RESUMO
Interleukin (IL)-7 acts via the IL-7 receptor in metastatic tumor progression in prostate cancer (PC). The current study aimed to evaluate thymoquinone (Tq), an active constituent from Nigella sativa against IL-7-driven tumor progression and metastatic invasion in PC cells. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to assess the proliferation of PC cells. Enzyme-linked immunosorbent assay was used to detect the expression of IL-7 and matrix metalloproteinases (MMPs). Tumor-cell transendothelial, scratch wound and cell scatter assays were performed to mimic metastasis. Western immunoblotting was used to measure the level of proteins. Tq effectively controlled the proliferation of DU-145, PC-3, and LNCaP cells with GI50 of 10.18, 12.40, and 16.78 µM, respectively. IL-7 and IL-7R were natively expressed in all PC types, while maximal expression was detected in DU-145. IL-7 promoted metastatic events, such as transendothelial migration, cell scatter, and cell invasion of DU-145 cells in a dose-dependent manner that was inhibited by Tq. Furthermore, Tq also downregulated p-Akt and NF-κB in DU-145 cells induced by IL-7 antibody and reduced the levels of MMP-3 and MMP-7 in these cells in a dose-dependent manner. Collectively, Tq has excellent efficacy in controlling tumor progression, migration, and invasion of DU-145 cells that were driven by the activation of MMPs through IL-7/Akt/NF-κB signaling.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Benzoquinonas/farmacologia , Interleucina-7/antagonistas & inibidores , Neoplasias da Próstata/tratamento farmacológico , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Benzoquinonas/química , Benzoquinonas/isolamento & purificação , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Interleucina-7/metabolismo , Masculino , Metaloproteinase 3 da Matriz/metabolismo , Metaloproteinase 7 da Matriz/metabolismo , NF-kappa B/antagonistas & inibidores , NF-kappa B/metabolismo , Nigella sativa/química , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/metabolismo , Células Tumorais CultivadasRESUMO
Chronic myeloid leukemia (CML) is caused by the fusion of the BCR activator of RhoGEF and GTPase activating protein (BCR) and ABL proto-oncogene, the nonreceptor tyrosine kinase (ABL) genes. Although the tyrosine kinase inhibitors (TKIs) imatinib (IM) and nilotinib (NI) have remarkable efficacy in managing CML, the malignancies in some patients become TKI-resistant. Here, we isolated bone marrow (BM)-derived mesenchymal stem cells (MSCs) from several CML patients by Ficoll-Hypaque density-gradient centrifugation for coculture with K562 and BV173 cells with or without TKIs. We used real-time quantitative PCR to assess the level of interleukin 7 (IL-7) expression in the MSCs and employed immunoblotting to monitor protein expression in the BCR/ABL, phosphatidylinositol 3-kinase (PI3K)/AKT, and JAK/STAT signaling pathways. We also used a xenograft tumor model to examine the in vivo effect of different MSCs on CML cells. MSCs from patients with IM-resistant CML protected K562 and BV173 cells against IM- or NI-induced cell death, and this protection was due to increased IL-7 secretion from the MSCs. Moreover, IL-7 levels in the BM of patients with IM-resistant CML were significantly higher than in healthy donors or IM-sensitive CML patients. IL-7 elicited IM and NI resistance via BCR/ABL-independent activation of JAK1/STAT5 signaling, but not of JAK3/STAT5 or PI3K/AKT signaling. IL-7 or JAK1 gene knockdown abrogated IL-7-mediated STAT5 phosphorylation and IM resistance in vitro and in vivo Because high IL-7 levels in the BM mediate TKI resistance via BCR/ABL-independent activation of JAK1/STAT5 signaling, combining TKIs with IL-7/JAK1/STAT5 inhibition may have significant utility for managing CML.
Assuntos
Apoptose/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos , Inibidores de Proteínas Quinases/farmacologia , Transdução de Sinais/efeitos dos fármacos , Animais , Células da Medula Óssea/citologia , Linhagem Celular Tumoral , Técnicas de Cocultura , Proteínas de Fusão bcr-abl/metabolismo , Humanos , Interleucina-7/antagonistas & inibidores , Interleucina-7/genética , Interleucina-7/metabolismo , Janus Quinase 1/antagonistas & inibidores , Janus Quinase 1/genética , Janus Quinase 1/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Camundongos , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Proteínas Quinases/uso terapêutico , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas c-akt/metabolismo , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Fator de Transcrição STAT5/metabolismoRESUMO
Imatinib mesylate (IM) therapy has been shown to induce lower T cell counts in chronic myelogenous leukemia (CML) patients and an interference of IM with T cell receptor (TCR) signaling has been invoked to explain this observation. However, IL-7 and TCR signaling are both essential for lymphocyte survival. This study was undertaken to determine whether IM interferes with IL-7 or TCR signaling to explain lower T cell counts in patients. At diagnosis, CML patients have typically lower CD4+ counts in their blood, yet CD8+ counts are normal or even increased in some. Following the initiation of IM treatment, CD4+ counts were further diminished and CD8+ T lymphocytes were dramatically decreased. In vitro studies confirmed IM interference with TCR signaling through the inhibition of ERK phosphorylation and we showed a similar effect on IL-7 signaling and STAT5 phosphorylation (STAT5-p). Importantly however, using an in vivo mouse model, we demonstrated that IM impaired T cell survival through the inhibition of IL-7 and STAT5-p but not TCR signaling which remained unaffected during IM therapy. Thus, off-target inhibitory effects of IM on IL-7 and STAT5-p explain how T cell lymphopenia occurs in patients treated with IM.
