RESUMO
BACKGROUND AND PURPOSE: Multiple sclerosis (MS) is a complex disease of the central nervous system. As new drugs are becoming available, knowledge on diagnosis and treatment must continuously evolve. There is therefore a need for a reference tool compiling current data on benefit and safety, to aid professionals in treatment decisions and use of resources across Europe. The European Committee of Treatment and Research in Multiple Sclerosis (ECTRIMS) and the European Academy of Neurology (EAN) have joined forces to meet this need. The objective was to develop an evidence-based clinical practice guideline for the pharmacological treatment of people with MS to guide healthcare professionals in the decision-making process. METHODS: This guideline has been developed using the GRADE methodology and following the recently updated EAN recommendations for guideline development. Clinical questions were formulated in PICO format (patient, intervention, comparator, outcome) and outcomes were prioritized according to their relevance to clinical practice. An exhaustive literature search up to December 2016 was performed for each question and the evidence is presented narratively and, when possible, combined in a meta-analysis using a random-effects model. The quality of evidence for each outcome was rated into four categories - very high, high, low and very low - according to the risk of bias. GRADE evidence profiles were created using GRADEprofiler (GRADEpro) software (Version 3.6). The recommendations with assigned strength (strong, weak) were formulated based on the quality of evidence and the risk-benefit balance. Consensus between the panellists was reached by use of the modified nominal group technique. RESULTS: A total of 10 questions have been agreed, encompassing treatment efficacy, response criteria, strategies to address suboptimal response and safety concerns and treatment strategies in MS and pregnancy. The guideline takes into account all disease-modifying drugs approved by the European Medicine Agency at the time of publication. A total of 20 recommendations were agreed by the guideline working group members after three rounds of consensus.
Assuntos
Esclerose Múltipla/tratamento farmacológico , Neurologia/normas , Guias de Prática Clínica como Assunto/normas , Sociedades Médicas/normas , Europa (Continente) , HumanosRESUMO
BACKGROUND AND PURPOSE: In the SELECT study, treatment with daclizumab high-yield process (DAC HYP) versus placebo reduced the frequency of gadolinium-enhancing (Gd(+) ) lesions in patients with relapsing-remitting multiple sclerosis (RRMS). The objective of this post hoc analysis of SELECT was to evaluate the effect of DAC HYP on the evolution of new Gd(+) lesions to T1 hypointense lesions (T1 black holes). METHODS: SELECT was a randomized double-blind study of subcutaneous DAC HYP 150 or 300 mg or placebo every 4 weeks. Magnetic resonance imaging (MRI) scans were performed at baseline and weeks 24, 36 and 52 in all patients and monthly between weeks 4 and 20 in a subset of patients. MRI scans were evaluated for new Gd(+) lesions that evolved to T1 black holes at week 52. Data for the DAC HYP groups were pooled for analysis. RESULTS: Daclizumab high-yield process reduced the number of new Gd(+) lesions present at week 24 (P = 0.005) or between weeks 4 and 20 (P = 0.014) that evolved into T1 black holes at week 52 versus placebo. DAC HYP treatment also reduced the percentage of patients with Gd(+) lesions evolving to T1 black holes versus placebo. CONCLUSIONS: Treatment with DAC HYP reduced the evolution of Gd(+) lesions to T1 black holes versus placebo, suggesting that inflammatory lesions that evolved during DAC HYP treatment are less destructive than those evolving during placebo treatment.
