RESUMEN
OBJECTIVE: IL-6 is an important contributor to glucose and energy homeostasis through changes in whole-body glucose disposal, insulin sensitivity, food intake and energy expenditure. However, the relative contributions of peripheral versus central IL-6 signaling to these metabolic actions are presently unclear. A conditional mouse model with reduced brain IL-6Ra expression was used to explore how blunted central IL-6 signaling alters metabolic status in lean and obese mice. METHODS: Transgenic mice with reduced levels of central IL-6 receptor alpha (IL-6Ra) (IL-6Ra KD mice) and Nestin Cre controls (Cre+/- mice) were fed standard chow or high-fat diet for 20 weeks. Obese and lean mouse cohorts underwent metabolic phenotyping with various measures of energy and glucose homeostasis determined. Glucose-stimulated insulin secretion was assessed in vivo and ex vivo in both mouse groups. RESULTS: IL-6Ra KD mice exhibited altered body fat mass, liver steatosis, plasma insulin, IL-6 and NEFA levels versus Cre+/- mice in a diet-dependent manner. IL-6Ra KD mice had increased food intake, higher RER, decreased energy expenditure with diminished cold tolerance compared to Cre+/- controls. Standard chow-fed IL-6Ra KD mice displayed reduced plasma insulin and glucose-stimulated insulin secretion with impaired glucose disposal and unchanged insulin sensitivity. Isolated pancreatic islets from standard chow-fed IL-6Ra KD mice showed comparable morphology and glucose-stimulated insulin secretion to Cre+/- controls. The diminished in vivo insulin secretion exhibited by IL-6Ra KD mice was recovered by blockade of autonomic ganglia. CONCLUSIONS: This study shows that central IL-6Ra signaling contributes to glucose and energy control mechanisms by regulating food intake, energy expenditure, fuel flexibility and insulin secretion. A plausible mechanism linking central IL-6Ra signaling and pancreatic insulin secretion is through the modulation of autonomic output activity. Thus, brain IL-6 signaling may contribute to the central adaptive mechanisms engaged in response to metabolic stress.
Asunto(s)
Glucosa , Resistencia a la Insulina , Receptores de Interleucina-6 , Animales , Glucosa/metabolismo , Insulina/metabolismo , Secreción de Insulina/fisiología , Interleucina-6/metabolismo , Ratones , Receptores de Interleucina-6/deficiencia , Receptores de Interleucina-6/metabolismoRESUMEN
Although thousands of breast cancer cells disseminate and home to bone marrow until primary surgery, usually less than a handful will succeed in establishing manifest metastases months to years later. To identify signals that support survival or outgrowth in patients, we profile rare bone marrow-derived disseminated cancer cells (DCCs) long before manifestation of metastasis and identify IL6/PI3K-signaling as candidate pathway for DCC activation. Surprisingly, and similar to mammary epithelial cells, DCCs lack membranous IL6 receptor expression and mechanistic dissection reveals IL6 trans-signaling to regulate a stem-like state of mammary epithelial cells via gp130. Responsiveness to IL6 trans-signals is found to be niche-dependent as bone marrow stromal and endosteal cells down-regulate gp130 in premalignant mammary epithelial cells as opposed to vascular niche cells. PIK3CA activation renders cells independent from IL6 trans-signaling. Consistent with a bottleneck function of microenvironmental DCC control, we find PIK3CA mutations highly associated with late-stage metastatic cells while being extremely rare in early DCCs. Our data suggest that the initial steps of metastasis formation are often not cancer cell-autonomous, but also depend on microenvironmental signals.
