Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 160
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Nat Med ; 2(10): 1109-15, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8837609

RESUMO

A T-cell receptor (TCR) peptide vaccine from the V beta 5.2 sequence expressed in multiple sclerosis (MS) plaques and on myelin basic protein (MBP)-specific T cells boosted peptide-reactive T cells in patients with progressive MS. Vaccine responders had a reduced MBP response and remained clinically stable without side effects during one year of therapy, whereas nonresponders had an increased MBP response and progressed clinically. Peptide-specific T helper 2 cells directly inhibited MBP-specific T helper 1 cells in vitro through the release of interleukin-10, implicating a bystander suppression mechanism that holds promise for treatment of MS and other autoimmune diseases.


Assuntos
Doenças Autoimunes/terapia , Imunoterapia Ativa , Esclerose Múltipla/terapia , Fragmentos de Peptídeos/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Vacinas/imunologia , Adulto , Doenças Autoimunes/imunologia , Progressão da Doença , Método Duplo-Cego , Feminino , Antígenos HLA-DR/análise , Cadeias HLA-DRB1 , Humanos , Interleucina-10/fisiologia , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/imunologia , Proteína Básica da Mielina/imunologia , Projetos Piloto , Subpopulações de Linfócitos T/imunologia , Células Th2/imunologia , Vacinas/administração & dosagem
2.
J Exp Med ; 177(1): 57-68, 1993 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-7678116

RESUMO

Cloned CD4 T cell lines that recognize the Ac1-16 peptide of myelin basic protein bound to I-Au were isolated and used to analyze the immunopathogenesis of experimental autoimmune encephalomyelitis (EAE). T helper type 1 (Th1) clones induced disease, while Th2 clones did not. Using variants of a single cloned Th1 line, the surface expression of alpha 4 integrins (very late antigen 4 [VLA-4]) was identified as a major pathogenic factor. Encephalitogenic clones and nonencephalitogenic variants differ by 10-fold in their level of surface expression of alpha 4 integrin and in their ability to bind to endothelial cells and recombinant vascular cell adhesion molecule 1 (VCAM-1). The alpha 4 integrin-high, disease-inducing cloned Th1 T cells enter brain parenchyma in abundance, while alpha 4 integrin-low, nonencephalitogenic Th1 cells do not. Moreover, antibodies to alpha 4 integrin, its ligand VCAM-1, and intercellular adhesion molecule 1 all influence the pathogenicity of this encephalitogenic clone in vivo. The importance of the expression of VLA-4 for encephalitogenicity is not unique to cloned T cell lines, as similar results were obtained using myelin basic protein-primed lymph node T cells. alpha 4 integrin levels did not affect antigen responsiveness or production of the Th1 cytokines interleukin 2, interferon gamma, and lymphotoxin/tumor necrosis factor beta; and antibodies against alpha 4 integrin did not block antigen recognition in vitro. Thus, we conclude that surface expression of alpha 4 integrin is important in CD4 T cell entry into brain parenchyma. A general conclusion of these studies is that alpha 4 integrins may be crucial in allowing activated effector T cells to leave blood and enter the brain and other tissues to clear infections.


Assuntos
Encéfalo/imunologia , Linfócitos T CD4-Positivos/imunologia , Receptores de Antígeno muito Tardio/fisiologia , Animais , Anticorpos Monoclonais/imunologia , Linfócitos T CD4-Positivos/fisiologia , Moléculas de Adesão Celular/fisiologia , Movimento Celular , Células Clonais , Encefalomielite Autoimune Experimental/etiologia , Molécula 1 de Adesão Intercelular , Camundongos , Camundongos Endogâmicos BALB C , Proteína Básica da Mielina/imunologia , Receptores de Antígeno muito Tardio/análise , Molécula 1 de Adesão de Célula Vascular
3.
J Exp Med ; 170(2): 355-67, 1989 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-2474052

RESUMO

The major encephalitogenic epitope for Lewis rats is the 72-89 sequence of guinea pig basic protein (GP-BP) or rat basic protein (Rt-BP). T cells responsive to this epitope are I-A restricted and preferentially express the V alpha 2:V beta 8 gene combination in their TCR. In this work, we describe for the first time the delayed appearance of T cells specific for additional discrete determinant of BP, the nonencephalitogenic 55-68 sequence of GP-BP restricted by I-A, and the encephalitogenic 87-99 sequence of Rt-BP restricted by I-E. The TCR V alpha 2:V beta 8 gene combination was expressed by both encephalitogenic GP-BP S72-89 and Rt-BP S87-99 T cell specificities but not by GP-BP 44-68-specific T cells. This is the first demonstration of I-E-restricted encephalitogenic T cells in Lewis rats and supports the conclusion that the I-E class II locus is involved in autoimmune diseases.


