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1.
J Maxillofac Oral Surg ; 21(4): 1074-1077, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36896088

RESUMO

Purpose: The purpose of this study was to compare the patient journey through the head and neck clinic across 13 years of service improvement. We aimed to compare pick-up rates of cancer; number of patients receiving tissue diagnoses at first visit; and number of patients who were discharged on their first visit. Methods: In the one-stop head and neck cancer clinic, the demographic data, investigations and outcomes for 277 patients who attended in 2004 were compared to those of 205 patients who attended in 2017. The number of patients receiving ultrasonography and fine needle aspiration cytology was compared. Patient outcomes were analysed: specifically, the number discharged on first visit and the number of malignancies diagnosed. Results: The pick-up rate for malignancy from 2004 to 2017 has remained stable (17.3% vs 17.1%). The number of patients receiving ultrasound has remained stable from 264 (95%) in 2004 to 191 (93%) in 2017. The number undergoing FNA has decreased from 139 (50%) to 68 (33%) (p < 0.01). The number of patient's discharged on the first visit has significantly increased from 82 (30%) in 2004 to 89 (43%) in 2017 (p < 0.01). Conclusion: The one-stop clinic provides an effective and efficient means of head and neck lump assessment. Since inception of this service, the accuracy of diagnostic investigation has improved over time.

2.
Eur Arch Otorhinolaryngol ; 278(10): 4107-4112, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33555439

RESUMO

PURPOSE: To establish if day case superficial parotidectomy is feasible, safe and does not result in excess readmissions. METHOD: A retrospective review was carried out of all patients listed for superficial parotidectomy with day case intent by a single surgeon between January 2016 and December 2019 inclusively. The reasons for failure of same day discharge were established. Postoperative complications and readmissions were recorded. Our approach for a superficial parotidectomy typically includes the use of a 10Fr suction drain which is removed at 4 h postoperatively if the output is less than 30 ml. RESULTS: Ninety-one consecutive superficial parotidectomies listed for day case surgery were eligible for inclusion. Seventeen patients failed to be discharged on the same day and were admitted giving a day case success rate of 81%. Most of these (n = 9) occurred in the first year of adopting day case surgery. The most common reason to admit patients was a late finish (n = 8, 47%). Six patients (25%) were admitted due to anaesthetic complications. One patient had a surgical complication requiring admission. CONCLUSION: Our series demonstrates that day case superficial parotidectomy using a surgical drain is feasible, safe and does not result in an unacceptable readmission rate. In our experience, surgical complications are an uncommon cause for day case failure. The most common cause for day case failure was a late finish. Postoperative complications including bleeding, seroma/salivary collection and facial nerve palsy were in keeping with or better than those quoted in the literature.


Assuntos
Paralisia Facial , Neoplasias Parotídeas , Procedimentos Cirúrgicos Ambulatórios , Humanos , Glândula Parótida/cirurgia , Neoplasias Parotídeas/cirurgia , Complicações Pós-Operatórias/epidemiologia , Estudos Retrospectivos , Seroma
5.
Health Expect ; 23(3): 523-539, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32157777

RESUMO

BACKGROUND: Realizing patient partnership in research requires a shift from patient participation in ancillary roles to engagement as contributing members of research teams. While engaging patient partners is often discussed, impact is rarely measured. OBJECTIVE: Our primary aim was to conduct a scoping review of the impact of patient partnership on research outcomes. The secondary aim was to describe barriers and facilitators to realizing effective partnerships. SEARCH STRATEGY: A comprehensive bibliographic search was undertaken in EBSCO CINAHL, and Embase, MEDLINE and PsycINFO via Ovid. Reference lists of included articles were hand-searched. INCLUSION CRITERIA: Included studies were: (a) related to health care; (b) involved patients or proxies in the research process; and (c) reported results related to impact/evaluation of patient partnership on research outcomes. DATA EXTRACTION AND SYNTHESIS: Data were extracted from 14 studies meeting inclusion criteria using a narrative synthesis approach. MAIN RESULTS: Patient partners were involved in a range of research activities. Results highlight critical barriers and facilitators for researchers seeking to undertake patient partnerships to be aware of, such as power imbalances between patient partners and researchers, as well as valuing of patient partner roles. DISCUSSION: Addressing power dynamics in patient partner-researcher relationships and mitigating risks to patient partners through inclusive recruitment and training strategies may contribute towards effective engagement. Further guidance is needed to address evaluation strategies for patient partnerships across the continuum of patient partner involvement in research. CONCLUSIONS: Research teams can employ preparation strategies outlined in this review to support patient partnerships in their work.


