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1.
Genes Immun ; 10(5): 478-81, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19458623

RESUMO

Systemic lupus erythematosus (SLE) disproportionately affects women. Recent work demonstrates that men with Klinefelter's syndrome (47,XXY men) have a similar risk of developing SLE as do women. We present an unusual African-American family with two SLE-affected individuals in which one of the patients with SLE also has Turner's syndrome (46,X,del(X)(q13)). Although not definitive, this family raises interesting questions regarding the function of genes located on the X chromosome in the development of SLE. The paucity of case reports documenting the overlap of SLE with Turner's syndrome while there is an association of male SLE with Klinefelter's syndrome suggests a lower risk of SLE in women with Turner's syndrome. These observations are consistent with a gene dose effect at X with two X chromosomes (46,XX or 47,XXY) conferring higher risk and one X chromosome (46,XY or 45,XO) conferring lower risk of SLE.


Assuntos
Lúpus Eritematoso Sistêmico/genética , Síndrome de Turner/genética , Adolescente , Cromossomos Humanos X , Feminino , Humanos
2.
Clin Exp Immunol ; 149(3): 553-60, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17623049

RESUMO

Interleukin (IL)-18 is a potent stimulator of immunity and augments the severity of type II collagen-induced arthritis (CIA) in rats and mice by enhancing T helper 1 (Th1) cell activation, which increases the production of proinflammatory cytokines and arthritogenic antibodies. In this study, we show that recombinant IL-18 (rIL-18) also has a direct effect on normal rat chondrocytes maintained in vitro inducing them to produce proinflammatory factors including IL-6, regulated upon activation normal T cell expressed and secreted (RANTES), prostaglandin E(2) (PGE(2)) and prostaglandin F(2alpha) (PGF(2alpha)) in a dose- and time-dependent manner. The production of matrix metalloproteinase (MMP)-13, nitric oxide (NO), tumour necrosis factor (TNF)-alpha and IL-1beta were also enhanced, although less intensely. Neutralizing polyclonal anti-rIL-18 antibodies effectively blocked the production of IL-6, PGE(2) and RANTES, as well as mRNA expression for the same products in addition to IL-18 and TNF-alpha. In contrast, neutralizing antibodies to IL-1beta, TNF-alpha and IL-6 were ineffective in suppressing any of these products. Together, these findings suggest that IL-18 may play an important, possibly direct, role in mediating cartilage injury, which might not be amenable to treatment with currently utilized anti-cytokine agents. These findings suggest further that IL-18 antagonists might prove beneficial as anti-inflammatory and chondroprotective agents in the treatment of arthritis, and that the development of such agents for human use is worth consideration.


Assuntos
Cartilagem Articular/imunologia , Condrócitos/imunologia , Mediadores da Inflamação/metabolismo , Interleucina-18/imunologia , Animais , Cartilagem Articular/citologia , Células Cultivadas , Relação Dose-Resposta Imunológica , Regulação da Expressão Gênica/imunologia , RNA Mensageiro/genética , Ratos , Ratos Endogâmicos BB , Proteínas Recombinantes/imunologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos
3.
Bone ; 39(5): 1048-1052, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16875891

RESUMO

Prostaglandin E(2) (PGE(2)) plays a critical role in skeletal physiology and bone loss. PGE(2) production is regulated in vivo by at least two cyclooxygenase (COX) isozymes, COX-1 and COX-2. The purpose of this study was to investigate the in vivo effects of the selective deletion of COX-1 or COX-2 on bone mineral density (BMD), bone microarchitecture and bone strength in wild type (WT), COX-1(-/-) and COX-2(-/-) mice. Using a LUNAR PIXImus, BMD was measured in 18 (WT), 18 COX-1(-/-) and 16 COX-2(-/-) mice. COX-1(-/-) mice exhibited significantly higher BMD (0.0506 g/cm(2) +/- 0.0014 g/cm(2)) than either WT (0.0493 g/cm(2) +/- 0.0019, P < or = 0.05) or COX-2(-/-) (0.0473 g/cm(2) +/- 0.0034, P < or = 0.01) mice. COX-2(-/-) mice had significantly lower BMD than WT (P < or = 0.01) or COX-1(-/-) (P < or = 0.01). Flexure stress of the femurs, determined by breaking the bones with three-point bending, correlated with bone density. Although plasma levels of both Ca(2+) and PTH were comparable in wild type and COX-1(-/-) mice, both were elevated in COX-2(-/-) mice consistent with primary hyperparathyroidism. These studies suggest that COX enzymes are important regulators of BMD and bone strength in mice. The beneficial effect of absence of the COX-1 enzyme on skeletal parameters may be secondary to decreases in PGE(2). On the other hand, primary hyperparathyroidism and lower bone magnesium content may account for the lower BMD and impairments in bone strength of COX-2(-/-) mice. Further elucidation of the effects of the COX pathway on bone remodeling may provide important information on potential therapeutic targets for preventing and/or treating osteoporosis.