Asunto(s)
Interleucina-6/metabolismo , Células Madre Neoplásicas/metabolismo , Células Madre Neoplásicas/patología , Transducción de Señal , Médula Ósea/patología , Mama/citología , Neoplasias de la Mama/patología , Fosfatidilinositol 3-Quinasa Clase I/genética , Fosfatidilinositol 3-Quinasa Clase I/metabolismo , Receptor gp130 de Citocinas/metabolismo , Células Epiteliales/metabolismo , Células Epiteliales/patología , Femenino , Humanos , Interleucina-6/genética , Mutación , Metástasis de la Neoplasia/genética , Receptores de Interleucina-6/deficiencia , Receptores de Interleucina-6/metabolismo , Células del Estroma/metabolismo , Microambiente TumoralRESUMEN
IL-6 excess is central to the pathogenesis of multiple inflammatory conditions and is targeted in clinical practice by immunotherapy that blocks the IL-6 receptor encoded by IL6R We describe two patients with homozygous mutations in IL6R who presented with recurrent infections, abnormal acute-phase responses, elevated IgE, eczema, and eosinophilia. This study identifies a novel primary immunodeficiency, clarifying the contribution of IL-6 to the phenotype of patients with mutations in IL6ST, STAT3, and ZNF341, genes encoding different components of the IL-6 signaling pathway, and alerts us to the potential toxicity of drugs targeting the IL-6R.
Asunto(s)
Síndromes de Inmunodeficiencia/patología , Inflamación/patología , Receptores de Interleucina-6/deficiencia , Adolescente , Adulto , Niño , Preescolar , Femenino , Células HEK293 , Humanos , Recién Nacido , Masculino , Receptores de Interleucina-6/metabolismoRESUMEN
BACKGROUND: During the last decade, mesenchymal stem cells (MSCs) have gained much attention in the field of regenerative medicine due to their capacity to differentiate into different cell types and to promote immunosuppressive effects. However, the underlying mechanism of MSC-mediated immunoregulation is not fully understood so far. Macrophages are distinguished in classical activated, pro-inflammatory M1 and alternatively activated M2 cells, which possess different functions and transcriptional profiles with respect to inflammatory responses. As polarization is not fixed, macrophage functional plasticity might be modulated by the microenvironment allowing them to rapidly react to danger signals and maintaining tissue homeostasis. METHODS: Murine MSCs were preconditioned with IL-1ß and IFN-É£ to enhance their immunosuppressive capacity regarding macrophage polarization under M1- and M2a-polarizing conditions. Macrophage polarization was analyzed by real-time PCR, flow cytometry, and cytokine detection in culture supernatants. The role of MSC-derived nitric oxide (NO), prostaglandin E2 (PGE2), and IL-6 in this process has been evaluated using siRNA transfection and IL-6 receptor-deficient macrophages, respectively. RESULTS: Preconditioned, but not unprimed, MSCs secreted high levels of NO, IL-6, and PGE2. Co-culture with macrophages (M0) in the presence of M1 inducers (LPS + IFN-É£) led to significant reduction of CD86 and iNOS protein in macrophages and diminished TNF-α secretion. Additionally, CD86 and iNOS protein expression as well as NO and IL-10 secretion were markedly increased under M2a-polarizing culture conditions (IL-4). MSC-dependent macrophage polarization did not depend on direct cell-cell contact. Co-culturing in the presence of LPS and IFN-É£ resulted in the upregulation of M2a, M2b, and M2c marker genes, whereas in the presence of IL-4 only M2b markers were significantly increased. In turn, IL-10-producing regulatory M2b cells significantly inhibited IFN-É£ expression in CD4+ T lymphocytes. Finally, we show that MSC-mediated macrophage polarization strongly depends on IL-6, whereas a minor role for NO and PGE2 was found. CONCLUSIONS: Preconditioning of MSCs highly strengthens their capacity to regulate macrophage features and to promote immunosuppression. Repression of M1 polarization during inflammation and M2b polarization under anti-inflammatory conditions strongly depend on functional IL-6 signaling in macrophages. The potential benefit of preconditioned MSCs and IL-6 should be considered for future clinical treatment.