Assuntos
Participação do Paciente , Pesquisadores , Humanos , Narração
6.
Arthritis Rheumatol ; 69(3): 610-621, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27723268

RESUMO

OBJECTIVE: HLA-B27 is associated with the inflammatory spondyloarthritides (SpA), although subtypes HLA-B*27:06 and HLA-B*27:09 are not. These subtypes differ from the HLA-B*27:05 disease-associated allele primarily at residues 114 and 116 of the heavy chain, part of the F pocket of the antigen-binding groove. Dimerization of HLA-B27 during assembly has been implicated in disease onset. The purpose of this study was to investigate the factors that influence differences in dimerization between disease-associated and non-disease-associated HLA-B27 alleles. METHODS: HLA-B*27:05 and mutants resembling the HLA-B*27:06 and 09 subtypes were expressed in the rat C58 T cell line, the human CEM T cell line and its calnexin-deficient variant CEM.NKR. Immunoprecipitation, pulse-chase experiments, flow cytometry, and immunoblotting were performed to study the assembly kinetics, heavy-chain dimerization, and chaperone associations. RESULTS: By expressing HLA-B*27:05, 06-like, and 09 alleles on a restrictive rat transporter associated with antigen processing background, we demonstrate that a tyrosine expressed at p116, either alone or together with an aspartic acid residue at p114, inhibited HLA-B27 dimerization and increased the assembly rate. F-pocket residues altered the associations with chaperones of the early major histocompatibility complex class I folding pathway. Calnexin was demonstrated to participate in endoplasmic reticulum (ER) stress-mediated degradation of dimers, whereas the oxidoreductase ERp57 does not appear to influence dimerization. CONCLUSION: Residues within the F pocket of the peptide-binding groove, which differ between disease-associated and non-disease-associated HLA-B27 subtypes, can influence the assembly process and heavy-chain dimerization, events which have been linked to the initiation of disease pathogenesis.


Assuntos
Antígeno HLA-B27/classificação , Antígeno HLA-B27/genética , Chaperonas Moleculares/fisiologia , Dobramento de Proteína , Multimerização Proteica , Animais , Linhagem Celular , Ratos
7.
Biomed Opt Express ; 7(2): 302-11, 2016 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-26977341

RESUMO

A detailed microscopic analysis of renal podocyte substructure is essential to understand and diagnose nephrotic kidney disease. Currently only time consuming electron microscopy (EM) can resolve this substructure. We used structured illumination microscopy (SIM) to examine frozen sections of renal biopsies stained with an immunofluorescence marker for podocin, a protein localized to the perimeter of the podocyte foot processes and compared them with EM in both normal and nephrotic disease biopsies. SIM images of normal glomeruli revealed curvilinear patterns of podocin densely covering capillary walls similar to podocyte foot processes seen by EM. Podocin staining of all nephrotic disease biopsies were significantly different than normal, corresponding to and better visualizing effaced foot processes seen by EM. The findings support the first potential use of SIM in the diagnosis of nephrotic disease.

8.
Nano Lett ; 15(8): 5647-52, 2015 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-26186167

RESUMO

We report on a laser that is fully embedded within a single live cell. By harnessing natural endocytosis of the cell, we introduce a fluorescent whispering gallery mode (WGM) microresonator into the cell cytoplasm. On pumping with nanojoule light pulses, green laser emission is generated inside the cells. Our approach can be applied to different cell types, and cells with microresonators remain viable for weeks under standard conditions. The characteristics of the lasing spectrum provide each cell with a barcode-type label which enables uniquely identifying and tracking individual migrating cells. Self-sustained lasing from cells paves the way to new forms of cell tracking, intracellular sensing, and adaptive imaging.


