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1.
ACS Appl Nano Mater ; 6(2): 1315-1324, 2023 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-37789828

RESUMO

Extravasation of circulating tumor cells (CTCs) from the vasculature is a key step in cancer metastasis. CTCs bind to cell adhesion molecules (CAMs) expressed by endothelial cells (ECs) for flow arrest prior to extravasation. While a number of EC-expressed CAMs have been implicated in facilitating CTC binding, this work investigated the efficacy of inhibiting cancer cell binding to human lung microvascular ECs via antibody blocking of E-selectin using antibody-functionalized gold nanoshells (NS). The antibody-functionalized gold NS were synthesized using both directional and non-directional antibody conjugation techniques with variations in synthesis parameters (linker length, amount of passivating agents, and ratio of antibodies to NS) to gain a better understanding of these properties on the resultant hydrodynamic diameter, zeta potential, and antibody loading density. We quantified the ability of E-selectin antibody-functionalized NS to bind human lung microvascular endothelial cells (HMVEC-Ls) under non-inflamed and inflamed (TNF-α) conditions to inhibit binding of triple-negative MDA-MB-231s. E-selectin-targeted NS prepared using non-directional conjugation had higher antibody loading than those prepared via directional conjugation, resulting in the conjugates having similar overall binding to HMVEC-Ls at a given antibody concentration. E-selectin-targeted NS reduced MDA-MB-231 binding to HMVEC-Ls by up to 41% as determined using an in vitro binding assay. These results provide useful insights into the characteristics of antibody-functionalized NS prepared under different conditions while also demonstrating proof of concept that these conjugates hold potential to inhibit CTC binding to ECs, a critical step in extravasation during metastasis.

2.
BMC Gastroenterol ; 23(1): 306, 2023 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-37700260

RESUMO

BACKGROUND AND AIMS: Non-alcoholic fatty liver disease (NAFLD) has become the most common cause of chronic liver disease in wealthy societies, and is responsible for a significant rise in liver morbidity and mortality. Current treatments prioritise lifestyle interventions, predominantly diet and exercise management, but patients frequently fail to make the necessary behavioural adjustments. The current study seeks to identify those factors which influence patients' behaviour with respect to adherence to treatment regimes. METHODS: Novel areas of interest were investigated; locus of control, behavioural regulation and a range of mental health measures, due to their links to either poor lifestyle choices or abnormal eating as identified in previous literature. Data was gathered using self-report questionnaires, from 96 participants, who were split into three groups, NAFLD patients, non-NAFLD liver disease patients and healthy controls RESULTS: Data was analysed using a MANOVA, and followed up with a Tukey post-hoc test. Three factors were found to be significant by group; cognitive restraint, uncontrolled eating and SAPAS score (a measure of personality disorders). An association between personality disorders and NAFLD was identified. CONCLUSION: It is suggested that NAFLD patients are screened for personality disorders and, if identified, treated prior to the commencement of diet and exercise management.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Humanos , Hepatopatia Gordurosa não Alcoólica/complicações , Saúde Mental , Estilo de Vida , Exercício Físico
3.
Immunol Cell Biol ; 100(8): 636-652, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35713361

RESUMO

Special AT-binding protein 1 (SATB1) is a chromatin-binding protein that has been shown to be a key regulator of T-cell development and CD4+ T-cell fate decisions and function. The underlying function for SATB1 in peripheral CD8+ T-cell differentiation processes is largely unknown. To address this, we examined SATB1-binding patterns in naïve and effector CD8+ T cells demonstrating that SATB1 binds to noncoding regulatory elements linked to T-cell lineage-specific gene programs, particularly in naïve CD8+ T cells. We then assessed SATB1 function using N-ethyl-N-nitrosourea-mutant mice that exhibit a point mutation in the SATB1 DNA-binding domain (termed Satb1m1Anu/m1Anu ). Satb1m1Anu/m1Anu mice exhibit diminished SATB1-binding, naïve, Satb1m1Anu/m1Anu CD8+ T cells exhibiting transcriptional and phenotypic characteristics reminiscent of effector T cells. Upon activation, the transcriptional signatures of Satb1m1Anu/m1Anu and wild-type effector CD8+ T cells converged. While there were no overt differences, primary respiratory infection of Satb1m1Anu/m1Anu mice with influenza A virus (IAV) resulted in a decreased proportion and number of IAV-specific CD8+ effector T cells recruited to the infected lung when compared with wild-type mice. Together, these data suggest that SATB1 has a major role in an appropriate transcriptional state within naïve CD8+ T cells and ensures appropriate CD8+ T-cell effector gene expression upon activation.


