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1.
J Stroke Cerebrovasc Dis ; 32(11): 107384, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37742385

RESUMO

OBJECTIVES: We hypothesized that pregnant women would have an increased risk of spontaneous cervical artery dissection (sCeAD) affecting the carotid or vertebral arteries over one-year follow-up after the first trimester ultrasound compared to matched non-pregnant controls. MATERIALS AND METHODS: We queried a United States research network (TriNetX, Inc.) of de-identified medical records of >111 million patients, with data spanning 2008-2023. We included women aged ≥18 and excluded those with trauma and conditions potentially causative of sCeAD. Women were divided into cohorts based on a1 first trimester ultrasound and subsequent labor, delivery, or full-term pregnancy, or2 gynecological examination and no pregnancy. We used propensity matching to control for variables associated with sCeAD and calculated the risk ratio (RR) of sCeAD occurring over one-year follow-up from the index date of ultrasound or gynecological exam. RESULTS: After matching, the incidence rate of sCeAD in the pregnancy cohort was 8.0 (95% CI: 8.0-8.1) per 100,000 person-years, compared to 3.9 (95% CI: 3.9-3.9) per 100,000 person-years in the non-pregnancy cohort, yielding an RR (95% CI) of 2.06 (1.17-3.61; P= .0104). A cumulative incidence graph suggested that most cases of sCeAD in the pregnancy cohort occurred during pregnancy rather than the postpartum period. CONCLUSIONS: Our findings demonstrate that women have a twofold increased risk of sCeAD during pregnancy and the postpartum period compared to non-pregnant women. Further research is needed to determine whether maternal comorbidities such as preeclampsia account for these findings, and clarify when sCeAD occurs in relation to pregnancy or the postpartum period.

2.
Mol Pharm ; 15(12): 5802-5808, 2018 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-30380896

RESUMO

Full understanding of the barrier property of mucosal tissues is imperative for development of successful mucosal drug delivery strategies, particularly for biologics and nanomedicines. The contribution of the mucosal basement membrane (BM) to this barrier is currently not fully appreciated. This work examined the role of the BM as a barrier to intestinal absorption of model macromolecules (5 and 10 kDa dextrans) and 100 nm polystyrene nanoparticles. Dextrans and nanoparticles were applied either directly to BM-coated inserts or to an intestinal model, namely, differentiated intestinal epithelial monolayers (Caco-2) cultured on BM-modified inserts. The work shows that the BM per se does not impact the diffusion of dextran macromolecules but severely hinders the movement of nanoparticles. However, importantly, Caco-2 monolayers cultured on BM-coated inserts, which show a remarkably different morphology, display a significantly larger barrier to the translocation of one dextran, as well as nanoparticle systems compared to cells cultured on unmodified inserts. Therefore, this work shows that, in addition to presenting a direct physical barrier to the movement of nanoparticles, the BM also exerts an indirect barrier effect, likely due to its influence on epithelial cell physiology. This work is important as it highlights the currently unmet need to consider and further study the barrier properties of the BM in mucosal delivery of biologics and nanomedicines.


Assuntos
Membrana Basal/metabolismo , Permeabilidade da Membrana Celular , Absorção Intestinal , Mucosa Intestinal/metabolismo , Tamanho da Partícula , Produtos Biológicos/administração & dosagem , Produtos Biológicos/farmacocinética , Células CACO-2 , Dextranos/administração & dosagem , Dextranos/farmacocinética , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Humanos , Mucosa Intestinal/citologia , Nanopartículas/administração & dosagem , Nanopartículas/química , Poliestirenos/administração & dosagem , Poliestirenos/química , Poliestirenos/farmacocinética
3.
Appl Environ Microbiol ; 83(2)2017 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-27793830