Assuntos
Anticorpos Monoclonais Humanizados/farmacologia , Gadolínio/farmacologia , Imageamento por Ressonância Magnética/métodos , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Esclerose Múltipla Recidivante-Remitente/patologia , Avaliação de Resultados em Cuidados de Saúde , Adulto , Daclizumabe , Método Duplo-Cego , Feminino , Gadolínio/administração & dosagem , Humanos , Aumento da Imagem , Masculino , Pessoa de Meia-IdadeRESUMO
BACKGROUND: Laquinimod, an oral novel immunomodulator, was shown to reduce MRI-measured disease activity in relapsing-remitting MS (RRMS) patients. OBJECTIVES: To determine whether the safety and efficacy profile of laquinimod, as shown in a placebo-controlled 36-week trial (LAQ/5062), is sustained and reproducible. METHODS: Two hundred and fifty seven patients entered the extension phase in which MRI was performed at the beginning and at the end of the active extension phase. Clinical assessments were performed at weeks 4, 12 and every 12 weeks thereafter. RESULTS: Two hundred and thirty nine (93%) patients completed the extension phase and 222 (86.3%) had a final scan available. Gadolinium-enhanced (GdE) T1 lesions were significantly reduced for patients switching from placebo to 0.3/ 0.6 mg doses (52%, p = 0.0006). In patients initially randomized to 0.6 mg in LAQ/5062 the reduction of MRI activity observed in the placebo-controlled phase was maintained in the extension. The proportion of GdE-free patients for those who switched from placebo increased from a baseline of 31% to 47% at the end of the extension phase (p = 0.01). The most prominent safety signal was elevations of liver enzymes, reversible in all cases. CONCLUSIONS: The good efficacy and the excellent safety and tolerability profiles of laquinimod 0.6 mg/day are confirmed in this extension study.
Assuntos
Fatores Imunológicos/administração & dosagem , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Quinolonas/administração & dosagem , Administração Oral , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Avaliação da Deficiência , Método Duplo-Cego , Humanos , Fatores Imunológicos/efeitos adversos , Imageamento por Ressonância Magnética , Esclerose Múltipla Recidivante-Remitente/patologia , Quinolonas/efeitos adversosRESUMO
Plasmacytoid dendritic cells (pDCs) are of crucial importance in immune regulation and response to microbial factors. In multiple sclerosis (MS), pDCs from peripheral blood showed an immature phenotype, but its role in susceptibility to MS is not determined. Because infectious diseases are established triggers of exacerbations in MS, in this study we have characterized the expression of Toll-like receptors (TLR) and the maturation and functional properties of peripheral blood pDCs from clinically stable, untreated MS patients in response to signals of innate immunity. After stimulation of TLR-9, interferon (IFN)-alpha production by pDCs was significantly lower in MS (n = 12) compared to healthy controls (n = 9). In an allogenic two-step co-culture assay we found an impaired effect of TLR-9 stimulation on IFN-gamma expression of autologous naive T cells in MS patients (n = 4). In peripheral blood mononuclear cells, TLR-9 stimulation with type A CpG ODN resulted in a higher expression of TLR-1, -2, -4, -5 and -8 in MS patients (n = 7) compared with healthy controls (n = 11). These findings suggest an altered innate immune response to microbial stimuli in MS patients and may help understanding of why common infectious agents trigger MS attacks.
Assuntos
Infecções Bacterianas/imunologia , Células Dendríticas/imunologia , Esclerose Múltipla/imunologia , Adulto , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Estudos de Casos e Controles , Células Dendríticas/metabolismo , Feminino , Citometria de Fluxo , Humanos , Imunidade Inata , Imunização , Interferon gama/análise , Interferon gama/metabolismo , Leucaférese , Masculino , Esclerose Múltipla/metabolismo , Oligodesoxirribonucleotídeos/farmacologia , Reação em Cadeia da Polimerase/métodos , Estatísticas não Paramétricas , Receptor Toll-Like 9/agonistas , Receptores Toll-Like/análise , Receptores Toll-Like/metabolismoRESUMO
Multiple sclerosis (MS) brain tissue, spleen, and PBMC were studied using immunocytochemistry and FACS for immunoreactivity for lymphotoxin (LT) and TNF. Both cytokines were identified in acute and chronic active MS lesions but were absent from chronic silent lesions. LT was associated with CD3+ lymphocytes and Leu-M5+ microglia cells at the lesion edge and to a lesser extent, in adjacent white matter. TNF was associated with astrocytes in all areas of the lesion, and with foamy macrophages in the center of the active lesion. In acute lesions, immunoreactivity for TNF in endothelial cells was noted at the lesion edge. No LT or TNF reactivity was detected in Alzheimer's or Parkinson's disease brain tissues but was present at lower levels in central nervous system (CNS) tissue from other inflammatory conditions, except for adrenoleucodystrophy which displayed high levels of LT in microglia. No increase in LT and TNF reactivity was detected in spleen and PBMC of MS patients suggesting specific reactivity within the CNS. These results indicate that LT and TNF may be involved in the immunopathogenesis of MS, and can be detected in both inflammatory cells and cells endogenous to the CNS.
