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1.
Mult Scler Relat Disord ; 57: 103332, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35158426

RESUMO

BACKGROUND: To date, no specific scales have been developed to explore the impact of neuromyelitis optica spectrum disorder (NMOSD)-related disability on quality of life (QoL). The Expanded Disability Status Scale (EDSS) and the EuroQol 5-dimensions (EQ-5D) have been used to assess disability and QoL, respectively, in patients with NMOSD. However, there is limited evidence surrounding their use in this condition. We compared EDSS and EQ-5D data across two clinical trials to quantify the relationship between disability and QoL in patients with NMOSD. METHODS: SAkuraSky (NCT02028884) and SAkuraStar (NCT02073279) were Phase 3, multicenter, randomized, international, double-blind, placebo-controlled, parallel-assignment studies of satralizumab, administered in combination with baseline immunosuppressants (SAkuraSky) or as monotherapy (SAkuraStar). EDSS and EQ-5D were assessed at baseline and at 24-week intervals thereafter. The relationship between disability and QoL was assessed by estimating EQ-5D utilities (UK tariff) for each incremental EDSS category. A repeated-measures linear model was used to regress health utilities on EDSS score-derived health states. RESULTS: Overall, 176 patients underwent at least one EDSS assessment and completed an EQ-5D survey and were included in this analysis. There was a clear association between mean EQ-5D score and EDSS score, with decreases in QoL being observed at each incremental increase in disability. The relationship between EDSS and EQ-5D score remained consistent across the different treatment groups. CONCLUSIONS: These results, generated from high-quality clinical trial data, demonstrated a strong and consistent relationship between disability and QoL in patients with NMOSD.


Assuntos
Pessoas com Deficiência , Neuromielite Óptica , Humanos , Imunossupressores , Neuromielite Óptica/tratamento farmacológico , Qualidade de Vida , Inquéritos e Questionários
2.
Brain Sci ; 11(9)2021 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-34573267

RESUMO

There is increasing interest in the development and deployment of digital solutions to improve patient care and facilitate monitoring in medical practice, e.g., by remote observation of disease symptoms in the patients' home environment. Digital health solutions today range from non-regulated wellness applications and research-grade exploratory instruments to regulated software as a medical device (SaMD). This paper discusses the considerations and complexities in developing innovative, effective, and validated SaMD for multiple sclerosis (MS). The development of SaMD requires a formalised approach (design control), inclusive of technical verification and analytical validation to ensure reliability. SaMD must be clinically evaluated, characterised for benefit and risk, and must conform to regulatory requirements associated with device classification. Cybersecurity and data privacy are also critical. Careful consideration of patient and provider needs throughout the design and testing process help developers overcome challenges of adoption in medical practice. Here, we explore the development pathway for SaMD in MS, leveraging experiences from the development of Floodlight™ MS, a continually evolving bundled solution of SaMD for remote functional assessment of MS. The development process will be charted while reflecting on common challenges in the digital space, with a view to providing insights for future developers.

3.
J Med Econ ; 24(1): 581-588, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33879033

RESUMO

BACKGROUND: This US claims-based study aimed to identify and characterize temporal trends in diagnostic pathways for patients likely to have neuromyelitis optica spectrum disorder (NMOSD). METHODS: Patients were identified from IBM MarketScan Commercial Databases if, within 1 year, they had two NMOSD claims separated by ≥ 60 days; two transverse myelitis (TM) or optic neuritis (ON) claims separated by ≥ 60 days, and one additional symptom (TM, ON, or area postrema syndrome); or one NMOSD claim and one additional symptom. The first NMOSD or TM/ON claim was the index date, and the second claim was the diagnosis date. Similar methodology was used in temporal trend and incidence and prevalence analyses. RESULTS: Among 1,901 patients with NMOSD, 34.2% were identified by two NMO claims, 53.2% by ON or TM +1 symptom, and 12.6% by one NMOSD claim +1 symptom. Anti-aquaporin-4 immunoglobin G (AQP4-IgG) autoantibody tests and magnetic resonance imaging was used for 23.0% and 71.9% of cases, respectively. Across cohorts, 21.4-49.1% had multiple sclerosis (MS) diagnosis claims prior to index date, and 37.3-60.6% had an MS diagnosis, 14.9-31.0% had MS disease-modifying therapy (DMT) claims and 6.3-44.8% had immunosuppressive therapy (IST) claims <1 year after diagnosis. Over time, there were slight changes in MS diagnosis claims, AQP4-IgG autoantibody testing, and DMT and IST use before and after NMOSD diagnosis. LIMITATIONS: This study is limited by the information available in US claims databases, which included the potential for misclassification of NMOSD based solely on claims codes and lack of reimbursement for AQP4-IgG testing by insurance companies. CONCLUSIONS: Among patients likely to have NMOSD, low AQP4-IgG testing rates, IST use, frequent MS diagnosis claims, and DMT use highlight the need for a diagnostic algorithm and timely treatment of NMOSD.


