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1.
Ann Rheum Dis ; 75(5): 879-82, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26458738

RESUMO

OBJECTIVE: Ankylosing spondylitis (AS) is a chronic inflammatory disease affecting the spine and pelvis of young adults. On the HLA-B27 genetic background, the occurrence of AS is influenced by the intestinal microbiota. The goal of our study was to test whether breast feeding, which influences microbiota, can prevent the development of AS. METHODS: First, 203 patients with HLA-B27-positive AS fulfilling the modified New York criteria were recruited in the Department of Rheumatology, Ste Marguerite hospital in Marseilles. A total of 293 healthy siblings were also recruited to make up a control group within the same families. Second, 280 healthy controls, and 100 patients with rheumatoid arthritis and their siblings were recruited. The data collected were age, gender, number of brothers and sisters, age at disease onset, type and duration of feeding (breast or bottle). RESULTS: Patients with AS had been breast fed less often than healthy controls. In families where children were breast fed, the patients with AS were less often breast fed than their healthy siblings (57% vs 72%), giving an OR for AS onset of 0.53 (95% CI (0.36 to 0.77), p value=0.0009). Breast feeding reduced familial prevalence of AS. The frequency of breast feeding was similar in the AS siblings and in the 280 unrelated controls. However, patients with AS were less often breast fed compared with the 280 unrelated controls (OR 0.6, 95% CI (0.42 to 0.89), p<0.01). CONCLUSIONS: Our study suggests a breastfeeding-induced protective effect on the occurrence of AS. To our knowledge, this is the first study of breastfeeding history in patients with AS.


Assuntos
Aleitamento Materno/estatística & dados numéricos , Espondilite Anquilosante/prevenção & controle , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Artrite Reumatoide/prevenção & controle , Alimentação com Mamadeira/estatística & dados numéricos , Feminino , Microbioma Gastrointestinal , Predisposição Genética para Doença , Antígeno HLA-B27/genética , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Irmãos , Espondilite Anquilosante/genética , Espondilite Anquilosante/microbiologia , Fatores de Tempo , Adulto Jovem
2.
Nat Genet ; 23(1): 94-8, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10471507

RESUMO

Members of the CCN (for CTGF, cyr61/cef10, nov) gene family encode cysteine-rich secreted proteins with roles in cell growth and differentiation. Cell-specific and tissue-specific differences in the expression and function of different CCN family members suggest they have non-redundant roles. Using a positional-candidate approach, we found that mutations in the CCN family member WISP3 are associated with the autosomal recessive skeletal disorder progressive pseudorheumatoid dysplasia (PPD; MIM 208230). PPD is an autosomal recessive disorder that may be initially misdiagnosed as juvenile rheumatoid arthritis. Its population incidence has been estimated at 1 per million in the United Kingdom, but it is likely to be higher in the Middle East and Gulf States. Affected individuals are asymptomatic in early childhood. Signs and symptoms of disease typically develop between three and eight years of age. Clinically and radiographically, patients experience continued cartilage loss and destructive bone changes as they age, in several instances necessitating joint replacement surgery by the third decade of life. Extraskeletal manifestations have not been reported in PPD. Cartilage appears to be the primary affected tissue, and in one patient, a biopsy of the iliac crest revealed abnormal nests of chondrocytes and loss of normal cell columnar organization in growth zones. We have identified nine different WISP3 mutations in unrelated, affected individuals, indicating that the gene is essential for normal post-natal skeletal growth and cartilage homeostasis.