Assuntos
Encefalomielite Autoimune Experimental/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Proteína Básica da Mielina/imunologia , Linfócitos T/imunologia , Sequência de Aminoácidos , Animais , Células Clonais , Epitopos , Hipersensibilidade Tardia/imunologia , Memória Imunológica , Dados de Sequência Molecular , Proteína Básica da Mielina/genética , Ratos , Ratos Endogâmicos Lew , Fatores de Tempo
4.
Science ; 196(4295): 1219-21, 1977 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-67639

RESUMO

Two amino acid sequences from the same regions of guinea pig and bovine myelin basic protein which induce experimental allergic encephalomyelitis in Lewis rats were synthesized. The sequences of these two regions may be defined by residues 69 to 84 of the bovine basic protein. The encephalitogenic sequence from guinea pig basic protein (peptide S49), H-Gly-Ser-Leu-Pro-Gln-Lys-Ala-Gin-Arg-Pro-Gin-Asp-Glu-Asn-OH, is a much more potent encephalitogen than that of H-Gly-Ser-Leu-Pro-Gln-Lys-Ala-Gln-Gly-His-Arg-Pro-Gln-Asp-Glu-Asn-OH (peptide S8) found in the bovine protein. The primary structures of the two determinants are similar; however, a Gly-His deletion from the guinea pig sequence is noted. Study of the encephalitogenicity of peptide S49, peptide S8, and the parent proteins suggests that the difference in the encephalitogenic potency of the parent proteins in Lewis rats is due to a natural modification in the primary structure of their respective encephalitogenic determinants.


Assuntos
Encefalomielite Autoimune Experimental/etiologia , Proteína Básica da Mielina , Peptídeos , Sequência de Aminoácidos , Animais , Bovinos , Epitopos , Cobaias , Masculino , Proteína Básica da Mielina/imunologia , Peptídeos/imunologia , Ratos , Ratos Endogâmicos Lew , Especificidade da Espécie , Relação Estrutura-Atividade
5.
Science ; 251(4992): 430-2, 1991 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-1989076

RESUMO

Encephalitogenic T cells specific for myelin basic protein share common V beta 8 peptide sequences in their T cell receptor (TCR) that can induce autoregulatory T cells and antibodies that prevent clinical signs of experimental autoimmune encephalomyelitis (EAE). It is not known, however, if TCR peptides can treat established disease. To test its therapeutic value, TCR-V beta 8-39-59 peptide was injected into rats with clinical signs of EAE. This treatment reduced disease severity and speeded recovery, apparently by boosting anti-V beta 8 T cells and antibodies raised naturally in response to encephalitogenic V beta 8+ T cells. These results demonstrate that synthetic TCR peptides can be used therapeutically, and implicate the TCR-V beta 8-39-59 sequence as a natural idiotope involved in EAE recovery. Similarly, human TCR peptides may be effective in enhancing natural regulation of autoreactive T cells that share common V genes.


Assuntos
Doenças Autoimunes/terapia , Encefalomielite/terapia , Fragmentos de Peptídeos , Fragmentos de Peptídeos/uso terapêutico , Receptores de Antígenos de Linfócitos T , Receptores de Antígenos de Linfócitos T/uso terapêutico , Sequência de Aminoácidos , Animais , Formação de Anticorpos , Doenças Autoimunes/imunologia , Encefalomielite/imunologia , Ensaio de Imunoadsorção Enzimática , Hipersensibilidade Tardia , Soros Imunes/imunologia , Imunidade Celular , Imunoterapia , Dados de Sequência Molecular , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/imunologia , Ratos , Ratos Endogâmicos Lew , Receptores de Antígenos de Linfócitos T/química , Receptores de Antígenos de Linfócitos T/imunologia , Linfócitos T/imunologia
6.
Cancer Res ; 47(9): 2433-9, 1987 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-3567928