Assuntos
Rastreamento de Células/métodos , Animais , Movimento Celular , Sobrevivência Celular , Células Cultivadas , Células HEK293 , Humanos , Lasers , Macrófagos/citologia , Camundongos , Microglia/citologia , Células NIH 3T3
9.
PLoS One ; 10(5): e0125158, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25992777

RESUMO

Determining the identity of cells of the immune system usually involves destructive fixation and chemical staining, or labeling with fluorescently labeled antibodies recognising specific cell surface markers. Completely label-free identification would be a significant advantage in conditions where untouched cells are a priority. We demonstrate here the use of Wavelength Modulated Raman Spectroscopy, to achieve label-free identification of purified, unfixed and untouched populations of major immune cell subsets isolated from healthy human donors. Using this technique we have been able to distinguish between CD4(+) T lymphocytes, CD8(+) T lymphocytes and CD56(+) Natural Killer cells at specificities of up to 96%. Additionally, we have been able to distinguish between CD303(+) plasmacytoid and CD1c(+) myeloid dendritic cell subsets, the key initiator and regulatory cells of many immune responses. This demonstrates the ability to identify unperturbed cells of the immune system, and opens novel opportunities to analyse immunological systems and to develop fully label-free diagnostic technologies.


Assuntos
Separação Celular/métodos , Células Dendríticas/citologia , Citometria de Fluxo/métodos , Células Matadoras Naturais/citologia , Análise Espectral Raman/métodos , Subpopulações de Linfócitos T/citologia , Humanos
10.
Arthritis Rheumatol ; 66(11): 2976-88, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25132672

RESUMO

OBJECTIVE: HLA-B27 forms misfolded heavy chain dimers, which may predispose individuals to inflammatory arthritis by inducing endoplasmic reticulum (ER) stress and the unfolded protein response (UPR). This study was undertaken to define the role of the UPR-induced ER-associated degradation (ERAD) pathway in the disposal of HLA-B27 dimeric conformers. METHODS: HeLa cell lines expressing only 2 copies of a carboxy-terminally Sv5-tagged HLA-B27 were generated. The ER stress-induced protein ER degradation-enhancing α-mannosidase-like protein 1 (EDEM1) was overexpressed by transfection, and dimer levels were monitored by immunoblotting. EDEM1, the UPR-associated transcription factor X-box binding protein 1 (XBP-1), the E3 ubiquitin ligase hydroxymethylglutaryl-coenzyme A reductase degradation 1 (HRD1), and the degradation-associated proteins derlin 1 and derlin 2 were inhibited using either short hairpin RNA or dominant-negative mutants. The UPR-associated ERAD of HLA-B27 was confirmed using ER stress-inducing pharamacologic agents in kinetic and pulse chase assays. RESULTS: We demonstrated that UPR-induced machinery can target HLA-B27 dimers and that dimer formation can be controlled by alterations to expression levels of components of the UPR-induced ERAD pathway. HLA-B27 dimers and misfolded major histocompatibility complex class I monomeric molecules bound to EDEM1 were detected, and overexpression of EDEM1 led to inhibition of HLA-B27 dimer formation. EDEM1 inhibition resulted in up-regulation of HLA-B27 dimers, while UPR-induced ERAD of dimers was prevented in the absence of EDEM1. HLA-B27 dimer formation was also enhanced in the absence of XBP-1, HRD1, and derlins 1 and 2. CONCLUSION: The present findings indicate that the UPR ERAD pathway can dispose of HLA-B27 dimers, thus presenting a potential novel therapeutic target for modulation of HLA-B27-associated inflammatory disease.


Assuntos
Degradação Associada com o Retículo Endoplasmático/fisiologia , Retículo Endoplasmático/fisiologia , Antígeno HLA-B27/fisiologia , Proteínas de Membrana/fisiologia , Dobramento de Proteína , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/efeitos dos fármacos , Proteínas de Ligação a DNA/fisiologia , Células HeLa , Humanos , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/efeitos dos fármacos , RNA Interferente Pequeno/farmacologia , Fatores de Transcrição de Fator Regulador X , Transdução de Sinais/fisiologia , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/efeitos dos fármacos , Fatores de Transcrição/fisiologia , Ubiquitina-Proteína Ligases/antagonistas & inibidores , Ubiquitina-Proteína Ligases/efeitos dos fármacos , Ubiquitina-Proteína Ligases/fisiologia , Proteína 1 de Ligação a X-Box
11.
Eur J Cancer ; 50(5): 1025-34, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24462375

