose , Imageamento Tridimensional , Peptídeos Cíclicos/farmacologia , Sequência de Aminoácidos , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular , Feminino , Humanos , Camundongos Endogâmicos C57BL , Microscopia de Fluorescência , Neutrófilos/citologia , Neutrófilos/efeitos dos fármacos , Peptídeos Cíclicos/administração & dosagem , Peptídeos Cíclicos/síntese química , Peptídeos Cíclicos/química , Fagocitose/efeitos dos fármacos , Fosfatidilserinas/metabolismo
8.
Nat Commun ; 11(1): 4071, 2020 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-32792491

RESUMO

Arrest of oligodendrocyte (OL) differentiation and remyelination following myelin damage in multiple sclerosis (MS) is associated with neurodegeneration and clinical worsening. We show that Glutathione S-transferase 4α (Gsta4) is highly expressed during adult OL differentiation and that Gsta4 loss impairs differentiation into myelinating OLs in vitro. In addition, we identify Gsta4 as a target of both dimethyl fumarate, an existing MS therapy, and clemastine fumarate, a candidate remyelinating agent in MS. Overexpression of Gsta4 reduces expression of Fas and activity of the mitochondria-associated Casp8-Bid-axis in adult oligodendrocyte precursor cells, leading to improved OL survival during differentiation. The Gsta4 effect on apoptosis during adult OL differentiation was corroborated in vivo in both lysolecithin-induced demyelination and experimental autoimmune encephalomyelitis models, where Casp8 activity was reduced in Gsta4-overexpressing OLs. Our results identify Gsta4 as an intrinsic regulator of OL differentiation, survival and remyelination, as well as a potential target for future reparative MS therapies.


Assuntos
Glutationa Transferase/metabolismo , Oligodendroglia/citologia , Oligodendroglia/metabolismo , Animais , Apoptose/genética , Apoptose/fisiologia , Caspase 8/genética , Caspase 8/metabolismo , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Células Cultivadas , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Glutationa Transferase/genética , Homeostase/genética , Homeostase/fisiologia , Imuno-Histoquímica , Masculino , Microglia/citologia , Microglia/metabolismo , Microscopia Eletrônica de Transmissão , Mitocôndrias/metabolismo , Esclerose Múltipla/genética , Esclerose Múltipla/metabolismo , Fagocitose/genética , Fagocitose/fisiologia , Processamento de Proteína Pós-Traducional , Ratos , Reação em Cadeia da Polimerase em Tempo Real , Remielinização/genética , Remielinização/fisiologia
9.
PLoS One ; 15(8): e0238006, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32857814

RESUMO

This study aimed to evaluate the effects of two prebiotics in different concentrations on nutrient digestibility, fermentative products and immunological variables in adult dogs. Twenty-four adult dogs were randomly divided into six blocks according to their metabolic body weights (BW0.75); within these groups, dogs were randomized to four treatments: control without prebiotics (CO); inclusion of 0.5% prebiotic blend Yes-Golf (B1); inclusion of 1.0% galactooligosaccharide (GOS); and inclusion of 1.0% prebiotic blend Yes-Golf (B2). The experiment lasted 30 days, with 20 days adaptation and 10 days stool and blood collection. Results were analyzed for normality and means were separated by ANOVA and adjusted by the Tukey test at the significance level of 5.0%. Prebiotic supplementation had no effect on apparent digestibility coefficients (ADC), total stool production and fecal scores (p > 0.05). Prebiotics evaluated also did not alter fecal pH, nor the concentrations of ammonia, lactic acid, short chain fatty acids (SCFA) and most fecal branched chain fatty acids (BCFA) (p > 0.05). The addition of GOS decreased the concentration of iso-valeric acid (p = 0.0423). Regarding immunological variables, concentrations of fecal IgA were not influenced by the treatments. Treatments GOS and B2 increased the total number of polymorphonuclear cells, as well as the oxidative burst in relation to treatments B1 and CO (p < 0.0001). Treatment B2 improved the rate of S. aureus phagocytosis in relation to CO (p = 0.0111), and both the GOS and B2 treatments had a better index for E. coli phagocytosis than the CO treatment (p = 0.0067). In conclusion, there was indication that both prebiotics GOS and B2 at 1.0% inclusion improved the immunity of healthy dogs.