RESUMO

A tumor surface antigen (BTA-BT20-68K) was isolated from a human mammary carcinoma cell line (BT-20). The antigen (Mr 68,000) induced the formation of high titer antibodies which recognized BTA-BT20-68K as a cell surface marker by the immune adherence hemagglutination test and recognized the soluble antigen by solid phase radioimmunoassay. The antibodies which failed to recognize human beta-2-microglobulin, alpha-fetoprotein, and carcinoembryonic antigen were cytotoxic to the parent BT-20 tumor cells at high serum dilutions. The antibodies recognized a similar tumor surface marker isolated directly from human breast adenocarcinomas, but failed to recognize human lymphocyte antigens isolated from BT-20 cells or bound to human lymphocytes bearing human lymphocyte antigen markers in common with those of BT-20 cells. Added to BT-20 tumor cells in culture and in the absence of complement, antibody-dose-related inhibition of tumor cell growth was documented. In the presence of complement, the antibodies were highly cytotoxic to the parent cells. These results demonstrate the presence of a unique tumor surface marker with chemical and immunological properties in common with that isolated directly from human breast adenocarcinomas.


Assuntos
Anticorpos Antineoplásicos/análise , Antígenos de Neoplasias/análise , Antígenos de Superfície/análise , Neoplasias da Mama/imunologia , Adenocarcinoma/imunologia , Adesão Celular , Divisão Celular , Linhagem Celular , Reações Cruzadas , Eletroforese em Gel de Poliacrilamida , Humanos , Peso Molecular
7.
Biochim Biophys Acta ; 1293(1): 23-30, 1996 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-8652624

RESUMO

Residues 69-84 of guinea pig myelin basic protein contain the encephalitogenic determinant for the Lewis rat. Insertion of histidine and glycine at positions 77 and 78 in bovine MBP greatly reduces the encephalitogenicity of the protein. Synthetic peptides analogous to this region of MBP containing glycine and histidine are encephalitogenic if they lack the N-terminal half, residues 69-74. However, if they contain both histidine plus the N-terminal half, encephalitogenicity is abolished, suggesting that an interaction of histidine with an amino acid in the N-terminal half changes the conformation or the properties of the peptide. This was investigated by measuring the 1H-NMR spectra of synthetic peptides analogous to this region of MBP, both containing histidine but with and without the N-terminal half. The major difference in the spectra of the two peptides was the pH dependence of line broadening of the histidine resonances. The histidine C2H and C4H resonances were broadened at intermediate pH values in both peptides. However, sharpening of the lines at high pH showed a different pH dependence in the two peptides. For the longer peptide containing the N-terminal half, the lines did not sharpen until the pH was increased above 10.2, coinciding with the pKa of Lys-74. Acetylation of this peptide caused the pH at which the lines began to sharpen to drop to 8.8. In the shorter peptide, lacking the N-terminal half and Lys-74, the lines also sharpened at pH 8.8. The greater broadening which persisted up above pH 10 for the longer peptide suggests slow exchange between two different conformations or environments of the histidine. One of these could be a conformation in which the deprotonated histidine hydrogen bonds with Lys-74. The Lys side-chain resonances indicated a decrease in rotational freedom above the pKa of histidine, consistent with this conclusion. Although this putative interaction between His and Lys-74 did not appear to have a significant effect on the overall conformation of the peptide, it could result in a reduction in encephalitogenicity by altering the properties of the peptide. This could affect processing and presentation of this determinant by antigen presenting cells.


Assuntos
Histidina/química , Lisina/química , Proteína Básica da Mielina/química , Peptídeos/química , Acetilação , Sequência de Aminoácidos , Animais , Bovinos , Encefalomielite Autoimune Experimental/induzido quimicamente , Cobaias , Ligação de Hidrogênio , Concentração de Íons de Hidrogênio , Espectroscopia de Ressonância Magnética , Dados de Sequência Molecular , Proteína Básica da Mielina/farmacologia , Peptídeos/farmacologia , Conformação Proteica , Ratos , Ratos Endogâmicos Lew
8.
FEBS Lett ; 231(1): 212-6, 1988 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-2834224

RESUMO

Interactions between two alpha-toxins and the synthetic peptides alpha 179-191 from both calf and human acetylcholine receptor alpha-subunit sequences have been studied by measurements of quenching of intrinsic fluorescence after toxin addition. Dissociation constants of approx. 5 x 10(-8) M for binding of calf peptide by both alpha-cobratoxin and erabutoxin a have been estimated. The binding of alpha-cobratoxin to calf peptide, which leads to marked quenching of fluorescence intensity, is inhibited by a 10(4) molar excess of acetylcholine. The human alpha 179-191 peptide binds to alpha-cobratoxin, but not, under comparable conditions, to erabutoxin a.