Assuntos
Linfotoxina-alfa/metabolismo , Esclerose Múltipla/patologia , Fator de Necrose Tumoral alfa/metabolismo , Doença Aguda , Doença Crônica , Humanos , Técnicas Imunoenzimáticas , Leucócitos Mononucleares/metabolismo , Linfócitos/metabolismo , Neuroglia/metabolismo , Baço/metabolismoRESUMO
Recent evidence has revealed an unsuspected suppressive role played by neutrophils during microbial infections. An especially intriguing aspect of this role is the ability of neutrophils to produce interleukin (IL)-10 following interaction with lipopolysaccharide (LPS)-stimulated regulatory T (Treg) cells. The present study demonstrates that generation of IL-10 in neutrophils induced by LPS-stimulated Treg cells required direct cell-cell contact. This effect was dependent on the binding of CD11b and intercellular adhesion molecule 1. Neither stimulation of neutrophils with LPS nor their culture with unstimulated Treg cells, CD3/CD28 monoclonal antibodies-stimulated Treg cells, or T conventional cells affected intracellular IL-10 expression. IL-10-positive neutrophils were also induced by exogenous IL-10, providing an example of a positive feedback loop. Both LPS-stimulated Treg cells and exogenous IL-10 exclusively promoted posttranslational modifications of histones, H3K4me3 and H3Ac Lys4, that activate IL-10 genomic locus in neutrophils, while the promoter of IL-10 gene was inactive in resting, LPS-stimulated neutrophils, following blocking of direct interaction with LPS-stimulated Treg cells or in LPS-preactivated neutrophils incubated with LPS-stimulated Treg cells. We additionally confirmed the presence of IL-10-producing neutrophils in vivo in patients with periodontal abscess induced by Gram-negative bacteria, as opposed to neutrophils isolated from the site of aseptic inflammation in patients with neuromyelitis optica.
Assuntos
Comunicação Celular/imunologia , Interleucina-10/imunologia , Neutrófilos/imunologia , Processamento de Proteína Pós-Traducional , Linfócitos T Reguladores/imunologia , Anticorpos Monoclonais/farmacologia , Sítios de Ligação , Antígeno CD11b/genética , Antígeno CD11b/imunologia , Antígenos CD28/genética , Antígenos CD28/imunologia , Complexo CD3/genética , Complexo CD3/imunologia , Técnicas de Cocultura , Retroalimentação Fisiológica , Histonas/genética , Histonas/imunologia , Humanos , Molécula 1 de Adesão Intercelular/genética , Molécula 1 de Adesão Intercelular/imunologia , Interleucina-10/genética , Interleucina-10/farmacologia , Lipopolissacarídeos/farmacologia , Ativação Linfocitária , Neuromielite Óptica/genética , Neuromielite Óptica/imunologia , Neuromielite Óptica/patologia , Neutrófilos/patologia , Abscesso Periodontal/genética , Abscesso Periodontal/imunologia , Abscesso Periodontal/patologia , Cultura Primária de Células , Regiões Promotoras Genéticas , Ligação Proteica , Transdução de Sinais , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/patologiaRESUMO
OBJECTIVE: To assess the relationship between CD56(bright) natural killer (NK) cells and multiple sclerosis (MS) disease activity in patients with relapsing-remitting MS treated with daclizumab high-yield process (DAC HYP). METHODS: Data were from patients enrolled in a 52-week randomized, double-blind, placebo-controlled study of DAC HYP and its extension study. Assessments included relationships of CD56(bright) NK cell numbers (identified using fluorescence-activated cell sorting) at weeks 4 and 8 with the numbers of new or newly enlarging T2-hyperintense lesions between weeks 24 and 52 and the annualized relapse rate. RESULTS: In DAC HYP-treated patients but not placebo-treated patients, the numbers of CD56(bright) NK cells increased over 52 weeks of treatment, and their numbers at weeks 4 and 8 predicted the number of new or newly enlarging T2-hyperintense lesions between weeks 24 and 52 of treatment (p ≤ 0.005 for each comparison). Similar but nonsignificant trends were observed between CD56(bright) NK cell counts and the annualized relapse rate in DAC HYP-treated patients. DAC HYP-treated patients who showed lower levels of expansion of CD56(bright) NK cells still developed fewer new or newly enlarging T2-hyperintense lesions than placebo-treated patients during the first year of treatment. CONCLUSIONS: CD56(bright) NK cells appear to mediate some of the treatment-related effects of DAC HYP, but their numbers do not account for the full effect of DAC HYP on MS-related outcomes.