Asunto(s)
Comunicación Celular/inmunología , Interferón gamma/farmacología , Interleucina-1beta/farmacología , Interleucina-6/inmunología , Macrófagos/inmunología , Células Madre Mesenquimatosas/inmunología , Animales , Antígeno B7-2/genética , Antígeno B7-2/inmunología , Células de la Médula Ósea/citología , Células de la Médula Ósea/efectos de los fármacos , Células de la Médula Ósea/inmunología , Comunicación Celular/genética , Diferenciación Celular , Técnicas de Cocultivo , Dinoprostona/inmunología , Dinoprostona/metabolismo , Regulación de la Expresión Génica , Interleucina-10/genética , Interleucina-10/inmunología , Interleucina-4/farmacología , Interleucina-6/genética , Macrófagos/citología , Macrófagos/efectos de los fármacos , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Óxido Nítrico/inmunología , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo II/genética , Óxido Nítrico Sintasa de Tipo II/inmunología , Receptores de Interleucina-6/deficiencia , Receptores de Interleucina-6/genética , Receptores de Interleucina-6/inmunología , Transducción de Señal , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/inmunologíaRESUMEN
BACKGROUND: We previously demonstrated that the local immune status correlated with the glioma prognosis. Interleukin-6 (IL6) was identified as an important local immune-related risk marker related to unfavourable prognosis. In this study, we further investigated the role and regulation of IL6 signalling in glioma. METHODS: The expression and prognostic value of IL6 and the IL6 receptor (IL6R) were explored in The Cancer Genome Atlas (TCGA) and REMBRANDT databases and clinical samples. Functional effects of genetic knockdown and overexpression of IL6R or IL6 stimulation were examined in vitro and in tumours in vivo. The effects of the nuclear factor of activated T cells-1 (NFAT1) on the promoter activities of IL6R and IL6 were also examined. RESULTS: High IL6- and IL6R-expression were significantly associated with mesenchymal subtype and IDH-wildtype gliomas, and were predictors of poor survival. Knockdown of IL6R decreased cell proliferation, invasion and neurosphere formation in vitro, and inhibited tumorigenesis in vivo. IL6R overexpression or IL6 stimulation enhanced the invasion and growth of glioma cells. TCGA database searching revealed that IL6- and IL6R-expression were correlated with that of NFAT1. In glioma cells, NFAT1 enhanced the promoter activities of IL6R and IL6, and upregulated the expression of both IL6R and IL6. CONCLUSION: NFAT1-regulated IL6 signalling contributes to aggressive phenotypes of gliomas, emphasizing the role of immunomodulatory factors in glioma malignant progression.
Asunto(s)
Glioma/patología , Interleucina-6/metabolismo , Factores de Transcripción NFATC/metabolismo , Fenotipo , Transducción de Señal , Línea Celular Tumoral , Proliferación Celular , Regulación Neoplásica de la Expresión Génica , Técnicas de Silenciamiento del Gen , Humanos , Invasividad Neoplásica , Receptores de Interleucina-6/deficiencia , Receptores de Interleucina-6/genéticaRESUMEN
Previously, we demonstrated that the soluble IL-6R (sIL-6R) plays an important role in the host antiviral response through induction of type I IFN and sIL-6R-mediated antiviral action via the IL-27 subunit p28; however, the mechanism that underlies sIL-6R and p28 antiviral action and whether type III IFN is involved remain unknown. In this study, we constructed a sIL-6R and p28 fusion protein (sIL-6R/p28 FP) and demonstrated that the fusion protein has stronger antiviral activity than sIL-6R alone. Consequently, knockout of sIL-6R inhibited virus-triggered IFN-λ1 expression. In addition, sIL-6R/p28 FP associated with mitochondrial antiviral signaling protein and TNFR-associated factor 6, the retinoic acid-inducible gene I adapter complex, and the antiviral activity mediated by sIL-6R/p28 FP was dependent on mitochondrial antiviral signaling protein. Furthermore, significantly reduced binding of p50/p65 and IFN regulatory factor 3 to the IFN-λ1 promoter was observed in sIL-6R knockout cells compared with the control cells. Interestingly, a novel heterodimer of c-Fos and activating transcription factor 1 was identified as a crucial transcriptional activator of IFN-λ1 The sIL-6R/p28 FP upregulated IFN-λ1 expression by increasing the binding abilities of c-Fos and activating transcription factor 1 to the IFN-λ1 promoter via the p38 MAPK signaling pathway. In conclusion, these results demonstrate the important role of sIL-6R/p28 FP in mediating virus-induced type III IFN production.