Assuntos
Proteínas Neurotóxicas de Elapídeos/metabolismo , Citocromos/metabolismo , Venenos Elapídicos/metabolismo , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Receptores Colinérgicos/metabolismo , Animais , Bovinos , Grupo dos Citocromos d , Erabutoxinas/metabolismo , Humanos , Substâncias Macromoleculares , Ligação Proteica , Espectrometria de Fluorescência
9.
Transplantation ; 21(2): 129-32, 1976 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-766331

RESUMO

Tilorone is a synthetic amino-alkoxyfluorenone with demonstrated antiviral and antitumor properties. This study gives evidence for immunosuppressive properties of the substance as well. Buffalo rats (AgB6) received skin grafts from rats of the Fischer (AgB1) strain. Control animals rejected in 9.9 +/- 1.1 days, compared to 13.7 +/- 2.3 days for recipients treated with Tilorone. Steroids when combined with Tilorone further prolonged skin allografts to 16.7 +/- 2.6 days. Heart allografts from Fischer (AgB1) and Brown-Norway (AgB3) to Lewis (AgB1) also were performed. In the Fischer to Lewis combination, allograft survival was prolonged from 14.7 +/- 1.0 to 31.0 +/- 3.8 days. In the Brown-Norway to Lewis combination, treated rats rejected in 10.2 +/- 1.4 days versus 6.6 +/- 1.1 days for controls. Increased levels of cytotoxic antibody specific to lymphocytes of the donor strain were noted in Tilorone-treated animals. The mechanism by which Tilorone prolongs allografts may well involve a combination of interferon production and specific suppression of thymus-derived lymphocytes.


Assuntos
Fluorenos/farmacologia , Rejeição de Enxerto , Transplante de Coração , Transplante de Pele , Tilorona/farmacologia , Animais , Anticorpos/análise , Testes Imunológicos de Citotoxicidade , Masculino , Ratos , Ratos Endogâmicos BN , Ratos Endogâmicos BUF , Ratos Endogâmicos Lew , Transplante Homólogo
10.
J Neuroimmunol ; 31(1): 59-66, 1991 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-1701448

RESUMO

Adoptively-transferred experimental allergic encephalomyelitis (EAE) was induced in the SWR (H-2q) strain of mouse using lymph node cells, spleen cells, or cell lines sensitized to whole myelin basic protein (MBP). With the aid of synthetic peptides, the minimal encephalitogenic epitope of MBP for the SWR strain was localized to amino acids 87-99 of the MBP molecule. The 87-99 sequence is also encephalitogenic for the SJL strain of mouse and the Lewis rat. EAE was induced with a protocol similar to that for the induction of EAE in the SJL strain with the exception that sublethal irradiation of recipients was necessary. Mice developed typical clinical and pathological EAE 6-14 days post-transfer of cells sensitized to either whole MBP or peptide 87-99, after which they remitted. No relapses were observed. Thus, adoptively transferred EAE can be induced in irradiated H-2q mice for which the encephalitogenic epitope is one of the nested encephalitogenic epitopes for SJL (H-2s) mice, namely residues 87-99.


Assuntos
Encefalomielite Autoimune Experimental/imunologia , Epitopos/análise , Imunoterapia Adotiva , Proteína Básica da Mielina/imunologia , Animais , Feminino , Cobaias , Camundongos , Fragmentos de Peptídeos/imunologia , Receptores de Antígenos de Linfócitos T/fisiologia , Linfócitos T/imunologia
11.
J Neuroimmunol ; 29(1-3): 139-47, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-1698812

RESUMO

Subacute encephalomyelitis (SAME) in Lewis rats following infection with a neurotropic measles virus (MV) is associated with a cell-mediated autoimmune response (CMAI) to myelin basic protein (MBP). MBP-selected CD4+ T cell lines both from measles-infected animals as well as from rats challenged with guinea pig MBP (Gp-MBP) had a similar pattern of response in the presence of synthetic peptides to Gp-MBP and specifically responded in vitro only to the encephalitogenic and not the non-encephalitogenic or other control peptides. In primary splenic lymphocyte cultures from SAME animals, however, a low but significant T-cell response was obtained against the non-encephalitogenic peptide S67 (residues 69-81) of the Gp-MBP. Moreover, immunization of MV-infected rats with this peptide induced clinical and histological experimental allergic encephalomyelitis (EAE) in 38% of the animals. The results of the study show that the non-encephalitogenic peptide S67 can be rendered encephalitogenic in rats when an additional stimulus is given in the form of MV infection. The data indicate further that MV infection of the central nervous system (CNS) enhances the susceptibility of the CNS to autoimmune T cell aggression.


