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1.
Diabetes Metab ; 50(1): 101495, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38000504

RESUMO

OBJECTIVE: Randomized controlled trials (RCTs) have demonstrated the superiority of metabolic surgery (MS) over medical therapy (MT) in patients with obesity and type 2 diabetes, leading, to a joint statement in 2016 proposing MS to patients with class I obesity and uncontrolled glycemia. Yet, these RCTs included few patients with class I obesity (body mass index 30-35 kg/m2) and even fewer patients with overweight. Our aim was to provide an updated systematic review (SR) with meta-analysis (MA) of RCTs reporting diabetes remission (DR) after MS in these patients. RESEARCH DESIGN AND METHODS: We included in the SR with MA only RCTs with at least 24-month follow-up found in Medline, Cochrane Library, Embase, and LiSSA between January 2008 and September 2022 comparing DR post-MT versus post-MS. We calculated relative risk (RR) and 95 % confidence intervals (CIs) using the Mantel-Haenszel random-effects approach to examine differences in DR between patients allocated to MS versus MT. RESULTS: DR was significantly higher in MS versus MT after 36 months' follow-up in patients with obesity (RR = 6.65 [95 %CI 2.24;19.79]; I² = 27 %; 5 trials, 404 patients), but also specifically in patients with class I obesity (RR = 5.27 [1.31;21.23]; I² = 0 %; 4 trials, 80 patients). Furthermore, and in line with previous results, all additional MAs performed in patients with obesity in this work favor MS (specifically Roux-en-Y gastric bypass) over MT at 24, 36 (only) and 60 months of follow-up. CONCLUSIONS: Although the data available in patients with class I obesity and type 2 diabetes remains limited, MA shows higher rates of DR after MS compared with MT after 36 months' follow-up in these patients. Consequently, the French National Authority for Health French (HAS) recommends MS for these patients.


Assuntos
Cirurgia Bariátrica , Diabetes Mellitus Tipo 2 , Derivação Gástrica , Humanos , Obesidade/complicações , Obesidade/epidemiologia , Obesidade/cirurgia , Derivação Gástrica/métodos , Diabetes Mellitus Tipo 2/cirurgia , Sobrepeso
3.
Therapie ; 71(1): 69-96, 2016 Feb.
Artigo em Inglês, Francês | MEDLINE | ID: mdl-27080633

RESUMO

Health technology assessment (HTA) is a rapidly developing area and the value of taking non-clinical fields into consideration is growing. Although the health-economic aspect is commonly recognised, evaluating organisational impact has not been studied nearly as much. The goal of this work was to provide a definition of organisational impact in the sector of medical devices by defining its contours and exploring the evaluation methods specific to this field. Following an analysis of the literature concerning the impact of technologies on organisations as well as the medical literature, and also after reviewing the regulatory texts in this respect, the group of experts identified 12 types of organisational impact. A number of medical devices were carefully screened using the criteria grid, which proved to be operational and to differentiate properly. From the analysis of the practice and of the methods described, the group was then able to derive a few guidelines to successfully evaluate organisational impact. This work shows that taking organisational impact into consideration may be critical alongside of the other criteria currently in favour (clinically and economically). What remains is to confer a role in the decision-making process on this factor and one that meets the economic efficiency principle.


Assuntos
Equipamentos e Provisões/normas , Avaliação da Tecnologia Biomédica/métodos , Análise Custo-Benefício , Equipamentos e Provisões/economia , Guias como Assunto , Humanos , Avaliação da Tecnologia Biomédica/economia , Avaliação da Tecnologia Biomédica/legislação & jurisprudência
4.
Therapie ; 70(1): 57-68, 2015.
Artigo em Inglês, Francês | MEDLINE | ID: mdl-25747839

RESUMO

Medical devices (MDs) cover a wide variety of products. They accompany changes in medical practice in step with technology innovations. Innovations in the field of MDs can improve the conditions of use of health technology and/or modify the organisation of care beyond the strict diagnostic or therapeutic benefit for the patients. However, these non purely clinical criteria seem to be only rarely documented or taken into account in the assessment of MDs during reimbursement decisions at national level or for formulary listing by hospitals even though multidimensional models for the assessment of health technologies have been developed that take into account the views of all stakeholders in the healthcare system In this article, after summarising the background concerning the assessment of health technologies in France, a definition of non-clinical criteria for the assessment of MDs is proposed and a decision tree for the assessment of MDs is described. Future lines of approach are proposed as a conclusion.