Asunto(s)
Interferones/metabolismo , Interleucina-27/metabolismo , Receptores de Interleucina-6/metabolismo , Transducción de Señal , Factor de Transcripción Activador 1/genética , Factor de Transcripción Activador 1/metabolismo , Humanos , Factor 3 Regulador del Interferón/inmunología , Factor 3 Regulador del Interferón/metabolismo , Interferones/biosíntesis , Interferones/inmunología , Interleucina-27/química , Interleucina-27/genética , Interleucina-27/inmunología , Interleucina-6/inmunología , Interleucina-6/metabolismo , Regiones Promotoras Genéticas , Subunidades de Proteína/inmunología , Proteínas Proto-Oncogénicas c-fos/metabolismo , Receptores de Interleucina-6/deficiencia , Proteínas Recombinantes de Fusión/metabolismo , Regulación hacia Arriba , Proteínas Quinasas p38 Activadas por Mitógenos/genética , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismoRESUMEN
OBJETIVO: Determinar los niveles de interleuquina-6 (IL-6) en el vítreo de pacientes con desprendimiento de retina (DdR). MATERIAL Y MÉTODO: Mediante vitrectomía vía pars plana, se recogieron muestras no diluidas de vítreo de 40 pacientes sin antecedentes de cirugía vítrea o intraocular previa, que fueron divididos en 2 grupos: A (n = 20) pacientes con DdR y B (n = 20) pacientes con membrana premacular y agujero macular. La concentración de IL-6 se determinó mediante radioinmunoensayo. RESULTADOS: La concentración vítrea de IL-6 en el grupo A fue 122,4 + -16 pg/mL (rango 91,5-620) y en el grupo B fue 46 +/- 23 pg/mL (rango 3-150) (p < 0,001). CONCLUSIONES: Estos resultados demuestran que la concentración vítrea de IL-6 está más elevada en los pacientes con DdR en comparación con el grupo control
OBJECTIVE: To measure interleuquin-6 (IL-6) levels in the vitreous body of patients with retinal detachment (RD). PATIENTS AND METHODS: Undiluted vitreous samples were obtained from 40 patients with no history of prior vitreous or intraocular surgery. Patients were divided into two groups: A (n = 20) patients with RD and B (n = 20) patients with pre-retinal macular membranes and macular holes. IL-6 was determined using radioimmunoassay. RESULTS: IL-6 vitreous concentration in group A was 122.4 + -16 pg/mL (range 91.5-620) and in group B was 46 +/- 23 pg/mL (range 3-150) (p < .001). CONCLUSIONS: These results show that the concentration of IL-6 in the vitreous body was significantly higher in patients with RD than in the control group
Asunto(s)
Femenino , Humanos , Masculino , Receptores de Interleucina-6/administración & dosificación , Receptores de Interleucina-6/metabolismo , Desprendimiento de Retina/diagnóstico , Desprendimiento de Retina/metabolismo , Vitrectomía/métodos , Perforaciones de la Retina/patología , Consentimiento Informado/legislación & jurisprudencia , Factores de Crecimiento de Célula Hematopoyética/administración & dosificación , Enfermedades del Nervio Óptico/genética , Enfermedades del Nervio Óptico/metabolismo , Receptores de Interleucina-6/sangre , Receptores de Interleucina-6/deficiencia , Desprendimiento de Retina/complicaciones , Desprendimiento de Retina/patología , Vitrectomía/normas , Perforaciones de la Retina/metabolismo , Consentimiento Informado/normas , Factores de Crecimiento de Célula Hematopoyética/farmacología , Enfermedades del Nervio Óptico/complicaciones , Enfermedades del Nervio Óptico/diagnósticoRESUMEN
Interleukin (IL)-6-deficient, but not IL-6 receptor (IL-6R)deficient mice present with a delayed skin wound healing phenotype. Since IL-6 solely signals via the IL-6R and glycoprotein 130 (gp130), Il-6r-deficient mice are expected to exhibit a similar phenotype as Il-6-deficient mice. However, p28 (IL-30) and ciliary neurotrophic factor (CNTF) have been identified as additional lowaffinity ligands of the IL-6R/gp130/LIFR complex. IL-6 plays an inflammatory and regenerative role in inflammatory bowel disease (IBD). In the present study, we compared Il-6r-deficient mice with mice treated with neutralizing IL-6 monoclonal antibody (mAb) in a model of dextran sodium sulfate (DSS)-induced colitis. Our results, in agreement with those of previous reports, demonstrated that IL-6 mAbs slightly attenuated DSS-induced colitis during the regeneration phase. Il-6r-deficient mice and mice with tissue-specific deletion of the Il-6r in the myeloid cell lineage (LysMCre) with acute and chronic DSS-induced colitis were, however, indistinguishable from wild-type mice. Our data suggest that IL-6 and IL-6R have an additional role in colitis, apart from the IL-6/IL-6R classic and trans-signaling.