RESUMO

PURPOSE: Exosomes are small 50-100nm sized extracellular vesicles released from normal and tumour cells and are a source of a new intercellular communication pathway. Tumour exosomes promote tumour growth and progression. What regulates the release and homoeostatic levels of exosomes, in cancer, in body fluids remains undefined. METHODS: We utilised a human mammary epithelial cell line (HMEC B42) and a breast cancer cell line derived from it (B42 clone 16) to investigate exosome production and regulation. Exosome numbers were quantified using a Nanosight LM10 and measured in culture supernatants in the absence and presence of exosomes in the medium. Concentrated suspensions of exosomes from the normal mammary epithelial cells, the breast cancer cells and bladder cancer cells were used. The interaction of exosomes with tumour cells was also investigated using fluorescently labelled exosomes. RESULTS: Exosome release from normal human mammary epithelial cells and breast cancer cells is regulated by the presence of exosomes, derived from their own cells, in the extracellular environment of the cells. Exosomes from normal mammary epithelial cells also inhibit exosome secretion by breast cancer cells, which occurs in a tissue specific manner. Labelled exosomes from mammary epithelial cells are internalised into the tumour cells implicating a dynamic equilibrium and suggesting a mechanism for feedback control. CONCLUSIONS: These data suggest a previously unknown novel feedback regulatory mechanism for controlling exosome release, which may highlight a new therapeutic approach to controlling the deleterious effects of tumour exosomes. This regulatory mechanism is likely to be generic to other tumours.


Assuntos
Células Epiteliais/metabolismo , Exossomos/metabolismo , Glândulas Mamárias Humanas/citologia , Transdução de Sinais , Western Blotting , Neoplasias da Mama/química , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Células Cultivadas , Células Epiteliais/química , Exossomos/química , Espaço Extracelular/química , Espaço Extracelular/metabolismo , Feminino , Corantes Fluorescentes/química , Humanos , Microscopia Confocal , Compostos Orgânicos/química , Fatores de Tempo
12.
Invest Ophthalmol Vis Sci ; 55(1): 87-101, 2014 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-24282231

RESUMO

PURPOSE: To study melting characteristics and the morphology of human and mouse meibum. METHODS: Hot stage cross-polarized light microscopy (HSPM) and immunohistochemical approaches were used. RESULTS: Isolated human meibum, and meibum of mice (either isolated or within the meibomian ducts of mice), were found to be in liquid-crystal state at physiological temperatures. Melting of both types of meibum started at approximately 10°C and was completed at approximately 40°C. Melting curves of isolated meibum and meibum inside the meibomian ducts were multiphasic with at least two or three clearly defined phase transition temperatures, typically at approximately 12 ± 2°C (minor transition), 21 ± 3°C, and 32 ± 3°C, regardless the source of meibum. Melting was highly cooperative in nature. Samples of abnormal human meibum collected from dry eye patients with meibomian gland dysfunction often showed an increased presence of nonlipid, nonmelting, nonbirefringent, chloroform-insoluble inclusions of a protein nature. The inclusions were positively stained for cytokeratins. The presence of these inclusions was semiquantitatively characterized using a newly proposed 0 to 4 scale. In the presence of large amounts of these inclusions, melting characteristics of meibum and its structural integrity were altered. CONCLUSIONS: HSPM is an effective tool that is suitable for biophysical and morphological evaluation of meibum. Morphological properties and melting characteristics of human meibum were found to be similar to those of mice. Abnormal meibum of many dry eye patients contained large quantities of nonlipid, protein-like inclusions, which were routinely absent in meibum of normal controls.


Assuntos
Síndromes do Olho Seco/patologia , Lipídeos/análise , Glândulas Tarsais/patologia , Lágrimas/química , Adulto , Animais , Síndromes do Olho Seco/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Metabolismo dos Lipídeos , Masculino , Glândulas Tarsais/metabolismo , Camundongos , Microscopia de Polarização/métodos
13.
Br J Sociol ; 64(3): 526-47, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23998323

RESUMO

This paper investigates contemporary academic accounts of the public sphere. In particular, it takes stock of post-Habermasian public sphere scholarship, and acknowledges a lively and variegated debate concerning the multiple ways in which individuals engage in contemporary political affairs. A critical eye is cast over a range of key insights which have come to establish the parameters of what 'counts' as a/the public sphere, who can be involved, and where and how communicative networks are established. This opens up the conceptual space for re-imagining a/the public sphere as an assemblage. Making use of recent developments in Deleuzian-inspired assemblage theory - most especially drawn from DeLanda's (2006) 'new philosophy of society' - the paper sets out an alternative perspective on the notion of the public sphere, and regards it as a space of connectivity brought into being through a contingent and heterogeneous assemblage of discursive, visual and performative practices. This is mapped out with reference to the cultural politics of roadside memorialization. However, a/the public sphere as an assemblage is not simply a 'social construction' brought into being through a logic of connectivity, but is an emergent and ephemeral space which reflexively nurtures and assembles the cultural politics (and political cultures) of which it is an integral part. The discussion concludes, then, with a consideration of the contribution of assemblage theory to public sphere studies. (Also see Campbell 2009a).


