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1.
Front Neurol ; 13: 1010150, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36341094

RESUMO

Krabbe disease (KD), also known as globoid cell leukodystrophy, is a rare autosomal recessive condition caused by mutations in the galactocerebrosidase (GALC) gene. KD is more common in infants and young children than in adults. We reported the case of an adult-onset KD presenting with progressive myoclonic epilepsy (PME) and cortical lesions mimicking mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome. The whole-exome sequencing (WES) identified a pathogenic homozygous missense mutation of the GALC gene. Parents of the patient were heterozygous for the mutation. The clinical, electrophysiological, and radiological data of the patient were retrospectively analyzed. The patient was a 24-year-old woman presenting with generalized seizures, progressive cognitive decline, psychiatric symptoms, gait ataxia, and action-induced myoclonus. The brain magnetic resonance imaging (MRI) revealed a right occipital cortical ribbon sign without any other damage. This single case expands the clinical phenotypes of adult-onset KD.

2.
Am J Gastroenterol ; 117(2): 319-326, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-34797778

RESUMO

INTRODUCTION: Treated patients with celiac disease (CeD) and nonceliac gluten sensitivity (NCGS) report acute, transient, incompletely understood symptoms after suspected gluten exposure. To determine whether (i) blinded gluten exposure induces symptoms, (ii) subjects accurately identify gluten exposure, and (iii) serum interleukin-2 (IL-2) levels distinguish CeD from NCGS subjects after gluten exposure. METHODS: Sixty subjects (n = 20 treated, healed CeD; n = 20 treated NCGS; n = 20 controls) were block randomized to a single, double-blind sham (rice flour) or 3-g gluten challenge with 72-hours follow-up. Twelve serial questionnaires (100 mm visual analog scale; pain, bloating, nausea, and fatigue) and 10 serial plasma samples were collected. Mucosal permeability was assessed using both urinary lactulose-13C mannitol ratios and endoscopic mucosal impedance. RESULTS: Thirty-five of 40 (83%) subjects with CeD and NCGS reported symptoms with gluten (8 CeD, 9 NCGS) and sham (9 CeD, 9 NCGS) compared with 9 of 20 (45%) controls after gluten (n = 6) and sham (n = 3). There was no significant difference in symptoms among groups. Only 2 of 10 subjects with CeD and 4 of 10 NCGS identified gluten, whereas 8 of 10 subjects with CeD and 5 of 10 NCGS identified sham. A significant plasma IL-2 increase occurred only in subjects with CeD after gluten, peaking at 3 hours and normalizing within 24 hours postchallenge despite no significant intestinal permeability change from baseline. DISCUSSION: Symptoms do not reliably indicate gluten exposure in either subjects with CeD or NCGS. IL-2 production indicates a rapid-onset gluten-induced T-cell activation in CeD despite long-standing treatment. The effector site is unknown, given no increased intestinal permeability after gluten.


Assuntos
Doença Celíaca/sangue , Dieta Livre de Glúten/métodos , Glutens/efeitos adversos , Interleucina-2/sangue , Doença Aguda , Adulto , Biomarcadores/sangue , Doença Celíaca/dietoterapia , Método Duplo-Cego , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
3.
Front Immunol ; 12: 661622, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34093551

