RESUMO
Clinical management of delayed healing or non-union of long bone fractures and segmental defects poses a substantial orthopaedic challenge. There are suggestions in the literature that bone healing may be enhanced by inhibiting the activities of T and B lymphocytes, but this remains controversial. To examine this matter in more detail, sub-critical-sized segmental defects were created in the femora of mice and it was assessed whether there might be a benefit from the administration of a Food and Drug Administration (FDA)-approved drug that blocks T cell activation (tacrolimus). Defects were stabilised using an internal plate. In certain groups of animals, 1 mg/kg or 10 mg/kg tacrolimus was delivered locally to the defect site for 3 or 7 d using an implanted osmotic pump with a silicon catheter directing drug delivery into the defect area. Healing was monitored by weekly X-ray and assessed at 12 weeks by mechanical testing, µCT and histology. Radiographic and histological evaluations revealed that 100 % of defects healed well regardless of tacrolimus dosage or duration. A comparison of healed C57BL/6 and Rag1-/- femora by µCT and ex vivo torsion testing showed no differences within mouse strains in terms of bone volume, tissue volume, bone volume/tissue volume ratio, shear modulus, torsional rigidity or torsional stiffness. These data failed to support an important role for tacrolimus in modulating the natural healing of segmental defects under those experimental conditions.
Assuntos
Consolidação da Fratura/efeitos dos fármacos , Fraturas Ósseas/tratamento farmacológico , Fraturas Ósseas/metabolismo , Proteínas de Homeodomínio/metabolismo , Tacrolimo/farmacologia , Animais , Linfócitos B/efeitos dos fármacos , Linfócitos B/metabolismo , Fêmur , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Osteotomia/métodos , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo , Microtomografia por Raio-X/métodosRESUMO
Receptor activator of nuclear factor-kappaB-ligand (RANKL), encoded by the gene TNFSF11, is required for osteoclastogenesis, and its expression is upregulated in pathologic bone loss. Transcript variants of TNFSF11 messenger RNA (mRNA) have been described that encode a membrane-bound and a putative secreted form of RANKL. We identify a TNFSF11 transcript variant that extends the originally identified transcript encoding secreted RANKL. We demonstrate that this TNFSF11 transcript variant is expressed by the human osteosarcoma cell line, Saos-2, and by both primary human T cells and Jurkat T cells. Of relevance to the production of RANKL in pathologic bone loss, expression of this secreted TNFSF11 transcript is upregulated in Jurkat T cells and primary human T cells upon activation. Furthermore, this transcript can be translated and secreted in Jurkat T cells in vitro and is able to support osteoclast differentiation. Our data highlight the complexity of the TNFSF11 genomic locus, and demonstrate the potential for the expression of alternate mRNA transcripts encoding membrane-bound and secreted forms of RANKL. Implications of alternate mRNA transcripts encoding different RANKL protein isoforms should be carefully considered and specifically examined in future studies, particularly those implicating RANKL in pathologic bone loss.
Assuntos
Processamento Alternativo , Ligante RANK/genética , RNA Mensageiro/genética , Linfócitos T/metabolismo , Animais , Western Blotting , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Células Cultivadas , Humanos , Células Jurkat , Ativação Linfocitária , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Osteoclastos/citologia , Osteoclastos/efeitos dos fármacos , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Isoformas de Proteínas/farmacologia , Ligante RANK/metabolismo , Ligante RANK/farmacologia , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Regulação para CimaRESUMO
Despite extensive studies on the epidemiology of mental disorders and advances in the treatment of these conditions, there is a paucity of detailed information concerning the characteristics of psychiatric patients and how treatments are administered in routine psychiatric practice. This 1997 observational study collected detailed information from 417 psychiatrists on the demographic, diagnostic, clinical, and treatment characteristics of a systematic sample of 1228 patients. Six hundred thirty-seven patients (51.9%) were women and the mean patient age was 41.9 years. The most common diagnostic category (53.7%) was mood disorders, followed by schizophrenia/psychotic disorders (14.6%), anxiety disorders (9.3%), and disorders of childhood (7.7%). Six hundred seventy-one patients (54.6%) had at least one comorbid Axis I condition and almost half (49.8%) had a history of psychiatric hospitalization. Patients received a mean of 2.0 psychotherapeutic medications, most commonly antidepressants (62.3%). Findings demonstrate that psychiatrists in routine practice treat a patient population with severe, complex conditions.