Asunto(s)
Colitis/inducido químicamente , Colitis/metabolismo , Interleucina-6/metabolismo , Receptores de Interleucina-6/metabolismo , Animales , Anticuerpos Monoclonales/farmacología , Anticuerpos Neutralizantes/farmacología , Colitis/sangre , Colon/efectos de los fármacos , Colon/patología , Sulfato de Dextran , Dextranos/metabolismo , Susceptibilidad a Enfermedades , Fluoresceína-5-Isotiocianato/análogos & derivados , Fluoresceína-5-Isotiocianato/metabolismo , Integrasas/metabolismo , Masculino , Ratones Endogámicos C57BL , Especificidad de Órganos/efectos de los fármacos , Receptores de Interleucina-6/deficiencia , Pérdida de PesoRESUMEN
BACKGROUND: The mechanisms of paraneoplastic thrombocytosis in ovarian cancer and the role that platelets play in abetting cancer growth are unclear. METHODS: We analyzed clinical data on 619 patients with epithelial ovarian cancer to test associations between platelet counts and disease outcome. Human samples and mouse models of epithelial ovarian cancer were used to explore the underlying mechanisms of paraneoplastic thrombocytosis. The effects of platelets on tumor growth and angiogenesis were ascertained. RESULTS: Thrombocytosis was significantly associated with advanced disease and shortened survival. Plasma levels of thrombopoietin and interleukin-6 were significantly elevated in patients who had thrombocytosis as compared with those who did not. In mouse models, increased hepatic thrombopoietin synthesis in response to tumor-derived interleukin-6 was an underlying mechanism of paraneoplastic thrombocytosis. Tumor-derived interleukin-6 and hepatic thrombopoietin were also linked to thrombocytosis in patients. Silencing thrombopoietin and interleukin-6 abrogated thrombocytosis in tumor-bearing mice. Anti-interleukin-6 antibody treatment significantly reduced platelet counts in tumor-bearing mice and in patients with epithelial ovarian cancer. In addition, neutralizing interleukin-6 significantly enhanced the therapeutic efficacy of paclitaxel in mouse models of epithelial ovarian cancer. The use of an antiplatelet antibody to halve platelet counts in tumor-bearing mice significantly reduced tumor growth and angiogenesis. CONCLUSIONS: These findings support the existence of a paracrine circuit wherein increased production of thrombopoietic cytokines in tumor and host tissue leads to paraneoplastic thrombocytosis, which fuels tumor growth. We speculate that countering paraneoplastic thrombocytosis either directly or indirectly by targeting these cytokines may have therapeutic potential. (Funded by the National Cancer Institute and others.).