Assuntos
Mesilato de Imatinib/administração & dosagem , Interleucina-7/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Fator de Transcrição STAT5/genética , Animais , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD4-Positivos/patologia , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/patologia , Contagem de Células , Linhagem Celular Tumoral , Humanos , Mesilato de Imatinib/efeitos adversos , Interleucina-7/antagonistas & inibidores , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Linfopenia/genética , Linfopenia/patologia , Camundongos , Fosforilação/efeitos dos fármacos , Receptores de Antígenos de Linfócitos T/genética , Fator de Transcrição STAT5/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Increased understanding of pediatric acute lymphoblastic leukemia (ALL) pathobiology has led to dramatic improvements in patient survival. However, there is still a need to develop targeted therapies to enable reduced chemotherapy intensity and to treat relapsed patients. The interleukin-7 receptor α (IL-7Rα) signaling pathways are prime therapeutic targets because these pathways harbor genetic aberrations in both T-cell ALL and B-cell precursor ALL. Therapeutic targeting of the IL-7Rα signaling pathways may lead to improved outcomes in a subset of patients.
Assuntos
Interleucina-7/antagonistas & inibidores , Proteínas de Neoplasias/antagonistas & inibidores , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Humanos , Interleucina-7/metabolismo , Proteínas de Neoplasias/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismoRESUMO
The only biological treatments recognized and reimbursed for spondylarthritis in Switzerland are anti TNF. Other effective agents in rheumatoid arthritis were found to be of little use in this indication. Fortunately, in recent years appeared biological molecules blocking cytokines involved in new pathways of inflammation in particular that of IL7. They have been very effective against psoriasis and have a high potential in psoriatic arthritis and spondylarthritis. In parallel, synthetic small molecules capable of modulating the production of intracellular cytokines begin to be marketed. They also are potentially active in the same rheumatic diseases. The purpose of this article is to review these new drugs, in particular to review the progress of their development and commercialization status.
Assuntos
Antirreumáticos/uso terapêutico , Interleucina-7/antagonistas & inibidores , Janus Quinases/antagonistas & inibidores , Inibidores de Fosfodiesterase/uso terapêutico , Espondilartrite/tratamento farmacológico , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Anticorpos Monoclonais/uso terapêutico , Anticorpos Monoclonais Humanizados/uso terapêutico , Ensaios Clínicos como Assunto , Humanos , Espondilartrite/imunologia , Suíça , Resultado do TratamentoRESUMO
Our previously published data show that As(+3) in vivo and in vitro, at very low concentrations, inhibits lymphoid, but not myeloid stem cell development in mouse bone marrow. We also showed that the As(+3) metabolite, monomethylarsonous acid (MMA(+3)), was responsible for the observed pre-B cell toxicity caused by As(+3). Interleukin-7 (IL-7) is the primary growth factor responsible for pre-lymphoid development in mouse and human bone marrow, and Signal Transducer and Activator of Transcription 5 (STAT5) is a transcriptional factor in the IL-7 signaling pathway. We found that MMA(+3) inhibited STAT5 phosphorylation at a concentration as low as 50 nM in mouse bone marrow pre-B cells. Inhibition of STAT5 phosphorylation by As(+3) occurred only at a concentration of 500 nM. In the IL-7 dependent mouse pre-B 2E8 cell line, we also found selective inhibition of STAT5 phosphorylation by MMA(+3), and this inhibition was dependent on effects on JAK3 phosphorylation. IL-7 receptor expression on 2E8 cell surface was also suppressed by 50 nM MMA(+3) at 18 h. As further evidence for the inhibition of STAT5, we found that the induction of several genes required in B cell development, cyclin D1, E2A, EBF1, and PAX5, were selectively inhibited by MMA(+3). Since 2E8 cells lack the enzymes responsible for the conversion of As(+3) to MMA(+3) in vitro, the results of these studies suggest that As(+3) induced inhibition of pre-B cell formation in vivo is likely dependent on the formation of MMA(+3) which in turn inhibits IL-7 signaling at several steps in mouse pre-B cells.