Assuntos
Vírus da Influenza A , Proteínas de Ligação à Região de Interação com a Matriz , Animais , Linfócitos T CD8-Positivos , Diferenciação Celular , Ativação Linfocitária , Proteínas de Ligação à Região de Interação com a Matriz/metabolismo , Camundongos
5.
Trials ; 22(1): 792, 2021 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-34763711

RESUMO

BACKGROUND: Alcohol consumption causes a spectrum of liver abnormalities and leads to over 3 million deaths per year. Alcoholic hepatitis (AH) is a florid presentation of alcoholic liver disease characterized by liver failure in the context of recent and heavy alcohol consumption. The aim of this study is to explore the potential benefits of the IL-1ß antibody, canakinumab, in the treatment of AH. METHODS: This is a multicentre, double-blind, randomised placebo-controlled trial. Participants will be diagnosed with AH using clinical criteria. Liver biopsy will then confirm that all histological features of AH are present. Up to 58 participants will be recruited into two groups from 15 centres in the UK. Patients will receive an infusion of Canakinumab or matched placebo by random 1:1 allocation. The primary outcome is the difference between groups in the proportion of patients demonstrating histological improvement and will compare histological appearances at baseline with appearances at 28 days to assign a category of "improved" or "not improved". Patients with evidence of ongoing disease activity will receive a second infusion of canakinumab or placebo. Participants will be followed up for 90 days. Secondary outcomes include mortality and change in MELD score at 90 days. DISCUSSION: This phase II study will explore the benefits of the IL-1ß antibody, canakinumab, in the treatment of AH to provide proof of concept that inhibition of IL-1ß signalling may improve histology and survival for patients with AH. TRIAL REGISTRATION: EudraCT 2017-003724-79 . Prospectively registered on 13 April 2018.


Assuntos
Hepatite Alcoólica , Anticorpos Monoclonais Humanizados , Ensaios Clínicos Fase II como Assunto , Método Duplo-Cego , Hepatite Alcoólica/diagnóstico , Hepatite Alcoólica/tratamento farmacológico , Humanos , Estudos Multicêntricos como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento
6.
Contemp Clin Trials ; 107: 106485, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34139356

RESUMO

INTRODUCTION: The traditional double blind RCT is the 'gold standard' trial design. For a variety of reasons, these designs often fail to accrue enough participants to conclude. This is particularly challenging in localized prostate cancer. The cohort multiple randomised controlled trial (cmRCT) trial design may represent an alternative approach to delivering robust comparative data in prostate cancer. PATIENTS AND METHODS: IP3-PROSPECT is a cmRCT designed to test multiple prostate cancer interventions from eligible men in one cohort. Key to the design is two points of consent. First, at point of consent one, men referred for prostate cancer investigations are invited to join the cohort. They may then be randomly invited at a later date to consider an intervention at point of consent two. In the pilot phase we will test the acceptability and feasibility of developing the cohort. RESULTS: Acceptability and feasibility of the study will be measured by a combination of quantitative and qualitative methods. The primary outcome measure is the rate of consent to inclusion to the IP3-PROSPECT cohort. Secondary outcome measures include the completeness of data collection at sites and return rates of patient questionnaires. We will also interview patients and healthcare professionals to explore their thoughts on the implementation, practicality and efficiency of IP3-PROSPECT. CONCLUSION: The IP3-PROSPECT study will evaluate the cmRCT design in prostate cancer. Initially we will pilot the design, assessing for acceptability and feasibility. The cmRCT is an innovative design that offers potential for building a modern comparative evidence base for prostate cancer.