RESUMO

Escherichia coli K-12 W3110 grows in the presence of membrane-permeant organic acids that can depress cytoplasmic pH and accumulate in the cytoplasm. We conducted experimental evolution by daily diluting cultures in increasing concentrations of benzoic acid (up to 20 mM) buffered at external pH 6.5, a pH at which permeant acids concentrate in the cytoplasm. By 2,000 generations, clones isolated from evolving populations showed increasing tolerance to benzoate but were sensitive to chloramphenicol and tetracycline. Sixteen clones grew to stationary phase in 20 mM benzoate, whereas the ancestral strain W3110 peaked and declined. Similar growth occurred in 10 mM salicylate. Benzoate-evolved strains grew like W3110 in the absence of benzoate, in media buffered at pH 4.8, pH 7.0, or pH 9.0, or in 20 mM acetate or sorbate at pH 6.5. Genomes of 16 strains revealed over 100 mutations, including single-nucleotide polymorphisms (SNPs), large deletions, and insertion knockouts. Most strains acquired deletions in the benzoate-induced multiple antibiotic resistance (Mar) regulon or in associated regulators such as rob and cpxA, as well as the multidrug resistance (MDR) efflux pumps emrA, emrY, and mdtA Strains also lost or downregulated the Gad acid fitness regulon. In 5 mM benzoate or in 2 mM salicylate (2-hydroxybenzoate), most strains showed increased sensitivity to the antibiotics chloramphenicol and tetracycline; some strains were more sensitive than a marA knockout strain. Thus, our benzoate-evolved strains may reveal additional unknown drug resistance components. Benzoate or salicylate selection pressure may cause general loss of MDR genes and regulators. IMPORTANCE: Benzoate is a common food preservative, and salicylate is the primary active metabolite of aspirin. In the gut microbiome, genetic adaptation to salicylate may involve loss or downregulation of inducible multidrug resistance systems. This discovery implies that aspirin therapy may modulate the human gut microbiome to favor salicylate tolerance at the expense of drug resistance. Similar aspirin-associated loss of drug resistance might occur in bacterial pathogens found in arterial plaques.


Assuntos
Benzoatos/metabolismo , Evolução Biológica , Resistência Microbiana a Medicamentos/genética , Escherichia coli K12/efeitos dos fármacos , Conservantes de Alimentos/metabolismo , Salicilatos/metabolismo , Antibacterianos/farmacologia , Anti-Inflamatórios não Esteroides/metabolismo , Relação Dose-Resposta a Droga , Escherichia coli K12/genética , Escherichia coli K12/metabolismo , Regulação Bacteriana da Expressão Gênica
4.
bioRxiv ; 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-39026814

RESUMO

Temporal dynamics play a central role in models of emotion: "fear" is widely conceptualized as a phasic response to certain-and-imminent danger, whereas "anxiety" is a sustained response to uncertain-or-distal harm. Yet the underlying human neurobiology remains contentious. Leveraging an ethnoracially diverse sample, translationally relevant paradigm, and theory-driven modeling approach, we demonstrate that certain and uncertain threat recruit a shared threat-anticipation circuit. This circuit exhibits persistently elevated activation when anticipating uncertain threat encounters and a transient burst of activation in the moments before certain encounters. For many scientists and clinicians, feelings are the defining feature of human fear and anxiety. Here we used an independently validated brain signature to covertly decode the momentary dynamics of anticipatory distress for the first time. Results mirrored the dynamics of neural activation. These observations provide fresh insights into the neurobiology of threat-elicited emotions and set the stage for more ambitious clinical and mechanistic research.

5.
ACS Infect Dis ; 9(4): 716-738, 2023 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-36995299

RESUMO

The treatment of infections is becoming more difficult due to emerging resistance of pathogens to existing drugs. As such, alternative druggable targets, particularly those that are essential for microbe viability and thus make it harder to develop resistance, are desperately needed. In turn, once identified, safe and effective agents that disrupt these targets must be developed. Microbial acquisition and use of iron is a promising novel target for antimicrobial drug development. In this Review we look at the various facets of iron metabolism critical to human infection with pathogenic microbes and the various ways in which it can be targeted, altered, disrupted, and taken advantage of to halt or eliminate microbial infections. Although a variety of agents will be touched upon, the primary focus will be on the potential use of one or more gallium complexes as a new class of antimicrobial agents. In vitro and in vivo data on the activity of gallium complexes against a variety of pathogens including ESKAPE pathogens, mycobacteria, emerging viruses, and fungi will be discussed in detail, as well as pharmacokinetics, novel formulations and delivery approaches, and early human clinical results.


