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1.
Biochem Biophys Res Commun ; 526(4): 1021-1027, 2020 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-32317184

RESUMO

In the application of human umbilical cord-derived mesenchymal stem cells (UC-MSCs) as clinical therapeutics, long term cells ex vivo expansion results in decline in their function. It has been widely concerned that cellular senescence is associated with UC-MSCs immunomodulatory ability. In this study, we evaluated the effects of consecutive passages on cellular senescence and the immunomodulatory abilities of UC-MSCs. Long term-cultured UC-MSCs showed decreased proliferation, senescence phenotypes and impaired immunosuppressive effects on PHA induced peripheral blood mononuclear cell (PBMC) proliferation. We found that Nrf2, a transcription factor that responds to oxidative stress, that showed decreased expression in long term-cultured UC-MSCs, and the further knock-down of Nrf2 in UC-MSCs induced premature senescence, decreased proliferation ability and immunosuppressive abilities. Furthermore, the protein expression of IDO-1 were decreased in response to the downregulation of Nrf2 in UC-MSCs, suggesting that Nrf2 regulates the immunosuppressive properties of UC-MSCs via Nrf2-mediated IDO-1 expression. In conclusion, our results demonstrate that Nrf2 plays a key role in the regulation of the immunosuppressive properties of UC-MSCs, and we suggest that these findings might provide a strategy to enhance the functionality of UC-MSCs for use in therapeutic applications.


Assuntos
Senescência Celular , Terapia de Imunossupressão , Células-Tronco Mesenquimais/citologia , Fator 2 Relacionado a NF-E2/metabolismo , Cordão Umbilical/citologia , Técnicas de Cultura de Células , Proliferação de Células , Células Cultivadas , Regulação para Baixo , Técnicas de Silenciamento de Genes , Humanos , Fenótipo
2.
J Proteome Res ; 16(1): 264-273, 2017 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-27764940

RESUMO

The secreted proteins of bacteria are usually accompanied by virulence factors, which can cause inflammation and damage host cells. Identifying the secretomes arising from the interactions of bacteria and host cells could therefore increase understanding of the mechanisms during initial pathogenesis. The present study used a host-pathogen coculture system of Helicobacter pylori and monocytes (THP-1 cells) to investigate the secreted proteins associated with initial H. pylori pathogenesis. The secreted proteins from the conditioned media from H. pylori, THP-1 cells, and the coculture were collected and analyzed using SDS-PAGE and LC-MS/MS. Results indicated the presence of 15 overexpressed bands in the coculture. Thirty-one proteins were identified-11 were derived from THP-1 cells and 20 were derived from H. pylori. A potential adherence factor from H. pylori, elongation factor-Tu (EF-Tu), was selected for investigation of its biological function. Results from confocal microscopic and flow cytometric analyses indicated the contribution of EF-Tu to the binding ability of H. pylori in THP-1. The data demonstrated that fluorescence of EF-Tu on THP-1 cells increased after the addition of the H. pylori-conditioned medium. This study reports a novel secretory adherence factor in H. pylori, EF-Tu, and further elucidates mechanisms of H. pylori adaptation for host-pathogen interaction during pathogenesis.


Assuntos
Proteínas de Bactérias/genética , Helicobacter pylori/patogenicidade , Interações Hospedeiro-Patógeno , Fator Tu de Elongação de Peptídeos/genética , Proteoma/genética , Fatores de Virulência/genética , Sequência de Aminoácidos , Aderência Bacteriana , Proteínas de Bactérias/metabolismo , Linhagem Celular , Técnicas de Cocultura , Meios de Cultivo Condicionados/química , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Helicobacter pylori/genética , Helicobacter pylori/crescimento & desenvolvimento , Humanos , Monócitos/metabolismo , Monócitos/microbiologia , Fator Tu de Elongação de Peptídeos/metabolismo , Proteoma/metabolismo , Transdução de Sinais , Fatores de Virulência/metabolismo
3.
J Immunol ; 188(1): 68-76, 2012 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-22156340