Assuntos
Transtornos Mentais/terapia , Prática Profissional/estatística & dados numéricos , Psiquiatria/estatística & dados numéricos , Adolescente , Adulto , Idoso , Assistência Ambulatorial , Criança , Pré-Escolar , Feminino , Pesquisa sobre Serviços de Saúde/estatística & dados numéricos , Hospitalização , Humanos , Masculino , Transtornos Mentais/tratamento farmacológico , Transtornos Mentais/epidemiologia , Pessoa de Meia-Idade , Padrões de Prática Médica/estatística & dados numéricos , Distribuição Aleatória , Reprodutibilidade dos Testes , Estudos de Amostragem , Inquéritos e Questionários , Estados Unidos/epidemiologiaRESUMO
Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease in which unknown arthrogenic autoantigen is presented to CD4+ T cells. The strong association of the disease with an epitope within the HLA-DR chain shared between various alleles of HLA-DR4 and DR1 emphasizes the importance of antigen presentation. This immune response predominantly occurs in the synovial tissue and fluid of the joints and autoreactive T cells are readily demonstrable in both the synovial compartment and blood. Circulating dendritic cells (DC) are phenotypically and functionally identical with normal peripheral blood (PB) DC. In the synovial tissue, fully differentiated perivascular DC are found in close association with T cells and with B cell follicles, sometimes containing follicular DC. These perivascular DC migrate across the activated endothelium from blood and receive differentiative signals within the joint from monocyte-derived cytokines and CD40-ligand+ T cells. In the SF, DC manifest an intermediate phenotype, similar to that of monocyte-derived DC in vitro. Like a delayed-type hypersensitivity response, the rheumatoid synovium represents an effector site. DC at many effector sites have a characteristic pattern of infiltration and differentiation. It is important to note that the effector response is not self-limiting in RA autoimmune inflammation. In this article, we argue that the presentation of self-antigen by DC and by autoantibody-producing B cells is critical for the perpetuation of the autoimmune response. Permanently arresting this ongoing immune response with either pharmaceutical agents or immunotherapy is a major challenge for immunology.
Assuntos
Artrite Reumatoide/imunologia , Células Dendríticas/imunologia , Animais , Artrite Reumatoide/fisiopatologia , Linfócitos B/imunologia , Diferenciação Celular , Humanos , Imunoterapia , Monócitos/citologia , Proteínas Proto-Oncogênicas/imunologia , Membrana Sinovial/citologia , Membrana Sinovial/imunologia , Fator de Transcrição RelB , Fatores de Transcrição/imunologiaRESUMO
In this study, long-term outcome for patients with obsessive-compulsive disorder treated with serotonin reuptake inhibitor medications was examined. The records of 85 patients who had first been evaluated at least 1 year previously (the mean follow-up period was 773 days) were reviewed. Information was collected on age at onset of symptoms, time since first evaluation, and scores on several scales measuring symptom severity, including the Yale-Brown Obsessive Compulsive Scale. Comparison of these baseline data with Yale-Brown scale scores at the most recent follow-up visit showed that 74 (87%) of the patients had responded to treatment. No predictors of improvement were found.