RESUMO
Multiple sclerosis (MS) is a demyelinating disease in which an inflammatory cell infiltrate represents a characteristic pathologic feature of active lesions within the CNS. The possibility has been raised that cell-mediated immune mechanisms orchestrate the pathogenesis of MS. Cytokines play a particularly important role in cellular immune mechanisms. These soluble glycoproteins, nonimmunoglobulin in nature, act nonenzymatically to regulate immune cell function. A unique family of cytokines, the tumor necrosis factors (TNFs), demonstrate immunoregulatory activity but are also involved in the effector arm of cellular immune responses. Recently, studies both in vitro and in vivo have suggested a role for TNFs in the pathology of MS. This report summarizes data implicating TNFs in the mechanisms of MS and attempts to apply the anti-TNF approach in the future therapeutic strategy for this disease.
Assuntos
Anticorpos Monoclonais/uso terapêutico , Encefalomielite Autoimune Experimental/terapia , Imunoterapia Adotiva , Esclerose Múltipla/terapia , Receptores do Fator de Necrose Tumoral/imunologia , Fator de Necrose Tumoral alfa/imunologia , Animais , Antígenos CD/imunologia , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/metabolismo , Humanos , Camundongos , Esclerose Múltipla/imunologia , Esclerose Múltipla/metabolismo , Receptores do Fator de Necrose Tumoral/metabolismo , Receptores Tipo I de Fatores de Necrose Tumoral , Fator de Necrose Tumoral alfa/metabolismoRESUMO
We studied immunoreactivity for heat shock proteins (HSPs) in multiple sclerosis (MS) brain tissue and detected HSP-65 in chronic MS plaques at the edge of thinly myelinated (or remyelinated) areas. Serial-section immunocytochemistry and double staining revealed that HSP-65+ cells represented reactive, immature oligodendrocytes with strong reactivity for myelin basic protein and weak reactivity for galactocerebroside. Mature oligodendrocytes outside MS plaques did not stain for HSP-65. Control brain sections showed no HSP-65 reactivity. Oligodendrocytes expressed HSP-65 in mixed glial cell cultures. In this system in vitro, oligodendrocytes, but not astrocytes, showed constitutive expression of HSP-65. There was immunoreactivity for HSP-72 in astrocytes in MS and non-MS brains to a similar extent but no association between HSP-72 reactivity and MS plaques. Interestingly, HSP-65+ oligodendrocytes colocalized with T lymphocytes expressing the gamma delta T-cell receptor (TcR). Since HSP-65 has been implicated as a major antigen recognized by TcR gamma delta lymphocytes, our findings might represent a new immunologic interaction within MS plaques that leads to the destruction of immature oligodendrocytes involved in remyelination.