Assuntos
Seguro , Esclerose Múltipla , Neuromielite Óptica , Aquaporina 4 , Autoanticorpos , Humanos , Neuromielite Óptica/tratamento farmacológico , Neuromielite Óptica/epidemiologia
4.
J Inorg Biochem ; 155: 92-100, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26684582

RESUMO

Five new mononuclear Pt(II) complexes with 5-perfluoroalkyl-1,2,4-oxadiazolyl-pyridine and 3-perfluoroalkyl-1,2,4-triazolyl-pyridine ligands are reported. The ligands 2-(5-perfluoroheptyl-1,2,4-oxadiazole-3yl)-pyridine (pfhop), 2-(5-perfluoropropyl)-1,2,4-oxadiazole-3yl)-pyridine (pfpop), 2-(3-perfluoroheptyl-1-methyl-1,2,4-triazole-5yl)-pyridine (pfhtp), 2-(3-perfluoropropyl-1-methyl-1,2,4-triazole-5yl)-pyridine (pfptp) and their complexes [PtCl2(pfhop)2]·1.5 DMSO (2a), [PtCl2(pfpop)2]·1.5 DMSO (3a), [PtCl2(pfhtp)2]·1.5 DMSO (4a), PtCl2(pfhtp) (4b), [PtCl2(pfptp)2]·1.5 DMSO (5a) have been synthesized and structurally characterized. The complexes 2a, 3a, 4a and 5a have the same chemical environment of Pt(II) where PtCl2 moieties coordinate two molecules of ligand via N1 atom of pyridine in the case of pfhop and pfpop, and N2 atom of 1,2,4-triazole in the case of pfhtp and pfptp. For 4b, pfhtp behaves as bidentate ligand, coordinating Pt(II) ion via N4 atom of triazole and N1 atom of pyridine. All complexes have been tested in vitro by 3-(4,5-dimethyl-2-thiazolyl)bromide-2,5-diphenyl-2H-tetrazolium (MTT) test on four tumor cell lines MCF-7 (human breast cancer), HepG2 (human hepatocellular carcinoma), HCT116 (human colorectal carcinoma). Compounds 2a and 4b showed a dose-dependent anti-proliferative effect against the three tumor cell lines whereas did not affect viability of intestinal normal-like differentiated Caco-2 cells. The cell death of HepG2, MCF-7 and HCT116 induced by the compounds, was considered to be apoptotic by measuring the exposure of phosphatidylserine to the outer membrane and observing the typical apoptotic morphological change by acridine orange (AO)/ethidium bromide (EB) staining.


Assuntos
Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Compostos de Platina/síntese química , Piridinas/química , Laranja de Acridina/química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Etídio/química , Corantes Fluorescentes/química , Humanos , Ligantes , Compostos de Platina/química , Compostos de Platina/farmacologia , Espectroscopia de Prótons por Ressonância Magnética , Espectrofotometria Infravermelho
5.
Expert Rev Mol Med ; 14: e9, 2012 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-22490239

RESUMO

Opiates such as morphine and fentanyl, a major class of analgesics used in the clinical management of pain, exert their effects through the activation of opioid receptors. Opioids are among the most commonly prescribed and frequently abused drugs in the USA; however, the prolonged use of opiates often leads to the development of tolerance and addiction. Although blockade of opioid receptors with antagonists such as naltrexone and naloxone can lessen addictive impulses and facilitate recovery from overdose, systemic disruption of endogenous opioid receptor signalling through the use of these antagonistic drugs can have severe side effects. In the light of these challenges, current efforts have focused on identifying new therapeutic targets that selectively and specifically modulate opioid receptor signalling and function so as to achieve analgesia without the adverse effects associated with chronic opiate use. We have previously reported that opioid receptors interact with each other to form heteromeric complexes and that these interactions affect morphine signalling. Since chronic morphine administration leads to an enhanced level of these heteromers, these opioid receptor heteromeric complexes represent novel therapeutic targets for the treatment of pain and opiate addiction. In this review, we discuss the role of heteromeric opioid receptor complexes with a focus on mu opioid receptor (MOR) and delta opioid receptor (DOR) heteromers. We also highlight the evidence for altered pharmacological properties of opioid ligands and changes in ligand function resulting from the heteromer formation.