Assuntos
Transtorno Obsessivo-Compulsivo/tratamento farmacológico , Inibidores Seletivos de Recaptação de Serotonina/uso terapêutico , Adulto , Idade de Início , Idoso , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Transtorno Obsessivo-Compulsivo/diagnóstico , Transtorno Obsessivo-Compulsivo/psicologia , Escalas de Graduação Psiquiátrica , Índice de Gravidade de Doença , Resultado do TratamentoRESUMO
Major depression is a widespread, often chronic disorder affecting the individual, his or her family, and society as a whole. It incurs tremendous social and financial costs in the form of impaired relationships, lost productivity, and lost wages. Although chronic major depression is eminently treatable, it continues to be undertreated and underrecognized. This is particularly true in primary care settings, where physicians are usually the first to encounter chronic depression but are seldom trained to distinguish depression from other medical illnesses with similar symptoms. In addition, because of the stigma attached to depression, patients often characterize their symptoms as part of a physical illness or fail to report them to a clinician at all. This article discusses the epidemiology of depression, its impact and burden on society, and its special character (including diagnosis and treatment) as a chronic illness.
Assuntos
Efeitos Psicossociais da Doença , Transtorno Depressivo/epidemiologia , Doença Crônica , Custos e Análise de Custo , Atenção à Saúde/normas , Atenção à Saúde/estatística & dados numéricos , Atenção à Saúde/tendências , Transtorno Depressivo/economia , Transtorno Depressivo/terapia , Custos de Cuidados de Saúde/estatística & dados numéricos , Custos de Cuidados de Saúde/tendências , Humanos , Prevalência , Atenção Primária à Saúde/normas , Atenção Primária à Saúde/estatística & dados numéricos , Anos de Vida Ajustados por Qualidade de Vida , Recidiva , Estereotipagem , Estados Unidos/epidemiologiaRESUMO
Depression is a serious, often chronic disease that can be managed effectively with a chronic care model in primary care settings. Depressed persons are likely to be seen by a primary care physician, but their condition often goes unrecognized and untreated. There are effective treatment models that consist of efficacious psychotherapeutic and pharmacological interventions, use of evidence-based guidelines for primary care treatment of depression, development of explicit plans and protocols, reorganization of practice, longitudinal follow-up, patient self-management, decision-making support, access to community resources and leadership commitment. Moving these models into everyday practice requires overcoming both clinical and system barriers. Barriers consist of issues surrounding patients, providers, practices, plans, and purchasers. An understanding of these barriers at each level helps to provide a framework for the changes required to overcome them. The Robert Wood Johnson Foundation National Program on Depression in Primary Care will seek to apply simultaneously both clinical and system strategies in a new five-year initiative to overcome these barriers.
Assuntos
Antidepressivos/uso terapêutico , Continuidade da Assistência ao Paciente/organização & administração , Transtorno Depressivo/terapia , Acessibilidade aos Serviços de Saúde/organização & administração , Serviços de Saúde Mental/organização & administração , Atenção Primária à Saúde/normas , Doença Crônica , Tomada de Decisões , Transtorno Depressivo/tratamento farmacológico , Humanos , Relações Médico-Paciente , Psicoterapia , Estados UnidosRESUMO
In rheumatoid arthitis patients, three compartments need to be considered: peripheral blood (PB), synovial fluid (SF), and synovial tissue (ST). Dendritic cells (DC) characterized from each compartment have different properties. The methods given are based on cell sorting for isolation of cells, and flow cytometry and immunohistochemical staining for analysis of cells. Myeloid non-T cells are first enriched by density gradient centrifugation, sheep erythocyte rosetting, and, in some cases, magnetic immunodepletion. By flow cytometry, DC can then be analyzed or sorted based on two- or three-color immunofluorescence. Some variations on this basic theme are also outlined. The basic protocol for two-color immunohistochemistry of formalin-fixed ST is then given. This is based on the localization of the NFκB family member, RelB, to the nucleus of differentiated DC, and exclusion of B cells, macrophages, and follicular DC by double staining. Some variations that are particularly useful in frozen sections follow.