Assuntos
Pessoal de Saúde , Próstata , Método Duplo-Cego , Estudos de Viabilidade , Humanos , Masculino , Estudos Prospectivos , Inquéritos e Questionários
7.
Sci Rep ; 10(1): 1234, 2020 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-31988370

RESUMO

Climatic changes can induce geographic expansion and altitudinal shifts in the distribution of invasive species by offering more thermally suitable habitats. At the remote sub-Antarctic Kerguelen Islands, the predatory insect Merizodus soledadinus (Coleoptera: Carabidae), introduced in 1913, rapidly invaded coastal habitats. More recent colonisation of higher elevation habitats by this species could be underlain by their increased thermal suitability as the area has warmed. This study compared the effect of elevational range shift on the morphology and physiology of adult M. soledadinus sampled along two altitudinal transects (from the foreshore to 250 m a.s.l.) and a horizontal lowland transect orthogonal to the seashore (400 m length). Although high inter-individual and inter-transect variations in the traits examined were present, we observed that body mass of males and females tended to decrease with elevation, and that triglyceride contents decreased with distance from the shore. Moreover, protein contents of females as well as those of 26 metabolites were influenced significantly by distance to the foreshore. These results suggest that future climate change at the Kerguelen Islands will further assist the colonisation of lowland inland and higher altitude habitats by this aggressively invasive predator, by making previously sub-optimal habitats progressively more suitable.


Assuntos
Aclimatação/fisiologia , Altitude , Besouros/fisiologia , Animais , Regiões Antárticas , Mudança Climática , Ecossistema , Geografia , Espécies Introduzidas
8.
Ann Biomed Eng ; 48(7): 1864-1884, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31686312

RESUMO

The Wnt, Hedgehog, and Notch signaling pathways play a crucial role in early development and the maintenance of adult tissues. When dysregulated, these developmental signaling pathways can drive the formation and progression of cancer by facilitating cell survival, proliferation, and stem-like behavior. While this makes these pathways promising targets for therapeutic intervention, their pharmacological inhibition has been challenging due to the substantial complexity that exists within each pathway and the complicated crosstalk that occurs between the pathways. Recently, several small molecule inhibitors, ribonucleic acid (RNA) molecules, and antagonistic antibodies have been developed that can suppress these signaling pathways in vitro, but many of them face systemic delivery challenges. Nanoparticle-based delivery vehicles can overcome these challenges to enhance the performance and anti-cancer effects of these therapeutic molecules. This review summarizes the mechanisms by which the Wnt, Hedgehog, and Notch signaling pathways contribute to cancer growth, and discusses various nanoparticle formulations that have been developed to deliver small molecules, RNAs, and antibodies to cancer cells to inhibit these signaling pathways and halt tumor progression. This review also outlines some of the challenges that these nanocarriers must overcome to achieve therapeutic efficacy and clinical translation.


Assuntos
Sistemas de Liberação de Medicamentos , Proteínas Hedgehog/metabolismo , Nanopartículas , Neoplasias/tratamento farmacológico , Receptores Notch/metabolismo , Transdução de Sinais/efeitos dos fármacos , Humanos , Nanomedicina , Neoplasias/metabolismo , Via de Sinalização Wnt
9.
Contemp Clin Trials ; 71: 124-132, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29908336