Assuntos
Densidade Óssea/fisiologia , Osso e Ossos/fisiologia , Ciclo-Oxigenase 1/deficiência , Ciclo-Oxigenase 2/deficiência , Animais , Fenômenos Biomecânicos , Índice de Massa Corporal , Densidade Óssea/genética , Osso e Ossos/metabolismo , Cálcio/sangue , Ciclo-Oxigenase 1/genética , Ciclo-Oxigenase 2/genética , Dinoprostona/metabolismo , Feminino , Fêmur/metabolismo , Fêmur/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Knockout , Hormônio Paratireóideo/sangue
4.
Ann Rheum Dis ; 64(11): 1550-6, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15860512

RESUMO

BACKGROUND: Collagen induced arthritis (CIA) is an animal model of rheumatoid arthritis (RA) amenable to immunotherapy directed against tumour necrosis factor alpha (TNFalpha). OBJECTIVE: To evaluate whether local TNF receptor (TNF-R) gene therapy in DBA/1 mice exerts an influence beyond anti-inflammatory effects. Two measures of CIA pathogenesis were investigated-namely, immunity to collagen II (CII) 245-270 peptide (the major immunodominant epitope within bovine CII) and the preferential activation of T cell Vbeta8.2 variable region receptors in arthritic DBA/1 mice. METHODS: DBA/1 mice received single periarticular injections of media or retroviral vectors containing LacZ or human TNF-R into affected arthritic paws at disease onset. Disease severity was monitored, immune responses towards the immunodominant bovine CII 245-270 and subdominant CII 334-360 peptide epitopes were assessed by ELISA, and T cell Vbeta usage was analysed by real time polymerase chain reaction for the LacZ transduced, TNF-R, and viral-free media treated control animals. The therapeutic influence of TNF-R gene transduction was compared with other groups at different times after treatment. RESULTS: Reduced disease severity was seen 15-35 days after treatment, with a concomitant increase in immunity towards the subdominant CII 334-360 peptide epitope rather than the immunodominant CII 245-270 peptide in TNF-R treated animals. Early in the disease, TNF-R treated animals demonstrated a reduction of bias towards the otherwise predominant Vbeta8.2 T cell subset. CONCLUSIONS: TNF-R gene therapy influences cellular immunity in CIA, leading to overall disease amelioration, thus suggesting that TNF inhibition may have therapeutic potential beyond the control of inflammation in RA.


Assuntos
Artrite Experimental/terapia , Terapia Genética/métodos , Receptores do Fator de Necrose Tumoral/genética , Animais , Artrite Experimental/imunologia , Colágeno Tipo II/imunologia , Feminino , Expressão Gênica , Vetores Genéticos , Imunidade Celular , Epitopos Imunodominantes/imunologia , Interferon gama/biossíntese , Camundongos , Camundongos Endogâmicos DBA , Fragmentos de Peptídeos/metabolismo , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Retroviridae/genética , Índice de Gravidade de Doença , Transdução Genética , Transgenes/genética
5.
Arthritis Rheum ; 50(9): 3004-11, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15457470

RESUMO

OBJECTIVE: Previous studies have shown that an analog peptide of the immunodominant T cell determinant of type II collagen (CII), i.e., CII(256-276)(N(263), D(266)), was able to suppress the immune response to CII and the development of arthritis in DR1-transgenic mice. The present study tested the hypothesis that introduction of the same amino acid substitutions into full-length CII might improve the efficacy of the mutant collagen in achieving suppression of autoimmune arthritis. METHODS: Using recombinant technology, full-length CII was modified, while the native conformation was retained. Two point mutations were introduced within the immunodominant T cell determinant to convert the F(263) to N and E(266) to D, using a baculovirus expression system that has previously been utilized in the production of recombinant CII (rCII). RESULTS: The mutant rCII(N(263), D(266)) was capable of reducing the incidence and severity of arthritis as well as the antibody response to CII when administered to DR1-transgenic mice that display susceptibility to collagen-induced arthritis. More importantly, it was significantly more effective than the synthetic analog peptide, CII(256-276)(N(263), D(266)). Its mechanism of suppression may be explained by the secretion of predominantly Th2 cytokines by the T cells immunized with rCII(N(263), D(266)). Administration of rCII(N(263), D(266)) was ineffective in suppressing arthritis in IL4(-/-) mice, suggesting that the profound suppressive effects of rCII(N(263), D(266)) were mediated through the production of interleukin-4. CONCLUSION: These findings describe a promising specific immunotherapy for patients with DR1-mediated autoimmunity to CII.