Assuntos
Encéfalo/metabolismo , Proteínas de Choque Térmico/metabolismo , Esclerose Múltipla/metabolismo , Oligodendroglia/metabolismo , Adrenoleucodistrofia/metabolismo , Adrenoleucodistrofia/patologia , Adulto , Encéfalo/patologia , Células Cultivadas , Feminino , Imunofluorescência , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/patologia , Paraparesia Espástica Tropical/metabolismo , Paraparesia Espástica Tropical/patologia , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Panencefalite Esclerosante Subaguda/metabolismo , Panencefalite Esclerosante Subaguda/patologiaRESUMO
OBJECTIVE: To evaluate the rate of shedding of tumor necrosis factor (TNF) receptors (TNFRs) in MS patients. BACKGROUND: It was previously suggested that TNF might play a significant role in the immunopathologic mechanism of MS. TNF mediates its biologic effects by interacting with two distinct receptors: TNFR-p55 and TNFR-p75. Both of these receptors exist in soluble and membrane-bound forms. Soluble receptors have been shown to influence TNF activity in vitro and in vivo and maintain balance between active, free TNF and inactive form of this cytokine bound to its soluble receptors. METHODS: In the current study, the authors measured shedding of TNFRs from cell surface of peripheral blood mononuclear cells, peripheral blood lymphocytes, and monocytes in three groups of MS patients: relapsing-remitting in relapse, relapsing-remitting in remission, and chronic progressive. RESULTS: The authors observed a significant distortion in generation of both soluble TNF receptors. Whereas the TNFR-p55 was shed at lower rate compared with healthy volunteers, the shedding of TNFR-p75 was significantly higher in MS patients. CONCLUSION: Disturbance in TNFR shedding might contribute to the distortion of a fine balance between circulating TNF and its natural inhibitors in MS.
Assuntos
Esclerose Múltipla/metabolismo , Receptores do Fator de Necrose Tumoral/metabolismo , Antígenos CD/biossíntese , Antígenos CD/sangue , Células Cultivadas , Inibidores Enzimáticos/farmacologia , Humanos , Cinética , Linfócitos/metabolismo , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Proteína Quinase C/antagonistas & inibidores , Receptores do Fator de Necrose Tumoral/biossíntese , Receptores do Fator de Necrose Tumoral/sangue , Receptores Tipo I de Fatores de Necrose Tumoral , Receptores Tipo II do Fator de Necrose Tumoral , Solubilidade , Estaurosporina/farmacologia , Fator de Necrose Tumoral alfa/biossínteseRESUMO
The percentage of interleukin-2-receptor-positive peripheral blood lymphocytes in MS patients was significantly higher in acute relapse than in remission or in controls. After stimulation by phytohemagglutinin, the expression of interleukin-2 receptor on peripheral blood lymphocytes of MS patients was within the range of healthy controls, implying no general impairment of receptor expression. These results confirm other evidence that there is a small population of activated T lymphocytes in acute relapse of MS.
Assuntos
Linfócitos/imunologia , Esclerose Múltipla/imunologia , Receptores Imunológicos/imunologia , Adulto , Anticorpos Monoclonais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Proteína Básica da Mielina/imunologia , Bainha de Mielina/imunologia , Fito-Hemaglutininas/imunologia , Receptores de Interleucina-2 , RecidivaRESUMO
A clear message to emerge from the recent 6th International TNF Congress is that TNF-alpha, LT-alpha and possibly other TNF family members, are important integral mediators of the CNS stress response to threatened homeostasis and that either excessive or insufficient TNF-alpha production can have significant consequences upon correct CNS functioning. Experimental data are particularly relevant in light of recent evidence which shows some linkage between polymorphisms in the human TNF-alpha/LT-alpha locus and susceptibility to CNS infection and thus highlight such cytokine pathways as promising therapeutic targets for the management of certain CNS diseases. Judging by the significant advances that have been made recently in the field of cytokine neurobiology, and the currently explosive development of transgenic and gene mutant mouse models with which to probe the cellular and molecular mechanisms of TNF-alpha and LT-alpha action within the CNS, we can look forward to shortly understanding more precisely the important and diverse roles that these cytokines play in CNS health and disease.