RESUMO

Gold nanoparticles (GNPs), which are generally thought to be bio-inert and non-cytotoxic, have become one of the most ideal nanomaterials for medical applications. Once engulfed by phagocytes, the immunological effects of GNPs are still of concern and require detailed investigation. Therefore, this study explored the immunological significance of GNPs on TLR-mediated innate immunity in murine macrophages. GNP causes specific inhibition of TLR9 (CpG oligodeoxynucleotides; CpG-ODNs) signal in macrophages. The impaired CpG-ODN-induced TNF-α production is GNP concentration- and size-dependent in murine Raw264.7 cells: a GNP of 4 nm in size is more potent than a GNP of 11, 19, 35, or 45 nm in size. Consistent with cytokine inhibition, the CpG-ODN-induced phosphorylation of NF-κB and JNK as well as NF-κB activation are suppressed by GNPs. GNPs accumulate in lysosomes after phagocytosis and also increase TLR9-associated lysosomal cathepsin expression and activities, but this is irrelevant to TLR9 inhibition by GNPs in our studies. In addition, GNPs affected TLR9 translocation in response to CpG-ODNs and to phagosomes. Further exploring how GNPs inhibited TLR9 function, we found that GNPs could bind to high-mobility group box-1 (which is involved in the regulation of TLR9 signaling) inside the lysosomes. The current studies demonstrate that size-dependent inhibition of TLR9 function by GNP may be attributed to its binding to high-mobility group box-1.


Assuntos
Ouro , Macrófagos/imunologia , Nanopartículas Metálicas , Fagocitose/imunologia , Transdução de Sinais/imunologia , Receptor Toll-Like 9/imunologia , Animais , Linhagem Celular , Relação Dose-Resposta a Droga , Feminino , Proteína HMGB1/imunologia , Lisossomos/imunologia , Macrófagos/citologia , Camundongos , NF-kappa B/imunologia , Oligodesoxirribonucleotídeos/farmacologia , Tamanho da Partícula , Fagocitose/efeitos dos fármacos , Fagossomos/imunologia , Fosforilação/efeitos dos fármacos , Fosforilação/imunologia , Transdução de Sinais/efeitos dos fármacos , Fator de Necrose Tumoral alfa/imunologia
4.
Nature ; 453(7195): 672-6, 2008 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-18496526

RESUMO

Dengue haemorrhagic fever and dengue shock syndrome, the most severe responses to dengue virus (DV) infection, are characterized by plasma leakage (due to increased vascular permeability) and low platelet counts. CLEC5A (C-type lectin domain family 5, member A; also known as myeloid DAP12-associating lectin (MDL-1)) contains a C-type lectin-like fold similar to the natural-killer T-cell C-type lectin domains and associates with a 12-kDa DNAX-activating protein (DAP12) on myeloid cells. Here we show that CLEC5A interacts with the dengue virion directly and thereby brings about DAP12 phosphorylation. The CLEC5A-DV interaction does not result in viral entry but stimulates the release of proinflammatory cytokines. Blockade of CLEC5A-DV interaction suppresses the secretion of proinflammatory cytokines without affecting the release of interferon-alpha, supporting the notion that CLEC5A acts as a signalling receptor for proinflammatory cytokine release. Moreover, anti-CLEC5A monoclonal antibodies inhibit DV-induced plasma leakage, as well as subcutaneous and vital-organ haemorrhaging, and reduce the mortality of DV infection by about 50% in STAT1-deficient mice. Our observation that blockade of CLEC5A-mediated signalling attenuates the production of proinflammatory cytokines by macrophages infected with DV (either alone or complexed with an enhancing antibody) offers a promising strategy for alleviating tissue damage and increasing the survival of patients suffering from dengue haemorrhagic fever and dengue shock syndrome, and possibly even other virus-induced inflammatory diseases.


Assuntos
Vírus da Dengue/metabolismo , Vírus da Dengue/patogenicidade , Lectinas Tipo C/metabolismo , Receptores de Superfície Celular/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/metabolismo , Linhagem Celular , Interações Hospedeiro-Patógeno , Humanos , Interferon-alfa , Lectinas Tipo C/antagonistas & inibidores , Lectinas Tipo C/genética , Lectinas Tipo C/imunologia , Macrófagos/virologia , Proteínas de Membrana/metabolismo , Camundongos , Fosforilação , Ligação Proteica , Receptores de Superfície Celular/antagonistas & inibidores , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/imunologia , Fator de Transcrição STAT1/deficiência , Fator de Transcrição STAT1/genética , Fator de Necrose Tumoral alfa/metabolismo , Replicação Viral
5.
Ear Nose Throat J ; : 1455613241237772, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38439628

RESUMO

Objective: Nasopharyngeal melanoma is a rare mucosal malignant melanoma with high recurrence rate, metastasis rate and vascular invasion rate. In this paper, we report a case of primary nasopharyngeal mucosal melanoma. Methods: A case of primary nasopharyngeal mucosal melanoma was reported, and its clinical symptoms, pathological characteristics, treatment and follow-up were described in detail. Results: This report describes a 59-year-old male patient with persistent nasal congestion and suspected malignant nasopharyngeal neoplasm. Patients receive surgical resection and adjuvant radiotherapy after complete resection. Imaging studies showed no tissue invasion or lymph node metastases. The results of immunohistochemistry were Melan-A(+), HMB45(+), and S100(+). The final diagnosis was malignant nasopharyngeal melanoma. After 2 years of follow-up, the prognosis was good, and there was no metastasis or recurrence. Discussion: Nasopharyngeal melanoma is a rare malignancy with a poor prognosis, and surgical resection is the mainstay of treatment. Postoperative adjuvant therapy can improve the rate of local control of lesions. Early diagnosis and thorough examination are extremely important for the patient's prognosis.