RESUMO

There are approximately 256,000 heroin and other opiate users in England of whom 155,000 are in treatment for heroin (or opiate) addiction. The majority of people in treatment receive opiate substitution treatment (OST) (methadone and buprenorphine). However, OST suffers from high attrition and persistent heroin use even whilst in treatment. Contingency management (CM) is a psychological intervention based on the principles of operant conditioning. It is delivered as an adjunct to existing evidence based treatments to amplify patient benefit and involves the systematic application of positive reinforcement (financial or material incentives) to promote behaviours consistent with treatment goals. With an international evidence base for CM, NICE recommended that CM be implemented in UK drug treatment settings alongside OST to target attendance and the reduction of illicit drug use. While there was a growing evidence base for CM, there had been no examination of its delivery in UK NHS addiction services. The PRAISe trial evaluates the feasibility, acceptability, clinical and cost effectiveness of CM in UK addiction services. It is a cluster randomised controlled effectiveness trial of CM (praise and financial incentives) targeted at either abstinence from opiates or attendance at treatment sessions versus no CM among individuals receiving OST. The trial includes an economic evaluation which explores the relative costs and cost effectiveness of the two CM intervention strategies compared to TAU and an embedded process evaluation to identify contextual factors and causal mechanisms associated with variations in outcome. This study will inform UK drug treatment policy and practice. Trial registration ISRCTN 01591254.


Assuntos
Terapia Comportamental/métodos , Buprenorfina/administração & dosagem , Dependência de Heroína , Serviços de Saúde Mental , Metadona/administração & dosagem , Transtornos Relacionados ao Uso de Opioides , Reforço Psicológico , Adulto , Análise por Conglomerados , Uso Indevido de Medicamentos/prevenção & controle , Uso Indevido de Medicamentos/psicologia , Feminino , Dependência de Heroína/psicologia , Dependência de Heroína/terapia , Humanos , Masculino , Conduta do Tratamento Medicamentoso/organização & administração , Conduta do Tratamento Medicamentoso/normas , Serviços de Saúde Mental/economia , Serviços de Saúde Mental/organização & administração , Serviços de Saúde Mental/normas , Antagonistas de Entorpecentes/administração & dosagem , Transtornos Relacionados ao Uso de Opioides/psicologia , Transtornos Relacionados ao Uso de Opioides/terapia , Melhoria de Qualidade , Reino Unido
10.
Resuscitation ; 129: A9-A10, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29803704
12.
AJNR Am J Neuroradiol ; 38(11): 2187-2192, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28970241

RESUMO

BACKGROUND AND PURPOSE: Head CT is the current neuroimaging tool of choice in acute evaluation of pediatric head trauma. The potential cancer risks of CT-related ionizing radiation should limit its use in children. We evaluated the role of MR imaging, including a "black bone" sequence, compared with CT in detecting skull fractures and intracranial hemorrhages in children with acute head trauma. MATERIALS AND METHODS: We performed a retrospective evaluation of 2D head CT and brain MR imaging studies including the black bone sequence of children with head trauma. Two experienced pediatric neuroradiologists in consensus created the standard of reference. Another pediatric neuroradiologist blinded to the diagnosis evaluated brain MR images and head CT images in 2 separate sessions. The presence of skull fractures and intracranial posttraumatic hemorrhages was evaluated. We calculated the sensitivity and specificity of CT and MR imaging with the black bone sequence in the diagnosis of skull fractures and intracranial hemorrhages. RESULTS: Twenty-eight children (24 boys; mean age, 4.89 years; range, 0-15.5 years) with head trauma were included. MR imaging with the black bone sequence revealed lower sensitivity (66.7% versus 100%) and specificity (87.5% versus 100%) in identifying skull fractures. Four of 6 incorrectly interpreted black bone MR imaging studies showed cranial sutures being misinterpreted as skull fractures and vice versa. CONCLUSIONS: Our preliminary results show that brain MR imaging complemented by a black bone sequence is a promising nonionizing alternative to head CT for the assessment of skull fractures in children. However, accuracy in the detection of linear fractures in young children and fractures of aerated bone remains limited.