Assuntos
Acidentes de Trânsito/psicologia , Características Culturais , Pesar , Comportamento de Massa , Política , Setor Público , Identificação Social , Inglaterra , Humanos
14.
Clin Nucl Med ; 38(1): 1-6, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23242037

RESUMO

PURPOSE OF THE REPORT: Pancreatic carcinoma is known to demonstrate molecular features of hypoxia. The aim of this prospective pilot study is to analyze the hypoxia agent fluoromisonidazole (FMISO) using PET/CT in pancreatic carcinoma and to compare FMISO activity with glucose metabolism reflected by FDG. PATIENTS AND METHODS: Ten patients with pancreatic carcinoma underwent FMISO and FDG PET scans. FMISO and FDG PET/CT scans were analyzed by 2 PET physicians. Regions of interest drawn on the FDG images were transposed to the FMISO images after study coregistration. The FDG SUVmax was used to quantify metabolic activity and FMISO SUVmax and tumor-to-background (muscle) ratio to quantify hypoxia. RESULTS: Seven patients were diagnosed with pancreatic adenocarcinoma. The remaining patients had a neuroendocrine tumor, poorly differentiated/sarcomatoid carcinoma, and mucinous neoplasm. Visual analysis demonstrated increased FMISO activity in 2 pancreatic adenocarcinomas. All patients, however, had increased FDG activity at the tumor site. Mean FDG SUVmax was 6 (range: 3.8 to 9.5) compared to 2.3 for FMISO (range: 1 to 3.4). The 2 positive studies on visual analysis of FMISO did not correspond to the largest tumors, the studies with the highest FMISO or FDG SUVmax. There was no significant correlation between FMISO and FDG SUVmax values. CONCLUSIONS: The hypoxia imaging agent, FMISO, demonstrates minimal activity in pancreatic tumors. If FMISO PET/CT is to be included in clinical trial protocols of hypoxia in pancreatic cancer, it would require correlation with other imaging modalities to localize the tumor and allow semiquantitative analysis.


Assuntos
Misonidazol/análogos & derivados , Imagem Multimodal , Neoplasias Pancreáticas/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Adulto , Idoso , Hipóxia Celular , Feminino , Fluordesoxiglucose F18/farmacocinética , Humanos , Masculino , Pessoa de Meia-Idade , Misonidazol/farmacocinética , Neoplasias Pancreáticas/patologia
15.
Exp Cell Res ; 319(12): 1706-1713, 2013 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-23092844

RESUMO

Exosomes are secreted by many cell types and display multiple biological functions. The ability to both rapidly detect and quantify exosomes in biological samples would assist in the screening of agents that interfere with their release, and which may therefore be of clinical relevance. Nanoparticle tracking analysis, which detects the size and concentration of exosomes, was used to monitor the inhibition of exosome secretion from MDA-MB-231 breast cancer cells expressing inhibitory RNA targeted for Rab27a, a known component of the exosome pathway. Inhibition of both Rab27a and Rab27b was observed, resulting in alterations to intracellular CD63+ compartments and the release of fewer exosomes into the culture medium, as determined by nanoparticle tracking analysis and confirmed by immunoblotting and protein quantification. These data show that nanoparticle tracking analysis can be used effectively and rapidly to monitor the disruption of exosome secretion.