Assuntos
Equipamentos e Provisões/normas , Avaliação da Tecnologia Biomédica/normas , Biomarcadores , Análise Custo-Benefício , Procedimentos Clínicos , Árvores de Decisões , Equipamentos e Provisões/efeitos adversos , Equipamentos e Provisões/economia , França , Humanos , Reembolso de Seguro de Saúde , Invenções , Legislação de Dispositivos Médicos , Programas Nacionais de Saúde , Avaliação da Tecnologia Biomédica/organização & administração
6.
Therapie ; 69(4): 303-21, 2014.
Artigo em Inglês, Francês | MEDLINE | ID: mdl-25230354

RESUMO

Medical devices are characterized notably by a wide heterogeneity (from tongue depressors to hip prostheses, and from non-implantable to invasive devices), a short life cycle with recurrent incremental innovations (from 18 months to 5 years), and an operator-dependent nature. The objective of the current round table was to develop proposals and recommendations concerning the prerequisites needed in order to meet the French health authorities expectations concerning requests for post-approval studies for medical devices, required in cases where short and long-term consequences are unknown. These studies, which are the responsibility of the manufacturer or the distributor of the medical device, are designed to confirm the role of the medical device in the therapeutic management strategy in a real-life setting. There are currently approximately 150 post-approval studies underway, mainly concerning class III devices, and the majority face difficulties implementing the study or meeting the study objectives. In light of this, the round table endeavored to clearly identify the conditions for implementation of post-approval studies specific to the characteristics of medical devices. Various areas of progress have been envisaged to improve the performance of these studies, and by consequence, the efficiency of reimbursement of medical devices by the national health insurance. These include providing manufacturers with the opportunity to better anticipate post-approval requirements, defining a study-specific primary objective, integrating a phase allowing dialogue between the manufacturer, the health authorities and the scientific committee, and increasing awareness and training of health professionals on the impact of post-approval clinical studies in terms of the reimbursement of medical devices by the national insurance.


Assuntos
Aprovação de Equipamentos , Vigilância de Produtos Comercializados , Tecnologia Biomédica , Aprovação de Equipamentos/legislação & jurisprudência , Desenho de Equipamento , Equipamentos e Provisões/economia , França , Órgãos Governamentais , Guias como Assunto , Setor de Assistência à Saúde , Reembolso de Seguro de Saúde , Relações Interinstitucionais , Indústria Manufatureira , Vigilância de Produtos Comercializados/métodos , Vigilância de Produtos Comercializados/tendências
8.
Therapie ; 68(4): 193-208, 2013.
Artigo em Inglês, Francês | MEDLINE | ID: mdl-23981256

RESUMO

Medical devices are many and various, ranging from tongue spatulas to implantable or invasive devices and imaging machines; their lifetimes are short, between 18 months and 5 years, due to incessant incremental innovation; and they are operator-dependent: in general, the clinical user performs a fitting procedure (hip implant or pacemaker), a therapeutic procedure using a non-implantable invasive device (arrhythmic site ablation probe, angioplasty balloon, extension spondyloplasty system, etc.) or follow-up of an active implanted device (long-term follow-up of an implanted cardiac defibrillator or of a deep brain stimulator in Parkinson's patients). A round-table held during the XXVIII(th) Giens Workshops meeting focused on the methodology of scientific evaluation of medical devices and the associated procedures with a view to their pricing and financing by the French National Health Insurance system. The working hypothesis was that the available data-set was sufficient for and compatible with scientific evaluation with clinical benefit. Post-registration studies, although contributing to the continuity of assessment, were not dealt with. Moreover, the focus was restricted to devices used in health establishments, where the association between devices and technical medical procedures is optimally representative. An update of the multiple regulatory protocols governing medical devices and procedures is provided. Issues more specifically related to procedures as such, to non-implantable devices and to innovative devices are then dealt with, and the proposals and discussion points raised at the round-table for each of these three areas are presented.