Assuntos
Substâncias de Crescimento/genética , Proteínas Imediatamente Precoces , Peptídeos e Proteínas de Sinalização Intercelular , Mutação , Proteínas Oncogênicas , Osteocondrodisplasias/genética , Adolescente , Osso e Ossos/fisiologia , Proteínas de Sinalização Intercelular CCN , Cartilagem/crescimento & desenvolvimento , Cartilagem/fisiologia , Cromossomos Humanos Par 6 , Fator de Crescimento do Tecido Conjuntivo , Mãos/diagnóstico por imagem , Haplótipos , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Masculino , Dados de Sequência Molecular , Proteína Sobre-Expressa em Nefroblastoma , Osteocondrodisplasias/diagnóstico por imagem , Proteínas Proto-Oncogênicas , Radiografia
3.
Nat Med ; 2(3): 306-10, 1996 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8612229

RESUMO

Most patients with rheumatoid arthritis express particular HLA-DR alleles. The DRbeta1 chains of these alleles share a highly homologous amino acid motif, in their third hypervariable (HV3) region, and this motif seems to help the development of rheumatoid arthritis via unknown mechanisms. In an attempt to identify a ligand of this motif, we screened bacterial proteins. HV3 peptides from HLA-DRB1 alleles containing a QKRAA or RRRAA motif bound the 70-kD heat shock protein (HSP) from Escherichia coli, dnaK. In lymphoblastoid cells homozygous for these same HLA-DRB1 alleles the constitutive 70-kD HSP, HSP73, that targets selected proteins to lysosomes coprecipitated with HLA-DR. Thus the QKRAA and RRRAA amino acid motifs of HLA-DR mediate binding of HLA-DR to HSP73. This property may influence the intracellular route, processing or peptide associations of the HLA-DRbeta1 chain in these two rheumatoid arthritis-associated alleles.


Assuntos
Artrite Reumatoide/genética , Artrite Reumatoide/imunologia , Proteínas de Escherichia coli , Antígeno HLA-DR4/genética , Antígeno HLA-DR4/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Alelos , Sequência de Aminoácidos , Artrite Reumatoide/etiologia , Proteínas de Bactérias/metabolismo , Proteínas de Transporte/metabolismo , Escherichia coli/metabolismo , Proteínas de Choque Térmico HSC70 , Humanos , Técnicas In Vitro , Cinética , Ligantes , Dados de Sequência Molecular , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Ligação Proteica
4.
J Exp Med ; 177(1): 109-18, 1993 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-8418195

RESUMO

We have generated transgenic mice that express the immunoglobulin (Ig)M heavy chain and kappa light chain genes coding for a human IgM rheumatoid factor (RF), Les. Transgenic B cells expressing human IgM RF show striking similarities to their counterparts in normal humans. They comprise a significant proportion of the adult B cell population, but secrete only low levels of RF into the serum. The RF transgene-expressing B cells localize to primary B cell follicles and the mantle zone regions of secondary follicles in the spleen. Using these mice we have been able to show that one of the central functions of normal RF-expressing B cells may be to act as highly efficient antigen-presenting cells for low concentrations of immune-complexed antigen. High levels of secretion of IgM RF can not be induced under normal circumstances, although RF-expressing B cells proliferate well in vitro to both aggregated human IgG and anti-human IgM antibodies. However, these mice are not intrinsically secretion deficient. By crossing the RF transgenic mice with the autoimmune MRL/lpr background, we find a dramatic increase, > 200-fold, in levels of serum RF. The results strongly suggest that a major function of normal resting RF B cells is unrelated to antibody secretion. Rather, the RF B cells in the follicles may play a role in antigen presentation and regulation of immune responses to antibody-bound nonself-, and possibly self-antigens. This physiologic role of RF B cells may be disrupted in RF-associated autoimmune disease.


Assuntos
Linfócitos B/fisiologia , Imunoglobulina M/biossíntese , Fator Reumatoide/biossíntese , Animais , Complexo Antígeno-Anticorpo/imunologia , Células Apresentadoras de Antígenos/fisiologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Receptores Fc/fisiologia , Fator Reumatoide/genética
5.
Ann Dermatol Venereol ; 137(1): 12-20, 2010 Jan.
Artigo em Francês | MEDLINE | ID: mdl-20110063