Assuntos
Anti-Infecciosos , Gálio , Humanos , Gálio/farmacologia , Anti-Infecciosos/farmacologia , Anti-Infecciosos/uso terapêutico , Ferro/metabolismo , Sistemas de Liberação de Medicamentos
6.
Nature ; 442(7106): 997-1002, 2006 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-16921386

RESUMO

Contrary to the proinflammatory role of mast cells in allergic disorders, the results obtained in this study establish that mast cells are essential in CD4+CD25+Foxp3+ regulatory T (T(Reg))-cell-dependent peripheral tolerance. Here we confirm that tolerant allografts, which are sustained owing to the immunosuppressive effects of T(Reg) cells, acquire a unique genetic signature dominated by the expression of mast-cell-gene products. We also show that mast cells are crucial for allograft tolerance, through the inability to induce tolerance in mast-cell-deficient mice. High levels of interleukin (IL)-9--a mast cell growth and activation factor--are produced by activated T(Reg) cells, and IL-9 production seems important in mast cell recruitment to, and activation in, tolerant tissue. Our data indicate that IL-9 represents the functional link through which activated T(Reg) cells recruit and activate mast cells to mediate regional immune suppression, because neutralization of IL-9 greatly accelerates allograft rejection in tolerant mice. Finally, immunohistochemical analysis clearly demonstrates the existence of this novel T(Reg)-IL-9-mast cell relationship within tolerant allografts.


Assuntos
Tolerância Imunológica/imunologia , Mastócitos/imunologia , Linfócitos T Reguladores/imunologia , Animais , Contagem de Células , Regulação da Expressão Gênica/genética , Rejeição de Enxerto/imunologia , Interleucina-9/imunologia , Interleucina-9/metabolismo , Mastócitos/citologia , Mastócitos/metabolismo , Camundongos , Camundongos Endogâmicos , Pele/citologia , Pele/imunologia , Transplante de Pele/imunologia , Fatores de Tempo , Transplante Homólogo/imunologia
7.
ACS Infect Dis ; 8(10): 2096-2105, 2022 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-36049087

RESUMO

Pseudomonas aeruginosa is a highly antibiotic-resistant opportunistic pathogenic bacteria that is responsible for thousands of deaths each year. Infections with P. aeruginosa disproportionately impact individuals with compromised immune systems as well as cystic fibrosis patients, where P. aeruginosa lung infection is a leading cause of morbidity and mortality. In previous work, we showed that a combination of gallium (Ga) nitrate and Ga protoporphyrin worked well in several bacterial infection models but its mechanism of action (MOA) is unknown. In the current work, we have investigated the MOA of Ga combination therapy in P. aeruginosa and its analysis in the in vivo model. In P. aeruginosa treated with Ga combination therapy, we saw a decrease in catalase and superoxide dismutase (SOD) activity, key antioxidant enzymes, which could correlate with a higher potential for oxidative stress. Consistent with this hypothesis, we found that, following combination therapy, P. aeruginosa demonstrated higher levels of reactive oxygen species, as measured using the redox-sensitive fluorescent probe, H2DCFDA. We also saw that the Ga combination therapy killed phagocytosed bacteria inside macrophages in vitro. The therapy with low dose was able to fully prevent mortality in a murine model of P. aeruginosa lung infection and also significantly reduced lung damage. These results support our previous data that Ga combination therapy acts synergistically to kill P. aeruginosa, and we now show that this may occur through increasing the organism's susceptibility to oxidative stress. Ga combination therapy also showed itself to be effective at treating infection in a murine pulmonary-infection model.


Assuntos
Gálio , Pseudomonas aeruginosa , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Antioxidantes/farmacologia , Bactérias , Catalase/farmacologia , Corantes Fluorescentes , Gálio/farmacologia , Humanos , Camundongos , Nitratos/farmacologia , Protoporfirinas/farmacologia , Espécies Reativas de Oxigênio , Superóxido Dismutase
8.
J Phys Chem A ; 115(1): 25-9, 2011 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-21142131

RESUMO

The neutral molecule temperature dependence of the rate coefficient for the electron transfer reaction from H(2)O to N(2)(+) is determined using a coaxial molecular beam radio frequency ring electrode ion trap (CoMB-RET) method. The temperature of the N(2)(+) ions was maintained at 100 K, while the effusive water beam temperature was varied from 300 to 450 K. The result demonstrates the neutral molecule rotational/translational energy dependence on the rate coefficient of an ion-dipolar molecule reaction. It is found that the rate coefficient in the above temperature range follows the prediction of the simplest ion-dipole capture model. Use of different buffer gas collisional cooling in both the ion source and the RET reveals the effects of both translational and vibrational energy of the N(2)(+) ions.