6.
Ying Yong Sheng Tai Xue Bao ; 35(5): 1312-1320, 2024 May.
Artigo em Zh | MEDLINE | ID: mdl-38886430

RESUMO

Understanding the influences of climate change and human activities on vegetation change is the foundation for effective ecosystem management. Based on the 250 m MODIS-NDVI data from 2002 to 2020, we employed Theil-Sen Median trend analysis and the Mann-Kendall test to quantify vegetation change in Hunan Province. By combining with meteorological, nighttime light index, land cover and other data, residual analysis and correlation analysis, we examined the impacts of human activities and climate change on vegetation dynamics at both the pixel level and the county level. The results showed that the normalized difference vegetation index (NDVI) in Hunan Province exhibited a spatial pattern of "overall improvement with localized degradation" during 2002-2020. Approximately 64.9% of the study area experienced significant vegetation improvement, mainly occurring in the western and central-southern parts of Hunan Province. 1.4% of the study area experienced significant vegetation degradation, mostly in the newly developed urban areas and the farmland in the Dongting Lake Plain. Human activities and climate change jointly promoted vegetation improvement in 67.9% of the study area. Human activities and climate contributed to 96% and 4% of the NDVI change, respectively. At the county level, human activities contributed to over 80% of the NDVI change in each district or county. The impacts of human activities on vegetation change exhibited significant spatial heterogeneity. Urban expansion led to vegetation degradation in the newly developed areas, while vegetation growth appeared in the old developed urban areas. The ecological restoration projects promoted vegetation restoration in the western part of Hunan Province. This study could help us better understand the spatiotemporal variations of vegetation and their responses to climate change and human activities, which would offer scientific basis for effective ecological restoration policy.


Assuntos
Mudança Climática , Ecossistema , Monitoramento Ambiental , China , Monitoramento Ambiental/métodos , Conservação dos Recursos Naturais , Imagens de Satélites , Atividades Humanas , Desenvolvimento Vegetal , Árvores/crescimento & desenvolvimento
7.
J Biol Chem ; 287(38): 32216-21, 2012 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-22833682

RESUMO

Retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs) are key RNA viral sensors for triggering antiviral immunity. The underlying mechanisms for RLRs to trigger antiviral immunity have yet to be explored. Here we report the identification of TAPE (TBK1-associated protein in endolysosomes) as a novel regulator of the RLR pathways. TAPE functionally and physically interacts with RIG-I, MDA5, and IPS-1 to activate the IFN-ß promoter. TAPE knockdown impairs IFN-ß activation induced by RLRs but not IPS-1. TAPE-deficient cells are defective in cytokine production upon RLR ligand stimulation. During RNA virus infection, TAPE knockdown or deficiency diminishes cytokine production and antiviral responses. Our data demonstrate a critical role for TAPE in linking RLRs to antiviral immunity.


Assuntos
RNA Helicases DEAD-box/metabolismo , Proteínas de Ligação a DNA/química , Proteínas Repressoras/química , Animais , Antivirais/química , Antivirais/farmacologia , Linhagem Celular Tumoral , Chlorocebus aethiops , Proteína DEAD-box 58 , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica , Células HEK293 , Humanos , Sistema Imunitário , Macrófagos/metabolismo , Camundongos , Camundongos Knockout , Ligação Proteica , Proteínas Serina-Treonina Quinases/química , Interferência de RNA , Receptores Imunológicos , Proteínas Repressoras/metabolismo , Transdução de Sinais , Células Vero
8.
J Biomed Sci ; 20: 65, 2013 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-24011333