Assuntos
Analgésicos , Dependência de Morfina , Naloxona/uso terapêutico , Naltrexona/uso terapêutico , Antagonistas de Entorpecentes/uso terapêutico , Multimerização Proteica/efeitos dos fármacos , Receptores Opioides delta , Receptores Opioides mu , Analgesia , Animais , Antagonismo de Drogas , Overdose de Drogas , Humanos , Dependência de Morfina/tratamento farmacológico , Dependência de Morfina/metabolismo , Naloxona/antagonistas & inibidores , Naltrexona/antagonistas & inibidores , Dor/tratamento farmacológico , Dor/metabolismo , Estrutura Quaternária de Proteína , Receptores Opioides delta/agonistas , Receptores Opioides delta/antagonistas & inibidores , Receptores Opioides delta/metabolismo , Receptores Opioides mu/agonistas , Receptores Opioides mu/antagonistas & inibidores , Receptores Opioides mu/metabolismo , Transdução de Sinais/efeitos dos fármacos , Estados Unidos
6.
PLoS One ; 7(3): e33961, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22448282

RESUMO

Agents that activate cannabinoid receptor pathways have been tested as treatments for cachexia, nausea or neuropathic pain in HIV-1/AIDS patients. The cannabinoid receptors (CB(1)R and CB(2)R) and the HIV-1 co-receptors, CCR5 and CXCR4, all signal via Gαi-coupled pathways. We hypothesized that drugs targeting cannabinoid receptors modulate chemokine co-receptor function and regulate HIV-1 infectivity. We found that agonism of CB(2)R, but not CB(1)R, reduced infection in primary CD4+ T cells following cell-free and cell-to-cell transmission of CXCR4-tropic virus. As this change in viral permissiveness was most pronounced in unstimulated T cells, we investigated the effect of CB(2)R agonism on to CXCR4-induced signaling following binding of chemokine or virus to the co-receptor. We found that CB(2)R agonism decreased CXCR4-activation mediated G-protein activity and MAPK phosphorylation. Furthermore, CB(2)R agonism altered the cytoskeletal architecture of resting CD4+ T cells by decreasing F-actin levels. Our findings suggest that CB(2)R activation in CD4+ T cells can inhibit actin reorganization and impair productive infection following cell-free or cell-associated viral acquisition of CXCR4-tropic HIV-1 in resting cells. Therefore, the clinical use of CB(2)R agonists in the treatment of AIDS symptoms may also exert beneficial adjunctive antiviral effects against CXCR4-tropic viruses in late stages of HIV-1 infection.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Canabinoides/farmacologia , Infecções por HIV/prevenção & controle , Infecções por HIV/virologia , Receptor CB2 de Canabinoide/agonistas , Receptores CXCR4/metabolismo , Linfócitos T CD4-Positivos/virologia , Células Cultivadas , Quimiocinas/metabolismo , Infecções por HIV/imunologia , HIV-1/patogenicidade , Humanos , Fusão de Membrana , Receptor CB1 de Canabinoide/agonistas , Replicação Viral
7.
PLoS One ; 7(1): e29805, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22299025

RESUMO

Human CD4(+) T cells process and present functional class II MHC-peptide complexes, but the endogenous peptide repertoire of these non-classical antigen presenting cells remains unknown. We eluted and sequenced HLA-DR-bound self-peptides presented by CD4(+) T cells in order to compare the T cell-derived peptide repertoire to sequences derived from genetically identical B cells. We identified several novel epitopes derived from the T cell-specific proteome, including fragments of CD4 and IL-2. While these data confirm that T cells can present peptides derived from the T-cell specific proteome, the vast majority of peptides sequenced after elution from MHC were derived from the common proteome. From this pool, we identified several identical peptide epitopes in the T and B cell repertoire derived from common endogenous proteins as well as novel endogenous epitopes with promiscuous binding. These findings indicate that the endogenous HLA-DR-bound peptide repertoire, regardless of APC type and across MHC isotype, is largely derived from the same pool of self-protein.