RESUMO
Mobilized blood has supplanted bone marrow (BM) as the primary source of hematopoietic stem cells for autologous and allogeneic stem cell transplantation. Pharmacologically enforced egress of hematopoietic stem cells from BM, or mobilization, has been achieved by directly or indirectly targeting the CXCL12/CXCR4 axis. Shortcomings of the standard mobilizing agent, granulocyte colony-stimulating factor (G-CSF), administered alone or in combination with the only approved CXCR4 antagonist, Plerixafor, continue to fuel the quest for new mobilizing agents. Using Protein Epitope Mimetics technology, a novel peptidic CXCR4 antagonist, POL5551, was developed. In vitro data presented herein indicate high affinity to and specificity for CXCR4. POL5551 exhibited rapid mobilization kinetics and unprecedented efficiency in C57BL/6 mice, exceeding that of Plerixafor and at higher doses also of G-CSF. POL5551-mobilized stem cells demonstrated adequate transplantation properties. In contrast to G-CSF, POL5551 did not induce major morphological changes in the BM of mice. Moreover, we provide evidence of direct POL5551 binding to hematopoietic stem and progenitor cells (HSPCs) in vivo, strengthening the hypothesis that CXCR4 antagonists mediate mobilization by direct targeting of HSPCs. In summary, POL5551 is a potent mobilizing agent for HSPCs in mice with promising therapeutic potential if these data can be corroborated in humans.
Assuntos
Células-Tronco Hematopoéticas/efeitos dos fármacos , Proteínas/farmacologia , Receptores CXCR4/antagonistas & inibidores , Animais , Microambiente Celular , Sinergismo Farmacológico , Fator Estimulador de Colônias de Granulócitos/farmacologia , Células-Tronco Hematopoéticas/citologia , Macrófagos/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Osteoblastos/efeitos dos fármacosRESUMO
The CXCR4 antagonist AMD3100 is progressively replacing cyclophosphamide (CYP) as adjuvant to granulocyte colony-stimulating factor (G-CSF) to mobilize hematopoietic stem cells (HSC) for autologous transplants in patients who failed prior mobilization with G-CSF alone. It has recently emerged that G-CSF mediates HSC mobilization and inhibits bone formation via specific bone marrow (BM) macrophages. We compared the effect of these three mobilizing agents on BM macrophages, bone formation, osteoblasts, HSC niches and HSC reconstitution potential. Both G-CSF and CYP suppressed niche-supportive macrophages and osteoblasts, and inhibited expression of endosteal cytokines resulting in major impairment of HSC reconstitution potential remaining in the mobilized BM. In sharp contrast, although AMD3100 was effective at mobilizing HSC, it did not suppress osteoblasts, endosteal cytokine expression or reconstitution potential of HSC remaining in the mobilized BM. In conclusion, although G-CSF, CYP and AMD3100 efficiently mobilize HSC into the blood, their effects on HSC niches and bone formation are distinct with both G-CSF and CYP targeting HSC niche function and bone formation, whereas AMD3100 directly targets HSC without altering niche function or bone formation.
Assuntos
Medula Óssea/efeitos dos fármacos , Ciclofosfamida/farmacologia , Fator Estimulador de Colônias de Granulócitos/farmacologia , Hematínicos/farmacologia , Células-Tronco Hematopoéticas/efeitos dos fármacos , Compostos Heterocíclicos/farmacologia , Osteogênese/efeitos dos fármacos , Animais , Fármacos Anti-HIV/farmacologia , Antineoplásicos Alquilantes/farmacologia , Benzilaminas , Medula Óssea/metabolismo , Células Cultivadas , Ciclamos , Citometria de Fluxo , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/metabolismo , Técnicas Imunoenzimáticas , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase ReversaAssuntos
Terapia Comportamental , Clomipramina/uso terapêutico , Fluoxetina/uso terapêutico , Transtorno Obsessivo-Compulsivo/terapia , Adulto , Clomipramina/administração & dosagem , Terapia Combinada , Feminino , Fluoxetina/administração & dosagem , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Transtorno Obsessivo-Compulsivo/tratamento farmacológico , Transtorno Obsessivo-Compulsivo/prevenção & controle , Recidiva , Resultado do TratamentoRESUMO
Effective bone biomaterials provide structural support for bone regeneration and elicit minimal inflammatory or toxic effects in vivo. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a bacterially derived biodegradable polymer that possesses suitable mechanical strength for use as a bone biomaterial and has a slow rate of degradation in biological environments. Our previous in vitro study showed that many PHBV preparations are contaminated with bacterial lipopolysaccharide, and we developed a purification procedure to substantially remove it. Here, we have evaluated the in vivo biocompatibility of PHBV purified by H(2)O(2) treatment and solvent extraction. We utilized a murine tibial defect model consisting of a hole drilled through the diameter of the tibial diaphysis into which nonporous cylindrical plugs of purified PHBV were implanted. The animals were sacrificed at 1 week and 4 weeks postsurgery, and tibiae were examined using histological staining. The PHBV implant induced a mild inflammatory response 1 week after injury, which persisted for 4 weeks. Granuloma type tissues formed only when the implant protruded into the overlaying tissue. Woven bone formation occurred adjacent to the implant, which gave rise to lamellar bone and stabilized the implant indicating that the PHBV did not affect this process. Our data validated the murine defect model and indicate that solid PHBV induces a mild tissue reaction with bone deposition adjacent to the implant with no fibrous tissue present at 4 weeks post surgery.