Assuntos
Exossomos/metabolismo , Nanopartículas , Via Secretória , Proteínas rab de Ligação ao GTP/metabolismo , Linhagem Celular Tumoral , Humanos , RNA Interferente Pequeno , Tetraspanina 30/genética , Tetraspanina 30/metabolismo , Proteínas rab de Ligação ao GTP/genética , Proteínas rab27 de Ligação ao GTP
16.
PLoS One ; 7(6): e39049, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22701747

RESUMO

It is becoming clear that inflammation plays a significant role in a number of neurological and psychiatric conditions. Post mortem brain samples in Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, multiple sclerosis, schizophrenia and most recently autism spectrum condition, all exhibit neuroglial activation and inflammatory markers within the CSF. Many questions remain about the underlying molecular mechanisms. By adding the pro-inflammatory cytokine, TNF-α, to mouse brain tissue we demonstrated that the frontal lobes and temporal region, areas involved in higher functions such as memory and learning, are most susceptible to cytokine-induced inflammation via the NF-κB signalling pathway. We observed direct correlations between the volumetric increase and molecular expression indicating that therapeutic targets in these lobes may require different approaches when treating conditions with a central neuroinflammatory component.


Assuntos
Encefalite/metabolismo , Lobo Frontal/metabolismo , NF-kappa B/metabolismo , Transdução de Sinais/imunologia , Lobo Temporal/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Análise de Variância , Animais , Western Blotting , Encefalite/imunologia , Lobo Frontal/imunologia , Camundongos , Microscopia de Fluorescência , Lobo Temporal/imunologia , Fator de Necrose Tumoral alfa/imunologia
17.
Immunology ; 136(4): 380-4, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22533699

RESUMO

The canonical role of major histocompatibility complex class I (MHCI) molecules in antigen presentation involves the recognition of a short peptide of intracellular origin, bound to the upper surface of the class I molecule, by CD8(+) T lymphocytes. Assembly and loading of the MHCI is a highly regulated, chaperone-mediated process and only when the fully folded MHCI molecule is correctly loaded with peptide is it released from the endoplasmic reticulum for trafficking to the cell surface. Current models of the interactions of MHCI molecules with their cognate receptors visualize them functioning as monomeric entities. However, in recent years, new data have revealed MHCI molecules with the ability to form disulphide-linked dimeric structures, with several distinct dimer entities being elucidated. We describe here three types of MHCI dimers; HLA-B27 dimers formed predominantly through the possession of an unpaired cysteine within the peptide-binding groove; HLA-G dimers, which form through a cysteine on its external surface; and a novel population we term redox-induced dimers, which can form between cysteine residues in the cytoplasmic tail domains. The characteristics of these dimeric MHCI molecules and their role in both normal immune responses and in disease pathogenesis are reviewed in this article.


Assuntos
Antígeno HLA-B27/química , Antígeno HLA-B27/imunologia , Antígenos HLA-G/química , Antígenos HLA-G/imunologia , Antígenos de Histocompatibilidade Classe I/química , Antígenos de Histocompatibilidade Classe I/imunologia , Multimerização Proteica , Apresentação de Antígeno , Linfócitos T CD8-Positivos/imunologia , Genes MHC Classe I , Antígeno HLA-B27/metabolismo , Antígenos HLA-G/metabolismo , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos
18.
Immunology ; 136(2): 192-7, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22348503

RESUMO

Nanoparticle tracking analysis permits the determination of both the size distribution and relative concentration of microvesicles, including exosomes, in the supernatants of cultured cells and biological fluids. We have studied the release of microvesicles from the human lymphoblastoid T-cell lines Jurkat and CEM. Unstimulated, both cell lines release microvesicles in the size range 70-90 nm, which can be depleted from the supernatant by ultracentrifugation at 100 000 g, and by anti-CD45 magnetic beads, and which by immunoblotting also contain the exosome-associated proteins Alix and Tsg101. Incubation with known potentiators of exosome release, the ionophores monensin and A23187, resulted in a significant increase in microvesicle release that was both time and concentration dependent. Mass spectrometric analysis of proteins isolated from ultracentrifuged supernatants of A23187-treated cells revealed the presence of exosome-associated proteins including heat-shock protein 90, tubulin, elongation factor α1, actin and glyceraldehyde 3-phosphate dehydrogenase. Additionally, treatment of peripheral blood monocyte-derived dendritic cells with bacterial lipopolysaccharide displayed an increase in secreted microvesicles. Consequently, nanoparticle tracking analysis can be effectively applied to monitor microvesicle release from cells of the immune system.