Assuntos
Apresentação de Antígeno/fisiologia , Autoantígenos/imunologia , Linfócitos B/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Linfócitos T/imunologia , Apresentação de Antígeno/genética , Apresentação de Antígeno/imunologia , Complexo Antígeno-Anticorpo/química , Complexo Antígeno-Anticorpo/isolamento & purificação , Linfócitos B/metabolismo , Doadores de Sangue , Linfócitos T CD4-Positivos/metabolismo , Estudos de Casos e Controles , Linhagem Celular Transformada , Antígenos HLA-DR/genética , Antígenos HLA-DR/imunologia , Antígenos HLA-DR/metabolismo , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe II/metabolismo , Humanos , Modelos Biológicos , Peptídeos/química , Peptídeos/isolamento & purificação , Proteoma/análise , Proteoma/imunologia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Linfócitos T/metabolismo , Espectrometria de Massas em Tandem
8.
J Immunol ; 186(6): 3317-26, 2011 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-21300823

RESUMO

Studying the activity of homogeneous regulatory T cell (Treg) populations will advance our understanding of their mechanisms of action and their role in human disease. Although isolating human Tregs exhibiting low expression of CD127 markedly increases purity, the resulting Treg populations are still heterogeneous. To examine the complexity of the Tregs defined by the CD127 phenotype in comparison with the previously described CD4(+)CD25(hi) subpopulations, we subdivided the CD25(hi) population of memory Tregs into subsets based on expression of CD127 and HLA-DR. These subsets exhibited differences in suppressive capacity, ability to secrete IL-10 and IL-17, Foxp3 gene methylation, cellular senescence, and frequency in neonatal and adult blood. The mature, short telomere, effector CD127(lo)HLA-DR(+) cells most strongly suppressed effector T cells within 48 h, whereas the less mature CD127(lo)HLA-DR(-) cells required 96 h to reach full suppressive capacity. In contrast, whereas the CD127(+)HLA-DR(-) cells also suppressed proliferation of effector cells, they could alternate between suppression or secretion of IL-17 depending upon the stimulation signals. When isolated from patients with multiple sclerosis, both the nonmature and the effector subsets of memory CD127(lo) Tregs exhibited kinetically distinct defects in suppression that were evident with CD2 costimulation. These data demonstrate that natural and not induced Tregs are less suppressive in patients with multiple sclerosis.


Assuntos
Antígenos CD2/fisiologia , Antígenos CD4/biossíntese , Subunidade alfa de Receptor de Interleucina-2/biossíntese , Esclerose Múltipla/imunologia , Esclerose Múltipla/patologia , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/patologia , Adulto , Diferenciação Celular/imunologia , Células Cultivadas , Técnicas de Cocultura , Sangue Fetal/citologia , Sangue Fetal/imunologia , Sangue Fetal/metabolismo , Fatores de Transcrição Forkhead/biossíntese , Fatores de Transcrição Forkhead/farmacocinética , Humanos , Recém-Nascido , Subunidade alfa de Receptor de Interleucina-7/genética , Subunidade alfa de Receptor de Interleucina-7/metabolismo , Ativação Linfocitária/genética , Ativação Linfocitária/imunologia , Pessoa de Meia-Idade , Esclerose Múltipla/metabolismo , Transdução de Sinais/imunologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Subpopulações de Linfócitos T/patologia , Linfócitos T Reguladores/metabolismo , Adulto Jovem
9.
Nat Rev Immunol ; 10(7): 490-500, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20559327

RESUMO

Forkhead box P3 (FOXP3)(+) regulatory T (T(Reg)) cells are potent mediators of dominant self tolerance in the periphery. But confusion as to the identity, stability and suppressive function of human T(Reg) cells has, to date, impeded the general therapeutic use of these cells. Recent studies have suggested that human T(Reg) cells are functionally and phenotypically diverse. Here we discuss recent findings regarding human T(Reg) cells, including the ontogeny and development of T(Reg) cell subsets that have naive or memory phenotypes, the unique mechanisms of suppression mediated by T(Reg) cell subsets and factors that regulate T(Reg) cell lineage commitment. We discuss future studies that are needed for the successful therapeutic use of human T(Reg) cells.