Assuntos
Doenças do Sistema Nervoso Central/etiologia , Doenças do Sistema Nervoso Central/imunologia , Fator de Necrose Tumoral alfa/fisiologia , Animais , Doenças do Sistema Nervoso Central/terapia , HumanosRESUMO
Supernatants from multiple sclerosis (MS) T-lymphocytes cause damage to both myelin and glial cells in cerebellar cultures assessed visually and by radiolabel release. Control T-lymphocytes, even after phytohaemagglutinin (PHA) stimulation, yielded supernatants which induced only slight damage, and at later times patients with other neurological diseases (OND) gave variable results. These differences suggest that MS T-lymphocytes are pre-activated in vivo to produce demyelinating factors while control T-lymphocytes are not pre-activated to the same extent. The visual evidence of activation of cerebellar macrophage-like cells was a common finding after MS T-lymphocyte supernatant treatment but there was no correlation with the severity of demyelination. There was a positive correlation between the percentage IL-2 receptor-bearing lymphocytes and the degree of supernatant-induced in vitro demyelination.
Assuntos
Extratos Celulares/farmacologia , Esclerose Múltipla/patologia , Tecido Nervoso/efeitos dos fármacos , Linfócitos T/análise , Extratos de Tecidos/farmacologia , Linfócitos B/análise , Humanos , Macrófagos/efeitos dos fármacos , Macrófagos/ultraestrutura , Esclerose Múltipla/metabolismo , Bainha de Mielina/efeitos dos fármacos , Bainha de Mielina/ultraestrutura , Tecido Nervoso/metabolismo , Neuroglia/efeitos dos fármacos , Neuroglia/ultraestrutura , Técnicas de Cultura de Órgãos , Fito-Hemaglutininas/farmacologia , Receptores Imunológicos/metabolismo , Receptores de Interleucina-2 , Radioisótopos de Enxofre/metabolismoRESUMO
We have evaluated the effect of the type I (p-55, type beta) soluble tumor necrosis factor receptor (sTNFrI) in an animal model of multiple sclerosis. Experimental autoimmune encephalomyelitis (EAE) was induced in SJL/J mice by adoptive transfer of T lymphocytes sensitized to myelin basic protein (MBP). sTNFrI completely blocked both clinical signs of disease and pathological changes that included CNS demyelination and inflammatory cell infiltration. Effective inhibition of disease expression was obtained using several different regimens of subcutaneous (s.c.) injection. These included daily doses starting at day 0, every other day injections starting at day 0, daily doses starting on day 4, and two doses separated by 12 h on day 1 and 2. Furthermore, treatment with sTNFrI for 15 days completely protected these animals from the recurrent episodes of disease normally associated with adoptively transferred EAE. These findings suggest that TNF plays a major causative role in EAE and that the sTNFrI may prove to be a useful therapeutic approach in multiple sclerosis.
Assuntos
Encefalomielite Autoimune Experimental/prevenção & controle , Receptores do Fator de Necrose Tumoral/fisiologia , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Animais , Encéfalo/patologia , Doença Crônica , Encefalomielite Autoimune Experimental/patologia , Feminino , Camundongos , Esclerose Múltipla/terapiaRESUMO
Vaccination with naked DNA represents a therapeutic strategy currently under consideration in multiple sclerosis (MS). In this study, we tested the potential therapeutic effect of vaccination with a naked DNA construct encoding proteolipid protein (pRc/CMV-PLP) upon the outcome of subsequent sensitization for experimental autoimmune encephalomyelitis (EAE) actively-induced in SJL mice with PLP139-151 peptide in adjuvant. Intramuscular vaccination with the naked DNA pRc/CMV-PLP construct led to PLP expression in local muscle tissue that persisted for about 8 weeks. Early sensitization for EAE (4 weeks after DNA vaccination) caused recipient mice to develop a severe, exacerbated form of disease (in comparison to control mice), while late sensitization (>10 weeks) resulted in a milder, ameliorated form. In the groups sensitized <10 weeks post-DNA vaccination with pRc/CMV-PLP induction of a Th1-type cytokine response was noted. In contrast, sensitization >10 weeks post-DNA vaccination led to peripheral tolerance as evidenced by a decrease in T cell proliferation and cytotoxic T cell response, no Th2 response, and no increase in apoptosis. These data are novel in that they demonstrate a differential effect of DNA vaccination and have important implications for its use as a mechanism to enhance or modulate immune reactivity.