RESUMO

BACKGROUND: We and others have reported that autophagy is induced by dengue viruses (DVs) in various cell lines, and that it plays a supportive role in DV replication. This study intended to clarify whether DV infection could induce autophagy in vivo. Furthermore, the effect of DV induced autophagy on viral replication and DV-related pathogenesis was investigated. RESULTS AND CONCLUSIONS: The physiopathological parameters were evaluated after DV2 was intracranially injected into 6-day-old ICR suckling mice. Autophagy-related markers were monitored by immunohistochemical/immunofluorescent staining and Western blotting. Double-membrane autophagic vesicles were investigated by transmission-electron-microscopy. DV non-structural-protein-1 (NS1) expression (indicating DV infection) was detected in the cerebrum, medulla and midbrain of the infected mice. In these infected tissues, increased LC3 puncta formation, LC3-II expression, double-membrane autophagosome-like vesicles (autophagosome), amphisome, and decreased p62 accumulation were observed, indicating that DV2 induces the autophagic progression in vivo. Amphisome formation was demonstrated by colocalization of DV2-NS1 protein or LC3 puncta and mannose-6-phosphate receptor (MPR, endosome marker) in DV2-infected brain tissues. We further manipulated DV-induced autophagy by the inducer rapamycin and the inhibitor 3-methyladenine (3MA), which accordingly promoted or suppressed the disease symptoms and virus load in the brain of the infected mice.We demonstrated that DV2 infection of the suckling mice induces autophagy, which plays a promoting role in DV replication and pathogenesis.


Assuntos
Autofagia , Vírus da Dengue/fisiologia , Dengue/fisiopatologia , Dengue/virologia , Carga Viral , Adenina/análogos & derivados , Adenina/farmacologia , Animais , Animais Recém-Nascidos , Antimetabólitos/farmacologia , Western Blotting , Imunofluorescência , Imunoquímica , Imunossupressores/farmacologia , Camundongos , Camundongos Endogâmicos ICR , Microscopia Eletrônica de Transmissão , Sirolimo/farmacologia , Replicação Viral
9.
Biomed Microdevices ; 15(3): 539-51, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23420191

RESUMO

Seasonal and novel influenza infections have the potential to cause worldwide pandemics. In order to properly treat infected patients and to limit its spread, a rapid, accurate and automatic influenza diagnostic tool needs to be developed. This study therefore presents a new integrated microfluidic system for the rapid detection of influenza infections. It integrated a suction-type, pneumatic-driven microfluidic control module, a magnetic bead-based fluorescent immunoassay (FIA) and an end-point optical detection module. This new system can successfully distinguish between influenza A and B using a single chip test within 15 min automatically, which is faster than existing devices. By utilizing the micromixers to thoroughly wash out the sputum-like mucus, this microfluidic system could be used for the diagnosis of clinical specimens and reduced the required sample volume to 40 µL. Furthermore, the results of diagnostic assays from 86 patient specimens have demonstrated that this system has 84.8 % sensitivity and 75.0 % specificity. This developed system may provide a powerful platform for the fast screening of influenza infections.


Assuntos
Imunoensaio/métodos , Vírus da Influenza A/isolamento & purificação , Influenza Humana/virologia , Imãs/química , Técnicas Analíticas Microfluídicas/métodos , Microesferas , Vírion/isolamento & purificação , Anticorpos Monoclonais/imunologia , Humanos , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H1N1/fisiologia , Vírus da Influenza A Subtipo H3N2/imunologia , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/fisiologia , Vírus da Influenza A/imunologia , Vírus da Influenza A/fisiologia , Limite de Detecção , Fatores de Tempo
10.
J Immunol ; 187(12): 6483-90, 2011 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-22079981

RESUMO

Dengue virus infection can lead to life-threatening dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS) in patients. Abnormal activation of the coagulation and fibrinolysis system is one of the hallmarks associated with DHF/DSS patients. However, the mechanisms that cause pathology in DHF/DSS patients are still unclear. Because conversion of plasminogen (Plg) to plasmin (Plm) is the first step in the activation of fibrinolysis, Abs against Plg found in DHF/DSS patients may be important. Therefore, to investigate the specificity, function, and possible origin of these Abs, we generated several Plg cross-reactive mAbs from DENV-immunized mice. An IgG mAb, 6H11, which recognizes an epitope associated with a dengue envelope protein, demonstrated a high level of cross-reactivity with Plg. The 6H11 Ab was further characterized with regard to its effect on Plg activation. Using Plm-specific chromogenic substrate S-2251, we found that mAb 6H11 demonstrated serine protease activity and could convert Plg directly to Plm. The serine protease activity of mAb 6H11 was further confirmed using serine protease chromogenic substrate S-2288. In addition, we found several Plg cross-reactive mAbs that could enhance urokinase-induced Plg activation. Lastly, mAb 6H11 could induce Plm activity and increase the level of D-dimer (a fibrin degradation product) in both human and mouse platelet-poor plasma. Taken together, these data suggest DENV-induced Plg cross-reactive Abs may enhance Plg conversion to Plm, which would be expected to contribute to hyperfibrinolysis in DHF/DSS patients.