Assuntos
Fatores de Transcrição Forkhead/imunologia , Linfócitos T Reguladores/imunologia , Animais , Diferenciação Celular , Fatores de Transcrição Forkhead/metabolismo , Humanos , Memória Imunológica , Imunoterapia , Antígenos Comuns de Leucócito/metabolismo , Camundongos , Modelos Imunológicos , Fenótipo , Tolerância a Antígenos Próprios , Subpopulações de Linfócitos T/citologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Linfócitos T Reguladores/citologia , Linfócitos T Reguladores/metabolismo
10.
J Immunol ; 185(1): 46-54, 2010 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-20498357

RESUMO

The secretion of IL-9, initially recognized as a Th2 cytokine, was recently attributed to a novel CD4 T cell subset termed Th9 in the murine system. However, IL-9 can also be secreted by mouse Th17 cells and may mediate aspects of the proinflammatory activities of Th17 cells. Here we report that IL-9 is secreted by human naive CD4 T cells in response to differentiation by Th9 (TGF-beta and IL-4) or Th17 polarizing conditions. Yet, these differentiated naive cells did not coexpress IL-17 and IL-9, unless they were repeatedly stimulated under Th17 differentiation-inducing conditions. In contrast to the naive cells, memory CD4 T cells were induced to secrete IL-9 by simply providing TGF-beta during stimulation, as neither IL-4 nor proinflammatory cytokines were required. Furthermore, the addition of TGF-beta to the Th17-inducing cytokines (IL-1beta, IL-6, IL-21, IL-23) that induce memory cells to secrete IL-17, resulted in the marked coexpression of IL-9 in IL-17 producing memory cells. The proinflammatory cytokine mediating TGF-beta-dependent coexpression of IL-9 and IL-17 was identified to be IL-1beta. Moreover, circulating monocytes were potent costimulators of IL-9 production by Th17 cells via their capacity to secrete IL-1beta. Finally, to determine whether IL-9/IL-17 coproducing CD4 cells were altered in an inflammatory condition, we examined patients with autoimmune diabetes and demonstrated that these subjects exhibit a higher frequency of memory CD4 cells with the capacity to transition into IL-9(+)IL-17(+) cells. These data demonstrate the presence of IL-17(+)IL-9(+) CD4 cells induced by IL-1beta that may play a role in human autoimmune disease.


Assuntos
Interleucina-17/biossíntese , Interleucina-9/biossíntese , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Auxiliares-Indutores/metabolismo , Fator de Crescimento Transformador beta1/fisiologia , Adulto , Polaridade Celular/imunologia , Células Cultivadas , Técnicas de Cocultura , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/patologia , Regulação da Expressão Gênica/imunologia , Humanos , Imuno-Histoquímica , Mediadores da Inflamação/metabolismo , Mediadores da Inflamação/fisiologia , Interleucina-9/genética , Interleucina-9/metabolismo , Pessoa de Meia-Idade , Fase de Repouso do Ciclo Celular/imunologia , Adulto Jovem
11.
J Immunol ; 183(2): 945-52, 2009 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-19553543

RESUMO

Although it has long been known that human CD4(+) T cells can express functional class II MHC molecules, the role of lysosomal proteases in the T cell class II MHC processing and presentation pathway is unknown. Using CD4(+) T cell clones that constitutively express class II MHC, we determined that cathepsin S is necessary for invariant chain proteolysis in T cells. CD4(+)HLA-DR(+) T cells down-regulated cathepsin S expression and activity 18 h after activation, thereby ceasing nascent class II MHC product formation. This blockade resulted in the loss of the invariant chain fragment CLIP from the cell surface, suggesting that-like professional APC-CD4(+) HLA-DR(+) cells modulate self-Ag presentation as a consequence of activation. Furthermore, cathepsin S expression and activity, and concordantly cell surface CLIP expression, was reduced in HLA-DR(+) CD4(+) T cells as compared with B cells both in vitro and ex vivo.