RESUMO

BACKGROUND: The cutaneous adverse effects of TNFalpha inhibitors and their potential implication in the onset of associated dermatoses remain poorly understood. PURPOSE: To describe the different clinical dermatological situations seen in patients treated with TNFalpha inhibitors. PATIENTS AND METHODS: We conducted a prospective, observational study of patients followed at the Dermatology Department of the CHU Nord university teaching hospital of Marseilles. All patients, referred by various departments, were treated with TNFalpha inhibitors and presented cutaneous events. RESULTS: Forty-one patients were included in the study. Various cutaneous manifestations were observed, including: 15 psoriatic rashes, six skin infections, three eczema rashes, three cases of lupic syndrome, two anaphylactic reactions to infusion and two cutaneous drug reactions. An original case of parapsoriasis was observed. Cutaneous tumors are rarely described. DISCUSSION: This study confirms the multiple clinical dermatological situations observed in patients treated with TNFalpha inhibitors and illustrates the need for good coordination between dermatologists and other specialists in order to ensure optimal management of this population.


Assuntos
Anticorpos Monoclonais/efeitos adversos , Toxidermias/etiologia , Imunoglobulina G/efeitos adversos , Imunossupressores/efeitos adversos , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Adalimumab , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anafilaxia/induzido quimicamente , Anticorpos Monoclonais/uso terapêutico , Anticorpos Monoclonais Humanizados , Toxidermias/epidemiologia , Eczema/induzido quimicamente , Etanercepte , Feminino , Humanos , Imunoglobulina G/uso terapêutico , Imunossupressores/uso terapêutico , Infliximab , Lúpus Eritematoso Cutâneo/induzido quimicamente , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Receptores do Fator de Necrose Tumoral/uso terapêutico , Dermatopatias Infecciosas/etiologia , Dermatopatias Papuloescamosas/induzido quimicamente , Adulto Jovem
6.
Ann Rheum Dis ; 68(4): 591-4, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18957483

RESUMO

OBJECTIVE: To identify new IgG autoantibodies in sera from patients with rheumatoid arthritis (RA). METHODS: We tested serum samples from 19 patients with RA with given human leukocyte antigen (HLA)-DR genotypes, from 7 patients with spondylarthropathy, 2 patients with lupus, 4 patients with systemic sclerosis and 10 healthy individuals on 8268 human protein arrays. RESULTS: We identified four antigens (peptidyl arginine deiminase 4 (PAD4), protein kinase Cbeta1 (PKCbeta1), phosphatylinositol 4 phosphate 5 kinase type II gamma (PIP4K2C) and v raf murine sarcoma viral oncogene homologue B1 catalytic domain (BRAF)) that were recognised almost uniquely by sera from patients with RA on protein arrays. Using purified proteins, we confirmed that PAD4 and BRAF are recognised almost uniquely by patients with RA. CONCLUSION: We identified PAD4 and BRAF as RA specific autoantigens.


Assuntos
Artrite Reumatoide/imunologia , Autoanticorpos/sangue , Autoantígenos/imunologia , Imunoglobulina G/imunologia , Análise Serial de Proteínas , Autoanticorpos/imunologia , Western Blotting/métodos , Estudos de Casos e Controles , Ensaio de Imunoadsorção Enzimática/métodos , Humanos , Hidrolases/sangue , Hidrolases/imunologia , Proteína Quinase C/sangue , Proteína Quinase C/imunologia , Proteína Quinase C beta , Proteína-Arginina Desiminase do Tipo 4 , Desiminases de Arginina em Proteínas , Proteínas Proto-Oncogênicas B-raf/sangue , Proteínas Proto-Oncogênicas B-raf/imunologia
7.
Clin Exp Rheumatol ; 26(4): 627-31, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18799094