Assuntos
Materiais Biocompatíveis/química , Regeneração Óssea , Substitutos Ósseos , Poliésteres/química , Próteses e Implantes , Tíbia/metabolismo , Animais , Bactérias/metabolismo , Osso e Ossos/metabolismo , Peróxido de Hidrogênio/química , Lipopolissacarídeos/metabolismo , Masculino , Camundongos , Microscopia Eletrônica de Varredura/métodos , Mucosa/metabolismo , Solventes/químicaRESUMO
OBJECTIVES: Receptor activator of NF-kappaB ligand (RANKL) and osteoprotegerin (OPG) have been demonstrated to be critical regulators of osteoclast generation and activity. In addition, RANKL has been implicated as an important mediator of bone erosion in rheumatoid arthritis (RA). However, the expression of RANKL and OPG at sites of pannus invasion into bone has not been examined. The present study was undertaken to further elucidate the contribution of this cytokine system to osteoclastogenesis and subsequent bone erosion in RA by examining the pattern of protein expression for RANKL, OPG and the receptor activator of NF-kappaB (RANK) in RA at sites of articular bone erosion. METHODS: Tissues from 20 surgical procedures from 17 patients with RA were collected as discarded materials. Six samples contained only synovium or tenosynovium remote from bone, four samples contained pannus-bone interface with adjacent synovium and 10 samples contained both synovium remote from bone and pannus-bone interface with adjacent synovium. Immunohistochemistry was used to characterize the cellular pattern of RANKL, RANK and OPG protein expression immediately adjacent to and remote from sites of bone erosion. RESULTS: Cellular expression of RANKL protein was relatively restricted in the bone microenvironment; staining was focal and confined largely to sites of osteoclast-mediated erosion at the pannus-bone interface and at sites of subchondral bone erosion. RANK-expressing osteoclast precursor cells were also present in these sites. OPG protein expression was observed in numerous cells in synovium remote from bone but was more limited at sites of bone erosion, especially in regions associated with RANKL expression. CONCLUSIONS: The pattern of RANKL and OPG expression and the presence of RANK-expressing osteoclast precursor cells at sites of bone erosion in RA contributes to the generation of a local microenvironment that favours osteoclast differentiation and activity. These data provide further evidence implicating RANKL in the pathogenesis of arthritis-induced joint destruction.