Assuntos
Interleucina-7/antagonistas & inibidores , Compostos Organometálicos/toxicidade , Células Precursoras de Linfócitos B/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Animais , Arsênio/toxicidade , Interleucina-7/fisiologia , Janus Quinase 1/antagonistas & inibidores , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fosforilação , Células Precursoras de Linfócitos B/imunologia , Células Precursoras de Linfócitos B/fisiologia , Fator de Transcrição STAT5/antagonistas & inibidores , Fator de Transcrição STAT5/metabolismoRESUMO
Chronic allograft nephropathy (CAN) is a major cause of graft loss following kidney transplantation and may result from the interactions of various immune and non-immune factors. The aim of the present study was to establish an in vitro model of glomerular mesangial cell injury in order to examine the gene expression levels of indoleamine 2,3-dioxygenase (IDO), heme oxygenase-1 (HO-1) and interleukin-7 (IL-7) in mesangial cells during the healing process as well as to investigate the effects of various immunosuppressants on the expression of these genes. The HBZY-1 glomerular mesangial cell line was pre-treated in vitro with cytochalasin B for 2 h to induce reversible damage. Following the pre-treatment, the HBZY-1 cells were divided into five groups: Blank control group, cyclosporine A (CsA) group, tacrolimus (Tac) group, mycophenolate mofetil (MMF) group and rapamycin (RAPA) group. After treating the mesangial cells with each immunosuppressive drug for 6, 12 or 24 h, the mRNA and protein expression levels of IDO, HO-1 and IL-7 were examined using reverse transcription quantitative polymerase chain reaction (RT-qPCR), western blot and immunohistochemical analyses. The results showed that expression levels of HO-1 were significantly upregulated in response to treatment with CsA, FK506, RAPA and MMF, whereas the expression levels of IL-7 were markedly downregulated by treatment with the above immunosuppressants. CsA, FK506 and MMF significantly enhanced the expression levels of IDO, whereas RAPA exhibited no apparent effect on IDO. The present study may contribute to the understanding of the pathogenesis of CAN and provide novel strategies for the prevention and treatment of CAN.
Assuntos
Mesângio Glomerular/efeitos dos fármacos , Heme Oxigenase-1/genética , Imunossupressores/farmacologia , Indolamina-Pirrol 2,3,-Dioxigenase/genética , Interleucina-7/genética , Linhagem Celular , Ciclosporina/farmacologia , Citocalasina B/farmacologia , Regulação da Expressão Gênica , Mesângio Glomerular/citologia , Mesângio Glomerular/metabolismo , Heme Oxigenase-1/metabolismo , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Interleucina-7/antagonistas & inibidores , Interleucina-7/metabolismo , Ácido Micofenólico/análogos & derivados , Ácido Micofenólico/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais , Sirolimo/farmacologia , Tacrolimo/farmacologiaRESUMO
INTRODUCTION: The discovery of IL-7 and thymic stromal lymphopoietin (TSLP) has been a major step in the understanding of arthritis. IL-7 amplifies the inflammation induced by other cytokines, primarily TNF. In animal models of arthritis, inhibition of IL-7 limits inflammation and joint erosion. TSLP is an IL-7-like cytokine that triggers dendritic cell-mediated Th2-type inflammatory responses and is considered as a master switch for allergic inflammation. TSLP is a downstream molecule of TNF-α and as such may be involved in the pathophysiology of inflammatory arthritis. AREAS COVERED: This review summarizes current knowledge of the role of IL-7 and TSLP derived from both animal models and studies in patients with rheumatoid arthritis (RA). The emergence of IL-7 blockade as a future therapy in RA is highlighted, along with the potential goals and limitations of this therapeutic approach. The write-up also highlights the functional capacities of TSLP in arthritis. EXPERT OPINION: Evidences suggest important roles for IL-7 and TSLP in the pathogenesis of RA and can be viewed as potential therapeutic targets. Regulation of these at genetic level is a promising investigational area. Given the difficulty in reconstituting T cells in patients with RA, therapeutic approaches that minimize the elimination of T cells are likely to be more desirable.
Assuntos
Antirreumáticos/farmacologia , Artrite Reumatoide/tratamento farmacológico , Citocinas/antagonistas & inibidores , Interleucina-7/antagonistas & inibidores , Terapia de Alvo Molecular , Animais , Antirreumáticos/uso terapêutico , Artrite Reumatoide/fisiopatologia , Linfócitos B/imunologia , Linfócitos T CD4-Positivos/imunologia , Citocinas/genética , Citocinas/fisiologia , Avaliação Pré-Clínica de Medicamentos , Regulação da Expressão Gênica , Humanos , Imunoglobulinas/fisiologia , Interleucina-7/deficiência , Interleucina-7/genética , Interleucina-7/farmacologia , Interleucina-7/fisiologia , Macrófagos/imunologia , Camundongos , Camundongos Knockout , Receptores de Citocinas/fisiologia , Receptores de Interleucina-7/fisiologia , Selênio/farmacologia , Selênio/uso terapêutico , Líquido Sinovial/metabolismo , Linfopoietina do Estroma do TimoRESUMO
During early stages of B-lineage differentiation in bone marrow, signals emanating from IL-7R and pre-BCR are thought to synergistically induce proliferative expansion of progenitor cells. Paradoxically, loss of pre-BCR-signaling components is associated with leukemia in both mice and humans. Exactly how progenitor B cells perform the task of balancing proliferative burst dependent on IL-7 with the termination of IL-7 signals and the initiation of L chain gene rearrangement remains to be elucidated. In this article, we provide genetic and functional evidence that the cessation of the IL-7 response of pre-B cells is controlled via a cell-autonomous mechanism that operates at a discrete developmental transition inside Fraction C' (large pre-BII) marked by transient expression of c-Myc. Our data indicate that pre-BCR cooperates with IL-7R in expanding the pre-B cell pool, but it is also critical to control the differentiation program shutting off the c-Myc gene in large pre-B cells.