RESUMO

OBJECTIVE: To test whether the presence of RA associated HLA-DRB1*0101, HLA-DRB1*0401 and HLA-DRB1*0404 alleles individually influences anti-cyclic citrullinated peptide antibodies (anti-CCP) production. METHODS: The frequency of anti-CCP antibodies was calculated in the sera of 260 RA patients expressing either two (double dose genotypes SE+/SE+), one (single dose genotypes SE+/SE-) or no RA associated HLA-DR alleles (SE-/SE-). Anti-CCP antibodies titers were also determined. RESULTS: RA associated HLA-DR alleles are not mandatory for production of anti-CCP. We found that 68% of SE-/SE- patients were anti-CCP positive. There was no significant difference in anti-CCP between SE negative patient (SE-/SE-) and patients expressing at least one SE (SE+/SE+ and SE+/SE-) (p=0.140). We observed no statistical difference in anti-CCP between RA patients expressing one or two SE (82% vs. 77%, p=0.577). Among SE+/SE-patients, HLA-DRB1*0404 was associated with anti-CCP with a statistically significant difference compared with SE negative patients (90% anti-CCP positive, p=0.02). HLA-DRB1*0404 was also associated with high titers of anti CCP with a statistically significant difference compared with HLA-DRB1*0401 and HLA-DRB1*0101 patients (p=0.025). CONCLUSIONS: The RA-associated HLA-DRB1*0404 allele was the most strongly associated with the presence of anti-CCP in RA sera. Moreover, HLA-DRB1*0404 patients had higher titers of anti CCP than patients with other RA associated HLA-DR alleles.


Assuntos
Artrite Reumatoide/genética , Artrite Reumatoide/imunologia , Autoanticorpos/sangue , Antígenos HLA-DR/genética , Peptídeos Cíclicos/imunologia , Artrite Reumatoide/sangue , Autoanticorpos/genética , Autoanticorpos/imunologia , Estudos de Casos e Controles , Feminino , Antígenos HLA-DR/imunologia , Cadeias HLA-DRB1 , Homozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Escleroderma Sistêmico/sangue , Escleroderma Sistêmico/imunologia
8.
J Clin Invest ; 99(8): 1818-22, 1997 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-9109425

RESUMO

The amino acid motif QKRAA, when expressed on HLA-DRB1, carries susceptibility to develop rheumatoid arthritis. This motif is the basis of strong B and T cell epitopes. Furthermore, it is highly overrepresented in protein databases, suggesting that it carries a function of its own. To identify this function, we used QKRAA peptide affinity columns to screen total protein extracts from Escherichia coli. We found that DnaK, the E. coli 70-kD heat shock protein, binds QKRAA. Of interest, DnaK has a natural ligand, DnaJ, that contains a QKRAA motif. We found that QKRAA-containing peptides inhibit the binding of DnaK to DnaJ. Furthermore, rabbit antibody to the QKRAA motif can inhibit binding of DnaJ to DnaK. These data suggest that QKRAA mediates the binding of E. coli chaperone DnaJ to its partner chaperone DnaK.


Assuntos
Proteínas de Escherichia coli , Antígenos HLA-DR/genética , Antígenos HLA-DR/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Proteínas de Choque Térmico/metabolismo , Sequência de Aminoácidos , Animais , Anticorpos , Artrite Reumatoide/etiologia , Artrite Reumatoide/genética , Artrite Reumatoide/imunologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Sítios de Ligação/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Antígenos HLA-DR/química , Cadeias HLA-DRB1 , Proteínas de Choque Térmico HSP40 , Proteínas de Choque Térmico HSP70/genética , Proteínas de Choque Térmico/genética , Humanos , Ligantes , Dados de Sequência Molecular , Ligação Proteica , Coelhos , Homologia de Sequência de Aminoácidos
9.
J Clin Invest ; 89(1): 327-31, 1992 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-1370300

RESUMO

Immunological responses to bacterial heat shock proteins have been implicated in the pathogenesis of arthritis in animals and humans. The predicted amino acid sequence of dnaJ, a heat shock protein from Escherichia coli, contains an 11-amino acid segment that is homologous to the third hypervariable region of the human histocompatibility antigen (HLA) DRB10401 (formerly known as HLA Dw4), the part of the molecule that carries susceptibility to rheumatoid arthritis. To test the biological significance of this finding, we expressed and purified recombinant dnaJ (rdnaJ), and determined its immunologic cross-reactivity with HLA DRB10401. A rabbit antipeptide antiserum raised against the sequence of the third hypervariable region of HLA DRB10401 specifically bound to 'dnaJ, thus confirming that a similar sequence is expressed on the bacterial protein. Of greater consequence, an antiserum to the 'dnaJ protein recognized not only a peptide from the third hypervariable region of HLA DRB10401, but also the intact HLA DRB10401 polypeptide. Furthermore, the antibody to 'dnaJ reacted with HLA DRB10401 homozygous B lymphoblasts, but not with HLA DRB11501, DRB10101, DRB10301, and DRB10701 (formerly known as HLA Dw2, DR 1, DR 3, and DR 7, in the same order) homozygous cells. These results demonstrate that exposure to a bacterial heat shock protein can elicit antibodies against the rheumatoid arthritis susceptibility sequence in the third hypervariable region of HLA DRB10401.