Assuntos
Adjuvantes Imunológicos/uso terapêutico , Artrite Experimental/tratamento farmacológico , Colágeno Tipo II/uso terapêutico , Animais , Artrite Experimental/imunologia , Bovinos , Colágeno Tipo II/imunologia , Citocinas/imunologia , Regulação para Baixo , Antígeno HLA-DR1/imunologia , Humanos , Camundongos , Camundongos Transgênicos , Modelos Animais , Mutação , Células Th2/imunologia
6.
Clin Exp Immunol ; 136(3): 440-7, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15147345

RESUMO

Interleukin (IL)-18 is a member of the IL-1 cytokine family. Its expression is increased in rheumatoid arthritis synovium, and its proinflammatory effects have been demonstrated in experimental models of murine arthritis. Here, we investigate the actions of varying doses of recombinant rat IL-18 (rIL-18) on the course of type II collagen-induced arthritis (CIA) in BB rats, including clinical and immune events, plus splenic cytokine production. Small doses of rIL-18 (10 and 50 microg/rat) administered intraperitoneally (i.p.) increased arthritis incidence and severity (P < 0.01) when a low-potency CII preparation was used for immunization. IgG1 and IgG2a anti-CII antibody levels were significantly greater in rats given 10 and 50 microg rIL-18 doses than controls. rIL-18 significantly increased levels of proinflammatory cytokines [interferon (IFN)-gamma, IL-2, tumour necrosis factor (TNF)-alpha and IL-6] produced by splenocyte cultures. Larger doses of rIL-18 (300 microg/rat) suppressed arthritis and immunity. To ascertain whether the pro-arthritic effects of IL-18 could be attenuated, rats were treated with neutralizing rabbit anti-rIL-18 IgG before immunization with a high-potency CII preparation. When given serially for 3 weeks, the incidence and severity of CIA, in addition to anti-CII IgG2a and splenic IL-6 and IFN-gamma production, were all significantly reduced. Similar results were noted when antibody was given twice, just before arthritis onset. These results demonstrate that IL-18 plays an important proinflammatory role in the pathogenesis of CIA which is achieved, in part, by an immunostimulatory action. Neutralizing endogenous IL-18 with antibodies attenuated CIA, CII immunity and cytokine responses. These studies support the use of IL-18 antagonists as treatments for inflammatory arthritis.


Assuntos
Artrite Experimental/imunologia , Interleucina-18/fisiologia , Membrana Sinovial/imunologia , Animais , Anticorpos Monoclonais/uso terapêutico , Artrite Experimental/tratamento farmacológico , Colágeno , Feminino , Interferon gama/imunologia , Interleucina-18/farmacologia , Interleucina-2/imunologia , Interleucina-6/imunologia , Masculino , Ratos , Ratos Endogâmicos BB , Fator de Necrose Tumoral alfa/imunologia
7.
Am J Med Sci ; 324(2): 101-3, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12187928

RESUMO

Relapsing polychondritis (RP) is a disease characterized by inflammation and the destruction of cartilage. The detection of antibodies to native type II collagen (CII) in the sera of some patients with relapsing polychondritis suggests that autoimmunity to this cartilage specific protein plays a role in the pathogenesis of the disease. RP is so rare that controlled therapeutic trials have not been carried out. We describe herein a child with RP who had amelioration of symptoms and a deviation in the cellular immune response to CII after being treated with daily oral CII as a toleragen.


Assuntos
Colágeno Tipo II/administração & dosagem , Policondrite Recidivante/tratamento farmacológico , Policondrite Recidivante/imunologia , Pró-Colágeno/administração & dosagem , Administração Oral , Autoimunidade , Criança , Colágeno Tipo II/imunologia , Citocinas/metabolismo , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Pró-Colágeno/imunologia , Linfócitos T/imunologia , Resultado do Tratamento
8.
Arthritis Rheum ; 46(4): 1086-93, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11953988