9.
Expert Opin Drug Metab Toxicol ; 17(5): 611-625, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33759677

RESUMO

INTRODUCTION: The lungs possess many xenobiotic metabolizing enzymes which influence the pharmacokinetics and safety of inhaled medicines. Anticipating metabolism in the lungs provides an opportunity to optimize new inhaled medicines and overcome challenges in their development. AREAS COVERED: This article summarizes current knowledge on xenobiotic metabolizing enzymes in the lungs. The impact of metabolism on inhaled medicines is considered with examples of how this impacts small molecules, biologics and macromolecular formulation excipients. Methods for measuring and predicting xenobiotic lung metabolism are critically reviewed and the potential for metabolism to influence inhalation toxicology is acknowledged. EXPERT OPINION: Drugs can be optimized by molecular modification to (i) reduce systemic exposure using a 'soft drug' approach, (ii) improve bioavailability by resisting metabolism, or (iii) use a prodrug approach to overcome pharmacokinetic limitations. Drugs that are very labile in the lungs may require a protective formulation. Some drug carriers being investigated for PK-modification rely on lung enzymes to trigger drug release or biodegrade. Lung enzyme activity varies with age, race, smoking status, diet, drug exposure and preexisting lung disease. New experimental technologies to study lung metabolism include tissue engineered models, improved analytical capability and in silico models.


Assuntos
Sistemas de Liberação de Medicamentos , Pulmão/metabolismo , Xenobióticos/metabolismo , Administração por Inalação , Animais , Disponibilidade Biológica , Simulação por Computador , Portadores de Fármacos/química , Humanos , Pulmão/enzimologia , Pneumopatias/fisiopatologia , Pró-Fármacos , Engenharia Tecidual , Xenobióticos/administração & dosagem , Xenobióticos/efeitos adversos
10.
J Immunol ; 181(7): 4752-60, 2008 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-18802078

RESUMO

Granzyme B (GZB) has been implicated as an effector mechanism in regulatory T cells (T(reg)) suppression. In a model of T(reg)-dependent graft tolerance, it is shown that GZB- deficient mice are unable to establish long-term tolerance. Moreover, mice overexpressing the inhibitor of GZB, serine protease inhibitor 6, are also resistant to tolerization to alloantigen. Graft survival was shorter in bone marrow-mixed chimeras reconstituted with GZB-deficient T(reg) as compared with wild-type T(reg). Whereas there was no difference in graft survival in mixed chimeras reconstituted with wild-type, perforin-deficient, or Fas ligand-deficient T(reg). Finally, data also show that if alloreactive effectors cannot express FoxP3 and be induced to convert in the presence of competent T(reg), then graft tolerance is lost. Our data are the first in vivo data to implicate GZB expression by T(reg) in sustaining long-lived graft survival.


Assuntos
Sobrevivência de Enxerto/imunologia , Granzimas/biossíntese , Granzimas/fisiologia , Transplante de Pele/imunologia , Linfócitos T Reguladores/enzimologia , Linfócitos T Reguladores/imunologia , Sequência de Aminoácidos , Animais , Transplante de Medula Óssea/imunologia , Células Cultivadas , Técnicas de Cocultura , Fatores de Transcrição Forkhead/biossíntese , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/fisiologia , Sobrevivência de Enxerto/genética , Granzimas/deficiência , Granzimas/genética , Imunidade Inata/genética , Proteínas de Membrana/biossíntese , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Mutantes , Camundongos Transgênicos , Dados de Sequência Molecular , Serina Endopeptidases/biossíntese , Serina Endopeptidases/genética , Serpinas/biossíntese , Serpinas/genética , Transplante de Pele/patologia , Linfócitos T Reguladores/patologia , Tolerância ao Transplante/genética , Tolerância ao Transplante/imunologia
11.
Sci Rep ; 10(1): 21753, 2020 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-33303896

RESUMO

Identifying emergent patterns of coronavirus disease 2019 (COVID-19) at the local level presents a geographic challenge. The need is not only to integrate multiple data streams from different sources, scales, and cadences, but to also identify meaningful spatial patterns in these data, especially in vulnerable settings where even small numbers and low rates are important to pinpoint for early intervention. This paper identifies a gap in current analytical approaches and presents a near-real time assessment of emergent disease that can be used to guide a local intervention strategy: Geographic Monitoring for Early Disease Detection (GeoMEDD). Through integration of a spatial database and two types of clustering algorithms, GeoMEDD uses incoming test data to provide multiple spatial and temporal perspectives on an ever changing disease landscape by connecting cases using different spatial and temporal thresholds. GeoMEDD has proven effective in revealing these different types of clusters, as well as the influencers and accelerators that give insight as to why a cluster exists where it does, and why it evolves, leading to the saving of lives through more timely and geographically targeted intervention.