Assuntos
Artrite Reumatoide/imunologia , Linfócitos B/imunologia , Proteínas de Bactérias/imunologia , Epitopos/imunologia , Antígenos HLA-D/imunologia , Proteínas de Choque Térmico/imunologia , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Reações Cruzadas/imunologia , Escherichia coli/química , Proteínas de Escherichia coli , Variação Genética , Antígenos HLA-D/genética , Proteínas de Choque Térmico HSP40 , Proteínas de Choque Térmico/genética , Humanos , Fragmentos Fab das Imunoglobulinas/imunologia , Dados de Sequência Molecular , Homologia de Sequência do Ácido Nucleico
10.
BMC Genomics ; 6: 153, 2005 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-16271148

RESUMO

BACKGROUND: large scale and reliable proteins' functional annotation is a major challenge in modern biology. Phylogenetic analyses have been shown to be important for such tasks. However, up to now, phylogenetic annotation did not take into account expression data (i.e. ESTs, Microarrays, SAGE, ...). Therefore, integrating such data, like ESTs in phylogenetic annotation could be a major advance in post genomic analyses. We developed an approach enabling the combination of expression data and phylogenetic analysis. To illustrate our method, we used an example protein family, the peptidyl arginine deiminases (PADs), probably implied in Rheumatoid Arthritis. RESULTS: the analysis was performed as follows: we built a phylogeny of PAD proteins from the NCBI's NR protein database. We completed the phylogenetic reconstruction of PADs using an enlarged sequence database containing translations of ESTs contigs. We then extracted all corresponding expression data contained in EST database This analysis allowed us 1/To extend the spectrum of homologs-containing species and to improve the reconstruction of genes' evolutionary history. 2/To deduce an accurate gene expression pattern for each member of this protein family. 3/To show a correlation between paralogous sequences' evolution rate and pattern of tissular expression. CONCLUSION: coupling phylogenetic reconstruction and expression data is a promising way of analysis that could be applied to all multigenic families to investigate the relationship between molecular and transcriptional evolution and to improve functional annotation.


Assuntos
Regulação da Expressão Gênica , Hidrolases/genética , Animais , Artrite Reumatoide/genética , Biologia Computacional , Mapeamento de Sequências Contíguas , Bases de Dados Genéticas , Bases de Dados de Proteínas , Evolução Molecular , Etiquetas de Sequências Expressas , Expressão Gênica , Biblioteca Gênica , Genoma , Genoma Humano , Genômica , Humanos , Hidrolases/química , Camundongos , Modelos Estatísticos , Família Multigênica , Análise de Sequência com Séries de Oligonucleotídeos , Filogenia , Desiminases de Arginina em Proteínas , Proteínas , Distribuição Tecidual , Transcrição Gênica
11.
Immunol Res ; 16(1): 121-6, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9048213

RESUMO

Susceptibility to developing rheumatoid arthritis (RA) maps to a highly conserved amino acid motif located in the third hypervariable region of different HLA-DRB1 chains. This motif, namely QKRAA, QRRAA, or RRRAA, helps the development of RA by an unknown mechanism. The QKRAA motif predisposes to more severe disease than the QRRAA or RRRAA motifs. The QKRAA motif carries particular properties: it is a strong B- and T-cell epitope, it shapes the T cell repertoire, it is overrepresented in protein databases, and it is a binding motif for bacterial and human 70-kDa heat-shock proteins. In this article, we propose different models to explain how the QKRAA motif might contribute to RA.