Assuntos
Artrite Reumatoide/metabolismo , Reabsorção Óssea/metabolismo , Proteínas de Transporte/análise , Articulações/química , Glicoproteínas de Membrana/análise , Membrana Sinovial/química , Adolescente , Adulto , Artrite Reumatoide/patologia , Reabsorção Óssea/patologia , Diferenciação Celular , Criança , Pré-Escolar , Glicoproteínas/análise , Humanos , Imuno-Histoquímica/métodos , Articulações/patologia , Osteoclastos/patologia , Osteoprotegerina , Ligante RANK , Receptor Ativador de Fator Nuclear kappa-B , Receptores Citoplasmáticos e Nucleares/análise , Receptores do Fator de Necrose Tumoral/análise , Membrana Sinovial/metabolismoRESUMO
Dendritic cells (DC) are likely to play a significant role in immune-mediated diseases such as autoimmunity and allergy. To date there are few treatments capable of inducing permanent remission in rheumatoid arthritis (RA) and elucidation of the role of DC may provide specific strategies for disease intervention. Dendritic cells have proven to be powerful tools for immunotherapy and investigations are under way to determine their clinical efficacy in transplantation and viral and tumour immunotherapy. The present review will focus on the current view of DC and their role in autoimmunity, in particular RA. Two possible roles for DC in the pathogenesis of RA will be proposed, based on recent advances in the field.
Assuntos
Artrite Reumatoide/imunologia , Doenças Autoimunes/imunologia , Autoimunidade/imunologia , Células Dendríticas/fisiologia , Animais , Apresentação de Antígeno , Artrite Reumatoide/fisiopatologia , Artrite Reumatoide/terapia , Autoantígenos/metabolismo , Doenças Autoimunes/fisiopatologia , Doenças Autoimunes/terapia , Diferenciação Celular , Células Dendríticas/imunologia , Humanos , Hipersensibilidade/imunologia , Imunoterapia , Ativação Linfocitária , Líquido Sinovial/imunologia , Linfócitos T/fisiologiaRESUMO
OBJECTIVE: Differentiated dendritic cells (DC) and other antigen-presenting cells are characterized by the nuclear location of RelB, a member of the nuclear factor kappaB/Rel family. To characterize and enumerate differentiated DC in rheumatoid arthritis (RA) peripheral blood (PB), synovial fluid (SF), and synovial tissue (ST), the expression and location of RelB were examined. METHODS: RelB protein expression and cellular location were determined in RA PB, SF, and ST by flow cytometry and immunohistochemical analysis of purified cells or formalin-fixed tissue. DNA-binding activity of RelB was determined by electrophoretic mobility shift-Western immunoblotting assays. RESULTS: Circulating RA PBDC resembled normal immature PBDC in that they did not express intracellular RelB protein. In RA ST serial sections, cells containing nuclear RelB (nRelB) were enriched in perivascular regions. A mean +/- SD of 84 +/- 10% of these cells were DC. The remaining nRelB+,HLA-DR+ cells comprised B cells and macrophages. Only 3% of sorted SFDC contained nRelB. However, RelB present in the nucleus of these SFDC was capable of binding DNA, and therefore capable of transcriptional activity. CONCLUSION: Circulating DC precursors differentiate and express RelB after entry into rheumatoid ST. Differentiated DC can thus be identified by immunohistochemistry in formalin-fixed ST. Signals for DC maturation may differ between RA ST and SF, resulting in nuclear location of RelB predominantly in ST. This is likely to have functional consequences for the DC in these sites.
Assuntos
Artrite Reumatoide/patologia , Células Dendríticas/citologia , Proteínas Proto-Oncogênicas/biossíntese , Líquido Sinovial/química , Fatores de Transcrição/biossíntese , Células Apresentadoras de Antígenos/fisiologia , Diferenciação Celular , Núcleo Celular/química , DNA/metabolismo , Proteínas de Ligação a DNA/fisiologia , Citometria de Fluxo , Humanos , Imuno-Histoquímica , Proteínas Proto-Oncogênicas/sangue , Teste de Radioalergoadsorção , Membrana Sinovial/química , Fator de Transcrição RelB , Fatores de Transcrição/sangue , Translocação GenéticaRESUMO
Mice with targeted RelB mutations demonstrated an essential role for RelB in immune responses and in myeloid dendritic cell differentiation. Human studies suggested a more global transcriptional role in antigen presentation. Burkitt lymphoma cell lines were used as a model to examine the role of RelB in antigen presentation. After transient transfection of BJAB with RelB, strong nuclear expression of RelB-p50 heterodimers was associated with increased APC function and expression of CD40 and MHC class I. Antisense RelB in DG75 reduced antigen-presenting capacity and CD40-mediated up-regulation of MHC molecules. The data indicate that RelB transcriptional activity directly affects antigen presentation and CD40 synthesis. Stimulation of RelB transcriptional activity may provide a positive feedback loop for facilitating productive APC/T cell interactions.