Assuntos
Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/prevenção & controle , Vacinas de DNA/imunologia , Animais , Apoptose/imunologia , Autoantígenos/imunologia , Divisão Celular/imunologia , Citomegalovirus/genética , Testes Imunológicos de Citotoxicidade , Doenças Desmielinizantes/imunologia , Encefalomielite Autoimune Experimental/patologia , Feminino , Imunoterapia Ativa , Linfonodos/citologia , Camundongos , Camundongos Endogâmicos , Esclerose Múltipla/imunologia , Esclerose Múltipla/patologia , Esclerose Múltipla/prevenção & controle , Proteína Proteolipídica de Mielina/genética , Proteína Proteolipídica de Mielina/imunologia , Plasmídeos/imunologia , Medula Espinal/imunologia , Medula Espinal/patologia , Linfócitos T/citologiaRESUMO
Supernates from myelin basic protein (MBP)-reactive T cell lines have been tested by a battery of assays for cytotoxicity against oligodendrocytes in vitro. All supernates tested demonstrated cytotoxic activity in both a dose- and time-dependent manner that ranged from 29.1% to 55.8% after 48 h incubation. Oligodendrocyte cytotoxicity mediated by MBP-reactive T cell lines was not antigen specific since lines reactive with purified protein derivative (PPD) of tuberculin showed similar cytotoxicity. Supernates cytotoxic to oligodendrocytes were equally effective against syngeneic and non-syngeneic target cells, but had no effect upon astrocytes. Neutralization studies revealed that oligodendrocyte cytotoxicity mediated by MBP-reactive T cell supernates could only be partially attributed to lymphotoxin/tumor necrosis factor activity, and was not associated with perforin, serine proteinase or N-methyl-D-aspartate (NMDA) receptor agonists.
Assuntos
Citotoxicidade Imunológica , Ativação Linfocitária , Oligodendroglia/imunologia , Linfócitos T/imunologia , Animais , Astrócitos/imunologia , Linhagem Celular , Feminino , Camundongos , Proteína Básica da Mielina/imunologia , Testes de Neutralização , Oligodendroglia/citologia , Solubilidade , Linfócitos T/citologiaRESUMO
In this study we present evidence that gammadelta T cells are present in the normal mouse central nervous system (CNS). Compared with matching spleen gammadelta T cells, CNS gammadelta T cells expressed only the CD45RBlow phenotype, suggesting that CNS gammadelta T cells belong to the memory cell population. Approximately 20% expressed exclusively the CD8alphabeta heterodimer, consistent with a thymic origin. Gammadelta T cells in both spleen and CNS expressed higher levels of the IL-2rbeta (CD122), as well as Fas and FasL, than alphabeta T cells, suggesting that these cells function as immunoregulatory T cells. RT-PCR analysis showed almost exclusive use of Vdelta6 in the CNS whereas more Vdelta genes were expressed in the spleen. Sequencing of Vdelta6 RT-PCR products demonstrated a polyclonal population of T cells in the spleen but a more clonal population within the CNS. The predominant CNS sequence was found in all animals studied and was also detected in the spleen. From these data we conclude that a selective component of circulating gammadelta T cells traffics through the CNS. Thus, all major populations of lymphocytes can be detected in the normal CNS and as such may play specific roles in the immunological surveillance of that organ.