Assuntos
Colo/efeitos dos fármacos , Oligossacarídeos/farmacologia , Prebióticos , Animais , Colo/imunologia , Colo/microbiologia , Dieta/veterinária , Cães , Ácidos Graxos Voláteis/análise , Fezes/química , Microbioma Gastrointestinal/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Leucócitos/citologia , Leucócitos/efeitos dos fármacos , Leucócitos/metabolismo , Fagocitose/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Staphylococcus aureus/fisiologia
10.
PLoS One ; 15(8): e0235898, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32833999

RESUMO

Myo/Nog cells were discovered in the chick embryo epiblast. Their expression of MyoD reflects a commitment to the skeletal muscle lineage and capacity to differentiate into myofibroblasts. Release of Noggin by Myo/Nog cells is essential for normal morphogenesis. Myo/Nog cells rapidly respond to wounding in the skin and eyes. In this report, we present evidence suggesting that Myo/Nog cells phagocytose tattoo ink in tissue sections of human skin and engulf cell corpses in cultures of anterior human lens tissue and magnetic beads injected into the anterior chamber of mice in vivo. Myo/Nog cells are distinct from macrophages in the skin and eyes indicated by the absence of labeling with an antibody to ionized calcium binding adaptor molecule 1. In addition to their primary roles as regulators of BMP signaling and progenitors of myofibroblasts, Myo/Nog cells behave as nonprofessional phagocytes defined as cells whose primary functions are unrelated to phagocytosis but are capable of engulfment.


Assuntos
Miofibroblastos/citologia , Fagócitos/citologia , Células-Tronco/citologia , Animais , Proteínas de Transporte/metabolismo , Diferenciação Celular , Células Cultivadas , Embrião de Galinha , Feminino , Humanos , Cristalino/citologia , Cristalino/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteína MyoD/metabolismo , Miofibroblastos/metabolismo , Fagócitos/metabolismo , Fagocitose , Coelhos , Pele/citologia , Pele/metabolismo , Células-Tronco/metabolismo
11.
PLoS One ; 15(7): e0236887, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32735621

RESUMO

Lawsonia intracellularis, an obligately intracellular enteric bacterium, infects intestinal epithelial cells, but may also be found within macrophages in the intestinal lamina propria of affected pigs. Macrophages play an important role in host defense against infectious agents, but the role of this cell in L. intracellularis infection is not well understood. The aim of this study was to evaluate the permissibility of macrophages to L. intracellularis infection in vitro. Pure culture of L. intracellularis was added to swine peripheral blood monocyte-derived macrophages. Viability of intracytoplasmic L. intracellularis was evaluated at different time points by transmission electron microscopy (TEM). Potential replication of L. intracellularis in macrophages was also evaluated by qPCR. By TEM, phagocytosis L. intracellularis within of phagolysosomes were observed 1-hour post-infection (hpi) and bacterial structures in binary fission at 48 hpi. The number of intracellular bacteria was determined at 1, 4, 24, 48, and 72 hpi by qPCR in infected macrophages and compared to the number of intracellular bacteria from culture in McCoy cells. In both cell lines, the amount of L. intracellularis was decreased at 4 hpiand increased at 24 hpi. The number of intracellular bacteria continued to increase in McCoy cells over time. This is the first study showing interaction, survival and propagation of L. intracellularis in macrophages. These findings are critical to establish an experimental model for future studies of the pathogenesis of porcine proliferative enteropathy and the potential persistence of L. intracellularis in macrophages during chronic infections.


Assuntos
Infecções por Desulfovibrionaceae/veterinária , Lawsonia (Bactéria) , Macrófagos/microbiologia , Animais , Linhagem Celular , Enteropatias/microbiologia , Enteropatias/veterinária , Lawsonia (Bactéria)/crescimento & desenvolvimento , Lawsonia (Bactéria)/ultraestrutura , Fagocitose , Suínos , Doenças dos Suínos/microbiologia
12.
Acta Neuropathol Commun ; 8(1): 147, 2020 08 26.
Artigo em Inglês | MEDLINE | ID: covidwho-730088