Assuntos
Células Apresentadoras de Antígenos/imunologia , Linfócitos B/imunologia , Núcleo Celular/metabolismo , Complexo Principal de Histocompatibilidade , Proteínas Proto-Oncogênicas/metabolismo , Fatores de Transcrição/metabolismo , Células Apresentadoras de Antígenos/efeitos dos fármacos , Linhagem Celular , Humanos , Oligonucleotídeos Antissenso/farmacologia , Transporte Proteico , Proteínas Proto-Oncogênicas/genética , Fator de Transcrição RelB , Fatores de Transcrição/genéticaRESUMO
IL-10 down-regulates the APC function of many dendritic cells (DC), including human peripheral blood (PB) DC. In rheumatoid arthritis (RA), synovial fluid (SF) DC express markers of differentiation and are effective APC despite abundant synovial IL-10. The regulation of DC responsiveness to IL-10 was therefore examined by comparing the effect of IL-10 on normal PB and RA SF DC. Whereas IL-10 down-modulated APC function and MHC class II and B7 expression of PB DC, IL-10 had no such effect on SF DC. Since SF DC have differentiated in vivo in the presence of proinflammatory cytokines, PB DC were cocultured in the presence of IL-10 and either GM-CSF, IL-1beta, TNF-alpha, IL-6, or TGF-beta. GM-CSF, IL-1beta, and TNF-alpha were all able to restore APC function. Whereas the effects of IL-10 on PB DC were shown to be mediated by IL-10R1, neither PB nor RA SF DC constitutively expressed IL-10R1 mRNA or detectable surface protein. In contrast, IL-10R1 protein was demonstrated in PB and SF DC whole cell lysates, suggestive of predominant intracellular localization of the receptor. Thus, DC responsiveness to IL-10 may be regulated through modulation of cell surface IL-10R1 expression or signaling.
Assuntos
Artrite Reumatoide/imunologia , Células Dendríticas/imunologia , Imunossupressores/farmacologia , Interleucina-10/fisiologia , Membrana Sinovial/imunologia , Apresentação de Antígeno/imunologia , Células Apresentadoras de Antígenos/imunologia , Antígenos CD/biossíntese , Antígeno B7-2 , Células Cultivadas , Células Dendríticas/metabolismo , Regulação para Baixo/imunologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/fisiologia , Antígenos HLA-DR/biossíntese , Humanos , Imunidade Inata , Interleucina-1/fisiologia , Interleucina-10/antagonistas & inibidores , Glicoproteínas de Membrana/biossíntese , Monócitos/imunologia , RNA Mensageiro/biossíntese , Receptores de Interleucina/biossíntese , Receptores de Interleucina/genética , Receptores de Interleucina/fisiologia , Receptores de Interleucina-10 , Transdução de Sinais/imunologia , Membrana Sinovial/patologia , Fator de Necrose Tumoral alfa/fisiologiaRESUMO
OBJECTIVE: Infiltration of rheumatoid arthritis (RA) synovial tissue (ST) by differentiated dendritic cells (DC) is a consistent feature in patients with active disease. However, mononuclear cells (MNC), including DC, may be nonspecifically chemoattracted to inflammatory sites regardless of etiology. Therefore, to evaluate the specificity of ST infiltration by differentiated DC, synovial biopsies from patients with RA, spondylarthropathy (SpA), osteoarthritis (OA), and gout were examined. METHODS: Formalin-fixed ST sections were analyzed by double immunohistochemical staining for vascularity and infiltration by differentiated DC, lymphocytes, and macrophages. RESULTS: DC containing nuclear RelB were found in perivascular MNC aggregates from patients with all arthritides studied. Infiltration by differentiated DC was similar in RA and SpA ST, but reduced in OA ST. Differentiated DC were always observed in close association with lymphocytes, and the correlation between these variables suggested that the infiltration of inflammatory sites by DC and lymphocytes was associated. CONCLUSION: Perivascular infiltration by DC, lymphocytes, and macrophages is nonspecifically related to inflammation, but signals present in RA and SpA ST lead to more intense cellular infiltration and accumulation.