Assuntos
Artrite Reumatoide/imunologia , Antígenos HLA-DR/imunologia , Antígeno HLA-DR4/imunologia , Sequência de Aminoácidos , Antígenos HLA-DR/fisiologia , Antígeno HLA-DR4/fisiologia , Humanos , Dados de Sequência Molecular
12.
Hum Immunol ; 60(3): 245-9, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10321961

RESUMO

OBJECTIVE: To study the influence of DMA and DMB genes on susceptibility to Rheumatoid Arthritis (RA). METHODS: HLA-DRB1, DMA and DMB polymorphisms were defined by PCR SSOP in 203 European Mediterranean RA patients and 181 unrelated healthy controls. RESULTS: No significant difference in the phenotype frequencies of DMA and DMB alleles was observed between patients and controls. We found decreased frequencies of DMA*0102 and DMB*0104 in patients but this did not reach significance. These decreased frequencies could be due to a positive linkage disequilibrium with DRB1*0701, an allele which is underrepresented in RA patients. In stratified analysis with RA susceptibility Epitope positive (SE) DRB1 alleles, there was no significant difference in DMA and DMB phenotype frequencies between SE/SE, SE/X, and X/X patients versus controls. Among SE/X subjects, no significant difference in DM distribution frequencies was observed in DRB1*0101/X, 0102/X, 0401/X, 0404/X and 0405/X groups. CONCLUSION: DMA and DMB polymorphism does not seem to influence susceptibility to develop RA. Differences in DMA phenotype frequencies between patients and controls are secondary to linkage disequilibrium with DRB1 alleles.


Assuntos
Artrite Reumatoide/genética , Predisposição Genética para Doença , Antígenos HLA-D/genética , Antígenos HLA-DR/genética , Antígenos de Histocompatibilidade Classe II , Adulto , Artrite Reumatoide/epidemiologia , Artrite Reumatoide/imunologia , França/epidemiologia , Cadeias HLA-DRB1 , Humanos , Desequilíbrio de Ligação , Região do Mediterrâneo/epidemiologia , Pessoa de Meia-Idade , Fenótipo , Polimorfismo Genético
13.
Int Rev Immunol ; 17(5-6): 263-71, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-10036634

RESUMO

Susceptibility to develop Rheumatoid arthritis (RA) maps to a highly conserved amino acid motif expressed in the third hypervariable region of different HLA-DRB1 alleles. This motif, namely QKRAA, QRRAA or RRRAA helps the development of RA by an unknown mechanism. In the past ten years, we have extensively studied the unique properties of the QKRAA motif of HLA-DRB1*0401 and have found: (1) That it can constitute B and T cell epitopes on many infectious agents; (2) That it can shape the T cell repertoire; (3) That it is overrepresented in protein databases; (4) That it constitutes a binding motif for the highly conserved family of 70 kD heat shock proteins. This may cause abnormal trafficking of HLA-DRB1*0401 in B cells and/or abnormal T cell responses to bacterial and human 70 kD heat shock proteins in people who express HLA-DRB1*0401.


Assuntos
Artrite Reumatoide/imunologia , Antígenos HLA-DR/imunologia , Proteínas de Choque Térmico/imunologia , Apresentação de Antígeno/imunologia , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito T/imunologia , Cadeias HLA-DRB1 , Humanos
14.
Autoimmunity ; 26(2): 123-8, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9546814

RESUMO

Susceptibility to develop Rheumatoid arthritis (RA) maps to a highly conserved amino acid motif ("the shared epitope") expressed in the third hypervariable region of different HLA-DRB1 alleles. This motif, namely QKRAA, QRRAA or RRRAA helps the development of RA by an unknown mechanism. However, it is now established that the shared epitope can 1. Shape the T cell repertoire. 2. Interact with 70 kD heat shock proteins.