Assuntos
Algoritmos , COVID-19/epidemiologia , Bases de Dados Factuais , Monitoramento Epidemiológico , Sistemas de Informação Geográfica , Pandemias , SARS-CoV-2 , Humanos
12.
Environ Mol Mutagen ; 59(4): 290-301, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29368350

RESUMO

Human exposure to airborne particulate matter (PM) is associated with adverse cardiopulmonary health effects, including lung cancer. Ambient PM represents a heterogeneous mixture of chemical classes including transition metals, polycyclic aromatic hydrocarbons (PAHs) and their derivatives such as nitro-PAHs, many of which are classified as putative carcinogens. As the primary site of human exposure to PM is the lungs, we investigated the response of two alveolar epithelial cell lines, the tumour-derived A549 and newly described TT1 cells, to fine and coarse PM collected from background and roadside locations. We show that coarse PM elicits a genotoxic response in the TT1 cells, with the strongest signal associated with the background sample. This response could be recapitulated using the organic extract derived from this sample. No responses were observed in PM-challenged A549 cells. Fine PM failed to elicit a genotoxic response in either cell line despite the higher PAH concentrations within this fraction. Consistent with the lack of a simplistic association between PM PAH content and the observed genotoxic response, TT1 cells treated with benzo[a]pyrene (BaP) demonstrated no increase in the selected markers. In contrast, a pattern of response was observed in TT1 cells challenged with 3-nitrobenzanthrone (3-NBA) similar to that with coarse PM. Together, these data illustrated the suitability of the TT1 cell line for assessing PM-induced genotoxicity and challenge the contention that fine roadside PM poses the higher cancer risk. Furthermore, the response to 3-NBA and not BaP suggests a major contribution of nitro-PAHs to the overall toxicity of PM. Environ. Mol. Mutagen. 59:290-301, 2018. © 2018 The Authors Environmental and Molecular Mutagenesis published by Wiley Periodicals, Inc. on behalf of Environmental Mutagen Society.


Assuntos
Células Epiteliais Alveolares/efeitos dos fármacos , Dano ao DNA , Material Particulado/toxicidade , Hidrocarbonetos Policíclicos Aromáticos , Células A549 , Linhagem Celular , Ensaio de Imunoadsorção Enzimática , Humanos , Testes de Mutagenicidade , Tamanho da Partícula , Hidrocarbonetos Policíclicos Aromáticos/toxicidade
13.
Environ Entomol ; 45(6): 1432-1438, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-28028090

RESUMO

We identified 41 species of native bees from a total of 1,083 specimens collected at cultivated highbush blueberry plantings throughout Rhode Island in 2014 and 2015. Andrena spp., Bombus spp., and Xylocopa virginica (L.) were collected most often. Bombus griseocollis (DeGeer), B. impatiens Cresson, B. bimaculatus Cresson, B. perplexus Cresson, and Andrena vicina Smith collected the largest mean numbers of blueberry pollen tetrads. The largest mean percent blueberry pollen loads were carried by the miner bees Andrena bradleyi Viereck (91%), A. carolina Viereck (90%), and Colletes validus Cresson (87%). The largest mean total pollen grain loads were carried by B. griseocollis (549,844), B. impatiens (389,558), X. virginica (233,500), and B. bimaculatus (193,132). Xylocopa virginica was the fourth and fifth most commonly collected bee species in 2014 and 2015, respectively. They exhibit nectar robbing and females carried relatively low blueberry pollen loads (mean 33%). Overall, we found 10 species of bees to be the primary pollinators of blueberries in Rhode Island.