RESUMO

Improved blood tests assessing the functional status of rare gluten-specific CD4+ T cells are needed to effectively monitor experimental therapies for coeliac disease (CD). Our aim was to develop a simple, but highly sensitive cytokine release assay (CRA) for gluten-specific CD4+ T cells that did not require patients to undergo a prior gluten challenge, and would be practical in large, multi-centre clinical trials. We developed an enhanced CRA and used it in a phase 2 clinical trial ("RESET CeD") of Nexvax2, a peptide-based immunotherapy for CD. Two participants with treated CD were assessed in a pilot study prior to and six days after a 3-day gluten challenge. Dye-dilution proliferation in peripheral blood mononuclear cells (PBMC) was assessed, and IL-2, IFN-γ and IL-10 were measured by multiplex electrochemiluminescence immunoassay (ECL) after 24-hour gluten-peptide stimulation of whole blood or matched PBMC. Subsequently, gluten-specific CD4+ T cells in blood were assessed in a subgroup of the RESET CeD Study participants who received Nexvax2 (maintenance dose 900 µg, n = 12) or placebo (n = 9). The pilot study showed that gluten peptides induced IL-2, IFN-γ and IL-10 release from PBMCs attributable to CD4+ T cells, but the PBMC CRA was substantially less sensitive than whole blood CRA. Only modest gluten peptide-stimulated IL-2 release could be detected without prior gluten challenge using PBMC. In contrast, whole blood CRA enabled detection of IL-2 and IFN-γ before and after gluten challenge. IL-2 and IFN-γ release in whole blood required more than 6 hours incubation. Delay in whole blood incubation of more than three hours from collection substantially reduced antigen-stimulated IL-2 and IFN-γ secretion. Nexvax2, but not placebo treatment in the RESET CeD Study was associated with significant reductions in gluten peptide-stimulated whole blood IL-2 and IFN-γ release, and CD4+ T cell proliferation. We conclude that using fresh whole blood instead of PBMC substantially enhances cytokine secretion stimulated by gluten peptides, and enables assessment of rare gluten-specific CD4+ T cells without requiring CD patients to undertake a gluten challenge. Whole blood assessment coupled with ultra-sensitive cytokine detection shows promise in the monitoring of rare antigen-specific T cells in clinical studies.


Assuntos
Antígenos/imunologia , Linfócitos T CD4-Positivos/imunologia , Doença Celíaca/imunologia , Citocinas/imunologia , Glutens/imunologia , Fragmentos de Peptídeos/imunologia , Adulto , Idoso , Sequência de Aminoácidos , Linfócitos T CD4-Positivos/metabolismo , Doença Celíaca/sangue , Doença Celíaca/diagnóstico , Células Cultivadas , Citocinas/sangue , Método Duplo-Cego , Feminino , Humanos , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Masculino , Pessoa de Meia-Idade , Peptídeos/imunologia , Peptídeos/metabolismo , Sensibilidade e Especificidade
4.
United European Gastroenterol J ; 8(1): 108-118, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32213060

RESUMO

BACKGROUND: Diagnosing coeliac disease (CD) in patients on a gluten-free diet (GFD) is difficult. Ingesting gluten elevates circulating interleukin (IL)-2, IL-8 and IL-10 in CD patients on a GFD. OBJECTIVE: We tested whether cytokine release after gluten ingestion differentiates patients with CD from those with self-reported gluten sensitivity (SR-GS). METHODS: Australian patients with CD (n = 26) and SR-GS (n = 18) on a GFD consumed bread (estimated gluten 6 g). Serum at baseline and at 3 and 4 h was tested for IL-2, IL-8 and IL-10. Separately, Norwegian SR-GS patients (n = 49) had plasma cytokine assessment at baseline and at 2, 4 and 6 h after food bars containing gluten (5.7 g), fructan or placebo in a previous double-blind crossover study. RESULTS: Gluten significantly elevated serum IL-2, IL-8 and IL-10 at 3 and 4 h in patients with CD but not SR-GS. The highest median fold-change from baseline at 4 h was for IL-2 (8.06, IQR: 1.52-24.0; P < 0.0001, Wilcoxon test). The two SR-GS cohorts included only one (1.5%) confirmed IL-2 responder, and cytokine responses to fructan and placebo were no different to gluten. Overall, cytokine release after gluten was present in 22 (85%) CD participants, but 2 of the 4 non-responders remained clinically well after 1 y on an unrestricted diet. Hence, cytokine release occurred in 22 (92%) of 24 'verified' CD participants. CONCLUSIONS: Gluten challenge with high-sensitivity cytokine assessment differentiates CD from SR-GS in patients on a GFD and identifies patients likely to tolerate gluten reintroduction. Systemic cytokine release indicating early immune activation by gluten in CD individuals cannot be detected in SR-GS individuals.