RESUMO

We document the neuropathologic findings of a 73-year old man who died from acute cerebellar hemorrhage in the context of relatively mild SARS-CoV2 infection. The patient developed sudden onset of headache, nausea, and vomiting, immediately followed by loss of consciousness on the day of admission. Emergency medical services found him severely hypoxemic at home, and the patient suffered a cardiac arrest during transport to the emergency department. The emergency team achieved return of spontaneous circulation after over 17 min of resuscitation. A chest radiograph revealed hazy bilateral opacities; and real-time-PCR for SARS-CoV-2 on the nasopharyngeal swab was positive. Computed tomography of the head showed a large right cerebellar hemorrhage, with tonsillar herniation and intraventricular hemorrhage. One day after presentation, he was transitioned to comfort care and died shortly after palliative extubation. Autopsy performed 3 h after death showed cerebellar hemorrhage and acute infarcts in the dorsal pons and medulla. Remarkably, there were microglial nodules and neuronophagia bilaterally in the inferior olives and multifocally in the cerebellar dentate nuclei. This constellation of findings has not been reported thus far in the context of SARS-CoV-2 infection.


Assuntos
Infartos do Tronco Encefálico/patologia , Doenças Cerebelares/patologia , Infecções por Coronavirus/patologia , Hemorragias Intracranianas/patologia , Microglia/patologia , Neurônios/patologia , Fagocitose , Pneumonia Viral/patologia , Idoso , Betacoronavirus , Infartos do Tronco Encefálico/complicações , Infartos do Tronco Encefálico/diagnóstico por imagem , Doenças Cerebelares/complicações , Doenças Cerebelares/diagnóstico por imagem , Núcleos Cerebelares/patologia , Infecções por Coronavirus/complicações , Infecções por Coronavirus/diagnóstico , Cefaleia/etiologia , Parada Cardíaca/etiologia , Humanos , Hipóxia/etiologia , Hemorragias Intracranianas/complicações , Hemorragias Intracranianas/diagnóstico por imagem , Masculino , Bulbo/diagnóstico por imagem , Bulbo/patologia , Núcleo Olivar/patologia , Pandemias , Pneumonia Viral/complicações , Pneumonia Viral/diagnóstico , Tegmento Pontino/diagnóstico por imagem , Tegmento Pontino/patologia , Tomografia Computadorizada por Raios X
13.
Sheng Wu Gong Cheng Xue Bao ; 36(7): 1431-1439, 2020 Jul 25.
Artigo em Chinês | MEDLINE | ID: mdl-32748601

RESUMO

The purpose of this study is to provide a culture for mouse bone marrow-derived macrophages (BMDM) and peritoneal macrophages (PM) and to characterize their molecular and cellular biology. The cell number and purity from the primary culture were assessed by cell counter and flow cytometry, respectively. Morphological features were evaluated by inverted microscope. Phagocytosis by macrophages was detected by the neutral red dye uptake assay. Phenotypic markers were analyzed by real-time fluorescent quantitative PCR. Our results show that the cell number was much higher from culture of BMDM than PM, while there was no significant difference regarding the percentage of F4/80+CD11b+ cells (98.30%±0.53% vs. 94.83%±1.42%; P>0.05). The proliferation rate of BMDM was significantly higher than PM in the presence of L929 cell conditioned medium, by using CCK-8 assay. However, PM appeared to adhere to the flask wall and extend earlier than BMDM. The phagocytosis capability of un-stimulated BMDM was significantly higher than PM, as well as lipopolysaccharide (LPS)-stimulated BMDM, except the BMDM stimulated by low dose LPS (0.1 µg/mL). Furthermore, Tnfα expression was significantly higher in un-stimulated BMDM than PM, while Arg1 and Ym1 mRNA expression were significantly lower than PM. The expression difference was persistent if stimulated by LPS+IFN-γ or IL-4. Our data indicate that bone marrow can get larger amounts of macrophages than peritoneal cavity. However, it should be aware that the molecular and cellular characteristics were different between these two culture systems.