Asunto(s)
Interleucina-6/antagonistas & inhibidores , Neoplasias Glandulares y Epiteliales/complicaciones , Neoplasias Ováricas/complicaciones , Síndromes Paraneoplásicos , Trombocitosis/etiología , Animales , Anticuerpos Monoclonales/uso terapéutico , Plaquetas/inmunología , Modelos Animales de Enfermedad , Supervivencia sin Enfermedad , Femenino , Humanos , Interleucina-6/sangre , Interleucina-6/inmunología , Estimación de Kaplan-Meier , Ratones , Ratones Noqueados , Neoplasias Glandulares y Epiteliales/sangre , Neoplasias Glandulares y Epiteliales/tratamiento farmacológico , Neoplasias Ováricas/sangre , Neoplasias Ováricas/tratamiento farmacológico , Recuento de Plaquetas , Modelos de Riesgos Proporcionales , Receptores de Interleucina-6/deficiencia , Transducción de Señal , Trombopoyetina/antagonistas & inhibidores , Trombopoyetina/sangreRESUMEN
IL-6 modulates immune responses and is essential for timely wound healing. As the functions mediated by IL-6 require binding to its specific receptor, IL-6Ralpha, it was expected that mice lacking IL-6Ralpha would have the same phenotype as IL-6-deficient mice. However, although IL-6Ralpha-deficient mice share many of the inflammatory deficits seen in IL-6-deficient mice, they do not display the delay in wound healing. Surprisingly, mice with a combined deficit of IL-6 and IL-6Ralpha, or IL-6-deficient mice treated with an IL-6Ralpha-blocking Ab, showed improved wound healing relative to mice with IL-6 deficiency, indicating that the absence of the receptor contributed to the restoration of timely wound healing, rather than promiscuity of IL-6 with an alternate receptor. Wounds in mice lacking IL-6 showed delays in macrophage infiltration, fibrin clearance, and wound contraction that were not seen in mice lacking IL-6Ralpha alone and were greatly reduced in mice with a combined deficit of IL-6 and IL-6Ralpha. MAPK activation-loop phosphorylation was elevated in wounds of IL-6Ralpha-deficient mice, and treatment of wounds in these mice with the MEK inhibitor U0126 resulted in a delay in wound healing suggesting that aberrant ERK activation may contribute to improved healing. These findings underscore a deeper complexity for IL-6Ralpha function in inflammation than has been recognized previously.
Asunto(s)
Interleucina-6/deficiencia , Interleucina-6/inmunología , Receptores de Interleucina-6/deficiencia , Receptores de Interleucina-6/inmunología , Cicatrización de Heridas/inmunología , Animales , Southern Blotting , Western Blotting , Ensayo de Inmunoadsorción Enzimática , Genotipo , Inmunohistoquímica , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal/inmunología , Piel/lesiones , Piel/metabolismoRESUMEN
IL-6 responses are classically orchestrated via a membrane-bound IL-6R (CD126) alpha subunit (classical IL-6R signaling) or through a soluble form of this cognate receptor (IL-6 trans signaling). Appraisal of IL-6R expression on human and mouse T cells emphasized that IL-6R expression is closely linked with that of CCR7 and CD62L. In this regard, infiltrating effector T cells from clinical and experimental peritonitis episodes lose IL-6R expression, and anti-CD3/CD28 Ab costimulation of peripheral T cells in vitro leads to a downregulation in IL-6R expression. Consequently, IL-6 signaling through membrane-bound IL-6R seems to be limited to naive or central memory T cell populations. Loss of IL-6R expression by activated T cells further suggests that these effector cells might still retain IL-6 responsiveness via IL-6 trans signaling. Using IL-6R-deficient mice and recombinant tools that modulate the capacity of IL-6 to signal via its soluble receptor, we report that local control of IL-6 trans signaling regulates the effector characteristics of the T cell infiltrate and promotes the maintenance of IL-17A-secreting CD4(+) T cells. Therefore, we concluded that classical IL-6R signaling in naive or central memory CD4(+) T cells is required to steer their effector characteristics, whereas local regulation of soluble IL-6R activity might serve to maintain the cytokine profile of the Th cell infiltrate. Therefore, the activation status of a T cell population is linked with an alteration in IL-6 responsiveness.