Assuntos
Doença Celíaca/diagnóstico , Citocinas/sangue , Dieta Livre de Glúten , Hipersensibilidade Alimentar/diagnóstico , Glutens/administração & dosagem , Adulto , Idoso , Austrália , Pão/efeitos adversos , Doença Celíaca/sangue , Doença Celíaca/dietoterapia , Doença Celíaca/imunologia , Citocinas/imunologia , Diagnóstico Diferencial , Feminino , Hipersensibilidade Alimentar/sangue , Hipersensibilidade Alimentar/dietoterapia , Hipersensibilidade Alimentar/imunologia , Glutens/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Autorrelato , Adulto Jovem
5.
Sci Adv ; 5(8): eaaw7756, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31457091

RESUMO

Celiac disease (CeD), caused by immune reactions to cereal gluten, is treated with gluten -elimination diets. Within hours of gluten exposure, either perorally or extraorally by intradermal injection, treated patients experience gastrointestinal symptoms. To test whether gluten exposure leads to systemic cytokine production time -related to symptoms, series of multiplex cytokine measurements were obtained in CeD patients after gluten challenge. Peptide injection elevated at least 15 plasma cytokines, with IL-2, IL-8, and IL-10 being most prominent (fold-change increase at 4 hours of 272, 11, and 1.2, respectively). IL-2 and IL-8 were the only cytokines elevated at 2 hours, preceding onset of symptoms. After gluten ingestion, IL-2 was the earliest and most prominent cytokine (15-fold change at 4 hours). Supported by studies of patient-derived gluten-specific T cell clones and primary lymphocytes, our observations indicate that gluten-specific CD4+ T cells are rapidly reactivated by antigen -exposure likely causing CeD-associated gastrointestinal symptoms.


Assuntos
Doença Celíaca/patologia , Citocinas/sangue , Glutens/administração & dosagem , Adulto , Idoso , Linfócitos T CD4-Positivos/classificação , Linfócitos T CD4-Positivos/metabolismo , Doença Celíaca/imunologia , Doença Celíaca/metabolismo , Método Duplo-Cego , Feminino , Genótipo , Glutens/efeitos adversos , Antígenos HLA/genética , Humanos , Interleucina-10/sangue , Interleucina-2/sangue , Interleucina-8/sangue , Masculino , Pessoa de Meia-Idade , Efeito Placebo , Vômito/etiologia , Adulto Jovem
6.
Lancet Gastroenterol Hepatol ; 2(7): 479-493, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28506538