Assuntos
Células da Medula Óssea , Macrófagos , Fagocitose , Animais , Células da Medula Óssea/fisiologia , Células Cultivadas , Meios de Cultivo Condicionados , Lipopolissacarídeos/metabolismo , Macrófagos/classificação , Macrófagos/fisiologia , Camundongos
14.
PLoS One ; 15(7): e0232307, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32667911

RESUMO

In the mammalian gut CD103+ve myeloid DCs are known to suppress inflammation threatened by luminal bacteria, but stimuli driving DC precursor maturation towards this beneficial phenotype are incompletely understood. We isolated CD11+ve DCs from mesenteric lymph nodes (MLNs) of healthy mice; CD103+ve DCs were 8-24 fold more likely than CD103-ve DCs to exhibit extensive of prior phagocytosis of apoptotic intestinal epithelial cells. However, CD103+ve and CD103-ve MLN DCs exhibited similar ex vivo capacity to ingest apoptotic cells, indicating that apoptotic cells might drive immature DC maturation towards the CD103+ve phenotype. When cultured with apoptotic cells, myeloid DC precursors isolated from murine bone marrow and characterised as lineage-ve CD103-ve, displayed enhanced expression of CD103 and ß8 integrin and acquired increased capacity to induce T regulatory lymphocytes (Tregs) after 7d in vitro. However, DC precursors isolated from αv-tie2 mice lacking αv integrins in the myeloid line exhibited reduced binding of apoptotic cells and complete deficiency in the capacity of apoptotic cells and/or latent TGF-ß1 to enhance CD103 expression in culture, whereas active TGF-ß1 increased DC precursor CD103 expression irrespective of αv expression. Fluorescence microscopy revealed clustering of αv integrin chains and latent TGF-ß1 at points of contact between DC precursors and apoptotic cells. We conclude that myeloid DC precursors can deploy αv integrin to orchestrate binding of apoptotic cells, activation of latent TGF-ß1 and acquisition of the immunoregulatory CD103+ve ß8+ve DC phenotype. This implies that a hitherto unrecognised consequence of apoptotic cell interaction with myeloid phagocytes is programming that prevents inflammation.


Assuntos
Antígenos CD/metabolismo , Apoptose , Células Dendríticas/imunologia , Regulação da Expressão Gênica , Imunomodulação , Cadeias alfa de Integrinas/metabolismo , Integrina alfaV/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Animais , Células Dendríticas/citologia , Células Dendríticas/metabolismo , Feminino , Camundongos Endogâmicos C57BL , Células Mieloides/citologia , Fagocitose , Linfócitos T Reguladores/imunologia
15.
Nat Commun ; 11(1): 3638, 2020 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-32686667

RESUMO

Surface charge plays a fundamental role in determining the fate of a nanoparticle, and any encapsulated contents, in vivo. Herein, we describe, and visualise in real time, light-triggered switching of liposome surface charge, from neutral to cationic, in situ and in vivo (embryonic zebrafish). Prior to light activation, intravenously administered liposomes, composed of just two lipid reagents, freely circulate and successfully evade innate immune cells present in the fish. Upon in situ irradiation and surface charge switching, however, liposomes rapidly adsorb to, and are taken up by, endothelial cells and/or are phagocytosed by blood resident macrophages. Coupling complete external control of nanoparticle targeting together with the intracellular delivery of encapsulated (and membrane impermeable) cargos, these compositionally simple liposomes are proof that advanced nanoparticle function in vivo does not require increased design complexity but rather a thorough understanding of the fundamental nano-bio interactions involved.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Lipossomos/química , Nanopartículas/química , Animais , Cátions/metabolismo , Lipossomos/farmacologia , Lipossomos/uso terapêutico , Macrófagos , Membranas/metabolismo , Nanomedicina/métodos , Nanopartículas/uso terapêutico , Fagocitose , Peixe-Zebra
16.
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
17.
Int J Nanomedicine ; 15: 4151-4169, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32606670