Assuntos
Autoimunidade , Vírus do Sarampo/imunologia , Proteína Básica da Mielina/imunologia , Animais , Linhagem Celular , Encefalomielite Autoimune Experimental/etiologia , Encefalomielite Autoimune Experimental/imunologia , Epitopos/análise , Cobaias , Imunização , Ativação Linfocitária , Fragmentos de Peptídeos/imunologia , Ratos , Ratos Endogâmicos Lew , Linfócitos T/imunologia
12.
J Neuroimmunol ; 39(3): 251-60, 1992 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1379608

RESUMO

The V beta 8 CDR2 consensus peptide, residues 44-54, is highly effective in the treatment of clinical experimental autoimmune encephalomyelitis (EAE) in Lewis rats. To monitor immunological changes during EAE resulting from TCR peptide therapy, the frequencies of encephalitogenic and regulatory T cells were quantitated in lymph nodes, blood, and spinal cord. The frequency of T cells specific for basic protein and its major encephalitogenic epitope, residues 72-89, increased during EAE to about 1 cell per 100,000 lymph node or blood cells at the peak of clinical disease, and then declined. In contrast, the frequency of these T cells in spinal cord was highest, 50 per 100,000, prior to onset of clinical signs, and then decreased rapidly prior to spontaneous recovery. Injection of 100 micrograms of TCR V beta 8-44-54 peptide caused a decrease within 1-5 days in the frequencies of guinea pig basic-protein (GP-BP) and 72-89-reactive T cells in blood and spinal cord, and in the total number of infiltrating cells in spinal cord. In lymph nodes, 72-89-reactive T cells decreased as T cells specific for a protective epitope, residues 55-69 of GP-BP increased, suggesting epitope switching at the site of GP-BP immunization. Conversely, the frequency of T cells specific for the V beta 8-44-54 peptide increased, especially in blood and spinal cord, whereas T cell frequencies to control antigens were unchanged. These data document the critical presence of encephalitogenic T cells within the spinal cord during clinical EAE, and demonstrate that rapid and profound changes in T cell frequencies in the periphery and spinal cord are triggered by TCR peptide therapy.


Assuntos
Encefalomielite Autoimune Experimental/terapia , Fragmentos de Peptídeos/uso terapêutico , Receptores de Antígenos de Linfócitos T/fisiologia , Medula Espinal/efeitos dos fármacos , Linfócitos T/efeitos dos fármacos , Sequência de Aminoácidos , Animais , Encefalomielite Autoimune Experimental/imunologia , Epitopos , Feminino , Cobaias , Dados de Sequência Molecular , Proteína Básica da Mielina/imunologia , Ratos , Medula Espinal/imunologia , Medula Espinal/patologia , Linfócitos T/imunologia
13.
J Neuroimmunol ; 1(3): 311-24, 1981 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-6174544

RESUMO

Among the antibodies contained in a rabbit antiserum to synthetic peptide sequence TTHYGSLPQKAQGHRPQDEG (S82) of bovine myelin basic protein (residues 65-83 plus glycine), was a population reactive with a C-terminal determinant of S82 and cross-reactive with S79 (AQGHRPQDEG) but not S6 (AQGHRPQDENG). This antibody population was purified 153-fold by affinity chromatography from a minicolumn containing S79 coupled to CH-Sepharose 4B(TM) and eluted with 3 M MgCl2. The purified antibodies were then coupled to CNBr-activated Sepharose 4B(TM) and used to purify 125I-labelled, acylated S79 ([125I]S79), 3 M MgCl2 once again having been used to elute the labelled ligand. Sips distribution studies revealed appreciable heterogeneity of binding affinities of unpurified antibodies in their reaction with affinity-purified [125I]S79 or of purified antibodies in their reaction with unpurified [125I]S79 (heterogeneity constant a = 0.34 and 0.36, respectively). In contrast Sips distribution data indicated considerable restriction of binding of the purified antibodies in their reaction with purified labelled ligand (a = 0.92) with an average affinity constant of K0 = 1.56 X 10(8) M-1. The results indicate that the heterogeneous spectrum of binding affinities originally displayed by the unpurified S79-reactive antibodies in their reaction with unpurified labelled S79 was due both to the presence of some antibodies characterized by high affinity binding (K0 greater than 10(9) M-1) and of some labelled ligand with low binding affinity. The affinity chromatographic method as here described should prove advantageous in purifying and eventually characterizing picomolar amounts of serum factors, previously postulated to be fragments of myelin basic protein, that are reactive with reagent antibodies up to an affinity level of 10(8) M-1.