RESUMO

OBJECTIVE: Past attempts to isolate type IX collagen (CIX) from cartilage using limited proteolysis yielded partially degraded material. Recent application of recombinant technology, however, has allowed the preparation of intact native CIX. We used the murine collagen-induced arthritis model to characterize the immunologic properties of recombinant human CIX (rCIX) produced using a baculovirus expression system. METHODS: A panel of B10 congenic mice was immunized with rCIX emulsified with Freund's complete adjuvant (CFA). The ability of the rCIX to induce tolerance and suppress arthritis was determined by administration intravenously or orally before challenge with CII/CFA. RESULTS: None of the mice immunized with rCIX developed overt arthritis, although 2 of 5 HLA-DR1 transgenic mice developed limited digital erythema and swelling. Recombinant CIX administered by either route effectively induced suppression of arthritis, although the suppression was less pronounced than that induced with CII. Immune responses to CIX and CII were specific, suggesting that bystander suppression, rather than cross-reactivity with CII, was instrumental in suppressing arthritis. CONCLUSION: These data show that CIX down-regulates arthritis in mice while having no associated risk of inducing arthritis.


Assuntos
Artrite Experimental/imunologia , Colágeno Tipo IX/imunologia , Administração Oral , Adulto , Animais , Artrite Experimental/genética , Predisposição Genética para Doença , Haplótipos , Humanos , Tolerância Imunológica , Injeções Intravenosas , Masculino , Camundongos , Camundongos Congênicos , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/farmacologia , Linfócitos T/imunologia
9.
Clin Immunol ; 102(2): 185-91, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11846461

RESUMO

Collagen-induced arthritis (CIA) is a murine model of autoimmune-mediated polyarthritis. CIA can be prevented by the administration (intravenously) of CII, inducing regulatory CD4+ T cells which produce Th2 cytokines. However, the relative importance of IL-4 in suppressing arthritis remains unclear. To address this question, a neutralizing monoclonal antibody to IL-4 was given to mice treated with tolerized, CII-specific cells. The antibody significantly reversed the expected suppression of arthritis. Moreover, CII administered intravenously to DBA/1 IL4-/- mice (developed by backcrossing C57B1/6 IL4-/- to wild-type DBA/1 mice) was completely ineffective in suppressing disease. These data support the importance of IL-4 in the regulation of autoimmune arthritis. Compensatory increases in mRNA message for other Th2 cytokines were observed, but they did not restore suppression of arthritis. Antibodies to CII, mostly IgG2a, were increased in IL4-/- mice. These studies represent a unique opportunity to analyze the role of IL-4 and its absence on an autoimmune murine model of arthritis.


Assuntos
Artrite Experimental/imunologia , Colágeno Tipo II/imunologia , Interleucina-4/imunologia , Animais , Artrite Experimental/patologia , Autoimunidade , Modelos Animais de Doenças , Interleucina-4/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Knockout
10.
Arthritis Rheum ; 44(8): 1775-81, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11508428

RESUMO

OBJECTIVE: Joint inflammation in juvenile rheumatoid arthritis (JRA) is sometimes associated with an autoimmune response to type II collagen (CII), a cartilage-specific protein. To test the hypothesis that down-regulation of autoimmunity to CII can be accomplished in JRA by oral administration of CII, an open-label study of CII was performed in 9 patients with JRA. METHODS: Seven rheumatoid factor-negative JRA patients with polyarticular disease and 2 JRA patients with pauciarticular disease (1 with early onset and 1 with late onset) were treated for 3 months with oral bovine CII. Patients were examined for disease activity and underwent routine laboratory testing at monthly intervals. Two of the patients had flares of disease when treatment was discontinued, and these patients were re-treated for an additional 3 months. To test the hypothesis that oral tolerance induces an immune deviation of T cells, peripheral blood mononuclear cells from patients were collected before and after treatment and cultured with CII. Supernatants and RNA were collected and analyzed for the presence of various cytokines. RESULTS: Eight patient trials met the criteria for clinical improvement outlined by Giannini and coworkers in 1997. None of the patients had any side effects from the treatment. In 6 of the 8 patients who improved, interferon-gamma production decreased after oral CII therapy, correlating with clinical improvement, while 6 patients had increases in levels of transforming growth factor beta3. CONCLUSION: These results are encouraging. The possible beneficial effect of oral CII in JRA merits further investigation.