RESUMO

Purpose: Focused ultrasound (FUS) is a noninvasive method to produce thermal and mechanical destruction along with an immune-stimulatory effect against cancer. However, FUS ablation alone appears insufficient to generate consistent antitumor immunity. In this study, a multifunctional nanoparticle was designed to boost FUS-induced immune effects and achieve systemic, long-lasting antitumor immunity, along with imaging and thermal enhancement. Materials and Methods: PEGylated PLGA nanoparticles encapsulating astragalus polysaccharides (APS) and gold nanorods (AuNRs) were constructed by a simple double emulsion method, characterized, and tested for cytotoxicity. The abilities of PA imaging and thermal-synergetic ablation efficiency were analyzed in vitro and in vivo. The immune-synergistic effect on dendritic cell (DC) differentiation in vitro and the immune response in vivo were also evaluated. Results: The obtained APS/AuNR/PLGA-PEG nanoparticles have an average diameter of 255.00±0.1717 nm and an APS-loading efficiency of 54.89±2.07%, demonstrating their PA imaging capability and high biocompatibility both in vitro and in vivo. In addition, the as-prepared nanoparticles achieved a higher necrosis cell rate and induced apoptosis rate in an in vitro cell suspension assay, greater necrosis area and decreased energy efficiency factor (EEF) in an in vivo rabbit liver assay, and remarkable thermal-synergic performance. In particular, the nanoparticles upregulated the expression of MHC-II, CD80 and CD86 on cocultured DCs in vitro, followed by declining phagocytic function and enhanced interleukin (IL)-12 and interferon (INF)-γ production. Furthermore, they boosted the production of tumor necrosis factor (TNF)-α, IFN-γ, IL-4, IL-10, and IgG1 (P< 0.001) but not IgG2a. Immune promotion peaked on day 3 after FUS in vivo. Conclusion: The multifunctional APS/AuNR/PLGA-PEG nanoparticles can serve as an excellent synergistic agent for FUS therapy, facilitating real-time imaging, promoting thermal ablation effects, and boosting FUS-induced immune effects, which have the potential to be used for further clinical FUS treatment.


Assuntos
Astrágalo (Planta)/química , Neoplasias da Mama/terapia , Ouro/química , Nanopartículas Multifuncionais/química , Nanotubos/química , Polissacarídeos/química , Terapia por Ultrassom , Animais , Antígenos CD/metabolismo , Apoptose , Morte Celular , Diferenciação Celular , Linhagem Celular Tumoral , Proliferação de Células , Citocinas/metabolismo , Células Dendríticas/citologia , Feminino , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Imunoglobulina G/metabolismo , Linfócitos do Interstício Tumoral/imunologia , Camundongos Endogâmicos BALB C , Fagocitose , Técnicas Fotoacústicas , Poliésteres/síntese química , Poliésteres/química , Polietilenoglicóis/síntese química , Polietilenoglicóis/química , Coelhos , Nanomedicina Teranóstica , Fator A de Crescimento do Endotélio Vascular/metabolismo
18.
Medicine (Baltimore) ; 99(29): e20867, 2020 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-32702828

RESUMO

RATIONALE: Phagocytosis is an important physiological process for eliminating unnecessary substances or dead cells after tissue damage, such as inflammation or infarction. Phagocytosis was previously considered to be mainly performed by professional phagocytotic cells, such as macrophages. In contrast, we previously demonstrated that the phagocytosis of dead cells and unnecessary substances by myofibroblasts is as important as that by professional phagocytotic cells in myocardial infarction. Based on our discovery, we speculated that phagocytosis by myofibroblasts may be a more common pathological phenomenon also in other diseases than previously believed. PATIENT CONCERNS: A 44-year-old male patient with atopic dermatitis developed a cutaneous reddish nodule with an underlying induration on his thigh. INTERVENTIONS: The cutaneous lesion was surgically removed. DIAGNOSES: Histopathological examination demonstrated that the cutaneous lesion had solid infiltration by inflammatory cells, namely, plasma cells, histiocytes, and lymphocytes, in the dermis. The cutaneous lesion included mucinosis in the dermis. Inside the mucinosis, we detected cells with clear areas of mucinous substances. Some of the cells were α-smooth muscle actin-positive myofibroblasts. Electron microscopic images demonstrated that there were collagen bands in the cells with mucinous engulfment. Based on these pieces of evidence, we conclude that these mucinous phagocytotic cells were myofibroblasts, not professional phagocytotic cells, such as macrophages. OUTCOMES: There was no recurrence of the lesion. LESSONS: The clinical appearance of this case resembled that of previously reported solitary cutaneous focal mucinoses. However, our case had distinctive characteristics, such as the phagocytosis of mucinous substances by myofibroblasts, multiple mucinous lesions in a single eruption, and the presence of inflammatory cells, which have not been previously reported. For this distinct cutaneous lesion, a clear dermatological and pathological name has yet to be determined. We propose "myofibroblast phagocytic cutaneous mucinosis" as a candidate name. In addition, our discoveries suggest that phagocytosis by myofibroblasts is not rare but rather is a common pathological phenomenon that has been undetected or unrecognized.