Assuntos
Afinidade de Anticorpos , Proteína Básica da Mielina/imunologia , Anticorpos/análise , Ligação Competitiva , Reações Cruzadas , Epitopos , Radioisótopos do Iodo , Ligantes/imunologia , Proteína Básica da Mielina/análise , Fragmentos de Peptídeos/imunologia , Radioimunoensaio
14.
J Neuroimmunol ; 1(2): 205-16, 1981 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-6175660

RESUMO

The timing and intensity of the antibody responses to the marker determinants of synthetic peptide S81 and S82 sequences of bovine myelin basic protein (MBP) (residues 68-83 and 65-83, respectively) were studied in 20 Lewis rats and 6 rabbits. All rats immunized with either peptide in CFA responded with antibody development. All rabbits immunized with S82 and CFA developed both antibodies and experimental allergic encephalomyelitis. In contrast only one rabbit developed antibodies against S81 and none of the S81-challenged rabbits developed disease. On the basis of extrapolation of linear time-response curves to zero activity, the time of appearance of anti-peptide antibody activity in the Lewis rats was 15.1 +/- 1.7 days after a single immunization, a week longer than the normal latent period before appearance of anti-MBP antibodies. The time of appearance of anti-S82 antibody activity in rabbits exhibiting linear response curves was 18 days, 4 days after a booster immunization with S82 in incomplete Freund's adjuvant. The development of clinical signs of experimental allergic encephalomyelitis occurred within 4 weeks after initial challenge (a few days after boosting) and continued for 8--13 days in all S82-immunized rabbits.


Assuntos
Formação de Anticorpos , Proteína Básica da Mielina/imunologia , Sequência de Aminoácidos , Animais , Epitopos/imunologia , Masculino , Fragmentos de Peptídeos/imunologia , Coelhos/imunologia , Radioimunoensaio , Ratos , Ratos Endogâmicos Lew/imunologia , Fatores de Tempo
15.
J Neuroimmunol ; 1(2): 217-26, 1981 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-6175661

RESUMO

It was shown that 125I-labelled and unlabelled forms of synthetic encephalitogenic peptide S82 (residues 65-83 plus glycine) of bovine myelin basic protein (MBP-Bov) were equally competitive in dual-dilution radioimmunoassays with rat- and rabbit-anti-S82 antisera without causing much deviation even at the extremes of the dual-dilution binding curves (solved in terms of total S82). With other antisera the deviations caused by the addition of unlabelled S82 were much greater than would be expected among repetitive assays with labelled antigen alone, and the excessive deviations were usually more prominent in one region of the dual-dilution binding curve than in another. Thus, establishing equivalence between labelled and unlabelled antigen with respect to one antiserum even at several dilutions does not establish proportionate sharing with respect to all antisera at all antigen concentrations. A method of dual-dilution equilibrium competitive inhibition analysis was devised that took this precaution into account. By means of the method, synthetic MBP-Bov peptides representing different parts of the S82 sequence were compared with homologous S82 peptide for their inhibitory effects upon dually diluted [125I]S82-anti-S82 systems. By this process several different S82 determinants were pinpointed, some with high affinity antibodies, others with low affinity antibodies, yet others equally well at high or low affinity.