Assuntos
Subpopulações de Linfócitos B/imunologia , Subpopulações de Linfócitos B/metabolismo , Regulação para Baixo/imunologia , Interleucina-7/fisiologia , Proteínas Proto-Oncogênicas c-myc/genética , Células-Tronco/imunologia , Células-Tronco/metabolismo , Animais , Subpopulações de Linfócitos B/patologia , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Linhagem Celular , Células Cultivadas , Técnicas de Cocultura , Regulação para Baixo/genética , Técnicas de Introdução de Genes , Inibidores do Crescimento/biossíntese , Inibidores do Crescimento/genética , Interleucina-7/antagonistas & inibidores , Interleucina-7/metabolismo , Camundongos , Camundongos Knockout , Leucemia-Linfoma Linfoblástico de Células Precursoras B/imunologia , Leucemia-Linfoma Linfoblástico de Células Precursoras B/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patologia , Proteínas Proto-Oncogênicas c-myc/biossíntese , Receptores de Interleucina-7/antagonistas & inibidores , Receptores de Interleucina-7/fisiologia , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Células-Tronco/patologia , Células Estromais/imunologia , Células Estromais/metabolismo , Células Estromais/patologiaRESUMO
PURPOSE: To determine the effect of phosphodiesterase type-4 (PDE4) inhibition on IL-17-associated immunity in experimental dry eye disease (DED). METHODS: Murine DED was induced, after which a PDE4 inhibitor (cilomilast), dexamethasone, cyclosporine, or a relevant vehicle was administered topically. Real-time PCR, immunohistochemical staining, and flow cytometry were employed to evaluate the immuno-inflammatory parameters of DED with a focus on IL-17-associated immunity. Corneal fluorescein staining (CFS) was performed to evaluate clinical disease progression. RESULTS: DED induction increased proinflammatory cytokine expression, pathogenic immune cell infiltration, and CFS scores. Cilomilast significantly decreased the expression of TNF-α in the cornea (P ≤ 0.05) and IL-1α, IL-1ß, and TNF-α in the conjunctiva (P ≤ 0.05) as compared with vehicle control. Cilomilast treatment markedly decreased the presence of CD11b+ antigen-presenting cells in the central and peripheral cornea (P ≤ 0.05), and led to decreased conjunctival expression of cytokines IL-6, IL-23, and IL-17 (P ≤ 0.05). Moreover, cilomilast decreased the expression of IL-17 and IL-23 in the draining lymph nodes (P ≤ 0.05). Topical cilomilast was significantly more effective than vehicle at reducing CFS scores (P ≤ 0.05). The therapeutic efficacy of cilomilast was comparable or superior to that of dexamethasone and cyclosporine in all tested measures. CONCLUSIONS: Topical cilomilast suppresses the generation of IL-17-associated immunity in experimental DED.
Assuntos
Túnica Conjuntiva/metabolismo , Síndromes do Olho Seco/imunologia , Regulação da Expressão Gênica/efeitos dos fármacos , Imunidade Inata/efeitos dos fármacos , Interleucina-7/genética , Inibidores da Fosfodiesterase 4/administração & dosagem , RNA/genética , Animais , Túnica Conjuntiva/imunologia , Túnica Conjuntiva/patologia , Córnea/imunologia , Córnea/metabolismo , Córnea/patologia , Ácidos Cicloexanocarboxílicos/administração & dosagem , Modelos Animais de Doenças , Progressão da Doença , Síndromes do Olho Seco/tratamento farmacológico , Síndromes do Olho Seco/genética , Feminino , Citometria de Fluxo , Imuno-Histoquímica , Interleucina-7/antagonistas & inibidores , Interleucina-7/biossíntese , Camundongos , Camundongos Endogâmicos C57BL , Microscopia Confocal , Nitrilas/administração & dosagem , Soluções Oftálmicas , Reação em Cadeia da Polimerase em Tempo RealRESUMO
Lupus is characterized by disturbances in lymphocyte homeostasis, as demonstrated by the marked accumulation of activated/memory T cells. Here, we provide evidence that proliferation of the CD8+ precursors for the accumulating CD4â»CD8â» T cells in MRL-Fas(lpr) lupus-predisposed mice is, in part, driven by commensal antigens. The ensuing lymphadenopathy is associated with increased production of IL-7 due to expansion of fibroblastic reticular cells, the primary source of this cytokine. The excess IL-7 is not, however, consumed by CD4â»CD8â» T cells due to permanent down-regulation of IL-7Rα (CD127), but instead supports proliferation of autoreactive T cells and progression of autoimmunity. Accordingly, IL-7R blockade reduced T cell activation and autoimmune manifestations even when applied at advanced disease stage. These findings indicate that an imbalance favoring production over consumption of IL-7 may contribute to systemic autoimmunity, and correction of this imbalance may be a novel therapeutic approach in lymphoproliferative and autoimmune syndromes.