Assuntos
Apresentação de Antígeno , Antígenos de Diferenciação de Linfócitos B/metabolismo , Linfócitos T CD4-Positivos/imunologia , Catepsinas/fisiologia , Antígenos HLA-DR/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Autoantígenos , Linfócitos B , Catepsinas/análise , Catepsinas/genética , Células Clonais , Regulação para Baixo , Antígenos de Histocompatibilidade Classe II/metabolismo , Humanos , Ativação Linfocitária/imunologia , Lisossomos/enzimologia , Peptídeo Hidrolases/metabolismo
12.
Blood ; 113(18): 4240-9, 2009 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-19171879

RESUMO

Although implicated in antagonistic functions, both regulatory T cells (Tregs) and Th17 effector cells play an important role in controlling autoimmune pathogenesis. Paradoxically, recent studies indicate that Tregs have the capacity to produce interleukin-17 (IL-17), although the ability of these cells to retain their suppressive function remains unknown. Here we report that human Tregs within the CD4(+)CD45RA(-)CD25(high)CCR6(+)HLA-DR(-)FoxP3(+) population produce IL-17 when activated in the presence of the proinflammatory cytokines IL-1beta and IL-6, whereas IL-17 secretion was inhibited by TGFbeta. To assess the ability of a single Treg to secrete IL-17 and to suppress in vitro immune function, we isolated clones from this population. We found that IL-17(+)/FoxP3(+) Treg clones retain suppressive function and exhibit the plasticity to secrete IL-17 or suppress depending on the nature of the stimulus provided. IL-17 production by these Treg clones was accompanied by sustained FoxP3 expression and concomitant, but reversible, loss of suppressive activity. Our data demonstrate that at the single cell level a subset of in vitro suppressive FoxP3(+) cells can be driven to secrete IL-17 under inflammatory conditions. These findings suggest a new mechanism by which inflammation can drive Tregs to secrete IL-17, thereby dampening suppression and promoting an inflammatory milieu.


Assuntos
Tolerância Imunológica/fisiologia , Interleucina-17/biossíntese , Linfócitos T Reguladores/imunologia , Antígenos CD/metabolismo , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Fatores de Transcrição Forkhead/metabolismo , Antígenos HLA-DR/metabolismo , Humanos , Interleucina-17/antagonistas & inibidores , Interleucina-1beta/farmacologia , Interleucina-6/farmacologia , Ativação Linfocitária/efeitos dos fármacos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Linfócitos T/citologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Fator de Crescimento Transformador beta/farmacologia
13.
J Clin Immunol ; 28(6): 697-706, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18763026

RESUMO

INTRODUCTION: Multiple sclerosis (MS) is a complex genetic disease characterized by chronic inflammation of the central nervous system (CNS). The pathology of MS is largely attributed to autoreactive effector T cells that penetrate the blood-brain barrier and become activated within the CNS. As autoreactive T cells are present in the blood of both patients with MS and healthy individuals, other regulatory mechanisms exist to prevent autoreactive T cells from causing immune disorders. Active suppression by regulatory T (Treg) cells plays a key role in the control of self-antigen-reactive T cells and the induction of peripheral tolerance in vivo. In particular, the importance of antigen-specific Treg cells in conferring genetic resistance to organ-specific autoimmunity and in limiting autoimmune tissue damage has been documented in many disease models including MS. RESULTS: We have found that the frequency of Tregs in MS patients is unchanged from controls, but their function measured in vitro may be diminished, correlating with impaired inhibitory activity in vivo. This review discusses the immunopathology of MS with particular focus given to regulatory T cells and their potential for the development of new therapies to treat this disease.


Assuntos
Sistema Nervoso Central/imunologia , Esclerose Múltipla/imunologia , Linfócitos T Citotóxicos/imunologia , Linfócitos T Reguladores/imunologia , Animais , Autoimunidade , Sistema Nervoso Central/metabolismo , Sistema Nervoso Central/patologia , Receptor Celular 2 do Vírus da Hepatite A , Humanos , Imunoterapia , Proteínas de Membrana/imunologia , Proteínas de Membrana/metabolismo , Esclerose Múltipla/patologia , Esclerose Múltipla/terapia , Linfócitos T Citotóxicos/metabolismo , Linfócitos T Reguladores/metabolismo , Receptores Toll-Like/imunologia , Receptores Toll-Like/metabolismo
14.
Eur J Immunol ; 38(4): 921-4, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18395861

RESUMO

CD4+CD25+ regulatory T cells (Treg) appear to be critical in regulating immune responses to self-antigens. Treg deficiency is associated with several human autoimmune diseases. Although substantial progress has been made in the study of murine and human Treg, their fundamental mechanism of action remains unknown. In this review, we discuss the phenotype of human natural Treg, their functional mechanism, and their role in autoimmune disease.