Assuntos
Abelhas/fisiologia , Biodiversidade , Mirtilos Azuis (Planta) , Pólen/classificação , Polinização , Agricultura , Animais , Comportamento Apetitivo , Mirtilos Azuis (Planta)/fisiologia , Feminino , Masculino , Rhode Island
14.
J Immunol ; 175(3): 1651-7, 2005 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-16034105

RESUMO

CD4+CD25+ regulatory T cells (T(reg)) play an important role in maintaining immunologic tolerance. Glucocorticoid-induced TNFR family-related gene (GITR) expressed preferentially at high levels on T(reg) has been shown to be a key player of regulating T(reg)-mediated suppression. A recent study reports that NF-kappaB-inducing kinase (NIK) expression in thymic stroma is important for the normal production of T(reg) but not for its suppression capacity. In this report, we have shown that T(reg) from NIK-deficient mice display hyperproliferative activities upon GITR stimulation through an IL-2-independent mechanism. Furthermore, high dose IL-2, anti-CD28 stimulation, or GITR ligand-transduced bone marrow-derived dendritic cells used as APC (culture conditions which drive T(reg) proliferation in vitro) could not ablate this difference in proliferative activity between NIK-deficient and wild-type T(reg). Additional experiments have shown NIK-deficient mice have a higher ratio of CD4+CD25+CD62L(low) T(reg) both in thymus and periphery than their wild-type littermates. This CD62(low) subset is responsible for the hyperproliferative activity upon GITR stimulation. These data suggest a novel role of NIK in controlling the development and expansion of CD4+CD25+ regulatory T cells.


Assuntos
Proliferação de Células , Regulação da Expressão Gênica/imunologia , Ativação Linfocitária/genética , NF-kappa B/fisiologia , Proteínas Serina-Treonina Quinases/deficiência , Proteínas Serina-Treonina Quinases/genética , Receptores de Fator de Crescimento Neural/genética , Receptores do Fator de Necrose Tumoral/genética , Linfócitos T Reguladores/imunologia , Animais , Células da Medula Óssea/enzimologia , Células da Medula Óssea/imunologia , Células da Medula Óssea/metabolismo , Linhagem Celular , Linhagem Celular Transformada , Células Cultivadas , Células Dendríticas/enzimologia , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Vetores Genéticos , Proteína Relacionada a TNFR Induzida por Glucocorticoide , Interleucina-2/fisiologia , Camundongos , Camundongos Knockout , Proteínas Serina-Treonina Quinases/fisiologia , Receptores de Interleucina-2/biossíntese , Linfócitos T Reguladores/enzimologia , Linfócitos T Reguladores/metabolismo , Transdução Genética , Quinase Induzida por NF-kappaB
15.
J Immunol ; 170(11): 5786-92, 2003 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-12759463

RESUMO

This study investigated the relationship between HIV-1 replication and virus (HIV-1; CMV)-specific CD4(+) T cell frequency and function in HIV-1-infected children. HIV-1 gag p55-specific CD4(+) T cell IFN-gamma responses were detected in the majority of children studied. p55-specific responses were detected less commonly and at lower frequencies in children with <50 copies/ml plasma HIV-1 RNA than in children with active HIV-1 replication. In children with <50 copies/ml plasma HIV-1, p55-specific responses were detected only in children with evidence of ongoing HIV-1 replication, indicating a direct relationship between HIV-1 replication and HIV-specific CD4(+) T cell frequencies. In contrast, p55-specific proliferative responses were detected more frequently in children with <50 copies/ml plasma HIV-1. CMV-specific CD4(+) responses were more commonly detected and at higher frequencies in CMV-coinfected children with suppressed HIV-1 replication. The lack of HIV-specific CD4(+) proliferative responses, along with the preservation of CMV-specific CD4(+) responses in children with controlled HIV-1 replication, suggests that viral replication may have deleterious effects on HIV-1 and other virus-specific CD4(+) responses. Vaccination to stimulate HIV-specific CD4(+) T cell responses in these children may synergize with antiretroviral therapy to improve the long-term control of viral replication, and may perhaps allow the eventual discontinuation of antiretroviral therapy.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/virologia , Epitopos de Linfócito T/imunologia , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1/imunologia , Replicação Viral/imunologia , Adolescente , Adulto , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD4-Positivos/patologia , Divisão Celular/imunologia , Criança , Pré-Escolar , Doença Crônica , Citomegalovirus/imunologia , Regulação para Baixo/imunologia , Dosagem de Genes , Produtos do Gene gag/imunologia , Infecções por HIV/sangue , Infecções por HIV/patologia , HIV-1/genética , HIV-1/isolamento & purificação , Humanos , Lactente , Interferon gama/biossíntese , Ativação Linfocitária , Contagem de Linfócitos , Linfopenia/imunologia , Linfopenia/patologia , Linfopenia/virologia , Fosfoproteínas/imunologia , Precursores de Proteínas/imunologia , Carga Viral , Proteínas da Matriz Viral/imunologia
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