Assuntos
Artrite Reumatoide/genética , Antígenos HLA-DR/fisiologia , Alelos , Sequência de Aminoácidos , Artrite Reumatoide/imunologia , Sítios de Ligação , Mapeamento de Epitopos , Antígenos HLA-DR/química , Antígenos HLA-DR/genética , Proteínas de Choque Térmico HSP70/imunologia , Humanos , Dados de Sequência Molecular , Alinhamento de Sequência , Linfócitos T/imunologia , Linfócitos T/fisiologia
15.
Rheum Dis Clin North Am ; 18(4): 729-40, 1992 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1280844

RESUMO

Our experiments have led us to conclude that the rheumatoid arthritis shared epitope may act as a peptide that is important for positive and negative selection of T lymphocytes, that T lymphocytes are skewed by positive selection to recognize epitopes that are similar but not identical to self, and that peptide sequences that are similar to the RA-shared epitope are abundantly expressed by microorganisms that chronically infect most people. This combination of events could partly explain the association of the shared epitope with the severe forms of RA. The hypothesis cannot be tested directly, because we do not postulate that any unique population of autoreactive T cells is expanded in RA; however, the role of positive selection in molding the human T-cell repertoire to exogenous antigens can be tested by mapping T-cell antigenic determinants on the E. coli dnaJ protein or the gp110 protein of EBV in people with different HLA-DR types. Moreover, positive selection models imply that maternal antigens that cross the placenta can influence the T-cell repertoire. Thus, one might expect to find that the frequency of HLA-DR4 in the mothers of patients with RA who themselves lack the DR4 antigen, would be more frequent than predicted by chance alone. As the principles of positive selection are more precisely delineated in animal systems, it should become possible to ascertain more clearly how the shared epitope on HLA-DR molecules enhances the severity of autoimmune reactions; however, RA only occurs in humans; possibly because of the unique inability of human macrophages to replicate. Thus, only the direct analysis of patients can directly reveal the mechanisms of disease pathogenesis.


Assuntos
Artrite Reumatoide/genética , Meio Ambiente , Artrite Reumatoide/imunologia , Autoimunidade , Epitopos , Antígenos HLA/genética , Humanos , Tolerância Imunológica , Modelos Biológicos , Seleção Genética , Sinovite/imunologia , Linfócitos T/imunologia
16.
Clin Biochem ; 25(3): 209-12, 1992 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-1378777

RESUMO

Susceptibility to rheumatoid arthritis (RA) maps to residues QKRAA/QRRAA in the third hypervariable region of the HLA DR beta 1 chain. Peptides from the same area of MHC class II molecules are able to modulate the T-cell repertoire by deleting self-reactive T-cells. The Epstein Barr virus glycoprotein gp110 and the dna J heat-shock protein from E. coli mimic the third hypervariable region of HLA-Dw4DR beta 1. Thus, the same area of HLA DR beta 1 carries susceptibility to RA, modulates the T-cell repertoire and is mimicked by human pathogens. RA may originate from a particular shape imposed on the T-cell repertoire by the QKRAA/QRRAA sequence in the third hypervariable region of HLA DR beta 1.


Assuntos
Artrite Reumatoide/imunologia , Antígeno HLA-DR4/imunologia , Sequência de Aminoácidos , Epitopos/imunologia , Humanos , Modelos Biológicos , Dados de Sequência Molecular , Peptídeos/imunologia , Linfócitos T/imunologia
17.
Clin Exp Rheumatol ; 7 Suppl 3: S69-73, 1989.
Artigo em Inglês | MEDLINE | ID: mdl-2691162