Assuntos
Anticorpos Monoclonais/biossíntese , Anticorpos Antivirais/metabolismo , Autoanticorpos/metabolismo , Vírus da Dengue/imunologia , Plasminogênio/metabolismo , Adulto , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/metabolismo , Anticorpos Antivirais/biossíntese , Anticorpos Antivirais/fisiologia , Autoanticorpos/biossíntese , Autoanticorpos/fisiologia , Sítios de Ligação de Anticorpos/imunologia , Reações Cruzadas/imunologia , Dengue/imunologia , Dengue/virologia , Feminino , Fibrinolisina/metabolismo , Fibrinólise/imunologia , Humanos , Lactente , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Plasminogênio/imunologia , Ligação Proteica/imunologia , Dengue Grave/imunologia , Dengue Grave/virologia , Regulação para Cima/imunologia
11.
J Formos Med Assoc ; 112(1): 12-7, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23332424

RESUMO

Hemorrhage is one of the hallmarks of dengue hemorrhagic fever. However, the mechanisms that cause hemorrhage are unclear. In this review we focus on the possible factors that may be involved in the disturbance of coagulation and fibrinolysis during dengue virus (DENV) infection. Factors such as autoantibodies and cytokines induced by DENV infection as well as hemostatic molecules expressed on DENV-infected cells, and DENV viral proteins may all contribute to the defect of hemostasis during DENV infection. It is the combination of these viral and host factors that may tilt the balance of coagulation and fibrinolysis toward bleeding in dengue patients.


Assuntos
Transtornos da Coagulação Sanguínea/imunologia , Vírus da Dengue/imunologia , Fibrinólise/imunologia , Dengue Grave/complicações , Proteínas Virais/imunologia , Autoanticorpos/sangue , Citocinas/imunologia , Humanos , Mimetismo Molecular , Protrombina/metabolismo , Dengue Grave/sangue , Trombomodulina/sangue , Ativador de Plasminogênio Tecidual/sangue
12.
J Formos Med Assoc ; 112(1): 3-11, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23332423

RESUMO

Dengue is one of the most important vector-borne viral diseases. With climate change and the convenience of travel, dengue is spreading beyond its usual tropical and subtropical boundaries. Infection with dengue virus (DENV) causes diseases ranging widely in severity, from self-limited dengue fever to life-threatening dengue hemorrhagic fever and dengue shock syndrome. Vascular leakage, thrombocytopenia, and hemorrhage are the major clinical manifestations associated with severe DENV infection, yet the mechanisms remain unclear. Besides the direct effects of the virus, immunopathogenesis is also involved in the development of dengue disease. Antibody-dependent enhancement increases the efficiency of virus infection and may suppress type I interferon-mediated antiviral responses. Aberrant activation of T cells and overproduction of soluble factors cause an increase in vascular permeability. DENV-induced autoantibodies against endothelial cells, platelets, and coagulatory molecules lead to their abnormal activation or dysfunction. Molecular mimicry between DENV proteins and host proteins may explain the cross-reactivity of DENV-induced autoantibodies. Although no licensed dengue vaccine is yet available, several vaccine candidates are under development. For the development of a safe and effective dengue vaccine, the immunopathogenic complications of dengue disease need to be considered.


Assuntos
Autoimunidade , Dengue/imunologia , Anticorpos Facilitadores , Citocinas/imunologia , Dengue/virologia , Vírus da Dengue/imunologia , Humanos , Imunidade Celular , Vacinas Virais
13.
J Cataract Refract Surg ; 49(11): 1133-1139, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37586102

RESUMO

PURPOSE: To investigate the ciliary body anatomy and position of the implantable collamer lens (ICL) in low-vault eyes and analyze factors related to insufficient vault. SETTING: Zhongshan Ophthalmic Center, Guangzhou, China. DESIGN: Retrospective case-control observational study. METHODS: In this study, 73 eyes of 73 patients with an insufficient vault (<250 µm) were matched with 73 eyes with an ideal vault (250 to 750 µm). Ultrasound biomicroscopy was used to determine the ciliary body morphology and ICL position. The biometric parameters acquired by Scheimpflug tomography were compared. The correlation between the vault and these factors was analyzed, and the least absolute shrinkage and selection operator method was used to screen the risk factors for low vault. RESULTS: The low-vault group had a steeper corneal curvature, thicker lens thickness (LT), higher crystalline lens rise, and shorter axial length (AL) (all P < .005). The ciliary process length (CPL) and maximum ciliary body thickness (CBTmax) were significantly smaller, and the trabecular-ciliary angle (TCA), iris-ciliary angle (ICA), and ciliary sulcus width (CSW) were significantly greater in the low-vault eyes (all P < .005). The low-vault group had more ICL haptics below the ciliary process, and TCA, ICA, CPL, CBTmax, CSW, and haptic position were related to the postoperative vault (all P < .05). CPL, AL, and LT were identified as predictors of a low vault. CONCLUSIONS: Malposition of ICL haptics behind the ciliary process is a risk factor for low vault. A shorter CPL, thicker LT, and shorter AL are significant risk factors for the postoperative low vault.