Assuntos
Autoimunidade/imunologia , Interleucina-7/antagonistas & inibidores , Interleucina-7/metabolismo , Doenças Linfáticas/imunologia , Ativação Linfocitária , Receptores de Interleucina-7/antagonistas & inibidores , Linfócitos T/imunologia , Animais , Autoimunidade/genética , Western Blotting , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Interleucina-7/genética , Doenças Linfáticas/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos MRL lpr , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Receptores de Interleucina-7/genética , Receptores de Interleucina-7/metabolismoRESUMO
IL-7 signaling is essential to CD8 T cell development, activation, and homeostasis. We have previously shown decreased expression of the IL-7R alpha-chain (CD127) on CD8 T cells in HIV(+) patients and that this downregulation is mediated at least in part by the HIV Tat protein. We show in this study that CD127 has a prolonged t(1/2) in resting CD8 T cells and continuously recycles on and off the cell membrane. We also demonstrate soluble Tat protein significantly decreases the t(1/2) of CD127. Soluble Tat is taken up from the medium and accumulates in CD8 T cells with a peak of 6 h. Once inside the cell, Tat exits the endosomes during their normal acidification and enters the cytosol. Tat then translocates to the inner leaflet of the cell membrane, where it binds directly to the cytoplasmic tail of CD127, inducing receptor aggregation and internalization through a process dependent on microtubules. Tat appears to then target CD127 for degradation via the proteasome. By removing CD127 from the cell surface, the HIV Tat protein is thus able to reduce IL-7 signaling and impair CD8 T cell proliferation and function.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Membrana Celular/imunologia , Membrana Celular/metabolismo , Subunidades Proteicas/metabolismo , Receptores de Interleucina-7/metabolismo , Fase de Repouso do Ciclo Celular/imunologia , Produtos do Gene tat do Vírus da Imunodeficiência Humana/fisiologia , Linfócitos T CD8-Positivos/virologia , Membrana Celular/virologia , Células Cultivadas , Cicloeximida/farmacologia , Regulação para Baixo/imunologia , Endocitose , Endossomos/imunologia , Endossomos/metabolismo , Exocitose/imunologia , Humanos , Concentração de Íons de Hidrogênio , Interleucina-7/antagonistas & inibidores , Interleucina-7/fisiologia , Subunidades Proteicas/antagonistas & inibidores , Subunidades Proteicas/biossíntese , Inibidores da Síntese de Proteínas/farmacologia , Transporte Proteico/imunologia , Receptores de Interleucina-7/antagonistas & inibidores , Receptores de Interleucina-7/biossíntese , Transdução de Sinais/imunologia , Solubilidade , Produtos do Gene tat do Vírus da Imunodeficiência Humana/metabolismoRESUMO
Soluble CD127 (sCD127) appears to play an important role in the immunopathogenesis of several chronic infections, multiple sclerosis, and various cancers. The function of sCD127 and whether it influences IL-7 bioavailability or activity is unknown. In this study, we demonstrated that recombinant and native sources of sCD127 significantly inhibited IL-7-mediated STAT5 and Akt phosphorylation in CD8(+) T cells. IL-7-mediated proliferation and Bcl-2 expression were similarly reduced by sCD127. In each case, native sCD127 inhibited IL-7 activity to a greater degree than rsCD127. Anti-IL-7 activity was inherent to human plasma and could be reversed by depletion of CD127, revealing for the first time the biological activity of naturally occurring sCD127. Plasma sCD127 concentrations were increased in HIV(+) individuals compared with HIV(-) controls, correlated with IL-7 levels, and remained unchanged in HIV(+) individuals following 1 y of effective antiretroviral therapy. Determining the regulation and function of sCD127 may be critical for understanding both the pathogenesis of diseases in which IL-7 likely has a role (e.g., HIV infection, cancer) and its potential impact on IL-7 as a therapeutic approach.
Assuntos
Infecções por HIV/imunologia , Infecções por HIV/metabolismo , Interleucina-7/antagonistas & inibidores , Receptores de Interleucina-7/fisiologia , Regulação para Cima/imunologia , Células Cultivadas , Humanos , Interleucina-7/metabolismo , Fosforilação/imunologia , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/fisiologia , Receptores de Interleucina-7/biossíntese , Receptores de Interleucina-7/sangue , Fator de Transcrição STAT5/antagonistas & inibidores , Fator de Transcrição STAT5/fisiologia , Transdução de Sinais/imunologia , SolubilidadeRESUMO
Several recent in vitro investigations and experimental studies performed in animal models of osteoarthritis (OA) sustained the previously held view that interleukin (IL)-1 or tumour necrosis factor-alpha (TNFalpha) disrupt the metabolism of synovial joint tissues. The evidence to date indicates that, in addition to IL-1 and TNFalpha, other pro-inflammatory cytokines, including IL-6, members of the IL-6 protein superfamily, IL-7, IL-17 and IL-18, can also promote articular cartilage extracellular matrix protein degradation or synergize with other cytokines to amplify and accelerate cartilage destruction. Most importantly, many of these cytokines have been implicated in causing synovial tissue activation and damage to subchondral bone as well as altering cartilage homeostasis in spontaneously occurring or surgically induced animal models of OA and in transgenic mice genetically primed to develop OA. In this regard, these pro-inflammatory cytokines may also play a significant role in the pathogenesis of human OA. However, attempts to modify the progression of human OA in well designed, controlled clinical trials with an IL-1 receptor antagonist protein (IRAP) have not been successful. Several anabolic cytokines (also termed growth factors), including transforming growth factor-beta (TGF-beta), insulin-like growth factor-1 (IGF-1), fibroblast growth factor-2 (FGF-2), platelet-derived growth factor (PDGF) and connective tissue growth factor (CTGF), have also been proposed as regulators of skeletal long bone growth and development as well as cartilage and bone homeostasis. TGF-beta, IGF-1 and FGF-2, in particular, have been characterized as potential chondroprotective agents. Thus, enzymatic disruption and removal of these growth factors from cartilage extracellular matrix proteins, as in the case of TGF-beta and FGF-2, or disruption of their function, as in the case of the enhanced binding of free IGF-1 with IGF binding proteins in OA joint synovial fluid, may compromise and ultimately be responsible for the inadequate repair of articular cartilage in OA. An improved understanding of the cellular and molecular mechanisms by which pro-inflammatory and/or anabolic cytokines alter both the structure and function of synovial joints may eventually result in the commercial development of disease-modifying OA drugs (DMOADs). Since the prevalence of OA is high in the elderly population, future development of DMOADs must also take into account potential differences in the way DMOADs would be metabolized in the older individual compared with younger people.