RESUMO

BACKGROUND: A gluten-free diet is the only means to manage coeliac disease, a permanent immune intolerance to gluten. We developed a therapeutic vaccine, Nexvax2, designed to treat coeliac disease. Nexvax2 is an adjuvant-free mix of three peptides that include immunodominant epitopes for gluten-specific CD4-positive T cells. The vaccine is intended to engage and render gluten-specific CD4-positive T cells unresponsive to further antigenic stimulation. We assessed the safety and pharmacodynamics of the vaccine in patients with coeliac disease on a gluten-free diet. METHODS: We did two randomised, double-blind, placebo-controlled, phase 1 studies at 12 community sites in Australia, New Zealand, and the USA, in HLA-DQ2·5-positive patients aged 18-70 years who had coeliac disease and were on a gluten-free diet. In the screening period for ascending dose cohorts, participants were randomly assigned (1:1) by central randomisation with a simple block method to a double-blind crossover, placebo-controlled oral gluten challenge. Participants with a negative interferon γ release assay to Nexvax2 peptides after the screening oral gluten challenge were discontinued before dosing. For the biopsy cohorts, the screening period included an endoscopy, and participants with duodenal histology who had a Marsh score of greater than 1 were discontinued before dosing. Participants were subsequently randomly assigned to either Nexvax2 or placebo in ascending dose cohorts (2:1) and in biopsy cohorts (1:1) by central randomisation with a simple block method. In the three-dose study, participants received either Nexvax2 60 µg, 90 µg, or 150 µg weekly, or placebo over 15 days; in a fourth biopsy cohort, patients received either Nexvax2 at the maximum tolerated dose (MTD) or placebo. In the 16-dose study, participants received Nexvax2 150 µg or 300 µg or placebo twice weekly over 53 days; in a third biopsy cohort, patients also received either Nexvax2 at the MTD or placebo. In the 4-week post-treatment period, ascending dose cohorts underwent a further double-blind crossover, placebo-controlled oral gluten challenge, which had a fixed sequence, and biopsy cohorts had a gastroscopy with duodenal biopsies and quantitative histology within 2 weeks without oral gluten challenge. Participants, investigators, and study staff were masked to the treatment assignment, except for the study pharmacist. The primary endpoint was the number and percentage of adverse events in the treatment period in an intention-to-treat analysis. Both trials were completed and closed before data analysis. Trials were registered with the Australian New Zealand Clinical Trials Registry, numbers ACTRN12612000355875 and ACTRN12613001331729. FINDINGS: Participants were enrolled from Nov 28, 2012, to Aug 14, 2014, in the three-dose study, and from Aug 3, 2012, to Sept 10, 2013, in the 16-dose study. Overall, 62 (57%) of 108 participants were randomly assigned after oral gluten challenge and 20 (71%) of 28 participants were randomly assigned after endoscopy. In the three-dose study, nine participants were randomly allocated to Nexvax2 60 µg and three to placebo (first cohort), nine were allocated to Nexvax2 90 µg and four to placebo (second cohort), eight were allocated to Nexvax2 150 µg and four to placebo (third cohort), and three were allocated to Nexvax2 150 µg and three to placebo (biopsy cohort). In the 16-dose study, eight participants were randomly allocated to Nexvax2 150 µg and four to placebo (first cohort), ten were allocated to Nexvax2 300 µg and three to placebo (second cohort), and seven were allocated to Nexvax2 150 µg and seven to placebo (biopsy cohort). The MTD for Nexvax2 was 150 µg because of transient, acute gastrointestinal adverse events with onset 2-5 h after initial doses of the vaccine, similar to those caused by gluten ingestion. In the ascending dose cohorts in the three-dose study, six (55%) of 11 placebo recipients, five (56%) of nine who received Nexvax2 60 µg, seven (78%) of nine who received Nexvax2 90 µg, and five (63%) of eight who received Nexvax2 150 µg had at least one treatment-emergent adverse event, as did all three (100%) placebo recipients and one (33%) of three Nexvax2 150 µg recipients in the biopsy cohort. In the ascending dose cohorts of the 16-dose study, five (71%) of seven placebo-treated participants, six (75%) of eight who received Nexvax2 150 µg, and all ten (100%) who received Nexvax2 300 µg had at least one treatment-emergent adverse event, as did six (86%) of seven placebo recipients and five (71%) of seven Nexvax2 150 µg recipients in the biopsy cohort. Vomiting, nausea, and headache were the only treatment-emergent adverse events that occurred in at least 5% of participants in either study. Among participants given the MTD, eight gastrointestinal treatment-emergent adverse events occurred in four (50%) of eight participants in the third cohort and none (0%) of three participants in the biopsy cohort in the three-dose study, and five events occurred in five (63%) of eight participants in the first cohort and three events in two (29%) of seven participants in the biopsy cohort of the 16-dose study. Median villous height to crypt depth ratio in distal duodenal biopsies was not significantly different between those who received the vaccine at the MTD on either schedule and those who received placebo. Of the participants who completed the post-treatment oral gluten challenge per protocol, interferon γ release assay to Nexvax2 peptides was negative (responders to treatment) in two (22%) of nine placebo-treated participants in the three-dose study versus two (33%) of six who received Nexvax2 60 µg, five (63%) of eight who received Nexvax2 90 µg, and six (100%) of six who received Nexvax2 150 µg (p=0·007); in the 16-dose study, none (0%) of five placebo-treated participants had a negative assay versus six (75%) of eight who received Nexvax2 150 µg (p=0·021). INTERPRETATION: The MTD of Nexvax2 was 150 µg for twice weekly intradermal administration over 8 weeks, which modified immune responsiveness to Nexvax2 peptides without deterioration in duodenal histology. The gastrointestinal symptoms that followed the first intradermal administration of the vaccine resembled those associated with oral gluten challenge. These findings support continued clinical development of this potential therapeutic vaccine for coeliac disease. FUNDING: ImmusanT.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Doença Celíaca/terapia , Epitopos/imunologia , Oligopeptídeos/administração & dosagem , Vacinas/administração & dosagem , Adolescente , Adulto , Idoso , Biópsia , Doença Celíaca/patologia , Estudos Cross-Over , Dieta Livre de Glúten , Método Duplo-Cego , Esquema de Medicação , Duodeno/patologia , Feminino , Gastroenteropatias/etiologia , Humanos , Injeções Intradérmicas , Análise de Intenção de Tratamento , Masculino , Pessoa de Meia-Idade , Nova Zelândia , Oligopeptídeos/efeitos adversos , Oligopeptídeos/imunologia , Vacinas/efeitos adversos , Vacinas/imunologia , Adulto Jovem
7.
Se Pu ; 32(10): 1124-30, 2014 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-25739274