Assuntos
Cristalino , Lentes Intraoculares , Lentes Intraoculares Fácicas , Humanos , Corpo Ciliar/diagnóstico por imagem , Corpo Ciliar/cirurgia , Estudos Retrospectivos , Microscopia Acústica/métodos , Cristalino/diagnóstico por imagem
14.
J Biol Chem ; 286(9): 7043-51, 2011 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-21189260

RESUMO

The innate immune system elicits the first wave of immune responses against pathogen infection. Its operational modes are complex and have yet to be defined. Here, we report the identification of an innate immune regulator termed TAPE (TBK1-associated protein in endolysosomes), previously known as CC2D1A/Freud-1/Aki-1, which modulates the TLR3 and TLR4 pathways. We found that TAPE activated the TBK1, NF-κB, and ERK pathways leading to IFN-ß and inflammatory cytokine induction. TAPE was shown to colocalize with endosomal marker Rab5 and lysosomal marker LAMP1 in mammalian cells, suggesting that TAPE resided in endolysosomes. Knockdown of TAPE selectively impaired the TLR3 and endocytic TLR4 pathways to IFN-ß induction. Furthermore, TAPE interacted and synergized with Trif to activate IFN-ß. TAPE knockdown failed to block Trif-mediated IFN-ß induction, whereas Trif knockdown impaired the TLR3 and TAPE cooperation on IFN-ß induction, suggesting that TAPE acts upstream of Trif. Together, our data demonstrate a central role for TAPE in linking TLR3 and TLR4 to innate immune defenses at an early step.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Fatores Imunológicos/metabolismo , Transdução de Sinais/imunologia , Receptor 3 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo , Proteínas de Ligação a DNA/imunologia , Endossomos/imunologia , Endossomos/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/imunologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Células HEK293 , Humanos , Fatores Imunológicos/imunologia , Interferon beta/imunologia , Interferon beta/metabolismo , Lisossomos/imunologia , Lisossomos/metabolismo , Proteínas Serina-Treonina Quinases/imunologia , Proteínas Serina-Treonina Quinases/metabolismo , Receptor 3 Toll-Like/imunologia , Receptor 4 Toll-Like/imunologia
15.
Infect Immun ; 80(5): 1815-22, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22354022

RESUMO

Outer membrane proteins (OMPs) serve as the permeability channels for nutrients, toxins, and antibiotics. In Escherichia coli, OmpA has been shown to be involved in bacterial virulence, and OmpC is related to multidrug resistance. However, it is unclear whether OmpC also has a role in the virulence of E. coli. The aims of this study were to characterize the role of OmpC in antimicrobial resistance and bacterial virulence in E. coli. The ompC deletion mutant showed significantly decreased susceptibility to carbapenems and cefepime. To investigate the survival of E. coli exposed to the innate immune system, a human blood bactericidal assay showed that the ompC mutant increased survival in blood and serum but not in complement-inactivated serum. These effects were also demonstrated in the natural selection of OmpC mutants. Also, C1q interacted with E. coli through a complex of antibodies bound to OmpC as a major target. Bacterial survival was increased in the wild-type strain in a dose-dependent manner by adding free recombinant OmpC protein or anti-C1q antibody to human serum. These results demonstrated that the interaction of OmpC-specific antibody and C1q was the key step in initiating the antibody-dependent classical pathway for the clearance of OmpC-expressing E. coli. Anti-OmpC antibody was detected in human sera, indicating that OmpC is an immunogen. These data indicate that the loss of OmpC in E. coli is resistant to not only antibiotics, but also the serum bactericidal effect, which is mediated from the C1q and anti-OmpC antibody-dependent classical pathway.