Assuntos
Mucinoses/patologia , Miofibroblastos/fisiologia , Fagocitose , Dermatopatias/patologia , Adulto , Humanos , Masculino , Microscopia Eletrônica , Mucinoses/cirurgia , Dermatopatias/cirurgia
19.
Med Hypotheses ; 143: 110108, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32721804

RESUMO

The present hypothesis suggests an innovative therapeutic strategy to cease Covid 19 infection. It is based on the inhibition of Spike glycoprotein and ACE-2 receptor interaction that provides the entry of virus in human host cells, by targeting the S protein with a recombinant molecule made of the ACE-2 receptor ectodomain and an opsonin, the formed complex would enhance its phagocytosis.


Assuntos
Betacoronavirus , Infecções por Coronavirus/tratamento farmacológico , Proteínas Opsonizantes/química , Fagocitose , Pneumonia Viral/tratamento farmacológico , Glicoproteína da Espícula de Coronavírus/antagonistas & inibidores , Desenho de Fármacos , Humanos , Pandemias , Peptidil Dipeptidase A/química , Domínios Proteicos , Engenharia de Proteínas , Proteínas Recombinantes/química , Glicoproteína da Espícula de Coronavírus/química , Internalização do Vírus
20.
Cardiovasc Pathol ; 49: 107258, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32674045

RESUMO

BACKGROUND: Advanced atherosclerotic plaques tend to indicate an increased risk of cerebral ischemic events. SH2 domain-containing protein tyrosine phosphatase 1 (SHP-1) is a class I classical nonreceptor protein tyrosine phosphatase associated with plaque stability, as shown by analysis of a Gene Expression Omnibus (GEO) dataset showing differences in mRNA levels. However, the correlation between SHP-1 and human carotid plaque stability at the protein level remains unclear. METHODS AND RESULTS: Thirty-nine carotid plaque tissue samples were acquired from 39 carotid artery stenosis patients after carotid endarterectomy. Hematoxylin and eosin, Masson trichrome, and CD68 staining was performed for pathological characterization, and immunohistochemical staining for SHP-1 was carried out. Within stable and unstable plaques, SHP-1 mainly accumulated in the necrotic area, plaque shoulder, and fibrous cap, similar to the distribution of CD68. A quantitative analysis of SHP-1 was carried out. The relative SHP-1-positive cell area was higher in the vulnerable group than in the stable group (P < .001). The number of symptomatic patients in the vulnerable group was no greater than that in the stable group (P = .098). Moreover, the integrated optical density (IOD)/area of SHP-1 was significantly higher in the vulnerable group than in the stable group (P < .001). Besides, SHP-1 colocalized with CD68 and vascular cell adhesion protein 1(VCAM-1). CONCLUSIONS: We demonstrate that SHP-1 expression increases during carotid atherosclerotic plaque progression. The protein expression of SHP-1 was related to an increase in plaque instability in not only symptomatic but also asymptomatic patients with carotid artery stenosis. SHP-1 may play a role in atherosclerosis progression by macrophage polarization-mediated efferocytosis. Furthermore, SHP-1 may become a promising biomarker for plaque vulnerability in the future.


Assuntos
Artérias Carótidas/enzimologia , Estenose das Carótidas/enzimologia , Placa Aterosclerótica , Proteína Tirosina Fosfatase não Receptora Tipo 6/análise , Idoso , Apoptose , Biomarcadores/análise , Artérias Carótidas/patologia , Artérias Carótidas/cirurgia , Estenose das Carótidas/patologia , Estenose das Carótidas/cirurgia , Endarterectomia das Carótidas , Feminino , Fibrose , Humanos , Macrófagos/enzimologia , Macrófagos/patologia , Masculino , Pessoa de Meia-Idade , Necrose , Fagocitose , Ruptura Espontânea , Regulação para Cima
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