Assuntos
Antirreumáticos/uso terapêutico , Cartilagem Articular/patologia , Citocinas/antagonistas & inibidores , Fator 2 de Crescimento de Fibroblastos/fisiologia , Articulações/patologia , Osteoartrite/tratamento farmacológico , Transdução de Sinais/imunologia , Líquido Sinovial/metabolismo , Idoso , Antirreumáticos/imunologia , Artrite Experimental , Cartilagem/imunologia , Cartilagem/patologia , Cartilagem Articular/imunologia , Citocinas/imunologia , Humanos , Fator de Crescimento Insulin-Like I/imunologia , Fator de Crescimento Insulin-Like I/metabolismo , Proteína Antagonista do Receptor de Interleucina 1 , Interleucina-1/antagonistas & inibidores , Interleucina-1/imunologia , Interleucina-17/antagonistas & inibidores , Interleucina-17/imunologia , Interleucina-18/antagonistas & inibidores , Interleucina-18/imunologia , Interleucina-1beta/análise , Interleucina-1beta/imunologia , Interleucina-6/antagonistas & inibidores , Interleucina-6/imunologia , Interleucina-7/antagonistas & inibidores , Interleucina-7/imunologia , Articulações/imunologia , Articulações/metabolismo , Osteoartrite/imunologia , Fator de Crescimento Derivado de Plaquetas , Líquido Sinovial/efeitos dos fármacos , Fator de Crescimento Transformador beta/imunologia , Fator de Crescimento Transformador beta/fisiologia , Fator de Necrose Tumoral alfa/imunologia , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Systemic lupus erythematosus (SLE) is an autoimmune disease mediated by T and B cells. It is characterized by a variety of autoantibodies and systemic clinical manifestations. A tolerogenic peptide, designated hCDR1, ameliorated the serological and clinical manifestations of SLE in both spontaneous and induced models of lupus. In the present study, we evaluated the status of mature B cells in the bone marrow (BM) of SLE-afflicted mice, and determined the effect of treatment with the tolerogenic peptide hCDR1 on these cells. We demonstrate herein that mature B cells of the BM of SLE-afflicted (New Zealand Black x New Zealand White)F(1) mice were largely expanded, and that treatment with hCDR1 down-regulated this population. Moreover, treatment with hCDR1 inhibited the expression of the pathogenic cytokines [interferon-gamma and interleukin (IL)-10], whereas it up-regulated the expression of transforming growth factor-beta in the BM. Treatment with hCDR1 up-regulated the rates of apoptosis of mature B cells. The latter was associated with inhibited expression of the survival Bcl-xL gene and of IL-7 by BM cells. Furthermore, the addition of recombinant IL-7 abrogated the suppressive effects of hCDR1 on Bcl-xL in the BM cells and resulted in elevated levels of apoptosis. Hence, the down-regulated production of IL-7 contributes to the hCDR1-mediated apoptosis of mature B cells in the BM of SLE-afflicted mice.