Assuntos
Antibacterianos/farmacologia , Anticorpos Antibacterianos/imunologia , Farmacorresistência Bacteriana/genética , Escherichia coli/citologia , Escherichia coli/metabolismo , Porinas/metabolismo , Animais , Especificidade de Anticorpos , Antígenos de Bactérias , Complemento C1q , Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica/fisiologia , Genótipo , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Mutação , Porinas/genética , Proteínas Recombinantes
16.
J Cell Biochem ; 113(5): 1681-91, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22422622

RESUMO

Infection with dengue virus (DENV) causes diseases ranging from mild dengue fever to severe hemorrhage or shock syndrome. DENV infection of endothelial cells may cause cell apoptosis or vascular leakage and result in clinical illness of hemorrhage. However, the endothelial cell molecules involved in DENV infection and the mechanisms governing virus-cell interactions are still uncertain. Since protein disulfide isomerase (PDI) reducing function at the cell surface was shown to be required for entry of certain viruses and bacteria, we explored the role of PDI expressed on endothelial cell surface in DENV infection. Using siRNA to knock down PDI, DENV infection was reduced which could be reversed by treating cells with a reducing agent Tris(2-carboxyethyl)phosphine hydrochloride (TCEP). DENV-induced PDI surface expression was mediated through the Lys-Asp-Glu-Leu (KDEL) receptor-Src family kinase signal pathway. Furthermore, cell surface PDI colocalized with ß1 and ß3 integrins after DENV infection, and the activation of integrins was blocked by PDI inhibition. Finally, blockade of PDI inhibited DENV entry into endothelial cells. Our findings suggest a novel mechanism whereby surface PDI which causes integrin activation is involved in DENV entry, and DENV infection further increases PDI surface expression at later time points. These findings may have implications for anti-DENV drug design.


Assuntos
Dengue/etiologia , Dengue/metabolismo , Células Endoteliais/metabolismo , Células Endoteliais/virologia , Integrina beta1/metabolismo , Integrina beta3/metabolismo , Isomerases de Dissulfetos de Proteínas/metabolismo , Linhagem Celular , Membrana Celular/metabolismo , Membrana Celular/virologia , Dengue/virologia , Vírus da Dengue/patogenicidade , Retículo Endoplasmático/metabolismo , Células Endoteliais/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Complexo de Golgi/metabolismo , Humanos , Fosfinas/farmacologia , Isomerases de Dissulfetos de Proteínas/antagonistas & inibidores , Isomerases de Dissulfetos de Proteínas/genética , RNA Interferente Pequeno/genética , Receptores de Peptídeos/antagonistas & inibidores , Receptores de Peptídeos/genética , Receptores de Peptídeos/metabolismo , Substâncias Redutoras/farmacologia , Transdução de Sinais , Internalização do Vírus/efeitos dos fármacos
17.
PLoS Pathog ; 6(1): e1000718, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20062797

RESUMO

Cells infected with dengue virus release a high proportion of immature prM-containing virions. In accordance, substantial levels of prM antibodies are found in sera of infected humans. Furthermore, it has been recently described that the rates of prM antibody responses are significantly higher in patients with secondary infection compared to those with primary infection. This suggests that immature dengue virus may play a role in disease pathogenesis. Interestingly, however, numerous functional studies have revealed that immature particles lack the ability to infect cells. In this report, we show that fully immature dengue particles become highly infectious upon interaction with prM antibodies. We demonstrate that prM antibodies facilitate efficient binding and cell entry of immature particles into Fc-receptor-expressing cells. In addition, enzymatic activity of furin is critical to render the internalized immature virus infectious. Together, these data suggest that during a secondary infection or primary infection of infants born to dengue-immune mothers, immature particles have the potential to be highly infectious and hence may contribute to the development of severe disease.


Assuntos
Anticorpos Antivirais/imunologia , Vírus da Dengue/patogenicidade , Furina/metabolismo , Vírion/imunologia , Linhagem Celular , Dengue/imunologia , Vírus da Dengue/imunologia , Humanos , Receptores de IgG/imunologia , Receptores de IgG/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
18.
Clin Dev Immunol ; 2012: 876241, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22956971

RESUMO

Enterovirus 71 (EV71) is one of the most important causes of herpangina and hand, foot, and mouth disease. It can also cause severe complications of the central nervous system (CNS). Brain stem encephalitis with pulmonary edema is the severe complication that can lead to death. EV71 replicates in leukocytes, endothelial cells, and dendritic cells resulting in the production of immune and inflammatory mediators that shape innate and acquired immune responses and the complications of disease. Cytokines, as a part of innate immunity, favor the development of antiviral and Th1 immune responses. Cytokines and chemokines play an important role in the pathogenesis EV71 brain stem encephalitis. Both the CNS and the systemic inflammatory responses to infection play important, but distinctly different, roles in the pathogenesis of EV71 pulmonary edema. Administration of intravenous immunoglobulin and milrinone, a phosphodiesterase inhibitor, has been shown to modulate inflammation, to reduce sympathetic overactivity, and to improve survival in patients with EV71 autonomic nervous system dysregulation and pulmonary edema.