Assuntos
Artrite Juvenil/imunologia , Artrite Juvenil/terapia , Autoimunidade , Colágeno/uso terapêutico , Administração Oral , Adolescente , Autoantígenos/administração & dosagem , Autoantígenos/farmacologia , Autoantígenos/uso terapêutico , Células Cultivadas , Criança , Pré-Escolar , Colágeno/administração & dosagem , Colágeno/farmacologia , Citocinas/biossíntese , Citocinas/genética , Feminino , Humanos , Interferon gama/biossíntese , Interferon gama/genética , Masculino , RNA Mensageiro/biossíntese , Linfócitos T/metabolismo , Fator de Crescimento Transformador beta/biossíntese , Fator de Crescimento Transformador beta/genética , Resultado do Tratamento
11.
J Immunol ; 166(3): 1492-8, 2001 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-11160188

RESUMO

Rheumatoid arthritis (RA) is the most common, crippling human autoimmune disease. Using Western blotting and tandem mass spectroscopy, we have identified the endoplasmic reticulum chaperone BiP, a 78-kDa glucose-regulated protein, as a possible autoantigen. It preferentially stimulated increased proliferation of synovial T cells from patients with RA but not from patients with other arthritides. Mice with established collagen- or pristane-induced arthritis developed IgG Abs to BiP. Although BiP injected in CFA failed to induce arthritis in several strains of rats and mice, including HLA-DR4(+/-)- and HLA-DR1(+/+)-transgenic animals, it completely inhibited the development of arthritis when given i.v. 1 wk before the injection of type II collagen arthritis. Preimmunization with BiP suppressed the development of adjuvant arthritis in Lewis rats in a similar manner. This is the first report of a mammalian chaperone that is an autoantigen in human RA and in experimental arthritis and that can also prevent the induction of experimental arthritis. These findings may stimulate the development of new immunotherapies for the treatment of RA.


Assuntos
Artrite Experimental/imunologia , Artrite Experimental/prevenção & controle , Artrite Reumatoide/imunologia , Autoantígenos/imunologia , Proteínas de Transporte/administração & dosagem , Proteínas de Transporte/imunologia , Proteínas de Choque Térmico , Chaperonas Moleculares/administração & dosagem , Chaperonas Moleculares/imunologia , Adulto , Animais , Artrite Experimental/etiologia , Artrite Reumatoide/patologia , Autoanticorpos/biossíntese , Autoanticorpos/sangue , Autoantígenos/sangue , Autoantígenos/isolamento & purificação , Retículo Endoplasmático/imunologia , Chaperona BiP do Retículo Endoplasmático , Feminino , Humanos , Esquemas de Imunização , Injeções Intradérmicas , Injeções Intravenosas , Ativação Linfocitária , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Transgênicos , Pessoa de Meia-Idade , Ratos , Ratos Endogâmicos Lew , Ratos Wistar , Membrana Sinovial/imunologia , Membrana Sinovial/patologia , Linfócitos T/imunologia , Linfócitos T/patologia , Células Tumorais Cultivadas
12.
Free Radic Res ; 35(6): 693-707, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11811522

RESUMO

N(G),N(G)-dimethyl-L-arginine (asymmetric dimethylarginine or ADMA) and N(G)-monomethyl-L-arginine (L-NMMA) are post-translationally synthesized amino acids of nuclear proteins. Upon release during protein turnover, they are not used in protein synthesis, but are excreted or metabolized by dimethylarginine dimethylaminohydrolase (DDAH) found in many tissues. DDAH is present in monocytic and polynuclear cells of blood, but no report has appeared of its presence in red blood cells (RBCs). Because methylated arginines can inhibit nitric oxide synthase (NOS) and elevations are reported in several diseases, we explored whether RBCs express this enzyme. DDAH is present in RBCs as supported by hydrolysis of both ADMA and L-NMMA, but not symmetric dimethylarginine, and by immunoprecipitation/Westem blot using a specific monoclonal antibody to human DDAH. In a pilot study of end-stage renal disease (ESRD) patients, RBC DDAH activity with ADMA as substrate correlated inversely with age (p = 0.005) and enzyme activities were higher in patients with greater diastolic blood pressure drops during hemodialysis (p = 0.02). Similar correlations were found with white cell DDAH activity. Thus, human RBCs can hydrolyze methylated arginines. These findings indicate the RBC could be used to assess the status of DDAH in various disease states.


Assuntos
Amidoidrolases/metabolismo , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Eritrócitos/enzimologia , Óxido Nítrico Sintase/antagonistas & inibidores , Adulto , Fatores Etários , Western Blotting , Citrulina/metabolismo , Feminino , Humanos , Hidrólise , Falência Renal Crônica/enzimologia , Cinética , Masculino , Pessoa de Meia-Idade , Especificidade por Substrato
13.
J Immunol ; 164(4): 1820-8, 2000 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-10657630