Assuntos
Rastreamento de Células/métodos , Exossomos/imunologia , Nanopartículas , Linfócitos T/imunologia , Calcimicina/farmacologia , Proteínas de Ligação ao Cálcio/química , Proteínas de Ciclo Celular/química , Linhagem Celular , Proteínas de Ligação a DNA/química , Células Dendríticas/efeitos dos fármacos , Complexos Endossomais de Distribuição Requeridos para Transporte/química , Exossomos/efeitos dos fármacos , Humanos , Separação Imunomagnética , Ionóforos/farmacologia , Antígenos Comuns de Leucócito/química , Lipopolissacarídeos/farmacologia , Monensin/farmacologia , Linfócitos T/efeitos dos fármacos , Fatores de Transcrição/química
19.
Immunology ; 135(2): 133-9, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22044191

RESUMO

Many MHC class I molecules contain unpaired cysteine residues in their cytoplasmic tail domains, the function of which remains relatively uncharacterized. Recently, it has been shown that in the small secretory vesicles known as exosomes, fully folded MHC class I dimers can form through a disulphide bond between the cytoplasmic tail domain cysteines, induced by the low levels of glutathione in these extracellular vesicles. Here we address whether similar MHC class I dimers form in whole cells by alteration of the redox environment. Treatment of the HLA-B27-expressing Epstein-Barr virus-transformed B-cell line Jesthom, and the leukaemic T-cell line CEM transfected with HLA-B27 with the strong oxidant diamide, and the apoptosis-inducing and glutathione-depleting agents hydrogen peroxide and thimerosal, induced MHC class I dimers. Furthermore, induction of apoptosis by cross-linking FasR/CD95 on CEM cells with monoclonal antibody CH-11 also induced MHC class I dimers. As with exosomal MHC class I dimers, the formation of these structures on cells is controlled by the cysteine at position 325 in the cytoplasmic tail domain of HLA-B27. Therefore, the redox environment of cells intimately controls induction of MHC class I dimers, the formation of which may provide novel structures for recognition by the immune system.


Assuntos
Apoptose/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Apoptose/efeitos dos fármacos , Linhagem Celular , Dimerização , Antígenos de Histocompatibilidade Classe I/efeitos dos fármacos , Humanos , Peróxido de Hidrogênio/farmacologia , Oxirredução , Timerosal/farmacologia , Receptor fas/imunologia
20.
Antioxid Redox Signal ; 16(1): 33-43, 2012 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-21902594

RESUMO

AIMS: The human leukocyte antigen (HLA)-B27 is strongly associated with a group of inflammatory arthritic disorders known as the spondyloarthropathies (SpAs). The unusual biochemistry of HLA-B27 has been proposed to participate in disease development, especially the enhanced ability of HLA-B27 to form several heavy chain-dimer populations. HLA-B27 possesses three unpaired cysteine (C) residues at position 67, 308, and 325, in addition to the four conserved cysteine residues at p101, 164, 203, and 259. C67 was proposed to participate in dimer formation of recombinant HLA-B27 protein and in vivo heavy chain-dimers. However, the structurally conserved C164 was demonstrated to participate in endoplasmic reticulum (ER) resident heavy chain-dimer formation. We therefore wanted to determine whether these aggregates involve cysteines other than C164 and the basis for the difference between the observed heavy chain-dimer species. RESULTS: We determined that C164 and C101 can form distinct dimer structures and that the heterogenous nature of heavy chain-dimer species is due to differences in both redox status and conformation. Different HLA-B27 dimer populations can be found in physiologically relevant cell types derived from HLA-B27-positive patients with inflammatory arthritis. In addition, HLA-B27 dimer formation can be correlated with cellular stress induction. INNOVATION: The use of both mutagenesis and manipulating cellular redox environments demonstrates that HLA-B27 dimerization requires both specific cysteine?cysteine interactions and conformations with differing redox states. CONCLUSION: HLA-B27 heavy chain-dimerization is a complex process and these findings provide an insight into HLA-B27 misfolding and a potential contribution to inflammatory disease development.


Assuntos
Cisteína/metabolismo , Antígeno HLA-B27/química , Fator 6 Ativador da Transcrição/metabolismo , Sequência de Aminoácidos , Animais , Linhagem Celular , Sequência Conservada , Cisteína/genética , Retículo Endoplasmático/metabolismo , Estresse do Retículo Endoplasmático , Antígeno HLA-B27/genética , Antígeno HLA-B27/metabolismo , Humanos , Peso Molecular , Oxirredução , Multimerização Proteica/fisiologia , Ratos
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