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/patología , Mediadores de Inflamación/fisiología , Interleucina-17/metabolismo , Interleucina-6/fisiología , Peritonitis/inmunología , Receptores de Interleucina-6 , Transducción de Señal/inmunología , Linfocitos T Colaboradores-Inductores/inmunología , Animales , Linfocitos T CD4-Positivos/metabolismo , Movimiento Celular/genética , Movimiento Celular/inmunología , Células Cultivadas , Citocinas/biosíntesis , Citocinas/genética , Regulación hacia Abajo/genética , Regulación hacia Abajo/inmunología , Femenino , Humanos , Inmunofenotipificación , Mediadores de Inflamación/antagonistas & inhibidores , Interleucina-17/biosíntesis , Interleucina-6/deficiencia , Interleucina-6/genética , Activación de Linfocitos/genética , Activación de Linfocitos/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Peritonitis/microbiología , Peritonitis/patología , Receptores de Interleucina-6/deficiencia , Receptores de Interleucina-6/genética , Receptores de Interleucina-6/fisiología , Transducción de Señal/genética , Infecciones Estafilocócicas/inmunología , Infecciones Estafilocócicas/patología , Linfocitos T Colaboradores-Inductores/metabolismo , Linfocitos T Colaboradores-Inductores/patologíaRESUMEN
An 80-year-old female patient showed persistent lymphocytosis morphologically resembling the Japanese variant of hairy cell leukemia (HCL). However, flow cytometric analysis determined that these lymphocytes were of polyclonal B-cell origin, showing CD5-, CD10(-), CD11c(+), CD19(+), CD20(+), CD23(-), CD103(-), FMC7(-), HLA-DR(+) and surface membrane immunoglobulin (smIg) G(+) phenotype. The female patient also showed polyclonal hypergammaglobulinemia with bone marrow plasmacytosis. The patient was diagnosed as having hairy B-cell lymphoproliferative disorder (HBLD). Serum interleukin-6 (IL-6) level was elevated at the time of diagnosis in this patient, but IL-6 receptor (CD126) was not expressed on the hairy B-cells. Intracellular IL-6 was not detected in these cells either, suggesting that IL-6 did not play an important role in the B-lymphocytosis present in our patient with HBLD.
Asunto(s)
Linfocitos B/patología , Interleucina-6/sangre , Interleucina-6/fisiología , Leucemia de Células Pilosas/diagnóstico , Trastornos Linfoproliferativos/diagnóstico , Anciano de 80 o más Años , Diagnóstico Diferencial , Femenino , Citometría de Flujo , Humanos , Inmunofenotipificación , Japón , Leucemia de Células Pilosas/etiología , Linfocitosis , Trastornos Linfoproliferativos/etiología , Receptores de Interleucina-6/deficienciaRESUMEN
Interleukin-6 (IL-6) belongs to a family of cytokines that use receptors consisting of a common signal-transducing chain (gp130). Baf/3 cells transfected with the human IL-6 receptor (IL-6R) and gp130 (Baf/3-gp130/IL-6R) can only grow in medium containing IL-6. We attempted to interrupt the signal transducing pathway of IL-6 with the help of antisense oligonucleotides (ASOs) designed against the IL-6R. We used 18 different kinds of antisense oligonucleotides of overlapping sequences around the translational start codon of the human IL-6R. Sense ASOs were used as a control. The proliferation of cells was analysed by H-thymidine incorporation. Cell surface expression of the IL-6R was assessed by FACS analysis. We identified three ASOs which strongly inhibited the proliferation of IL-6 dependent transfected Baf/3 cells. Flow cytometric studies on the suppression of surface expression of IL-6R by ASOs showed a similar pattern. These results should help to clarify the structural requirements of functionally effective ASOs in the inhibition of IL-6R.