RESUMO

Respiratory challenge of mice with murine gammaherpesvirus 68 (gammaHV68) results in acute replication in respiratory epithelial cells and persistent, latent infection of B cells and macrophages. gammaHV68 elicits virus-specific Ab, and also nonspecifically activates B cells to Ab production through a CD4+ T cell-dependent process. The current analysis characterizes virus-specific and nonspecific Ab production at the single cell level and investigates the requirements and nature of the nonspecific response. Virus-specific Ab-forming cell (AFC) numbers were dwarfed by the increase in total AFC in all sites examined, indicating substantial nonspecific Ab production. Clear increases and decreases in specific and total AFC numbers occurred in the lymph nodes draining the respiratory tract and the spleen, but AFC numbers in the bone marrow (BM) increased to a plateau and remained constant. The longevity of the BM response was reflected in a sustained increase in virus-specific and total serum Ab levels. Generally, the IgG2a and IgG2b isotypes predominated. Analysis of cytokine-deficient mice, CD40 ligand-deficient mice, and radiation BM chimeras lacking MHC class II expression specifically on B cells indicated that nonspecific Ab production is independent of IL-6 or IFN-gamma, and dependent on cognate CD4+ T cell help. Several observations were consistent with polyclonal B cell activation by gammaHV68, including the induction of durable serum levels of IgG reactive with mammalian dsDNA and murine type II collagen. Our findings indicate new directions for studies of this valuable model of gamma-herpesvirus pathogenesis.


Assuntos
Especificidade de Anticorpos , Linfócitos B/imunologia , Linfócitos B/virologia , Gammaherpesvirinae/imunologia , Infecções por Herpesviridae/imunologia , Animais , Anticorpos Antivirais/biossíntese , Anticorpos Antivirais/sangue , Células Produtoras de Anticorpos/metabolismo , Autoanticorpos/biossíntese , Linfócitos B/metabolismo , Células da Medula Óssea/imunologia , Células da Medula Óssea/metabolismo , Células Clonais , Citocinas/deficiência , Citocinas/genética , Infecções por Herpesviridae/sangue , Cinética , Linfonodos/imunologia , Linfonodos/metabolismo , Ativação Linfocitária , Cooperação Linfocítica , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Baço/imunologia , Baço/metabolismo , Linfócitos T/imunologia
14.
Arthritis Rheum ; 43(12): 2687-93, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11145026

RESUMO

OBJECTIVE: To determine the effects of cyclooxygenase 1 (COX-1) and COX-2 gene deletion on collagen-induced arthritis (CIA). METHODS: Mice that were susceptible to CIA but lacked either the COX-1 or the COX-2 gene were immunized with type II collagen (CII), and the incidence and severity of arthritis were compared with findings in wild-type animals, by clinical and histologic examination. The immune response was assessed by measuring total CII IgG, IgG1, and IgG2 antibody production in sera from immunized mice. The passive transfer of arthritis, accomplished using anti-CII monoclonal antibodies, was tested in wild-type and COX-deficient (-/-) mice. Splenocytes cultured from CII-immunized wild-type and COX-/- mice were challenged with bovine alpha1(II), and cytokine production was assessed. RESULTS: COX-2 gene deletion reduced the incidence and severity of CIA compared with findings in wild-type and COX-1-/- mice. Histologic examination of joints after the onset of clinical arthritis revealed cartilage erosions, proliferation of the synovial lining, and inflammatory cell infiltration in wild-type and COX-1-/- mice, but not in COX-2-/- mice. COX-2-/- mice exhibited reduced anti-CII IgG antibody levels, indicating a decreased immune response. However, cytokine production by spleen cells from immunized mice indicated no cytokine deficiencies in COX-2-/- mice compared with wild-type or COX-1-/- mice. More important, arthritis could not be passively transferred to naive COX-2-/- mice, indicating a requirement for COX-2 in the pathogenesis of arthritis, independent of the immune response. CONCLUSION: COX-2-/- mice exhibit at least 2 defects resulting in down-modulation of the development of CIA: a reduced immune response to CII demonstrated by a markedly reduced antibody titer, and an "inflammatory" defect reflected by the inability to passively transfer arthritis to COX-2-/- mice.


Assuntos
Artrite/imunologia , Doenças Autoimunes/prevenção & controle , Isoenzimas/genética , Prostaglandina-Endoperóxido Sintases/genética , Animais , Anticorpos Monoclonais/imunologia , Formação de Anticorpos , Artrite/induzido quimicamente , Colágeno/imunologia , Ciclo-Oxigenase 2 , Citocinas/fisiologia , Deleção de Genes , Imunização , Imunização Passiva , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Baço/química , Baço/citologia
15.
J Immunol ; 164(1): 481-7, 2000 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-10605045