Assuntos
Tronco Encefálico/virologia , Citocinas/metabolismo , Encefalite Viral/imunologia , Enterovirus Humano A/imunologia , Infecções por Enterovirus/imunologia , Tronco Encefálico/patologia , Citocinas/sangue , Citocinas/líquido cefalorraquidiano , Encefalite Viral/diagnóstico , Encefalite Viral/terapia , Enterovirus Humano A/patogenicidade , Infecções por Enterovirus/diagnóstico , Infecções por Enterovirus/terapia , Humanos , Imunoglobulinas Intravenosas/uso terapêutico , Imunomodulação
19.
Artigo em Inglês | MEDLINE | ID: mdl-23077841

RESUMO

Antibody-dependent enhancement of infection (ADE) is central to explaining the development of severe disease at the end of post-dengue virus infection. Non-neutralizing anti-dengue antibodies bound to the dengue virion enhances the virus entrance into the target cells via the Fc receptor. The titer of enhancing antibodies in dengue patients is not determined during dengue virus infection. Sensitive flow cytometry detecting dengue virus-infected K562 cells was used to quantitate enhancing activity among Thai DF and DHF patients against four serotypes and the patient's dengue isolate. The titer was defined as the reciprocal of the final dilution that loses enhancing activity. The serum of Thai patients confirmed to have dengue infection were found to have high titers of enhancing antibodies and increased gradually through the convalescent phase of infection. The enhancing antibody titers were not different among the four serotypes or from the infecting isolate. The anti-dengue antibodies from dengue patients can enhance dengue virus infections in a concentration-dependent, serotype-independent manner.


Assuntos
Anticorpos Facilitadores/imunologia , Dengue/imunologia , Anticorpos Bloqueadores/imunologia , Anticorpos Antivirais/imunologia , Dengue/diagnóstico , Dengue/epidemiologia , Dengue/virologia , Citometria de Fluxo , Humanos , Células K562 , Receptores Fc/imunologia , Sorotipagem , Dengue Grave/diagnóstico , Dengue Grave/epidemiologia , Dengue Grave/imunologia , Dengue Grave/virologia , Tailândia/epidemiologia
20.
J Cell Biochem ; 112(3): 881-93, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21328461

RESUMO

The endoplasmic reticulum (ER) is essential for lipid biosynthesis, and stress signals in this organelle are thought to alter lipid metabolism. Elucidating the mechanisms that underlie the dysregulation of lipid metabolism in hepatocytes may lead to novel therapeutic approaches for the treatment of lipid accumulation. We first tested the effects of several inhibitors on lipid dysregulation induced by tunicamycin, an ER stress inducer. Triacsin C, an inhibitor of long-chain acyl-CoA synthetase (ACSL) 1, 3, and 4, was the most potent among these inhibitors. We then analyzed the expression of the ACSL family during ER stress. The expression of ACSL3 was induced by ER stress in HuH-7 cells and in mice livers. ACSL3 shRNA, but not ACSL1 shRNA, inhibited the induction of lipid accumulation. GSK-3ß inhibitors attenuated ACSL3 expression and the lipid accumulation induced by ER stress in HuH-7 cells. shRNA that target GSK-3ß also inhibited the upregulation of ACSL3 and lipid accumulation in HuH-7 and HepG2 cells. The hepatitis B virus mutant large surface protein, which is known to induce ER stress, increased the lipid content of cells. Similarly, Triacsin C, and GSK-3ß inhibitors abrogated the lipid dysregulation caused by the hepatitis B virus mutant large surface protein. Altogether, ACSL3 and GSK-3ß represent novel therapeutic targets for lipid dysregulation by ER stress.


Assuntos
Coenzima A Ligases/metabolismo , Retículo Endoplasmático/fisiologia , Quinase 3 da Glicogênio Sintase/metabolismo , Hepatócitos/metabolismo , Lipídeos/biossíntese , Fígado/metabolismo , Animais , Linhagem Celular Tumoral , Chaperona BiP do Retículo Endoplasmático , Inibidores Enzimáticos/farmacologia , Glicogênio Sintase Quinase 3 beta , Proteínas de Choque Térmico/metabolismo , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Interferência de RNA , Estresse Fisiológico , Triazenos/farmacologia , Tunicamicina/farmacologia , Regulação para Cima
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