RESUMO

Rheumatoid arthritis is associated with high titers of IgM and IgG autoantibodies against IgG (rheumatoid factors, RF) and is prevalent in individuals with the HLA haplotypes Dw4, Dw14 and DR1. Our investigations have aimed to determine the molecular genetic basis for RF autoantibody synthesis in people, in an effort to understand eventually how RF production may become improperly regulated in rheumatoid patients. The results have defined several cross-reactive idiotypes on the heavy and light chains of RFs that are serologic markers for specific immunoglobulin variable region genes. These autoantibody associated genes are highly conserved in human populations and are preferentially rearranged and expressed during early B cell development, and in certain lymphoproliferative diseases. They may be associated with a B cell subpopulation that is important for the processing and presentation to T cells of protein antigens trapped in immune complexes. These RF-associated idiotypes are eventually lost during the T cell dependent antibody diversification that accompanies rheumatoid arthritis. The stimuli for the diversification have not been clearly established. However, the rheumatoid arthritis disease susceptibility determinant on the beta-1 chain of individuals with the HLA Dw4, Dw14 or DR1 haplotypes is reproduced by the gp110 protein of the Epstein-Barr virus, and is a potent stimulus for T cell proliferation. Moreover, anti-gp110 antibodies are abundant in rheumatoid arthritis patients. Thus, it is possible that their continual binding and processing of gp110-IgG immune complexes by RF precursor B cells in the joints and other extravascular sites may lead to the emergence of self-reactive T cells that can trigger anti-IgG autoantibody synthesis in the absence of an external antigen.


Assuntos
Fator Reumatoide/biossíntese , Artrite Reumatoide/genética , Artrite Reumatoide/imunologia , Reações Cruzadas , Genes de Imunoglobulinas , Humanos , Idiótipos de Imunoglobulinas , Fator Reumatoide/genética
18.
Clin Rheumatol ; 5(2): 189-92, 1986 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-3488165

RESUMO

In a previous work, we had found that anti-B lymphocyte antibodies exist in rheumatoid arthritis. To investigate whether these antibodies were directed against surface immunoglobulins or not we have investigated if RA sera could recognize similar structures on other targets such as platelets (on which immunoglobulins and immune complexes are present) by a new ELISA method. No IgG antiplatelet antibody was found in 20 RA sera. But 7 out of these 20 RA sera had IgM antiplatelet antibodies when tested on platelets from 5 donors. The comparison of the positivities of these sera on B lymphocytes and platelets from the same donors showed a statistically significant reverse (X2 = 20,008, p much less than 0.0001) correlation. The target antigen and the meaning of these IgM antiplatelet antibodies, which seem to be associated with severe RA, is still under investigation.


Assuntos
Artrite Reumatoide/imunologia , Linfócitos B/imunologia , Plaquetas/imunologia , Imunoglobulina M/imunologia , Especificidade de Anticorpos , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
19.
Joint Bone Spine ; 67(2): 134-6, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10769107

RESUMO

Recurrent thrombosis is a common complication of various rheumatic disorders and is part of the definition of antiphospholipid syndrome. We report three cases of recurrent venous thrombosis due not only to antiphospholipid syndrome with a normal activated partial thromboplastin time but also to resistance to activated protein C caused by the factor V Leiden mutation. These three cases confirm that thrombotic disease is frequently multifactorial and suggest that resistance to activated protein C should be looked for routinely in patients with suggestive clinical manifestations, particularly when standard clotting tests are normal.


Assuntos
Resistência à Proteína C Ativada/genética , Síndrome Antifosfolipídica/complicações , Síndrome Antifosfolipídica/genética , Fator V/genética , Trombose Venosa/etiologia , Trombose Venosa/genética , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva
20.
Rev Med Interne ; 8(5): 475-80, 1987.
Artigo em Francês | MEDLINE | ID: mdl-3445028

RESUMO

The authors report the case of a 46-year old woman who, 7 years after bilateral implantation of a silicone breast prosthesis, presented with a seropositive rheumatoid arthritis involving the shoulders, wrists, metacarpophalangeal and interphalangeal joints of both hands, as well as the knees and ankles. Six months after the onset of the arthritis, she developed a Raynaud's syndrome and a lacrymal and salivary dry syndrome with unilateral axillary lymphadenopathy. No regression followed the removal of the breast prostheses, one of which was found broken.


Assuntos
Doenças Autoimunes/etiologia , Mama/cirurgia , Cirurgia Plástica/efeitos adversos , Doenças Autoimunes/fisiopatologia , Feminino , Humanos , Imunidade , Pessoa de Meia-Idade , Parafina/efeitos adversos , Falha de Prótese , Silicones/efeitos adversos
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