Assuntos
Lesões Encefálicas Traumáticas/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Fraturas Cranianas/diagnóstico por imagem , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Estudos Retrospectivos , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X/métodos
13.
BMC Res Notes ; 10(1): 93, 2017 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-28193287

RESUMO

BACKGROUND: Stress levels and psychological morbidity are high among undergraduate medical students (UGs), but there is a lack of research into the psychological health of UK graduate-entry medical students (GEs). GEs are likely to experience different (perhaps more severe) stressors and to cope with stress differently. We compared stress levels, psychological morbidity and coping styles in GE versus UG medical students studying at the same UK medical school in the same academic year. A cross-sectional self-rated questionnaire study of all first- and second-year GE and UG medical students was conducted. Perceived stress, psychological morbidity, recent adverse life events, stress-related personality traits and coping styles were assessed using standard questionnaires. RESULTS: 75% GEs and 46% UGs responded to the questionnaire. Both groups reported equally high levels, and similar profiles of, perceived stress and psychological morbidity. Levels of recent adverse life events and stress-related personality traits were similar in both groups. Compared to UGs, GEs were more likely to use active coping (p = 0.02) and positive reframing (p = 0.03), but were also more likely to use substances (alcohol and other drugs; p < 0.001) to help them cope. Unlike UGs, second-year GEs showed less perceived stress (p = 0.007) and psychological morbidity (p = 0.006) than first-year GEs although levels of both were still high. CONCLUSION: Our results show that both GE students and their younger UG counterparts on a traditional medical course have similar profiles of stress symptoms. They do, however, cope with stress differently. GEs are more likely to use active problem-focused coping strategies, and they are also more likely to cope by using substances (alcohol or other drugs). GE students need interventions to prevent maladaptive coping styles and encourage adaptive coping that are tailored to their needs. Such interventions should be targeted at first-year students. It is vital that these students develop positive coping skills to benefit them during training and in a future career that is inherently stressful.


Assuntos
Adaptação Psicológica/fisiologia , Educação de Pós-Graduação em Medicina/estatística & dados numéricos , Educação de Graduação em Medicina/estatística & dados numéricos , Estresse Psicológico/psicologia , Estudantes de Medicina/psicologia , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Estresse Psicológico/epidemiologia , Estudantes de Medicina/estatística & dados numéricos , Reino Unido/epidemiologia , Adulto Jovem
14.
J Evol Biol ; 29(6): 1257-67, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26998589

RESUMO

Specialization has often been claimed to be an evolutionary dead end, with specialist lineages having a reduced capacity to persist or diversify. In a phylogenetic comparative framework, an evolutionary dead end may be detectable from the phylogenetic distribution of specialists, if specialists rarely give rise to large, diverse clades. Previous phylogenetic studies of the influence of specialization on macroevolutionary processes have demonstrated a range of patterns, including examples where specialists have both higher and lower diversification rates than generalists, as well as examples where the rates of evolutionary transitions from generalists to specialists are higher, lower or equal to transitions from specialists to generalists. Here, we wish to ask whether these varied answers are due to the differences in macroevolutionary processes in different clades, or partly due to differences in methodology. We analysed ten phylogenies containing multiple independent origins of specialization and quantified the phylogenetic distribution of specialists by applying a common set of metrics to all datasets. We compared the tip branch lengths of specialists to generalists, the size of specialist clades arising from each evolutionary origin of a specialized trait and whether specialists tend to be clustered or scattered on phylogenies. For each of these measures, we compared the observed values to expectations under null models of trait evolution and expected outcomes under alternative macroevolutionary scenarios. We found that specialization is sometimes an evolutionary dead end: in two of the ten case studies (pollinator-specific plants and host-specific flies), specialization is associated with a reduced rate of diversification or trait persistence. However, in the majority of studies, we could not distinguish the observed phylogenetic distribution of specialists from null models in which specialization has no effect on diversification or trait persistence.


Assuntos
Evolução Biológica , Fenótipo , Filogenia , Plantas
16.
PLoS Pathog ; 10(5): e1004134, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24809749

RESUMO

Suppressor of cytokine signaling (SOCS) proteins are key regulators of innate and adaptive immunity. There is no described biological role for SOCS4, despite broad expression in the hematopoietic system. We demonstrate that mice lacking functional SOCS4 protein rapidly succumb to infection with a pathogenic H1N1 influenza virus (PR8) and are hypersusceptible to infection with the less virulent H3N2 (X31) strain. In SOCS4-deficient animals, this led to substantially greater weight loss, dysregulated pro-inflammatory cytokine and chemokine production in the lungs and delayed viral clearance. This was associated with impaired trafficking of influenza-specific CD8 T cells to the site of infection and linked to defects in T cell receptor activation. These results demonstrate that SOCS4 is a critical regulator of anti-viral immunity.