Assuntos
Sistema Nervoso Central/imunologia , Subpopulações de Linfócitos/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Linfócitos T/imunologia , Animais , Encéfalo/imunologia , Proteína Ligante Fas , Feminino , Citometria de Fluxo , Leucócitos/imunologia , Glicoproteínas de Membrana/metabolismo , Camundongos , Fenótipo , Receptores de Antígenos de Linfócitos T gama-delta/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Medula Espinal/imunologia , Baço/imunologia , Distribuição Tecidual , Receptor fas/metabolismoRESUMO
Epidural visual evoked potentials (VEP) were used to study the role of cytokines in the induction of pathophysiologic changes associated with inflammation in the central nervous system (CNS) of the rabbit. In normal rabbits, intraocular injection of human recombinant interferon-gamma (IFN-gamma) and tumor necrosis factor (TNF) increased the peak latency of the cortical VEP by more than 2 ms within 3 h of injection; equal volume injections of control substances had no effect. Alterations in conduction induced by IFN-gamma and TNF reversed within 24 h and could be reinduced by reinjection. Intraocular injection of recombinant human interleukin-1 beta (IL-1) induced a more progressive delay in conduction that peaked 24 h after intraocular challenge and reversed over the ensuing 48 h. Pathologic examination of the tissues indicated that the primary effect of these cytokines is on the vasculature and induces changes associated with inflammation. The results suggest that the acute reversible effects of cytokines on CNS function are associated with vascular events; further they support the sensitivity of the 'rabbit eye model' for studies on the pathophysiologic effect of inflammatory mediators on the CNS in vivo.
Assuntos
Fatores Biológicos/farmacologia , Vias Visuais/efeitos dos fármacos , Animais , Citocinas , Eletrorretinografia , Potenciais Evocados Visuais , Interferon gama/farmacologia , Interleucina-1/farmacologia , Condução Nervosa , Coelhos , Tempo de Reação , Retina/patologia , Fator de Necrose Tumoral alfa/farmacologia , Vias Visuais/patologia , Vias Visuais/fisiologiaRESUMO
The cytokines LTa and TNF have been implicated as major mediators of tissue injury in multiple sclerosis (MS). In this study we have assessed the frequency of specific polymorphisms for these genes in MS (n = 53) and controls (n = 81) using a highly sensitive, two stage nested polymerase chain reaction (PCR), with the second stage using mutation-specific primers. Genomic DNA was extracted from blood cells and the results confirmed by direct dideoxy chain termination sequencing. The frequency of the -308 G to A mutation in the TNF promoter region in normal controls was 15% and in MS was 24%. For LTa gene the exon 3 polymorphism allele A was detected in 36% of controls and 34% of the MS patients. In MS, the combined genotype TNF G + A and LTa C + C was present 6 times more frequently (12%) than in controls (2%), and patients with this genotype showed the highest EDSS scores. We found the TNF and LTa polymorphisms to occur independently from the HLA class II DR2 allele distribution in MS. Whilst the G - A polymorphism in TNF gene promoter has been studied previously in MS, with conflicting results, this is the first study that has addressed the exon 3 polymorphism in LTa in MS. The results indicate that this polymorphism is not linked with the higher genetic predisposition for MS, but that combined TNF G + A and LTa C + C genotype might contribute to development of the disease.
Assuntos
Linfotoxina-alfa/genética , Esclerose Múltipla/genética , Esclerose Múltipla/imunologia , Polimorfismo de Fragmento de Restrição , Fator de Necrose Tumoral alfa/genética , Alelos , Citocinas/imunologia , Citocinas/metabolismo , Ensaio de Imunoadsorção Enzimática , Frequência do Gene , Genótipo , Antígeno HLA-DR2/genética , Humanos , Linfotoxina-alfa/imunologia , Recidiva , Análise de Sequência de DNA , Fator de Necrose Tumoral alfa/imunologiaRESUMO
Chemokines are small proinflammatory cytokines that possess the ability to stimulate migration of inflammatory cells towards the tissue site of inflammation. Previous reports showed that several chemokines may be involved in the pathogenesis of experimental autoimmune encephalomyelitis (EAE), an animal model of autoimmune central nervous system (CNS) inflammation. Inflammatory cells respond to chemotactic chemokine gradient through the chemokine receptors (ChRs). The goal of this study was to analyze expression of ChRs belonging to CXC subfamily during different stages of chronic relapsing EAE. We found significantly increased expression of CXCR2 and CXCR4 in the spinal cord during the first and second disease attacks. The kinetics of this expression in CNS and blood suggests that CXCR2 is expressed by leukocytes migrating from the blood, but CXCR4 is expressed mainly by CNS parenchymal cells. Those results support the interpretation that chemokine-chemokine receptor interactions may play an important role in the development of CNS autoimmune inflammation.