Assuntos
Antígenos/análise , Ligação Competitiva , Proteína Básica da Mielina/imunologia , Fragmentos de Peptídeos/imunologia , Radioimunoensaio/métodos , Animais , Anticorpos/análise , Afinidade de Anticorpos , Proteína Básica da Mielina/análise , Coelhos , Ratos , Ratos Endogâmicos Lew
16.
J Neuroimmunol ; 22(3): 255-60, 1989 May.
Artigo em Inglês | MEDLINE | ID: mdl-2467920

RESUMO

T cell lines were selected from basic protein (BP)-immunized SJL/J mice using synthetic peptides encompassing the major SJL/J encephalitogenic determinant. Synthetic peptide-derived T cell lines proliferated in response to BP, the 89-169 peptidase fragment of BP and the synthetic peptides, pM87-99, pM90-99 and pM91-99. These lines transferred a demyelinating and chronic relapsing form of experimental autoimmune encephalomyelitis (EAE) into naive mice, and EAE induced by synthetic peptide-derived lines was more severe than that induced by whole BP-derived lines. This study demonstrates that T cell lines selected with synthetic peptides are encephalitogenic in SJL/J mice and offers an improved means for selecting SJL/J encephalitogenic T cell lines.


Assuntos
Encefalite/imunologia , Peptídeos/imunologia , Linfócitos T/imunologia , Animais , Divisão Celular , Linhagem Celular , Encefalite/patologia , Camundongos , Camundongos Endogâmicos , Proteína Básica da Mielina/imunologia , Fragmentos de Peptídeos/imunologia , Peptídeos/síntese química , Linfócitos T/citologia , Linfócitos T/fisiologia
17.
J Neuroimmunol ; 13(2): 143-58, 1986 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2430996

RESUMO

Specific ligand neutralization was used to probe the extent to which singular antibody affinity populations signified specific determinants in the neighborhood myelin basic protein (MBP) encephalitogens. The probes were individual members of a panel of synthetic peptide analogs subsuming encephalitogenic regions. Comparative Scatchard analyses of neutralized and unneutralized antisera helped to identify the particular peptide determinants involved in the original polyclonal antibody responses to the multiple antigenic determinants of encephalitogenic peptides. The range of affinities for an antibody population against a singular MBP peptide determinant was found to be relatively restricted while the range of affinities overall for all populations within a given antipeptide antiserum was found to be relatively wide and invariably discontinuous. Consequently, the individual discontinuous affinity populations could readily be dissected by application of the Rosenthal method of Scatchard curve analysis. It was found that the singular high affinity antibody population (5.6 x 10(7) M-1) of a Lewis rat antiserum to rat encephalitogenic GSLPQKAQRPQDENG (S49) was against a determinant near the N-terminal non-encephalitogenic end of the peptide. Only the low affinity antibody populations were found that had reactivity for determinants within the encephalitogenic region itself. The singular high affinity antibody population (5.97 x 10(7) M-1) of a rabbit antiserum to rabbit encephalitogenic TTHYGSLPQKAQGHRPQDEG (S82) was against a determinant centered about the tyrosyl residue, within the encephalitogenic region for the rabbit, but was completely cross-reactive with a specific circulating endogenous inhibitor. The results obtained with the rat and rabbit EAE sera were consistent with a previously advanced hypothesis that antibodies to determinants within encephalitogenic neighborhoods would effectively block the onset of EAE if high enough in affinity and not neutralized by an endogenous inhibitor.


Assuntos
Afinidade de Anticorpos , Proteína Básica da Mielina/imunologia , Animais , Encefalomielite Autoimune Experimental/imunologia , Epitopos/imunologia , Soros Imunes/imunologia , Testes de Neutralização , Fragmentos de Peptídeos/síntese química , Fragmentos de Peptídeos/imunologia , Coelhos , Radioimunoensaio , Ratos , Ratos Endogâmicos Lew
18.
J Neuroimmunol ; 13(1): 61-73, 1986 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-2428834

RESUMO

Fischer 344 rats, immunized with the synthetic encephalitogenic myelin basic protein peptide YS49 (YGSLPQKAQRPQDENG), produced heteroclitic antibodies that reacted much more extensively and with a much higher affinity with the cross-reacting encephalitogenic guinea pig sequence S49S (GSLPQKSQRSQDENG) than they did with the immunogenic YS49. On the other hand, antisera against S49S reacted in a normal manner with homologous S49S and cross-reacted only poorly with YS49. The phenomenon of heteroclisis in Fischer 344 rats correlated with the greater encephalitogenic potency of the cross-reacting entity. Kibler et al. (J. Exp. Med., 146 (1977) 1323-1331), by comparing the encephalitogenic guinea pig sequence to a less potent analog, had also previously observed what now would be termed a heteroclitic phenomenon at the T cell level in Lewis rats. In their hands, however, as well as in ours Lewis rat antisera against the encephalitogenic peptide region were much too complex to be analyzed with respect to heteroclisis. It was shown in the present experiments that by utilizing the Fischer 344 system one may also readily obtain heteroclisis at the B cell level against encephalitogenic peptides. Neither YS49 nor S49S as immunogen produced detectable antibody in Brown Norway (BN) rats with exception of two immunized with YS49. In those two cases heteroclitic antibodies were obtained that had a very low significant (greater than 3 SD above baseline) antigen binding capacity for S49S and no detectable reactivity for the homologous YS49 ligand.