Assuntos
Imunidade Adaptativa/genética , Citocinas/efeitos adversos , Citocinas/metabolismo , Inflamação/prevenção & controle , Vírus da Influenza A Subtipo H1N1/imunologia , Infecções por Orthomyxoviridae/imunologia , Proteínas Supressoras da Sinalização de Citocina/fisiologia , Animais , Linfócitos T CD8-Positivos/imunologia , Citoproteção/genética , Inflamação/genética , Inflamação/metabolismo , Mediadores da Inflamação/efeitos adversos , Mediadores da Inflamação/metabolismo , Vírus da Influenza A Subtipo H1N1/crescimento & desenvolvimento , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Infecções por Orthomyxoviridae/virologia , Carga Viral/genética
17.
Nat Commun ; 5: 3547, 2014 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-24675400

RESUMO

Modulation of CD8 coreceptor levels can profoundly affect T-cell sensitivity to antigen. Here we show that the heritable downregulation of CD8 during type 2 polarization of murine CD8(+) effector T cells in vitro and in vivo is associated with CpG methylation of several regions of the Cd8a locus. These epigenetic modifications are maintained long-term in vivo following adoptive transfer. Even after extended type 2 polarization, however, some CD8(low) effector cells respond to interferon-γ by re-expressing CD8 and a type 1 cytokine profile in association with partial Cd8a demethylation. Cd8a methylation signatures in naive, polarized and repolarized cells are distinct from those observed during the initiation, maintenance and silencing of CD8 expression by developing T cells in the thymus. This persistent capacity for epigenetic reprogramming of coreceptor levels on effector CD8(+) T cells enables the heritable tuning of antigen sensitivity in parallel with changes in type 1/type 2 cytokine balance.


Assuntos
Antígenos CD8/genética , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/imunologia , Diferenciação Celular , Epigênese Genética , Animais , Antígenos CD8/imunologia , Citocinas/genética , Citocinas/imunologia , Metilação de DNA , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL
18.
Biosecur Bioterror ; 10(3): 314-20, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22853775

RESUMO

Despite the tragic accidents in Fukushima and Chernobyl, the nuclear power industry will continue to contribute to the production of electric energy worldwide until there are efficient and sustainable alternative sources of energy. The Chernobyl nuclear accident, which occurred 26 years ago in the former Soviet Union, released an immense amount of radioactivity over vast territories of Belarus, Ukraine, and the Russian Federation, extending into northern Europe, and became the most severe accident in the history of the nuclear industry. This disaster was a result of numerous factors including inadequate nuclear power plant design, human errors, and violation of safety measures. The lessons learned from nuclear accidents will continue to strengthen the safety design of new reactor installations, but with more than 400 active nuclear power stations worldwide and 104 reactors in the Unites States, it is essential to reassess fundamental issues related to the Chernobyl experience as it continues to evolve. This article summarizes early and late events of the incident, the impact on thyroid health, and attempts to reduce agricultural radioactive contamination.


Assuntos
Contaminação Radioativa do Ar/estatística & dados numéricos , Acidente Nuclear de Chernobyl , Monitoramento Ambiental/estatística & dados numéricos , Neoplasias Induzidas por Radiação/prevenção & controle , Proteção Radiológica/estatística & dados numéricos , Liberação Nociva de Radioativos/estatística & dados numéricos , Agricultura , Contaminação Radioativa do Ar/prevenção & controle , Exposição Ambiental/estatística & dados numéricos , Contaminação Radioativa de Alimentos/prevenção & controle , Humanos , Neoplasias Induzidas por Radiação/epidemiologia , Proteção Radiológica/métodos , Liberação Nociva de Radioativos/prevenção & controle , Ucrânia , Gerenciamento de Resíduos/estatística & dados numéricos
19.
Nat Immunol ; 12(7): 616-23, 2011 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-21666690