Assuntos
Equipamentos e Provisões , Estudos de Avaliação como Assunto , Procedimentos Cirúrgicos Operatórios , Análise Custo-Benefício , Equipamentos e Provisões/economia , Equipamentos e Provisões/normas , França , Humanos , Invenções/economia , Invenções/normas , Legislação de Dispositivos Médicos/economia , Implantação de Prótese/instrumentação , Implantação de Prótese/legislação & jurisprudência , Implantação de Prótese/métodos , Implantação de Prótese/normas , Procedimentos Cirúrgicos Operatórios/economia , Procedimentos Cirúrgicos Operatórios/legislação & jurisprudência , Procedimentos Cirúrgicos Operatórios/métodos , Procedimentos Cirúrgicos Operatórios/normas
10.
Hum Immunol ; 71(1): 1-13, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19706316

RESUMO

Macrophages constitute major human immunodeficiency virus type 1 (HIV-1) reservoirs at the mucosal level, and their functional activity is modulated by cytokine environments that could play a role in HIV-1 mucosal spread. As proof of concept, we herein evaluated the modulation of HIV/macrophages interactions associated with two ubiquitous T(h)2 cytokines, namely, interleukin (IL)-4 and IL-13, using the in vitro model of R5-HIV-1 transfer from macrophages to T lymphocytes. Monocyte-derived macrophages differentiated in the presence of IL-4 (M-4) transferred the virus to T cells more efficiently than those differentiated in the presence of interleukin-13 (M-13), likely because to their high capacity to capture and produce HIV-1 and to recruit HIV-1 target T cell. However, M-13 harbored high levels of HIV DNA, similarly to M-4, and secreted HIV-activating factors. Notably, uninfected macrophages recruited HIV-1 target T cells (CCR4(+)IL-13(+) T(h)2 cells and CD4(+)CCR5(+) T cells), indicating their role in facilitating the HIV-1 spread by a passive manner. Strikingly, R5-HIV-1 reprogrammed macrophages toward a T(h)1 secretion pattern. Thus, T(h)2 microenvironment facilitates the emergence of HIV-1 macrophage reservoir and HIV-1 spread. In conclusion, secreted cytokines within mucosae may differentially influence both the HIV-1 production within the mucosal target cells reservoir and its spread thorough the mucosal tissue.


Assuntos
HIV-1/imunologia , Interleucina-13/imunologia , Interleucina-4/imunologia , Macrófagos/virologia , Receptores CCR5/imunologia , Linfócitos T/virologia , Diferenciação Celular , Células Cultivadas , Humanos , Macrófagos/citologia , Macrófagos/imunologia , Linfócitos T/imunologia
11.
Int J Technol Assess Health Care ; 25 Suppl 2: 68-74, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20030893

RESUMO

BACKGROUND: Several countries have developed policy frameworks allowing timely access to promising health technologies on the condition that additional evidence is generated. However, an important barrier to evidence generation is the lack of structured collaboration among health technology assessment (HTA) agencies. OBJECTIVES: One of the aims of Work Package 7 (WP7) of the European network for Health Technology Assessment (EUnetHTA) Project was to determine the types of structured collaboration that could facilitate evidence generation and to develop a Web-based toolkit to support such collaboration. METHODS: Collaboration modalities were defined by all WP7 Partners. Initial emphasis was on information sharing. Standardized forms for information sharing were developed and tested. An information technology development phase followed with the creation of the Web-based toolkit (Web site). RESULTS: Three levels of collaboration were agreed on: (i) sharing information, (ii) coordinated action, and (iii) joint action. The Web site allows access to structured and standardized forms for requesting information, posting information in response to a request, and posting information spontaneously. An online database contains all of the information requested or posted. Pilot tests on twenty-one promising technologies were satisfactory. CONCLUSIONS: This new Web site for sharing information on evidence generation should help countries reach robust decisions on the timely adoption of promising health technologies. It will only become fully operational if EUnetHTA Partners supply relevant, accurate, and updated information, and regularly use the Web site.


Assuntos
Tecnologia Biomédica , Medicina Baseada em Evidências/organização & administração , Cooperação Internacional , Internet , Europa (Continente) , Disseminação de Informação
12.
Int J Technol Assess Health Care ; 25 Suppl 2: 56-67, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20030892

RESUMO

BACKGROUND: Generation of additional evidence may be necessary to access new promising technologies (marketing approval or coverage). Access with evidence generation (AEG) is a more recent concept with regard to coverage than to marketing approval. OBJECTIVES: One aim of Work Package 7 (WP7) Strand A of the European network for Health Technology Assessment (EUnetHTA) was to provide an overview of national AEG mechanisms associated with marketing approvals and funding or coverage decisions. METHODS: A systematic literature review, surveys of WP7 Partners, and consultation of key people were used to obtain information on the AEG mechanisms used by twenty-three countries (twenty European countries, United States, Canada [Ontario], and Australia). RESULTS: Interest in the implementation of AEG policies, particularly at the coverage decision stage, is growing. An overview of national experiences was used to draw up a generally applicable five-step policy framework for AEG mechanisms that comprised (i) a first assessment identifying knowledge gaps; (ii) a decision conditional to evidence generation; (iii) generation of the evidence requested; (iv) re-assessment integrating the new evidence; (v) a revised decision. The critical factors for success that were identified were coordination, methodological guidance, funding, and a regulatory framework. Countries were categorized on the basis of current implementation of the proposed policy framework. CONCLUSIONS: International collaboration is necessary to gather a critical mass of high-quality data quickly and to ensure timely access to new promising technologies. The overview produced by WP7A has led to development of tools to facilitate collaboration on evidence generation.


Assuntos
Tecnologia Biomédica , Tomada de Decisões , Medicina Baseada em Evidências/organização & administração , Formulação de Políticas , Austrália , Europa (Continente) , Ontário , Estados Unidos
13.
AIDS Res Hum Retroviruses ; 25(5): 497-509, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19397398

RESUMO

The in vitro model of HIV-1 transcytosis through a monolayer of HEC-1 cells is thought to mimic the mucosal crossing of the virus that may occur in vivo. We evaluated whether the stimulation of HEC-1 by HIV may modulate HIV infection of macrophages. Thus, the ability to capture, produce, and transfer R5 viruses to T cells, attract T cells, and finally produce cytokines/chemokines, was compared between untreated macrophages (M0) and macrophages differentiated in the presence of medium collected at the basolateral pole of HEC-1, which were unstimulated [M(BL)] or stimulated with either R5-HIV-1Ba-L [M(BL-R5)] or X4-HIV-1NDK [M(BL-X4)]. M(BL-X4)-secreted CCR5-interacting chemokines integrated and replicated HIV less efficiently than did M(BL) and M(BL-R5). M(BL-R5) and M(BL-X4) similarly transmitted HIV to activated T cells. Interestingly, mannose-binding receptors and heparan sulfate proteoglycans were variously involved in HIV adsorption, whereas DC-SIGN mostly mediated the HIV transfer. Conversely to M(BL) and M(BL-X4), M(BL-R5) did not secrete eotaxin, GRO, ITAC, lymphotactin, MIP-1, MIP-3, and RANTES, which was associated with a weak capacity to recruit CD4(+)CXCR4(+)CCR5(+) T cells. In particular, M(BL-R5) specifically released soluble factors enhancing HIV production by recruited T cells. These submucosal-conditioned macrophages differentially captured, produced, and transferred R5-HIV-1 to T cells, according to the tropism of the virus deposited at the apical pole of HEC-1. These observations challenge the question of the in vivo involvement of HIV-1 as a supraepithelial stimulus that likely modulates the susceptibility for HIV-1 of submucosal target cells in favor of its transmission.


Assuntos
Enterócitos/virologia , HIV-1/imunologia , Macrófagos/virologia , Linhagem Celular , Células Cultivadas , Citocinas/metabolismo , Humanos , Linfócitos T/virologia
14.
Anal Chem ; 80(12): 4741-51, 2008 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-18484740

RESUMO

The increase of proinflammatory cytokines in vaginal secretions may serve as a surrogate marker of unwanted inflammatory reaction to microbicide products topically applied for the prevention of sexually transmitted diseases, including HIV-1. Interleukin (IL)-1beta and IL-6 have been proposed as indicators of inflammation and increased risk of HIV-1 transmission; however, the lack of information regarding detection platforms optimal for vaginal fluids and interlaboratory variation limit their use for microbicide evaluation and other clinical applications. This study examines fluid matrix variants relevant to vaginal sampling techniques and proposes a model for interlaboratory comparisons across current cytokine detection technologies. IL-1beta and IL-6 standards were measured by 12 laboratories in four countries, using 14 immunoassays and four detection platforms based on absorbance, chemiluminescence, electrochemiluminescence, and fluorescence. International reference preparations of cytokines with defined biological activity were spiked into (1) a defined medium simulating the composition of human vaginal fluid at pH 4.5 and 7.2, (2) physiologic salt solutions (phosphate-buffered saline and saline) commonly used for vaginal lavage sampling in clinical studies of cytokines, and (3) human blood serum. Assays were assessed for reproducibility, linearity, accuracy, and significantly detectable fold difference in cytokine level. Factors with significant impact on cytokine recovery were determined by Kruskal-Wallis analysis of variance with Dunn's multiple comparison test and multiple regression models. All assays showed acceptable intra-assay reproducibility; however, most were associated with significant interlaboratory variation. The smallest reliably detectable cytokine differences ( P < 0.05) derived from pooled interlaboratory data varied from 1.5- to 26-fold depending on assay, cytokine, and matrix type. IL-6 but not IL-1beta determinations were lower in both saline and phosphate-buffered saline as compared to vaginal fluid matrix, with no significant effect of pH. The (electro)chemiluminescence-based assays were most discriminative and consistently detected <2-fold differences within each matrix type. The Luminex-based assays were less discriminative with lower reproducibility between laboratories. These results suggest the need for uniform vaginal sampling techniques and a better understanding of immunoassay platform differences and cross-validation before the biological significance of cytokine variations can be validated in clinical trials. This investigation provides the first standardized analytic approach for assessing differences in mucosal cytokine levels and may improve strategies for monitoring immune responses at the vaginal mucosal interface.


Assuntos
Líquidos Corporais/química , Imunoensaio/métodos , Interleucina-1beta/análise , Interleucina-1beta/sangue , Interleucina-6/análise , Interleucina-6/sangue , Vagina/metabolismo , Feminino , Humanos , Padrões de Referência , Reprodutibilidade dos Testes
15.
Clin Vaccine Immunol ; 15(5): 872-84, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18353923

RESUMO

Heterosexual contact is the primary mode of human immunodeficiency virus (HIV) type 1 (HIV-1) transmission worldwide. The chemokine receptor CCR5 is the major coreceptor that is associated with the mucosal transmission of R5-tropic HIV-1 during sexual intercourse. The CCR5 molecule is thus a target for antibody-based therapeutic strategies aimed at blocking HIV-1 entry into cells. We have previously demonstrated that polyreactive natural antibodies (NAbs) from therapeutic preparations of immunoglobulin G and from human breast milk contain NAbs directed against CCR5. Such antibodies inhibit the infection of human macrophages and T lymphocytes by R5-tropic isolates of HIV in vitro. In the present study, we demonstrate that human immunoglobulins from the cervicovaginal secretions of HIV-seronegative or HIV-seropositive women contain NAbs directed against the HIV-1 coreceptor CCR5. Natural affinity-purified anti-CCR5 antibodies bound to CCR5 expressed on macrophages and dendritic cells and further inhibited the infection of macrophages and dendritic cells with primary and laboratory-adapted R5-tropic HIV but not with X4-tropic HIV. Natural anti-CCR5 antibodies moderately inhibited R5-tropic HIV transfer from monocyte-derived dendritic cells to autologous T cells. Our results suggest that mucosal anti-CCR5 antibodies from healthy immunocompetent donors may hamper the penetration of HIV and may be suitable for use in the development of novel passive immunotherapy regimens in specific clinical settings of HIV infection.


Assuntos
Células Dendríticas/virologia , Anticorpos Anti-HIV/farmacologia , HIV-1/efeitos dos fármacos , Macrófagos/virologia , Receptores CCR5/imunologia , Sítios de Ligação de Anticorpos/imunologia , Antagonistas dos Receptores CCR5 , Colo do Útero , Células Dendríticas/imunologia , Feminino , Anticorpos Anti-HIV/isolamento & purificação , Anticorpos Anti-HIV/metabolismo , Humanos , Macrófagos/imunologia , Receptores CCR5/biossíntese , Receptores CCR5/metabolismo , Vagina
16.
J Leukoc Biol ; 81(3): 642-53, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16971466

RESUMO

The ability of macrophages to adapt to changing cytokine environments results in the dominance of a particular functional phenotype of macrophages, which would play a significant role in HIV pathogenesis. In comparison with untreated macrophages (M0), we examined the role of macrophages derived from IFN-gamma-activated monocytes (M1) in the HIV spread. We show that M0 and M1 bind with the same efficiency HIV-1 with a predominant role of C-type lectins in the R5-HIV attachment and of the heparan sulfate proteoglycans in the X4-HIV attachment. Despite similar levels of R5- and X4-HIV DNA, M1 replicates and weakly transmits the virus to activated T cells by releasing CXCR4- and CCR5-interacting chemokines. The blockade of dendritic cell-specific ICAM-3-grabbing nonintegrin expressed on M1 by mAb does not interfere with the viral transfer. Uninfected M1 recruits HIV-sensitive T cells efficiently and releases soluble factors, enhancing the viral production by these recruited cells. This study highlights the role of IFN-gamma to induce a population of macrophages that archive HIV-1 within a latent stage and cause the persistence of the virus by favoring the recruitment of T cells or enhancing the viral replication in infected CD4(+) T cells.


Assuntos
Infecções por HIV/imunologia , HIV-1/efeitos dos fármacos , Interferon gama/farmacologia , Monócitos/imunologia , Linfócitos T/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos , Células Cultivadas , Progressão da Doença , Infecções por HIV/virologia , HIV-1/imunologia , Humanos , Imunofenotipagem , Macrófagos/classificação , Macrófagos/imunologia , Macrófagos/virologia , Modelos Biológicos , Monócitos/efeitos dos fármacos , Monócitos/virologia , Linfócitos T/imunologia , Linfócitos T/virologia , Replicação Viral/imunologia
17.
J Immunol ; 177(8): 5540-9, 2006 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-17015741

RESUMO

Human lactoferrin (Lf) is an iron binding glycoprotein that is present in several mucosal secretions. Many biological functions have been ascribed to Lf. In the present study, we showed that Lf limited specifically adsorption of R5- and X4-HIV-1-free particles on endometrial epithelial HEC-1A cells, by inhibiting virus adsorption on heparan-sulfated proteoglycans. But, Lf did not interfere with both R5 and X4-HIV transcytosis. We showed also the efficacy of Lf in preventing R5 and X4-HIV capture by dendritic cells. Conversely, we demonstrated that Lf-reacting natural Abs (NAbs) present within i.v. Ig-enhanced HIV attachment on dendritic cells by forming HIV-Lf-NAbs. HIV particles were able to directly interact with Lf following its interaction with NAbs. We also found Lf-reacting natural Abs within cervicovaginal secretions, suggesting the existence of Lf-NAbs complexes in women genital tract in vivo. In conclusion, this study highlights Lf as a potent microbicides and reports new function for NAbs within the genital compartment that may compartment that may abolish the inhibitory activity of microbicide compounds. Thus, we proposed a model in which Lf would appear as a double-edged sword that could have beneficial or detrimental effects depending on both cellular and molecular environments. This study highlights the use of Lf derivates as microbicide candidates to limit such interferences.


Assuntos
Anticorpos/imunologia , Células Dendríticas/imunologia , Células Epiteliais/imunologia , HIV-1/efeitos dos fármacos , Lactoferrina/farmacologia , Adsorção/efeitos dos fármacos , Anti-Infecciosos/química , Líquidos Corporais/imunologia , Linhagem Celular , Feminino , HIV-1/imunologia , Humanos , Lactoferrina/imunologia , Receptores CCR5 , Receptores CXCR4 , Vagina/imunologia
18.
Proc Natl Acad Sci U S A ; 101(39): 14210-5, 2004 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-15381781

RESUMO

The differentiation and maturation of dendritic cells (DCs) is governed by various signals in the microenvironment. Monocytes and DCs circulate in peripheral blood, which contains high levels of natural antibodies (NAbs). NAbs are germ-line-encoded and occur in the absence of deliberate immunization or microbial aggression. To assess the importance of NAbs in the milieu on DC development, we examined the status of DCs in patients with X-linked agammaglobulinemia, a disease characterized by paucity of B cells and circulating antibodies. We demonstrate that the in vitro differentiation of DCs is severely impaired in these patients, at least in part because of low levels of circulating NAbs. We identified NAbs reactive with the CD40 molecule as an important component that participates in the development of DCs. CD40-reactive NAbs restored normal phenotypes of DCs in patients. The maturation process induced by CD40-reactive NAbs was accompanied by an increased IL-10 and decreased IL-12 production. The transcription factor analysis revealed distinct signaling pathways operated by CD40-reactive NAbs compared to those by CD40 ligand. These results suggest that B cells promote bystander DC development through NAbs and the interaction between NAbs and DCs may play a role in steady-state migration of DCs.


Assuntos
Anticorpos/imunologia , Diferenciação Celular/imunologia , Células Dendríticas/fisiologia , Adolescente , Adulto , Agamaglobulinemia/sangue , Antígenos CD40/imunologia , Antígenos CD40/metabolismo , Ligante de CD40/metabolismo , Criança , Pré-Escolar , Citocinas/biossíntese , Células Dendríticas/citologia , Células Dendríticas/imunologia , Citometria de Fluxo , Doenças Genéticas Ligadas ao Cromossomo X/sangue , Humanos , Fenótipo , Transdução de Sinais
19.
Blood ; 104(10): 3249-56, 2004 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-15271794

RESUMO

The present study demonstrates that CD4(+)CD25(+) T cells, expanded in peripheral blood of HIV-infected patients receiving highly active antiretroviral therapy (HAART), exhibit phenotypic, molecular, and functional characteristics of regulatory T cells. The majority of peripheral CD4(+)CD25(+) T cells from HIV-infected patients expressed a memory phenotype. They were found to constitutively express transcription factor forkhead box P3 (Foxp3) messengers. CD4(+)CD25(+) T cells weakly proliferated to immobilized anti-CD3 monoclonal antibody (mAb) and addition of soluble anti-CD28 mAb significantly increased proliferation. In contrast to CD4(+)CD25(-) T cells, CD4(+)CD25(+) T cells from HIV-infected patients did not proliferate in response to recall antigens and to p24 protein. The proliferative capacity of CD4 T cells to tuberculin, cytomegalovirus (CMV), and p24 significantly increased following depletion of CD4(+)CD25(+) T cells. Furthermore, addition of increasing numbers of CD4(+)CD25(+) T cells resulted in a dose-dependent inhibition of CD4(+)CD25(-) T-cell proliferation to tuberculin and p24. CD4(+)CD25(+) T cells responded specifically to p24 antigen stimulation by expressing transforming growth factor beta (TGF-beta) and interleukin 10 (IL-10), thus indicating the presence of p24-specific CD4(+) T cells among the CD4(+)CD25(+) T-cell subset. Suppressive activity was not dependent on the secretion of TGF-beta or IL-10. Taken together, our results suggest that persistence of HIV antigens might trigger the expansion of CD4(+)CD25(+) regulatory T cells, which might induce a tolerance to HIV in vivo.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/virologia , Infecções por HIV/imunologia , Receptores de Interleucina-2/metabolismo , Terapia Antirretroviral de Alta Atividade , Antígenos CD4/metabolismo , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/metabolismo , Divisão Celular/imunologia , Epitopos , Infecções por HIV/tratamento farmacológico , Humanos , Imunofenotipagem , Interleucina-10/metabolismo , Fator de Crescimento Transformador beta/metabolismo
20.
Int Immunol ; 16(7): 1037-52, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15184347

RESUMO

Dendritic cells (DCs) generated in the presence of IFN-alpha (IFN-DCs) exhibit high expression of major histocompatibility and co-stimulatory molecules and a potent ability to stimulate CD8(+) T-cell responses. Here, we found that IFN-DCs were more potent stimulators of bulk and purified CD8(+) T-cell proliferation, as compared with IL-4-DCs. In contrast, IFN-DCs were less efficient than IL-4-DCs in stimulating allogeneic CD4(+) T-cell proliferation, due to a weak induction of naive CD4(+)CD45RO(-) T-cell proliferation by these DCs. However, both DC populations induced similar levels of proliferation of memory CD4(+)CD45RO(+) T cells. IFN-DCs and IL-4-DCs exhibited a similar phenotype and production of IL-10 following maturation induced by CD40 ligation. In contrast, IFN-DCs produced higher levels of IL-10 during the first days of differentiation. In addition, neutralization of IL-10 during the differentiation of DCs increased the expression of DC-LAMP and MHC class II by IFN-DCs, and the ability of IFN-DCs to stimulate allogeneic CD4(+) T-cell proliferation at similar levels, than IL-4-DCs. Independently of IL-10 production, IFN-DCs were found to induce higher levels of CD4(+)T-cell apoptosis, this effect being more sticking on naive T cells. Finally, we demonstrated that IFN-DCs induced a differentiation bias of naive CD4(+) T cells towards Th1 and Tr1 cells, compared to IL-4-DCs. Taken together, these results indicate that, despite the induction of Tr1 cells and enhanced apoptosis of naive CD4(+) T cells, IFN-DCs are potent stimulators of CD8(+) and memory CD4(+) T cells, and induce a strong polarization of naive CD4(+) T cells towards Th1 cells, further supporting their use in immune-based therapy.


Assuntos
Apoptose/imunologia , Linfócitos T CD4-Positivos/imunologia , Divisão Celular/imunologia , Células Dendríticas/imunologia , Interferon-alfa/imunologia , Interleucina-10/imunologia , Linfócitos T CD4-Positivos/citologia , Antígenos CD40/imunologia , Linfócitos T CD8-Positivos/imunologia , Células Cultivadas , Humanos , Memória Imunológica/imunologia , Interleucina-4/imunologia , Antígenos Comuns de Leucócito/imunologia , Proteína Tirosina Fosfatase não Receptora Tipo 1 , Células Th1/imunologia
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