RESUMO

A rapid method for the simultaneous identification and quantification of pesticide multiresidues in porphyra was developed using gel permeation chromatography (GPC) coupled to gas chromatography-mass spectrometry (GPC-GC/MS). Nineteen pesticides (organochlorines, organophosphoruses, triazines and pyrethroids) were selected as the target analytes. The pretreatment method was applied consisting of organic solvent extraction followed by dispersive solid-phase extraction with graphitized carbon black (GCB) and primary secondary amine (PSA) adsorbents. GPC was also employed online to remove the large molecules such as pigments and lipids. The quantitative analysis was carried out by external standard method using gas chromatography coupled with mass spectrometry in selective ion monitoring (SIM) mode. Moreover, a large volume of sample was allowed to be injected using the program of GPC programmed-temperature vaporizer of gas chromatography to improve the sensitivity of measurements. The results showed that the calibration curves were linear (r > 0.995) in the range of 10-1,000 µg/L for all the pesticides. The limits of detection (LODs) for the pesticides in porphyra were from 0.005 to 0.03 mg/kg, and the average recoveries were between 70% and 120%. The advantages of the method are simple, sensitive and shorter operation time for analysis of pesticide residues in porphyra samples.


Assuntos
Cromatografia em Gel , Cromatografia Gasosa-Espectrometria de Massas , Resíduos de Praguicidas/análise , Porphyra/química , Limite de Detecção , Piretrinas , Extração em Fase Sólida , Solventes
8.
Vascul Pharmacol ; 45(3): 154-62, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16765099

RESUMO

OBJECTIVE AND DESIGN: Elevated blood pressure and insulin resistance are strongly associated in patients. We explored the potential for the anti-hypertensive angiotensin II type 1-receptor (ATR(1)) antagonists to improve insulin sensitivity through modulation of the nuclear receptor PPARgamma, in vitro and in vivo compared to the potent insulin sensitizer, rosiglitazone. METHODS: PPARgamma modulation by ATR(1) antagonists was measured first by direct recruitment of PGC-1, followed by trans-activation reporter assays in cells, and promotion of adipogenesis in fibroblast and pre-adipocyte cell lines. Improvement of insulin sensitivity was measured as changes in levels of glucose, insulin, and adiponectin in ob/ob mice. RESULTS: Telmisartan, candesartan, irbesartan, and losartan (but not valsartan or olmesartan) each served as bona fide PPARgamma ligands in vitro, with EC(50) values between 3 and 5 micro mol/l. However, only telmisartan, and to a lesser extent candesartan, resulted in significant PPARgamma agonism in cells. In vivo, although rosiglitazone significantly lowered both glucose (33%, p<0.01) and insulin (61%, p<0.01) levels and increased expression of adiponectin (74%, p<0.001), sartan treatment had no effect. CONCLUSIONS: Many members of the sartan family of ATR(1) antagonists are PPARgamma ligands in cell-free assays but their modulation of PPARgamma in cells is relatively weak. Furthermore, none appear to improve insulin sensitivity in a rodent model under conditions where other insulin sensitizers, including rosiglitazone, do. These results question whether reported effects of sartans on insulin sensitivity may be through other means, and should guide further efforts to develop dual agents to treat hypertension and insulin resistance.


Assuntos
Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacologia , Hipoglicemiantes/farmacologia , Resistência à Insulina , PPAR gama/agonistas , Células 3T3-L1 , Adipogenia/efeitos dos fármacos , Adiponectina/sangue , Bloqueadores do Receptor Tipo 1 de Angiotensina II/química , Animais , Glicemia/efeitos dos fármacos , Chlorocebus aethiops , Relação Dose-Resposta a Droga , Hipoglicemiantes/química , Insulina/sangue , Masculino , Camundongos , Camundongos Obesos , Obesidade/sangue , Obesidade/metabolismo , PPAR gama/genética , PPAR gama/metabolismo , Regiões Promotoras Genéticas/efeitos dos fármacos , Proteínas Recombinantes/agonistas , Rosiglitazona , Relação Estrutura-Atividade , Tiazolidinedionas/farmacologia , Fatores de Transcrição/metabolismo , Transcrição Gênica/efeitos dos fármacos , Transfecção
9.
Mol Pharmacol ; 67(1): 69-77, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15475571