Assuntos
Autoimunidade/imunologia , Linfócitos T Reguladores/imunologia , Animais , Doenças Autoimunes/imunologia , Membrana Celular/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Humanos , Transdução de Sinais/imunologia
15.
J Immunol ; 180(5): 2876-85, 2008 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-18292509

RESUMO

Presentation of Ag by class II MHC is regulated by lysosomal proteases that not only destroy the class II invariant chain (Ii) chaperone but also generate the peptide Ag that is loaded onto the class II MHC dimer. We sought to determine the extent to which asparagine endopeptidase (AEP) influences human Ag and Ii processing. Our data confirm the constructive function of AEP in tetanus toxoid processing, but they are discordant with findings that suggest a destructive role for AEP in processing of the immunodominant myelin basic protein epitope. Furthermore, we observed no effect on invariant chain processing following AEP inhibition for several distinct allelic variants of human class II MHC products. We find that cysteine and aspartic proteases, as well as AEP, can act redundantly to initiate Ii processing. We detected considerable variation in lysosomal activity between different EBV-transformed B cell lines, but these differences do not result in altered regulation of invariant chain catabolism. We propose that, as for bound peptide Ag, the identity of the lysosomal enzyme that initiates invariant chain cleavage is dependent on the class II MHC allelic variants expressed.


Assuntos
Antígenos de Diferenciação de Linfócitos B/metabolismo , Ácido Aspártico Endopeptidases/biossíntese , Ácido Aspártico Endopeptidases/genética , Cisteína Endopeptidases/biossíntese , Cisteína Endopeptidases/genética , Regulação Enzimológica da Expressão Gênica/imunologia , Antígenos de Histocompatibilidade Classe II/metabolismo , Lisossomos/enzimologia , Sequência de Aminoácidos , Apresentação de Antígeno/genética , Apresentação de Antígeno/imunologia , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Ácido Aspártico Endopeptidases/fisiologia , Linfócitos B/enzimologia , Linfócitos B/imunologia , Linfócitos B/metabolismo , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Linhagem Celular Transformada , Células Clonais , Técnicas de Cocultura , Cisteína Endopeptidases/fisiologia , Heterogeneidade Genética , Antígenos HLA-D/genética , Antígenos HLA-D/metabolismo , Humanos , Dados de Sequência Molecular , Inibidores de Proteases/metabolismo , Processamento de Proteína Pós-Traducional/genética
16.
J Virol ; 77(18): 10113-8, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12941922

RESUMO

In an effort to develop an AIDS vaccine that elicits high-frequency cytotoxic-T-lymphocyte (CTL) responses with specificity for a diversity of viral epitopes, we explored two prototype multiepitope plasmid DNA vaccines in the simian-human immunodeficiency virus/rhesus monkey model to determine their efficiency in priming for such immune responses. While a simple multiepitope vaccine construct demonstrated limited immunogenicity in monkeys, this same multiepitope genetic sequence inserted into an immunogenic simian immunodeficiency virus gag DNA vaccine elicited high-frequency CTL responses specific for all of the epitopes included in the vaccine. Both multiepitope vaccine prototypes primed for robust epitope-specific CTL responses that developed following boosting with recombinant modified vaccinia virus Ankara vaccines expressing complete viral proteins. The natural hierarchy of immunodominance for these epitopes was clearly evident in the boosted monkeys. These studies suggest that multiepitope plasmid DNA vaccine-based prime-boost regimens can efficiently prime for CTL responses of increased breadth and magnitude, although they do not overcome predicted hierarchies of immunodominance.


Assuntos
Vacinas contra a SAIDS/imunologia , Linfócitos T Citotóxicos/imunologia , Vacinas de DNA/imunologia , Vacinas contra a AIDS/imunologia , Sequência de Aminoácidos , Animais , Epitopos , Macaca mulatta , Dados de Sequência Molecular , Plasmídeos , Vacinação , Vaccinia virus/genética , Vaccinia virus/imunologia
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