Assuntos
Anticorpos Heterófilos/imunologia , Proteína Básica da Mielina/imunologia , Ratos Endogâmicos F344/imunologia , Ratos Endogâmicos/imunologia , Sequência de Aminoácidos , Animais , Afinidade de Anticorpos , Oligopeptídeos/síntese química , Oligopeptídeos/imunologia , Ratos , Ratos Endogâmicos BN/imunologia , Relação Estrutura-Atividade
19.
J Neuroimmunol ; 49(1-2): 45-50, 1994 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-7507496

RESUMO

We investigated whether myelin basic protein (MBP)-reactive T cells from multiple sclerosis (MS) patients can recognize mouse MBP since this is an expected requirement for the transfer of experimental autoimmune encephalomyelitis (EAE) into severe combined immunodeficiency (SCID) mouse-human chimeras. Peripheral blood mononuclear cells from 11 MS patients were analyzed for in vitro proliferation to mouse MBP. Six patients (55%) responded to mouse MBP at the first or second stimulation. Five T cell lines, selected with mouse MBP from five MS patients, were analyzed for their proliferation to mouse and human MBP and to a panel of synthetic peptides of human MBP. Four of the five lines recognized mouse MBP. In vitro proliferation was restricted by MHC class II in one line tested for MHC restriction. One of the five lines recognized whole human MBP and all five of the lines responded to at least one of the five synthetic peptides corresponding to human MBP residues 8-28, 67-90, 84-102, 87-99 or 130-149. These results show that MS patient T cells recognize mouse MBP and suggest that distinct human MBP epitopes are immunologically cross-reactive with epitopes of mouse MBP.


Assuntos
Epitopos/análise , Esclerose Múltipla/imunologia , Proteína Básica da Mielina/imunologia , Linfócitos T/imunologia , Sequência de Aminoácidos , Animais , Linhagem Celular , Reações Cruzadas , Antígenos de Histocompatibilidade Classe I/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Humanos , Camundongos , Camundongos SCID , Dados de Sequência Molecular , Fragmentos de Peptídeos/imunologia
20.
J Neuroimmunol ; 44(1): 57-67, 1993 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7684400

RESUMO

Recent evidence supports the possible involvement of myelin basic protein (BP) as one of the target autoantigens in multiple sclerosis (MS), including elevated frequencies of MS blood and cerebrospinal fluid (CSF) T cells, and the presence in MS plaque tissue of V beta gene sequences and CDR3 motifs characteristic of BP-reactive T cells. Because of its proximity to the target organ, the CSF has long been thought to harbor T cells involved in the pathogenic process. In order to evaluate their frequency and response characteristics, BP-reactive T cells were isolated by limiting dilution from the CSF of patients with MS and other neurological diseases (OND) for quantitation and determination of epitope specificity and V alpha and V beta gene expression. In addition to isolates responsive to intact BP epitopes that were present at a significantly higher frequency in MS versus OND CSF, we here describe a second clonotype responsive to 'cryptic' BP epitopes that is present at approximately equal frequencies in MS and OND patients. In spite of their difference in recognition of intact versus 'cryptic' BP determinants, both clonotypes predominantly recognized epitopes in the N terminal half of human BP, using a similar V gene repertoire that included biased use of V alpha 2 and to a lesser degree V beta 7 and V beta 18. These V gene biases were not related to the epitope specificity of the T cells, indicating that V gene selection is not epitope-driven. These data suggest that there is differential recognition of intact versus 'cryptic' BP determinants in MS versus OND patients that may be related to the processing and presentation of BP to the immune system.


Assuntos
Líquido Cefalorraquidiano/citologia , Epitopos , Expressão Gênica , Proteína Básica da Mielina/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Linfócitos T/imunologia , Linfócitos T/fisiologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/líquido cefalorraquidiano , Esclerose Múltipla/imunologia , Doenças do Sistema Nervoso/líquido cefalorraquidiano , Doenças do Sistema Nervoso/imunologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA