RESUMO
Glucocorticoids are steroid hormones with strong anti-inflammatory and immunosuppressive effects that are produced in a diurnal fashion. Although glucocorticoids have the potential to induce interleukin-7 receptor (IL-7R) expression in T cells, whether they control T cell homeostasis and responses at physiological concentrations remains unclear. We found that glucocorticoid receptor signaling induces IL-7R expression in mouse T cells by binding to an enhancer of the IL-7Rα locus, with a peak at midnight and a trough at midday. This diurnal induction of IL-7R supported the survival of T cells and their redistribution between lymph nodes, spleen, and blood by controlling expression of the chemokine receptor CXCR4. In mice, T cell accumulation in the spleen at night enhanced immune responses against soluble antigens and systemic bacterial infection. Our results reveal the immunoenhancing role of glucocorticoids in adaptive immunity and provide insight into how immune function is regulated by the diurnal rhythm.
Assuntos
Ritmo Circadiano/fisiologia , Glucocorticoides/farmacologia , Receptores CXCR4/fisiologia , Receptores de Interleucina-7/fisiologia , Linfócitos T/imunologia , Animais , Células Cultivadas , Quimiocina CXCL12/biossíntese , Feminino , Memória Imunológica , Ativação Linfocitária , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Receptores de Glucocorticoides/fisiologiaRESUMO
Cry j 1 is a major allergen present in Japanese cedar (Cryptomeria japonica) pollens. Peptides with the core sequence of KVTVAFNQF from Cry j 1 ('pCj1') bind to HLA-DP5 and activate Th2 cells. In this study, we noticed that Ser and Lys at positions -2 and -3, respectively, in the N-terminal flanking (NF) region to pCj1 are conserved well in HLA-DP5-binding allergen peptides. A competitive binding assay showed that the double mutation of Ser(-2) and Lys(-3) to Glu [S(P-2)E/K(P-3)E] in a 13-residue Cry j 1 peptide (NF-pCj1) decreased its affinity for HLA-DP5 by about 2-fold. Similarly, this double mutation reduced, by about 2-fold, the amount of NF-pCj1 presented on the surface of mouse antigen-presenting dendritic cell line 1 (mDC1) cells stably expressing HLA-DP5. We established NF-pCj1-specific and HLA-DP5-restricted CD4+ T-cell clones from HLA-DP5 positive cedar pollinosis (CP) patients, and analyzed their IL-2 production due to the activation of mouse TG40 cells expressing the cloned T-cell receptor by the NF-pCj1-presenting mDC1 cells. The T-cell activation was actually decreased by the S(P-2)E/K(P-3)E mutation, corresponding to the reduction in the peptide presentation by this mutation. In contrast, the affinity of NF-pCj1·HLA-DP5 for the T-cell receptor was not affected by the S(P-2)E/K(P-3)E mutation, as analyzed by surface plasmon resonance. Considering the positional and side-chain differences of these NF residues from previously reported T-cell activating sequences, the mechanisms of enhanced T-cell activation by Ser(-2) and Lys(-3) of NF-pCj1 may be novel.
Assuntos
Alérgenos , Cryptomeria , Animais , Camundongos , Cryptomeria/química , Antígenos de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/análise , Proteínas de Plantas/química , Pólen , Peptídeos , Receptores de Antígenos de Linfócitos TRESUMO
OBJECTIVES: The treatments for rheumatoid arthritis (RA) have been greatly improved, and the tight control of disease activity yields superior clinical outcomes. This study aimed to elucidate the accompanying changes in hip destruction following the implementation of a treat-to-target strategy for patients with RA. METHODS: We extracted 190 hips over two periods, i.e. the early period (1998-2003) and the late period (2013-19), with 103 and 87 hips, respectively. The observed rheumatic changes, such as inward migration, upward migration, and femoral head collapse, were quantitatively evaluated, while osteoarthritic changes, such as the formation of a capital drop, were investigated from radiographs before primary total hip arthroplasty. RESULTS: A comparison of the two periods' data showed that the degree of inward migration (-3.44 vs. -7.45 mm; P < .001) and upward migration (+4.3 vs. +0.95 mm; P < .001) significantly decreased in the late-period group. The collapse of the femoral head was not significantly different. The incidence of capital drops was significantly higher in the late-period group (7.8% vs. 27.5%; P < .001). CONCLUSIONS: The degree of inward and upward migration representative of rheumatic changes reduced, whereas the frequency of capital drops as osteoarthritic changes increased during the late period.
Assuntos
Artrite Reumatoide , Artroplastia de Quadril , Humanos , Artrite Reumatoide/diagnóstico por imagem , Artrite Reumatoide/tratamento farmacológico , Artrite Reumatoide/cirurgia , Cabeça do Fêmur/cirurgia , Radiografia , Articulação do Quadril/diagnóstico por imagem , Articulação do Quadril/cirurgiaRESUMO
OBJECTIVES: This study aimed to determine the risk factors for vertebral fractures requiring surgery in patients with ankylosing spondylitis (AS). METHODS: We included 60 patients with AS diagnosed by using the modified New York criteria and who were treated in our department from April 2004 to March 2019. We evaluated age, sex, disease duration, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), ankylosed sacroiliac joint, bamboo spine, number of ankylosed vertebrae, and treatment (nonsteroidal antiinflammatory drugs (NSAIDs)), prednisolone (PSL), conventional synthetic disease-modifying antirheumatic drugs (csDMARDs), biological disease-modifying antirheumatic drugs (bDMARDs), spine surgery for vertebral fracture) at the final follow-up of the nonsurgical group and the preoperative follow-up of the surgical group. RESULTS: At the final follow-up, the mean age was 49 years, 46 patients (75%) were male, and the mean disease duration was 27 years. Additionally, 8 (13.3%) and 43 patients (71%) underwent surgical and medical treatments, respectively. The group of surgery for vertebral fracture had significantly higher CRP levels, which was also significantly associated with vertebral fracture surgery by multivariate analysis. CONCLUSIONS: CRP was identified as a risk factor for vertebral fractures requiring surgery. Control of systemic inflammation in patients with AS may reduce the risk of vertebral fractures requiring surgery.
RESUMO
Autoreactive CD4 T cells are thought to play pivotal roles in the pathogenesis of rheumatoid arthritis (RA). Recently, a subset of CD4 T cells that express high levels of programmed death-1 (PD-1) but are distinct from follicular helper T cells have been identified in the joints of RA patients and named peripheral helper T (Tph) cells. Because PD-1 is expressed on T cells chronically stimulated with the Ags, we tested a hypothesis that Tph cells are the pathogenic autoreactive CD4 T cells in RA. We found that human Tph cells in RA joints produce proinflammatory effector cytokines, including IFN-γ, TNF-α, and GM-CSF, in addition to B cell-helping cytokines, such as IL-21 and CXCL13. Flow cytometric analysis showed different bias of TCR Vß usage between PD-1high Tph cells and PD-1low/neg CD4 T cells, including Th1 cells, in the joint or memory CD4 T cells in the peripheral blood, whereas there was little difference between the latter two subsets. In line with this, deep sequencing of TCR demonstrated an overlap of expanded clones between peripheral blood memory CD4 T cells and PD-1low/neg CD4 T cells but not Tph cells in the joint. Interestingly, Tph cells preferentially exhibited autologous MLR in vitro, which required recognition of self-MHC class II and was pronounced by blocking PD-1 signaling. Taken together, these results suggest that Tph cells are the pathogenic autoreactive CD4 T cells in RA, which expand locally in the joints and are regulated by PD-1 signaling.
Assuntos
Artrite Reumatoide/imunologia , Linfócitos T CD4-Positivos/imunologia , Receptor de Morte Celular Programada 1/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Idoso , Artrite Reumatoide/metabolismo , Linfócitos T CD4-Positivos/metabolismo , Células Cultivadas , Quimiocina CXCL13/imunologia , Quimiocina CXCL13/metabolismo , Citocinas/imunologia , Citocinas/metabolismo , Feminino , Humanos , Mediadores da Inflamação/imunologia , Mediadores da Inflamação/metabolismo , Masculino , Pessoa de Meia-Idade , Receptor de Morte Celular Programada 1/metabolismo , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Antígenos de Linfócitos T/metabolismo , Transdução de Sinais/imunologia , Linfócitos T Auxiliares-Indutores/metabolismo , Células Th1/imunologia , Células Th1/metabolismoRESUMO
Rheumatoid arthritis (RA) is a chronic inflammatory disorder affecting systemic synovial tissues, leading to the destruction of multiple joints. Its etiology is still unknown, but T-cell-mediated autoimmunity has been thought to play critical roles, which is supported by experimental as well as clinical observations. Therefore, efforts have been made to elucidate the functions and antigen specificity of pathogenic autoreactive T cells, which could be a therapeutic target for disease treatment. Historically, T-helper (Th)1 and Th17 cells are hypothesized to be pathogenic T cells in RA joints; however, lines of evidence do not fully support this hypothesis, showing polyfunctionality of the T cells. Recent progress in single-cell analysis technology has led to the discovery of a novel helper T-cell subset, peripheral helper T cells, and attracted attention to the previously unappreciated T-cell subsets, such as cytotoxic CD4 and CD8 T cells, in RA joints. It also enables a comprehensive view of T-cell clonality and function. Furthermore, the antigen specificity of the expanded T-cell clones can be determined. Despite such progress, which T-cell subset drives inflammation is yet known.
Assuntos
Artrite Reumatoide , Humanos , Artrite Reumatoide/patologia , Subpopulações de Linfócitos T , Membrana Sinovial/patologia , Inflamação/patologia , Células Th17RESUMO
Cord factor, also called trehalose-6,6'-dimycolate (TDM), is a potent mycobacterial adjuvant. We herein report that the C-type lectin MCL (also called Clec4d) is a TDM receptor that is likely to arise from gene duplication of Mincle (also called Clec4e). Mincle is known to be an inducible receptor recognizing TDM, whereas MCL was constitutively expressed in myeloid cells. To examine the contribution of MCL in response to TDM adjuvant, we generated MCL-deficient mice. TDM promoted innate immune responses, such as granuloma formation, which was severely impaired in MCL-deficient mice. TDM-induced acquired immune responses, such as experimental autoimmune encephalomyelitis (EAE), was almost completely dependent on MCL, but not Mincle. Furthermore, by generating Clec4e(gfp) reporter mice, we found that MCL was also crucial for driving Mincle induction upon TDM stimulation. These results suggest that MCL is an FcRγ-coupled activating receptor that mediates the adjuvanticity of TDM.
Assuntos
Fatores Corda/imunologia , Encefalomielite Autoimune Experimental/imunologia , Lectinas Tipo C/imunologia , Proteínas de Membrana/metabolismo , Receptores de IgG/imunologia , Adjuvantes Imunológicos , Animais , Encefalomielite Autoimune Experimental/microbiologia , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Ativação de Macrófagos/imunologia , Macrófagos/imunologia , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Infecções por Mycobacterium/imunologia , Mycobacterium bovis/imunologia , Mycobacterium tuberculosis/imunologiaRESUMO
T cell development and homeostasis requires IL-7R α-chain (IL-7Rα) signaling. Tyrosine Y449 of the IL-7Rα is essential to activate STAT5 and PI3K, whereas PI3K recruitment requires IL-7Rα methionine M452. How IL-7Rα activates and regulates both signaling pathways differentially remains unclear. To characterize differential signaling, we established two lines of IL-7Rα mutant mice: IL-7R-Y449F mice and IL-7R-M452L mice. IL-7R-Y449F mice showed decreased PI3K and STAT5 signals, whereas IL-7R-M452L mice showed decreased PI3K but significantly increased STAT5 signaling, owing to a competition between PI3K and STAT5 signaling through Y449 of IL-7Rα. The number of T, B, and mature innate lymphoid cells were markedly reduced in IL-7R-Y449F mice, whereas IL-7R-M452L mice showed impaired early T cell development and memory precursor effector T cell maintenance with the downregulation of transcription factor T cell factor-1. Peripheral T cell numbers increased in IL-7R-M452L mice with enhanced survival and homeostatic proliferation. Furthermore, although wild type and IL-7R-Y449F mice showed comparable Th1/Th2 differentiation, IL-7R-M452L mice exhibited impaired Th17 differentiation. We conclude that PI3K competes with STAT5 under IL-7Rα and maintains an appropriate signal balance for modulating T cell development and homeostasis. To our knowledge, this study provides a new insight into complex regulation of IL-7Rα signaling, which supports immune development and responses.
Assuntos
Homeostase/imunologia , Fosfatidilinositol 3-Quinases/imunologia , Receptores de Interleucina-7/imunologia , Fator de Transcrição STAT5/imunologia , Linfócitos T/imunologia , Animais , Diferenciação Celular/imunologia , Imunidade Inata , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Fosfatidilinositol 3-Quinases/metabolismo , Receptores de Interleucina-7/metabolismo , Fator de Transcrição STAT5/metabolismo , Transdução de Sinais/imunologiaRESUMO
Efficacy of B-cell depletion therapy highlights the antibody-independent effector functions of B cells in rheumatoid arthritis (RA). Given type 1 helper T (Th1) cells abundant in synovial fluid (SF) of RA, we have determined whether Th1 cells could generate novel effector B cells. Microarray and qPCR analysis identified CXCL9/10 transcripts as highly expressed genes upon BCR/CD40/IFN-γ stimulation. Activated Th1 cells promoted the generation of CXCL9/10-producing T-bet+ B cells. Expression of CXCL9/10 was most pronounced in CXCR3+ switched memory B cells. Compared with peripheral blood, SFRA enriched highly activated Th1 cells that coexisted with abundant CXCL9/10-producing T-bet+ B cells. Intriguingly, anti-IFN-γ antibody and JAK inhibitors significantly abrogated the generation of CXCL9/10-producing T-bet+ B cells. B cell derived CXCL9/10 significantly facilitated the migration of CD4+ T cells. These findings suggest that Th1 cells generate the novel CXCL9/10-producing T-bet+ effector B cells that could be an ideal pathogenic B cell target for RA therapy.
Assuntos
Artrite Reumatoide/patologia , Subpopulações de Linfócitos B/imunologia , Células Th1/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Artrite Reumatoide/imunologia , Subpopulações de Linfócitos B/metabolismo , Quimiocina CXCL10/imunologia , Quimiocina CXCL10/metabolismo , Quimiocina CXCL9/imunologia , Quimiocina CXCL9/metabolismo , Quimiocina CXCL9/fisiologia , Feminino , Expressão Gênica , Humanos , Interferon gama/metabolismo , Ativação Linfocitária , Masculino , Pessoa de Meia-Idade , Células Th1/metabolismoRESUMO
BACKGROUND: Osteosarcoma (OS) is the most common malignant bone tumor and the prognosis of advanced cases is still poor. Recently, there have been several reports suggesting the relationship between innate immunity and OS, but the detailed mechanism is unknown. We demonstrate the relationship between OS and Toll-like receptor 4 (TLR4) which is one of the most important factors in innate immunity. METHODS: We established a syngenic mouse tumor model using C3H/HeN, C3H/HeJ mouse and a highly metastatic OS cell line, LM8. TLR4 activation with lipopolysaccharide (LPS) was performed on both mice and its influence on the progression of OS was evaluated. We also performed CD8 + cells depletion to examine the influence on TLR4 activation effects. RESULTS: Tumor volume of C3H/HeN mice was significantly smaller and overall survival of C3H/HeN mice was significantly longer than C3H/HeJ mice. We found more CD8+ cells infiltrating in lung metastases of C3H/HeN mice and depletion of CD8+ cells canceled the antitumor effects of LPS. CONCLUSION: TLR4 activation by LPS increased CD8+ cells infiltrating into lung metastases and suppressed OS progression in the mouse model. TLR4 activation may suppress the progression of OS via stimulating CD8+ cells and can be expected as a novel treatment for OS.
Assuntos
Neoplasias Ósseas/imunologia , Neoplasias Pulmonares/imunologia , Osteossarcoma/imunologia , Linfócitos T Citotóxicos/imunologia , Receptor 4 Toll-Like/metabolismo , Adjuvantes Imunológicos/administração & dosagem , Adolescente , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Ósseas/mortalidade , Neoplasias Ósseas/patologia , Neoplasias Ósseas/terapia , Linhagem Celular Tumoral/transplante , Quimioterapia Adjuvante , Criança , Pré-Escolar , Modelos Animais de Doenças , Progressão da Doença , Feminino , Humanos , Estimativa de Kaplan-Meier , Lipídeo A/administração & dosagem , Lipídeo A/análogos & derivados , Lipopolissacarídeos/administração & dosagem , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/secundário , Neoplasias Pulmonares/terapia , Depleção Linfocítica , Masculino , Camundongos , Pessoa de Meia-Idade , Osteossarcoma/mortalidade , Osteossarcoma/secundário , Osteossarcoma/terapia , Prognóstico , Intervalo Livre de Progressão , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/imunologia , Linfócitos T Citotóxicos/metabolismo , Receptor 4 Toll-Like/agonistas , Receptor 4 Toll-Like/imunologia , Carga Tumoral/imunologia , Adulto JovemRESUMO
Generation of neoantigens by citrullination is implicated in the production of anti-citrullinated protein Abs in rheumatoid arthritis, but citrullination is also a physiological process. To verify whether citrullin-specific B cells are immunologically ignorant or tolerant in normal conditions, transgenic (Tg) mice expressing IgM with the V region of an anti-cyclic citrullinated peptide (CCP) mAb cloned from a rheumatoid arthritis patient were generated. CCP-specific B cells developed in the anti-CCP IgM Tg mice with an alteration of bone marrow B cell fractions, and the number of mature B cells decreased compared with wild-type or the control anti-influenza nucleoprotein-specific IgM Tg mice. In addition, B cells in anti-CCP IgM Tg mice are functionally anergic. Thus, tolerance is induced in CCP-specific B cells in vivo, suggesting that the immune systems are naturally exposed to citrullinated Ags, and anti-CCP Ab production requires additional steps beyond the generation of neoantigens by citrullination.
Assuntos
Artrite Reumatoide/imunologia , Linfócitos B/imunologia , Imunoglobulina M/metabolismo , Peptídeos Cíclicos/imunologia , Receptores de Antígenos de Linfócitos B/metabolismo , Animais , Anticorpos Monoclonais/genética , Células Cultivadas , Anergia Clonal , Humanos , Tolerância Imunológica , Imunoglobulina M/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Engenharia de Proteínas , Receptores de Antígenos de Linfócitos B/genéticaRESUMO
Objectives: To assess long-term outcomes for seven biological disease-modifying antirheumatic drugs (bDMARDs) and one Janus kinase (JAK)-inhibitor in rheumatoid arthritis.Methods: We retrospectively analyzed data from 801 rheumatoid arthritis patients visiting our rheumatology clinic between 2003 and 2017. We determined drug survival rates, drug discontinuation, and switching rates in these patients.Results: Among the drugs administered to naïve subjects, the drug-survival rate was highest for tocilizumab, at 77.8% after 6 years, whereas the rates for golimumab, etanercept, abatacept, infliximab, and adalimumab, were 61.5%, 48.9%, 41.6%, 34.5%, and 34.4%, respectively. Switching drugs led to decreased survival rates. The discontinuation rates for all drugs due to adverse events and poor efficacy increased rapidly in the first 2 years and the first 6 months, respectively.Conclusions: This report is a long-term analysis of a large cohort of rheumatoid arthritis patients from a single rheumatology clinic in Japan. We conclude that to maximize the survival rate of antirheumatic drugs, it is important to maintain their effectiveness over long periods of time by appropriate drug choices and optimizing dosage before switching drugs.
Assuntos
Antirreumáticos/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Abatacepte/uso terapêutico , Adalimumab/uso terapêutico , Adulto , Anticorpos Monoclonais/uso terapêutico , Anticorpos Monoclonais Humanizados/uso terapêutico , Artrite Reumatoide/epidemiologia , Etanercepte/uso terapêutico , Feminino , Humanos , Infliximab/uso terapêutico , Janus Quinases/antagonistas & inibidores , Japão , Masculino , Pessoa de Meia-Idade , Taxa de SobrevidaRESUMO
Interleukin 21 (IL-21) is a pleiotropic common cytokine receptor γ chain cytokine that promotes the effector functions of NK cells and CD8+ T cells and inhibits CD8+ T cell exhaustion during chronic infection. We found that the absolute number of short-lived effector CD8+ T cells (SLECs) (KLRG1high CD127low) decreased significantly in IL-21 receptor-deficient (IL-21R-/-) mice during Mycobacterium bovis bacillus Calmette-Guérin (BCG) infection. Early effector CD8+ T cells (EECs) (KLRG1low CD127low) were normally generated in IL-21R-/- mice after infection. Exhausted CD8+ T cells (PD-1high KLRG1low) were also normally generated in IL-21R-/- mice after infection. Mixed bone marrow (BM) chimera and transfer experiments showed that IL-21R on CD8+ T cells was essential for the proliferation of EECs, allowing them to differentiate into SLECs after BCG infection. On the other hand, the number of SLECs increased significantly after infection with recombinant BCG (rBCG) that secreted an antigen 85B (Ag85B)-IL-21 fusion protein (rBCG-Ag85B-IL-21), but the number of exhausted CD8+ T cells did not change after rBCG-Ag85B-IL-21 infection. These results suggest that IL-21 signaling drives the differentiation of SLECs from EECs but does not inhibit the exhaustion of CD8+ T cells following BCG infection in mice.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Interleucinas/metabolismo , Mycobacterium bovis/imunologia , Subpopulações de Linfócitos T/imunologia , Tuberculose/imunologia , Animais , Linfócitos T CD8-Positivos/química , Diferenciação Celular , Modelos Animais de Doenças , Imunofenotipagem , Subunidade alfa de Receptor de Interleucina-7/análise , Lectinas Tipo C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores Imunológicos/análise , Receptores de Interleucina-21/análise , Receptores de Interleucina-21/deficiência , Subpopulações de Linfócitos T/químicaRESUMO
OBJECTIVES: Since the presence of IgM antibodies is a hallmark of ongoing immune response, we aimed to identify immunologically active rheumatoid arthritis (RA) patients by detecting IgM anti-citrullinated protein antibody (ACPA) levels. METHODS: IgM ACPA levels were determined in the serum of 176 RA patients by enzyme-linked immunosorbent assay, in which parameters of reactivity against citrullinated and non-citrullinated peptides were compared to ensure the specificity. Influence of IgM rheumatoid factor (RF) on IgM ACPA detection was examined by removing IgG, using protein G-conjugated beads, or by purifying ACPA, using citrullinated peptide-conjugated beads. RESULTS: Although IgM specific for citrullinated proteins was detected in some patients (11%), IgM molecules reactive to both citrullinated and non-citrullinated peptides were detected in a substantial number of patient samples (12%). IgM ACPA-positive reactions were associated with the presence of IgG ACPA and IgM RF. Surprisingly, protein G-mediated removal of IgG from the serum eliminated positivity for IgM ACPA, suggesting that IgG ACPA-IgM RF complex was being detected. This assumption was confirmed by the detection of IgM RF in the eluate of protein G beads and citrullinated peptide-conjugated beads. CONCLUSIONS: In an attempt to detect IgM ACPA, we mostly revealed false positive reactions due to the presence of IgM molecules, which were not specific for citrullinated proteins, and IgG ACPA-IgM RF immune complex. The latter complex had been proposed to play a role in the pathogenesis of RA, and here, for the first time, we have demonstrated its presence in the sera of RA patients.
Assuntos
Anticorpos Antiproteína Citrulinada/sangue , Complexo Antígeno-Anticorpo/sangue , Artrite Reumatoide/imunologia , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Fator Reumatoide/sangue , Adulto , Idoso , Artrite Reumatoide/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
The thymic medulla provides a microenvironment where medullary thymic epithelial cells (mTECs) express autoimmune regulator and diverse tissue-restricted genes, contributing to launching self-tolerance. Positive selection is essential for thymic medulla formation via a previously unknown mechanism. Here we show that the cytokine RANK ligand (RANKL) was produced by positively selected thymocytes and regulated the cellularity of mTEC by interacting with RANK and osteoprotegerin. Forced expression of RANKL restored thymic medulla in mice lacking positive selection, whereas RANKL perturbation impaired medulla formation. These results indicate that RANKL produced by positively selected thymocytes is responsible for fostering thymic medulla formation, thereby establishing central tolerance.
Assuntos
Células Epiteliais/imunologia , Ligante RANK/metabolismo , Receptor Ativador de Fator Nuclear kappa-B/metabolismo , Linfócitos T/imunologia , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Timo/imunologia , Fatores de Transcrição/metabolismo , Animais , Autoimunidade , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Camundongos , Osteoprotegerina/metabolismo , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Antígenos de Linfócitos T/metabolismo , Tolerância a Antígenos Próprios , Linfócitos T/citologia , Linfócitos T/metabolismo , Timo/citologia , Timo/metabolismo , Proteína AIRERESUMO
Notch signaling is an important regulator for the development and function of both αß and γδ T cells, whereas roles of Notch signaling in T cell maintenance remain unclear. We reported previously that the Notch-Hes1 pathway was involved in the intrathymic development of naturally occurring IL-17-producing (IL-17(+)) γδ T cells. To gain insight into additional roles for the Notch axis in the homeostasis of γδ T cells, we performed a genome-wide analysis of Notch target genes and identified the novel promoter site of IL-7Rα driven by the Notch-RBP-Jκ pathway. Constitutive Notch signaling had the potential to induce IL-7Rα expression on γδ T cells in vivo, as well as in vitro, whereas conditional deletion of RBP-Jκ abrogated IL-7Rα expression, but not Hes1 expression, by γδ T cells and selectively reduced the pool size of IL-7Rα(high) IL-17(+) γδ T cells in the periphery. In the absence of IL-7Rα-mediated signaling, IL-17(+) γδ T cells were barely maintained in adult mice. Addition of exogenous IL-7 in vitro selectively expanded IL-17(+) γδ T cells. Thus, our results revealed a novel role for the Notch-RBP-Jκ-IL-7Rα axis that is independent of Hes1 for homeostasis of IL-17(+) γδ T cells.
Assuntos
Proteína de Ligação a Sequências Sinal de Recombinação J de Imunoglobina/imunologia , Interleucina-17/biossíntese , Receptor Notch1/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Receptores de Interleucina-7/imunologia , Animais , Anticorpos/imunologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/biossíntese , Proliferação de Células/efeitos dos fármacos , Estudo de Associação Genômica Ampla , Proteínas de Homeodomínio/biossíntese , Homeostase , Proteína de Ligação a Sequências Sinal de Recombinação J de Imunoglobina/genética , Interferon gama/biossíntese , Interleucina-7/biossíntese , Interleucina-7/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Receptores de Interleucina-7/biossíntese , Transdução de Sinais , Linfócitos T/imunologia , Fatores de Transcrição HES-1RESUMO
OBJECTIVES: To retrospectively evaluate the long-term results of cementless total hip arthroplasty (THA) in patients with rheumatoid arthritis (RA) and postoperative patient mortality after THA. METHODS: This study included 191 hips in 149 RA patients who underwent cementless THA between 1998 and 2005. Mean age at surgery was 54.2 years, and mean follow-up was 12.6 years. Implant and patient survivorships were determined using the Kaplan-Meier method, and the associated influencing factors were determined. RESULTS: Implant survivals at 17 years were 99.5% for stems, 93.9% for cups, and 90.8% for liners. Among the liners used, THAs with highly cross-linked polyethylene showed better survivals compared with those with conventional polyethylene and alumina-bearing surface (93.4%, 90.9%, and 52.2%, respectively). A total of 64 deaths occurred; 45 patients died within 10 years and 19 patients died between 10 and 17 years. Malignancy (25.0%) was the leading cause of death, followed by pneumonia (20.8%) and sepsis (20.8%). The patient survival rate was 36.9% at 17 years after THA. Multivariate analysis exhibited that older age at operation and greater dose of concomitant corticosteroid resulted in shorter patient survivals. CONCLUSIONS: Cementless THA worked well in patients with RA. Mortality remained high among RA patients who needed THA.
Assuntos
Artroplastia de Quadril/métodos , Falha de Prótese/etiologia , Idoso , Artroplastia de Quadril/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
BACKGROUND: Klebsiella pneumoniae frequently causes life-threatening infection in children. Interleukin 17A (IL-17A) is known to be involved in protection against K. pneumoniae infection through activation of neutrophils. METHODS AND RESULTS: We found that IL-17A-producing γδ T cells existed more frequently in younger mice on examination of IL-17A-producing lymphocytes in the lung of naive mice at various ages. We hence compared the protective role of IL-17A-producing γδ T cells against pulmonary K. pneumoniae infection in young (3 weeks old) and adult (8-12 weeks old) mice. IL-17A-deficient mice were susceptible to K. pneumonia regardless of age. Cγ-, Vγ4/6-, or Vδ1-deficient mice were susceptible to K. pneumonia at young age, while interleukin 23p19 (IL-23p19)-deficient mice were susceptible at adult age. IL-17A-producing Vγ1-Vγ4- γδ T cells expressing canonical Vγ6/Vδ1 genes were dominant over IL-17A-producing Vγ4+ γδ T cells in the lungs of young mice after infection. The IL-17A-producing Vγ1-Vγ4- γδ T cells expressed an activation marker, CD69, and proliferated in an IL-23-independent manner, while the IL-17A-producing Vγ4+ γδ T cells expressing IL-23 receptor but no CD69 proliferated in IL-23-dependent manner. CONCLUSIONS: These results suggest that 2 types of IL-17A-producing γδ T cells are activated for host defense against K. pneumoniae infection by IL-23-dependent or independent mechanism.
Assuntos
Interleucina-17/metabolismo , Infecções por Klebsiella/imunologia , Klebsiella pneumoniae/imunologia , Pneumonia Bacteriana/imunologia , Linfócitos T/imunologia , Animais , Feminino , Interleucina-17/deficiência , Subunidade p19 da Interleucina-23/metabolismo , Camundongos Endogâmicos C57BL , Camundongos KnockoutRESUMO
γδ T cells develop at the double-negative (DN) 2 and DN3 stages and acquire functions to produce IL-17 and IFN-γ in fetal thymus. However, the relationship between differentiation stages and their functions was unclear. In this study, we found that, although IFN-γ-producing and IL-17-producing γδ T cells developed from DN2 cells, only IFN-γ-producing γδ T cells developed from DN3 cells, indicating the direct generation of IL-17-producing γδ T cells from the DN2 stage, not through the DN3 stage. Single-cell analysis revealed that DN2 cells contained heterogeneous γδ T cell precursors with or without an ability to develop IL-17 producers. Inactivation of B cell leukemia/lymphoma 11b, a zinc finger transcription factor responsible for transition from early to late stages of DN2 cells, completely abrogated the development of IL-17-producing γδ T cells, although a unique subset of IFN-γ-producing γδ T cells expressing a high level of promyelocytic leukemia zinc finger was able to develop. Thus, our results reveal that γδ T cells are functionally differentiated to IFN-γ and IL-17 producers at different developmental stages in fetal thymus.