Assuntos
Doenças Autoimunes/patologia , Células Dendríticas/citologia , Osteoartrite/patologia , Membrana Sinovial/citologia , Idoso , Idoso de 80 Anos ou mais , Diferenciação Celular/fisiologia , Feminino , Humanos , Artropatias/patologia , Masculino , Pessoa de Meia-Idade , Doenças da Coluna Vertebral/patologiaRESUMO
OBJECTIVES: To compare immunohistochemical scoring with clinical scoring and radiology for the assessment of rheumatoid arthritis (RA) disease activity, synovial tissue (ST) biopsied arthroscopically was assessed from 18 patients before and after commencement of disease-modifying anti-rheumatic drug (DMARD) therapy. METHODS: Lymphocytes, macrophages, differentiated dendritic cells (DC), vascularity, tumour necrosis factor (TNF) alpha and interleukin-1beta levels were scored. Clinical status was scored using the American College of Rheumatology (ACR) core set and serial radiographs were scored using the Larsen and Sharp methods. Histopathological evidence of activity included infiltration by lymphocytes, DC, macrophages, tissue vascularity, and expression of lining and sublining TNFalpha. These indices co-varied across the set of ST biopsies and were combined as a synovial activity score for each biopsy. RESULTS: The change in synovial activity with treatment correlated with the ACR clinical response and with decreased radiological progression by the Larsen score. The ACR response to DMARD therapy, the change in synovial activity score and the slowing of radiological progression were each greatest in patients with high initial synovial vascularity. CONCLUSIONS: The data demonstrate an association between clinical, radiological and synovial immunopathological responses to anti-rheumatic treatment in RA. High ST vascularity may predict favourable clinical and radiological responses to treatment.
Assuntos
Antirreumáticos/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Artrite Reumatoide/patologia , Membrana Sinovial/patologia , Idoso , Artrite Reumatoide/diagnóstico por imagem , Artrite Reumatoide/imunologia , Biópsia , Células Dendríticas/imunologia , Humanos , Interleucina-1/análise , Linfócitos/imunologia , Macrófagos/imunologia , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Radiografia , Membrana Sinovial/irrigação sanguínea , Membrana Sinovial/imunologia , Resultado do Tratamento , Fator de Necrose Tumoral alfa/análiseRESUMO
There is considerable evidence that osteoclasts are involved in the pathogenesis of focal bone erosion in rheumatoid arthritis. Tumor necrosis factor-related activation-induced cytokine, also known as receptor activator of nuclear factor-kappaB ligand (TRANCE/RANKL) is an essential factor for osteoclast differentiation. In addition to its role in osteoclast differentiation and activation, TRANCE/RANKL also functions to augment T-cell dendritic cell cooperative interactions. To further evaluate the role of osteoclasts in focal bone erosion in arthritis, we generated inflammatory arthritis in the TRANCE/RANKL knockout mouse using a serum transfer model that bypasses the requirement for T-cell activation. These animals exhibit an osteopetrotic phenotype characterized by the absence of osteoclasts. Inflammation, measured by clinical signs of arthritis and histopathological scoring, was comparable in wild-type and TRANCE/RANKL knockout mice. Microcomputed tomography and histopathological analysis demonstrated that the degree of bone erosion in TRANCE/RANKL knockout mice was dramatically reduced compared to that seen in control littermate mice. In contrast, cartilage erosion was present in both control littermate and TRANCE/RANKL knockout mice. These results confirm the central role of osteoclasts in the pathogenesis of bone erosion in arthritis and demonstrate distinct mechanisms of cartilage destruction and bone erosion in this animal model of arthritis.