RESUMO

Ertiprotafib belongs to a novel class of insulin sensitizers developed for treatment of type 2 diabetes. In insulin-resistant rodent models, ertiprotafib and a close analog lowered both fasting blood glucose and insulin levels and improved glycemic excursion during an oral glucose tolerance test. In addition, treatment of rodents improved lipid profiles, with significantly lowered triglyceride and free fatty acid levels. These results suggested that this therapeutic activity might involve mechanisms in addition to PTP1b inhibition. In this study, we demonstrate that ertiprotafib activates peroxisome proliferator-activated receptor (PPAR)alpha and PPARgamma at concentrations comparable with those of known agonists of these regulators. Furthermore, it is able to drive adipocyte differentiation of C3H10T(1/2) cells, a hallmark of PPARgamma activation. Livers from ertiprotafib-treated animals showed significant induction of acyl-CoA oxidase activity, probably caused by PPARalpha engagement in these animals. We also show that ertiprotafib inhibits PTP1b in vitro with nonclassic kinetics at concentrations above its EC(50) for PPAR agonism. Thus, the complete mechanism of action for ertiprotafib and related compounds in vivo may involve multiple independent mechanisms, including (but not necessarily limited to) PTP1b inhibition and dual PPARalpha/PPARgamma agonism. Ertiprotafib pharmacology and interpretation of clinical results must be seen in light of this complexity.


Assuntos
Adipócitos/citologia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/farmacologia , Hipolipemiantes/farmacologia , Fenilpropionatos/farmacologia , Tiofenos/farmacologia , Adipócitos/efeitos dos fármacos , Animais , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Diferenciação Celular/efeitos dos fármacos , Humanos , Insulina/sangue , Cinética , Lipídeos/sangue , Masculino , Camundongos , Camundongos Obesos , PPAR alfa/genética , PPAR gama/genética , Proteína Tirosina Fosfatase não Receptora Tipo 1 , Proteínas Tirosina Fosfatases/antagonistas & inibidores , Proteínas Recombinantes/metabolismo , Triglicerídeos/sangue
10.
Immunol Lett ; 83(2): 77-83, 2002 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-12067755

RESUMO

Antagonists of the B7 family of co-stimulatory molecules have the potential for altering immune responses therapeutically. To better define the requirements for such inhibitors, we have mapped the binding of an entire panel of blocking antibodies specific for human B7.1. By mutagenesis, each of the residues critical for blocking antibody binding appeared to fall entirely within the N-terminal V-set domain of B7.1. Thus, although antibody-antigen interacting surfaces can be quite large, these results indicate that a relatively small portion of the GFCC'C" face of this domain is crucial for further antagonist development.


Assuntos
Antígeno B7-1/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Bloqueadores/genética , Anticorpos Bloqueadores/imunologia , Antígeno B7-1/genética , Células COS , Mapeamento de Epitopos , Epitopos de Linfócito B , Humanos , Fragmentos Fc das Imunoglobulinas/genética , Fragmentos Fc das Imunoglobulinas/imunologia , Camundongos , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Mutação , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia
11.
J Biol Chem ; 277(9): 7363-8, 2002 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-11741888

RESUMO

The interaction of co-stimulatory molecules on T cells with B7 molecules on antigen presenting cells plays an important role in the activation of naive T cells. Consequently, agents that disrupt these interactions should have applications in treatment of transplant rejection as well as autoimmune diseases. To this end, specific small molecule inhibitors of human B7.1 were identified and characterized. These compounds inhibit the binding of B7.1 to both CD28 and CTLA4. Both classes of compounds appear to bind the same site, a relatively small portion of the GFCC'C" face of the N-terminal V-set domain of human B7.1, not present in the homologous B7.2 or even mouse B7.1. This site may represent a rare hot spot for small molecule antagonist design of inhibitors of cell-cell interactions, whose ligands may yield leads for the development of novel immunomodulatory medicines.


Assuntos
Antígeno B7-1/química , Antígeno B7-1/metabolismo , Animais , Sítios de Ligação , Antígenos CD28/biossíntese , Antígenos CD28/química , Antígenos CD28/metabolismo , Células CHO , Adesão Celular , Cricetinae , Ensaio de Imunoadsorção Enzimática , Humanos , Concentração Inibidora 50 , Cinética , Ligantes , Camundongos , Modelos Químicos , Ligação Proteica , Estrutura Terciária de Proteína , Fatores de Tempo
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