RESUMO

Two major T cell determinants are recognized by I-Ar-specific T cells in CII, the immunodominant CII610-618 (GPAGT AGA R) within CB10 and the subdominant CII445-453 (GPAGP AGE R) within CB8. Although the determinants differ by only two residues, CB8 is capable of inducing collagen-induced arthritis (CIA), while CB10 is not. We, therefore, investigated the structural differences between the two determinants that are critical to inducing arthritis. When the CB10 determinant was mutated to that of CB8 using recombinant techniques, the resulting mutant rCB10T614P,A617E product became arthritogenic. Conversely, when the CB8 determinant was mutated to that of CB10, the resulting mutant CB8P449T,E452A was no longer arthritogenic. Comparison of the epitope specificity of the autoantibodies induced by wild-type CB10 and mutant rCB10T614P, A617E revealed no qualitative differences. T cells from mice immunized with either CB10 or mutant rCB10 produced predominantly Th1 cytokines when cultured with the immunizing Ag. In contrast, when cultured with mouse CII, T cells from mice immunized with the nonarthritogenic CB10 produced predominantly Th2 (IL-4 and IL-10) cytokines whereas the arthritogenic mutant rCB10 induced predominantly Th1 (IFN-gamma) cytokines. We conclude that the T cell cytokine response most critical for the induction of CIA is that induced against the corresponding homologous murine T cell determinant and, further, that the structural differences between the T cell determinants in CB8 and -10 are important in breaking self tolerance and inducing autoimmune response.


Assuntos
Artrite Experimental/genética , Artrite Experimental/imunologia , Colágeno/genética , Colágeno/imunologia , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/imunologia , Proteínas Recombinantes/imunologia , Animais , Antígenos/biossíntese , Antígenos/imunologia , Antígenos/metabolismo , Artrite Experimental/etiologia , Autoanticorpos/biossíntese , Autoanticorpos/química , Colágeno/biossíntese , Citocinas/biossíntese , Hibridomas , Epitopos Imunodominantes/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Fragmentos de Peptídeos/biossíntese , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/metabolismo , Linfócitos T/imunologia , Linfócitos T/metabolismo
16.
Clin Immunol ; 92(3): 256-64, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10479530

RESUMO

Theoretically, the ability to produce recombinant type II collagen (CII) peptide fragments in a prokaryotic expression system would be extremely useful for preparing adequate amounts of CII peptides suitable for therapeutic uses. Bacteria do not contain the enzymes involved in the extensive posttranslational modifications that occur during the biosynthesis of CII, such as the hydroxylation of prolyl and lysyl residues and glycosylation of hydroxylysyl residues. As these posttranslational modifications may play a role in the immune and arthritogenic response to CII, it was unclear whether collagen expressed in Escherichia coli would be immunologically comparable to tissue-derived CII. Therefore, we prepared recombinant proteins for CB8 and CB10 by cloning CB8 (CII 403-551) and CB10 (CII 552-897) genes from bovine chondrocytes by RT-PCR technique and expressing them in an E. coli expression system. Characterization of these recombinant proteins revealed that both rCB8 and rCB10 stimulated T cell proliferation in a T cell determinant-specific manner. The T cells from mice immunized with rCB8 respond specifically to a synthetic peptide, CII 445-453, the CB8 T cell determinant. Conversely, rCB10-primed T cells respond strongly to CII 610-618, the CB10 T cell determinant. Recombinant CB8-induced autoantibodies that bound to mouse CB8 as effectively and in the same topographic distribution as tissue-derived CB8. Finally, when rCB8 and rCB10 proteins were used to immunize B10.RIII (H-2(r)) mice, rCB8 induced arthritis in 33% of the mice, very similar to the incidence induced by tissue-derived CB8 peptide. As was found to be the case with tissue-derived CB10, rCB10 was completely ineffective in inducing arthritis. Pathological changes of arthritic joints in the mice immunized with rCB8 were similar to those observed in mice immunized with tissue-derived CB8. Thus, these recombinant CII peptides expressed in E. coli can induce an effective immunologic response and suggest that functionally useful CII peptides can be generated by the prokaryotic expression system.