RESUMO

Type I natural killer T cells (NKT cells) are characterized by an invariant variable region 14-joining region 18 (V(α)14-J(α)18) T cell antigen receptor (TCR) α-chain and recognition of the glycolipid α-galactosylceramide (α-GalCer) restricted to the antigen-presenting molecule CD1d. Here we describe a population of α-GalCer-reactive NKT cells that expressed a canonical V(α)10-J(α)50 TCR α-chain, which showed a preference for α-glucosylceramide (α-GlcCer) and bacterial α-glucuronic acid-containing glycolipid antigens. Structurally, despite very limited TCRα sequence identity, the V(α)10 TCR-CD1d-α-GlcCer complex had a docking mode similar to that of type I TCR-CD1d-α-GalCer complexes, although differences at the antigen-binding interface accounted for the altered antigen specificity. Our findings provide new insight into the structural basis and evolution of glycolipid antigen recognition and have notable implications for the scope and immunological role of glycolipid-specific T cell responses.


Assuntos
Galactosilceramidas/imunologia , Células T Matadoras Naturais/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Adjuvantes Imunológicos/farmacologia , Sequência de Aminoácidos , Animais , Antígenos de Bactérias/imunologia , Antígenos CD1d/imunologia , Linhagem Celular , Galactosilceramidas/farmacologia , Glucuronatos/imunologia , Humanos , Camundongos , Camundongos Mutantes , Dados de Sequência Molecular , Receptores de Antígenos de Linfócitos T alfa-beta/genética
20.
Proc Natl Acad Sci U S A ; 108(23): 9536-41, 2011 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-21606376

RESUMO

Pathogen-specific responses are characterized by preferred profiles of peptide+class I MHC (pMHCI) glycoprotein-specific T-cell receptor (TCR) Variable (V)-region use. How TCRV-region bias impacts TCRαß heterodimer selection and resultant diversity is unclear. The D(b)PA(224)-specific TCR repertoire in influenza A virus-infected C57BL/6J (B6) mice exhibits a preferred TCRV-region bias toward the TRBV29 gene segment and an optimal complementarity determining region (CDR3) ß-length of 6 aa. Despite these restrictions, D(b)PA(224)-specific BV29(+) T cells use a wide array of unique CDR3ß sequences. Structural characterization of a single, TRBV29(+)D(b)P(A224)-specific TCRαß-pMHCI complex demonstrated that CDR3α amino acid side chains made specific peptide interactions, but the CDR3ß main chain exclusively contacted peptides. Thus, length but not amino acid sequence was key for recognition and flexibility in Vß-region use. In support of this hypothesis, retrovirus expression of the D(b)PA(224)-specific TCRVα-chain was used to constrain pairing within a naive/immune epitope-specific repertoire. The retrogenic TCRVα paired with a diversity of CDR3ßs in the context of a preferred TCRVß spectrum. Overall, these data provide an explanation for the combination of TCRV region bias and diversity within selected repertoires, even as they maintain exquisite pMHCI specificity.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Vírus da Influenza A Subtipo H3N2/imunologia , Infecções por Orthomyxoviridae/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Linfócitos T CD8-Positivos/metabolismo , Regiões Determinantes de Complementaridade/química , Regiões Determinantes de Complementaridade/genética , Regiões Determinantes de Complementaridade/imunologia , Citometria de Fluxo , Variação Genética , Camundongos , Camundongos Endogâmicos C57BL , Modelos Moleculares , Dados de Sequência Molecular , Infecções por Orthomyxoviridae/virologia , Conformação Proteica , Multimerização Proteica , Redobramento de Proteína , Estrutura Secundária de Proteína , Receptores de Antígenos de Linfócitos T/química , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T alfa-beta/química , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia
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