Assuntos
Anticorpos Monoclonais/imunologia , Subpopulações de Linfócitos B/imunologia , Células da Medula Óssea/imunologia , Interleucina-7/antagonistas & inibidores , Lúpus Eritematoso Sistêmico/imunologia , Fragmentos de Peptídeos/imunologia , Animais , Apoptose/imunologia , Modelos Animais de Doenças , Regulação para Baixo/imunologia , Feminino , Tolerância Imunológica/imunologia , Interferon gama/biossíntese , Interleucina-10/biossíntese , Interleucina-7/imunologia , Camundongos , Camundongos Endogâmicos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Baço/imunologia , Fator de Crescimento Transformador beta/biossíntese , Regulação para Cima/imunologiaRESUMO
Although the pathogenic role of B cells and CD4 T cells has been studied extensively, less is known about the role of CD8 T cells in autoimmunity and self-tolerance. To evaluate the role of CD8 T cells in autoimmunity and its modulation using self-peptides, we used mice expressing soluble OVA (sOVA) under control of the keratin-14 promoter. Spontaneous autoimmunity occurred when sOVA mice were crossed with OT-I mice, whose CD8 T cells carry a Valpha2/Vbeta5-transgenic TCR with specificity for the OVA(257-264) peptide. Eighty-three percent of OVA/OT-I mice died during the first 2 wk of life due to multiple organ inflammation. In contrast, preventive or therapeutic OVA(257-264) peptide injections induced a dose-dependent increase in survival. Healthy survivors exhibited reductions in peripheral CD8 T cells, CD8 coreceptor, and Valpha2 expression. Furthermore, CD8 T cells from healthy mice were anergic and could not be activated by exogenous IL-2. A block in IL-2/IL-7 signaling via the STAT5 pathway provided the basis for low surface expression of the CD8 coreceptor and failure of IL-2 to break CD8 T cell anergy. Thus, the soluble TCR ligand triggered multiple tolerance mechanisms in these sOVA/OT-I mice, making this treatment approach a potential paradigm for modulating human autoimmune diseases.
Assuntos
Doenças Autoimunes/terapia , Regulação para Baixo/imunologia , Interleucina-2/antagonistas & inibidores , Interleucina-7/antagonistas & inibidores , Ovalbumina/fisiologia , Fragmentos de Peptídeos/fisiologia , Receptores de Antígenos de Linfócitos T alfa-beta/antagonistas & inibidores , Receptores de Antígenos de Linfócitos T/antagonistas & inibidores , Fator de Transcrição STAT5/antagonistas & inibidores , Transdução de Sinais/imunologia , Animais , Doenças Autoimunes/imunologia , Doenças Autoimunes/mortalidade , Antígenos CD8/metabolismo , Galinhas , Anergia Clonal/genética , Anergia Clonal/imunologia , Regulação para Baixo/genética , Tolerância Imunológica/genética , Interleucina-2/fisiologia , Interleucina-7/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Ovalbumina/administração & dosagem , Ovalbumina/genética , Ovalbumina/imunologia , Fragmentos de Peptídeos/administração & dosagem , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/imunologia , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores de Antígenos de Linfócitos T alfa-beta/biossíntese , Fator de Transcrição STAT5/metabolismo , Fator de Transcrição STAT5/fisiologia , Transdução de Sinais/genética , Solubilidade , Análise de SobrevidaRESUMO
The primary function of IL-7 is to promote maturation and survival of T cells. Through microarray expression analysis, we previously observed that human blood eosinophils express mRNA for IL-7R alpha (CD127) and its common gamma chain (CD132). The purpose of this study was to determine whether eosinophils have functional IL-7 receptors and to assess the potential contribution of IL-7 to eosinophilic airway inflammation by evaluating its presence in bronchoalveolar lavage (BAL) fluid of subjects with atopic asthma before and after segmental bronchoprovocation with allergen. Immunoblot analysis revealed that CD127 is present in highly purified human blood eosinophils. Furthermore, eosinophils responded to IL-7 with phosphorylation of STAT5, up-regulation of the activation marker CD69, and prolonged survival. Neutralization of GM-CSF but not IL-5 significantly blunted these functional responses, suggesting that IL-7 mediates its effects by promoting eosinophil release of autologous GM-CSF. Notably, the suppressive effect of anti-GM-CSF on STAT5 phosphorylation occurred within 10 min of eosinophil exposure to IL-7. Thus, IL-7 likely activates eosinophil release of preformed rather than newly synthesized GM-CSF. The biological relevance of IL-7 to eosinophilia in vivo was implicated in a study of airway allergen challenge in patients with allergic asthma. IL-7 concentrations in BAL fluid increased significantly 48 h after segmental allergen challenge and were highly correlated with BAL eosinophils (r = 0.7, p < 0.001). In conclusion, the airway response to allergen is associated with the generation of IL-7, which may contribute to airway inflammation by promoting enhanced eosinophil activation and survival. Activation of eosinophils is a novel function for IL-7.