Asunto(s)
Interleucina-6/farmacología , Oligonucleótidos Antisentido/genética , Receptores de Interleucina-6/metabolismo , Transducción de Señal/efectos de los fármacos , Secuencia de Bases , División Celular/efectos de los fármacos , Línea Celular , Citometría de Flujo , Humanos , Oligonucleótidos Antisentido/farmacología , Receptores de Interleucina-6/biosíntesis , Receptores de Interleucina-6/deficiencia , Receptores de Interleucina-6/genética , Especificidad por Sustrato , Factores de TiempoRESUMEN
Adhesion molecules such as VCAM-1 and ICAM-1 are increased in the central nervous system (CNS) during inflammatory responses and contribute to extravasation of leukocytes across the blood-brain barrier (BBB) and into CNS parenchyma. Astrocytes contribute to the structural integrity of the BBB and can be induced to express VCAM-1 and ICAM-1 in response to cytokines such as TNF-alpha, IL-1beta, and IFN-gamma. In this study, we investigated the influence of IL-6 on astroglial adhesion molecule expression. IL-6, the soluble form of the IL-6R (sIL-6R), or both IL-6 plus sIL-6R, had no effect on VCAM-1 or ICAM-1 gene expression. Interestingly, the IL-6/sIL-6R complex inhibited TNF-alpha-induced VCAM-1 gene expression but did not affect TNF-alpha-induced ICAM-1 expression. The inhibitory effect of IL-6/sIL-6R complex was reversed by the inclusion of anti-IL-6R and gp130 Abs, demonstrating the specificity of the response. A highly active fusion protein of sIL-6R and IL-6, covalently linked by a flexible peptide, which is designated H-IL-6, also inhibited TNF-alpha-induced VCAM-1 expression. sIL-6R alone was an effective inhibitor of TNF-alpha-induced VCAM-1 due to endogenous IL-6 production. These results indicate that the IL-6 system has an unexpected negative effect on adhesion molecule expression in glial cells and may function as an immunosuppressive cytokine within the CNS.
Asunto(s)
Astrocitos/efectos de los fármacos , Regulación de la Expresión Génica , Interleucina-6/fisiología , Proteínas del Tejido Nervioso/fisiología , Receptores de Interleucina-6/deficiencia , Receptores de Interleucina-6/fisiología , Molécula 1 de Adhesión Celular Vascular/biosíntesis , Antígenos CD/fisiología , Astrocitos/metabolismo , Astrocitoma/patología , Barrera Hematoencefálica , Receptor gp130 de Citocinas , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Molécula 1 de Adhesión Intercelular/biosíntesis , Molécula 1 de Adhesión Intercelular/genética , Interleucina-6/farmacología , Glicoproteínas de Membrana/fisiología , Receptores de Interleucina-6/química , Proteínas Recombinantes de Fusión/farmacología , Proteínas Recombinantes/farmacología , Solubilidad , Células Tumorales Cultivadas , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Factor de Necrosis Tumoral alfa/farmacología , Molécula 1 de Adhesión Celular Vascular/genéticaRESUMEN
Cytokines stimulate granulopoiesis through signaling via receptors whose expression is controlled by lineage-specific transcription factors. Previously, we demonstrated that granulocyte colony-stimulating factor (G-CSF) receptor mRNA was undetectable and granulocyte maturation blocked in CCAAT enhancer binding protein alpha (C/EBPalpha)-deficient mice. This phenotype is distinct from that of G-CSF receptor-/- mice, suggesting that other genes are likely to be adversely affected by loss of C/EBPalpha. Here we demonstrate loss of interleukin 6 (IL-6) receptor and IL-6-responsive colony-forming units (CFU-IL6) in C/EBPalpha-/- mice. The observed failure of granulopoiesis could be rescued by the addition of soluble IL-6 receptor and IL-6 or by retroviral transduction of G-CSF receptors, demonstrating that loss of both of these receptors contributes to the absolute block in granulocyte maturation observed in C/EBPalpha-deficient hematopoietic cells. The results of these and other studies suggest that additional C/EBPalpha target genes, possibly other cytokine receptors, are also important for the block in granulocyte differentiation observed in vivo in C/EBPalpha-deficient mice.