Assuntos
Colágeno/genética , Fragmentos de Peptídeos/genética , Sequência de Aminoácidos , Animais , Formação de Anticorpos , Artrite/imunologia , Sequência de Bases , Bovinos , Condrócitos/química , Condrócitos/metabolismo , Clonagem Molecular , Colágeno/química , Colágeno/farmacologia , Escherichia coli/química , Escherichia coli/genética , Ativação Linfocitária/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos , Dados de Sequência Molecular , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/farmacologia , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Linfócitos T/imunologia
17.
Immunology ; 97(3): 466-73, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10447769

RESUMO

Intravenous (i.v.) administration of type II collagen (CII) is an effective way to induce tolerance and suppress disease in the collagen-induced arthritis (CIA) model. In this study, we demonstrated that a single i.v. dose of CII (as low as 0.1 mg/mouse) completely prevented the development of CIA. This suppression was accompanied by decreases in levels of antibody specific for the immunogen, bovine CII and autoantigen, mouse CII. Splenocytes obtained from CII-tolerized mice and stimulated with CII in vitro produced predominantly the T helper 2 (Th2)-type cytokines interleukin-4 (IL-4) and interleukin-10 (IL-10). In contrast, cells obtained from mice immunized with CII produced predominantly interferon-gamma (IFN-gamma). Two-colour flow cytometric analysis of cytokine expression and T-cell phenotype demonstrated that CD4+ cells and not CD8+ or gammadelta+ cells were the predominant regulatory cells producing IL-4 and IL-10. Transgenic mice bearing a T-cell receptor (TCR) specific for CII had a greater increase in the number of IL-4-secreting CD4+ cells, as well as a marked increase of IL-4 in culture supernatants. This cytokine was produced by transgene-bearing T cells. Elucidation of mechanisms for the induction of tolerance in mature T cells is an important line of study in autoimmune models because of the potential application for treating organ-specific autoimmune disease.


Assuntos
Artrite Experimental/imunologia , Linfócitos T CD4-Positivos/imunologia , Colágeno/imunologia , Tolerância Imunológica , Interleucinas/biossíntese , Animais , Artrite Experimental/prevenção & controle , Bovinos , Imunofenotipagem , Injeções Intravenosas , Interferon gama/biossíntese , Interleucina-10/biossíntese , Interleucina-4/biossíntese , Masculino , Camundongos , Camundongos Endogâmicos DBA , Camundongos Transgênicos , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Baço/imunologia
19.
Arthritis Rheum ; 42(6): 1204-8, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10366113

RESUMO

OBJECTIVE: To investigate the efficacy of oral type II collagen (CII) in the treatment of rheumatoid arthritis (RA), when added to existing therapy. METHODS: Patients with active RA (n = 190) were randomized into a 6-month, double-blind, placebo-controlled trial. Patients continued to take their current arthritis medications. Patients received either placebo or bovine CII, 0.1 mg/day for 1 month, then 0.5 mg/day for 5 months. RESULTS: There were no significant differences between the baseline characteristics of either group. The primary response parameter was the American College of Rheumatology (ACR) preliminary definition of improvement in RA (ACR 20). There was no statistically significant difference in the ACR 20 after 6 months (20.0% of placebo patients; 16.84% of bovine CII patients). There were significant differences in several clinical variables after treatment, all favoring the placebo group. CONCLUSION: Oral solubilized bovine CII, added to existing therapy, did not improve disease activity in patients with RA.


Assuntos
Antirreumáticos/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Colágeno/uso terapêutico , Administração Oral , Adolescente , Adulto , Idoso , Animais , Artrite Reumatoide/patologia , Bovinos , Colágeno/administração & dosagem , Método Duplo-Cego , Quimioterapia Combinada , Feminino , Humanos , Articulações/efeitos dos fármacos , Articulações/patologia , Masculino , Pessoa de Meia-Idade , Medição da Dor , Índice de Gravidade de Doença , Inquéritos e Questionários , Resultado do Tratamento
20.
Pediatr Dermatol ; 16(2): 146-50, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10337682

RESUMO

Oral corticosteroids are the main therapeutic choice for systemic lupus erythematosus (SLE). Adverse reactions to systemic corticosteroids rarely occur and the etiology is unclear in most cases. A 14-year-old girl with newly diagnosed SLE developed a pruritic bullous eruption while on prednisone. The patient had been treated successfully in the hospital with intravenous methylprednisolone. In preparation for discharge, the steroid preparation was changed to prednisone to which the patient reacted with a development of new crops of bullous lesions. Skin biopsy specimens of lesional areas showed a bullous eruption consistent with erythema multiforme. The patient underwent immediate and delayed hypersensitivity tests. Intradermal and patch tests to liquid prednisone were positive. The patient was discharged on oral methylprednisolone and has not had recurrence of the skin lesions. In conclusion, a case of prednisone sensitivity in a patient with SLE is presented here. An alternative preparation, methylprednisolone, was used to successfully treat her underlying condition.


Assuntos
Anti-Inflamatórios/efeitos adversos , Toxidermias/etiologia , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Prednisolona/efeitos adversos , Adolescente , Biópsia , Feminino , Humanos , Metilprednisolona/uso terapêutico , Pele/patologia
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