Assuntos
Alérgenos/administração & dosagem , Asma/imunologia , Asma/patologia , Eosinofilia/imunologia , Eosinofilia/patologia , Mediadores da Inflamação/fisiologia , Interleucina-7/fisiologia , Adulto , Anticorpos Monoclonais , Antígenos CD/biossíntese , Antígenos de Diferenciação de Linfócitos T/biossíntese , Asma/metabolismo , Comunicação Autócrina/imunologia , Testes de Provocação Brônquica/métodos , Sobrevivência Celular/imunologia , Células Cultivadas , Relação Dose-Resposta Imunológica , Eosinofilia/metabolismo , Feminino , Fator Estimulador de Colônias de Granulócitos e Macrófagos/antagonistas & inibidores , Fator Estimulador de Colônias de Granulócitos e Macrófagos/biossíntese , Fator Estimulador de Colônias de Granulócitos e Macrófagos/imunologia , Humanos , Mediadores da Inflamação/antagonistas & inibidores , Mediadores da Inflamação/imunologia , Interleucina-7/antagonistas & inibidores , Interleucina-7/imunologia , Lectinas Tipo C , Masculino , Receptores de Interleucina-7/metabolismo , Receptores de Interleucina-7/fisiologia , Regulação para Cima/imunologiaRESUMO
The transcription factor nuclear factor-kappa B (NF-kappaB) regulates the transcription of a number of genes involved in a variety of cellular responses, including cell survival, inflammation, and differentiation. NF-kappaB is activated by a variety of stimuli, proinflammatory cytokines, mitogens, growth factors, and stress-inducing agents. Aberrant NF-kappaB expression is considered to be one of the oncogenic factors of cancer and the constitutive activation of NF-kappaB is observed in several hematologic disorders [classic Hodgkin's lymphoma, diffuse large B cell lymphoma, and multiple myeloma (MM)], and the modulation of NF-kappaB activation is emerging as a promising novel anticancer therapeutic strategy.Therefore, we focused on the regulation of NF-kappaB activation in MM. When U266 cells were treated with 6-amino-4-quinazoline, an NF-kappaB activation inhibitor, we determined that it most effectively blocked the interleukin (IL)-6-induced activation of MAPK and JAK/STAT pathways among different signaling inhibitors. The results of the luciferase assay indicated that 6-amino-4-quinazoline inhibited NF-kappaB activation with diminished NF-kappaB protein bound to NF-kappaB DNA binding sites. In addition, 6-amino-4-quinazoline suppressed the production of IL-6, which affected MM cell proliferation. Furthermore, combined treatment with bortezomib and 6-amino-4-quinazoline effectively inhibited the IL-6 and soluble IL-6R-induced activation of STAT3 and extracellular signal-regulated kinase phosphorylation. Our data showed that the inhibition of NF-kappaB activation abrogated MM cell proliferation induced by the IL-6 pathway, and might represent a promising therapeutic strategy for the treatment of MM.
Assuntos
Antineoplásicos/farmacologia , Ácidos Borônicos/farmacologia , Interleucina-6/antagonistas & inibidores , Interleucina-6/farmacologia , Pirazinas/farmacologia , Quinazolinas/farmacologia , Western Blotting , Bortezomib , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sinergismo Farmacológico , Ensaio de Imunoadsorção Enzimática , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , Genes Reporter/efeitos dos fármacos , Humanos , Interleucina-7/antagonistas & inibidores , Luciferases/metabolismo , Mieloma Múltiplo/patologia , NF-kappa B/antagonistas & inibidores , Fosforilação , Fator de Transcrição STAT3/antagonistas & inibidores , Fator de Transcrição STAT3/farmacologia , Transdução de Sinais/efeitos dos fármacosRESUMO
IL-7 is a cytokine, which regulates development, maintenance and proliferation of T lymphocytes within the human immune system. Production of IL-7 is observed in a sterile environment such as thymus or bone marrow. However, it is also known that intestinal epithelial cells (IECs) residing in close contact with numerous bacterial stimuli also produce IL-7. Here we show that secretion of IL-7 by IECs is significantly suppressed upon stimulation by various bacterial components, including flagellin. Analysis of the intracellular mechanism by which flagellin regulates IL-7 production revealed that flagellin down-regulates expression of the two major transcripts encoding IL-7. Surprisingly, such function of flagellin was independent from the known transcriptional regulation of the IL-7 gene, as no significant change was observed in the transcriptional activity regulated by the previously identified promoter region. As the stability of IL-7 mRNA also remained unchanged upon flagellin stimulation, results suggested the possible involvement of a yet unknown transcriptional regulation of the IL-7 gene. These results describe a novel regulation of IL-7 production by bacterial stimuli, presumably mediated via Toll-like receptors. The present system might contribute to regulate the local lymphocyte pool, in response to the gut luminal or sub-mucosal bacterial abundance.
Assuntos
Flagelina/farmacologia , Interleucina-7/metabolismo , Linhagem Celular Tumoral , Neoplasias do Colo , Regulação para Baixo , Humanos , Interleucina-7/antagonistas & inibidores , Mucosa Intestinal/citologia , RNA Mensageiro/metabolismoRESUMO
Recent data from several groups demonstrate high levels of IL-7 in the joints of RA patients, but much lower levels in OA. In contrast, circulating levels of IL-7 in RA remain a point of debate. IL-7 has many roles in T cell, dendritic cell and bone biology in humans. Reduced levels of circulating IL-7 probably underlie a number of the dysfunctions associated with circulating T cells in RA and may provide a mechanism for some of the unexplained systemic manifestations of the disease. However, IL-7 in the joint may have a more sinister role, contributing to a vicious cycle perpetuating inflammation. Typically, IL-1beta and TNF-alpha increase the stromal production of IL-7 and in turn, IL-7 up-regulates the production of TNF-alpha by macrophages. Most importantly, IL-7 induces the production of osteoclastogenic cytokines by T cells, leading to the maturation of osteoclasts and therefore bone destruction. By linking the stroma with innate and adaptive immunity in RA, IL-7 may be directing the cellular network, leading to chronic inflammation and joint destruction. Blocking IL-7 may well therefore be of therapeutic value.