RESUMEN
Tuberculosis (TB) is the leading cause of mortality among infectious diseases worldwide. The study of molecular targets for therapy and diagnosis suggested that Notch signaling is an important pathway for the maintenance of the immune response during Mycobacterium tuberculosis (Mtb) infection. We evaluated the participation of the Notch pathway in the modulation of immune response during Mtb infection, and observed that patients with active TB had increased DLL4 expression in intermediate and non-classic monocytes. Further, patients with moderate and advanced lung injury have higher Notch1 expression in CD4+ T cells when compared to patients with a minimal lung injury. When we considered the severity of disease in active TB patients, the expression of the DLL4 in intermediate monocytes and the expression of Notch1 in CD4+ T cells are positively correlated with the degree of lung injury. In vitro, PBMCs treated with the Notch pharmacological inhibitor reduced the production of IL-17A and IL-2, whereas anti-hDLL4 treatment promoted a significant increase in TNF-α and phagocytosis. We suggest that Notch1 and DLL4 are associated with immune response activation in human tuberculosis, and can be a novel target to be exploited in the future in the searching of biomarkers.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Linfocitos T CD4-Positivos/metabolismo , Proteínas de Unión al Calcio/metabolismo , Pulmón/metabolismo , Mycobacterium tuberculosis/inmunología , Receptor Notch1/metabolismo , Tuberculosis Pulmonar/metabolismo , Adulto , Biomarcadores/metabolismo , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/microbiología , Estudios de Casos y Controles , Células Cultivadas , Citocinas/metabolismo , Progresión de la Enfermedad , Femenino , Interacciones Huésped-Patógeno , Humanos , Pulmón/inmunología , Pulmón/microbiología , Masculino , Persona de Mediana Edad , Fagocitosis , Índice de Severidad de la Enfermedad , Transducción de Señal , Tuberculosis Pulmonar/inmunología , Tuberculosis Pulmonar/microbiología , Adulto JovenRESUMEN
Wound healing is a well-coordinated process that involves inflammatory mediators and cellular responses; however, if any disturbances are present during this process, tissue repair is impaired. Chronic wounds are one of the serious long-term complications associated with diabetes mellitus. The chemokine receptor CCR4 and its respective ligands, CCL17 and CCL22, are involved in regulatory T cell recruitment and activation in inflamed skin; however, the role of regulatory T cells in wounds is still not clear. Our aim was to investigate the role of CCR4 and regulatory T cells in cutaneous wound healing in diabetic mice. Alloxan-induced diabetic wild- type mice (diabetic) developed wounds that were difficult to heal, differently from CCR4-/- diabetic mice (CCR4-/- diabetic), and also from anti-CCL17/22 or anti-CD25-injected diabetic mice that presented with accelerated wound healing and fewer regulatory T cells in the wound bed. Consequently, CCR4-/- diabetic mice also presented with alteration on T cells population in the wound and draining lymph nodes; on day 14, these mice also displayed an increase of collagen fiber deposition. Still, cytokine levels were decreased in the wounds of CCR4-/- diabetic mice on day 2. Our data suggest that the receptor CCR4 and regulatory T cells negatively affect wound healing in diabetic mice.
Asunto(s)
Quimiocina CCL17/antagonistas & inhibidores , Quimiocina CCL22/antagonistas & inhibidores , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Receptores CCR4/metabolismo , Cicatrización de Heridas/efectos de los fármacos , Aloxano/farmacología , Análisis de Varianza , Animales , Biopsia con Aguja , Quimiocina CCL17/farmacología , Quimiocina CCL22/farmacología , Quimiocinas/metabolismo , Diabetes Mellitus Experimental/patología , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Humanos , Inmunohistoquímica , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Cicatrización de Heridas/fisiologíaRESUMEN
Sepsis is a deadly disease characterized by an overwhelming release of inflammatory mediators and the activation of different types of cells. This altered state of cell activation, termed leukocyte reprogramming, contributes to patient outcome. However, the understanding of the process underlying sepsis and the role of regulatory T cells (Tregs) in sepsis remains to be elucidated. In this study, we investigated the role of CCR4, the CCL17/CCL22 chemokine receptor, in the innate and acquired immune responses during severe sepsis and the role of Tregs in effecting the outcome. In contrast with wild-type (WT) mice subjected to cecal ligation and puncture (CLP) sepsis, CCR4-deficient (CCR4-/-) septic mice presented an increased survival rate, significant neutrophil migration toward the infection site, a low bacterial count in the peritoneum, and reduced lung inflammation and serum cytokine levels. Thus, a better early host response may favor an adequate long-term response. Consequently, the CCR4-/- septic mice were not susceptible to secondary fungal infection, in contrast with the WT septic mice. Furthermore, Tregs cells from the CCR4-/- septic mice showed reduced suppressive effects on neutrophil migration (both in vivo and in vitro), lymphocyte proliferation and ROS production from activated neutrophils, in contrast with what was observed for Tregs from the WT septic mice. These data show that CCR4 is involved in immunosuppression after severe sepsis and suggest that CCR4+ Tregs negatively modulate the short and long-term immune responses.
Asunto(s)
Receptores CCR4/inmunología , Sepsis/inmunología , Linfocitos T Reguladores/inmunología , Animales , Femenino , Eliminación de Gen , Interleucina-10/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Activación Neutrófila , Especies Reactivas de Oxígeno/inmunología , Receptores CCR4/genética , Sepsis/genética , Sepsis/patología , Linfocitos T Reguladores/metabolismo , Linfocitos T Reguladores/patología , Factor de Necrosis Tumoral alfa/inmunologíaRESUMEN
The mechanism of immunosuppression induced by severe sepsis is not fully understood. The production of prostaglandin E2 (PGE2) during sepsis is well known, but its role in long-term consequences of sepsis has not been explored. The current study evaluates the role of PGE2 in the development of immunosuppression secondary to sepsis and its potential as therapeutic target. Cecal ligation and puncture was used as an experimental model for sepsis induction in Balb/c and C57BL/6 mice. Immunosuppression was evaluated by the response to secondary infection with Aspergillus fumigatus in sepsis survivors. The role of prostanoids was evaluated in vivo and in vitro by treatment with the cyclooxygenase inhibitor ketoprofen. Balb/c mice were more susceptible than C57BL/6 to severe sepsis and to secondary infection, with a greater mortality rate. Prostaglandin E2 concentrations found in bronchoalveolar lavage in sham and cecal ligation and puncture group after fungal challenge were much higher in Balb/c than in C57BL/6 mice. Ketoprofen treatment improved survival of septic Balb/c mice subjected to secondary infection, while also enhancing macrophage phagocytosis and neutrophil recruitment to the lungs. We identified a pivotal role for PGE2 acting on EP4 receptors in modulating cytokine production differentially by sham and septic macrophages. Furthermore, sepsis also altered key enzymes in PGE2 synthesis and degradation. Our results indicate the involvement of PGE2 in severe sepsis-induced immunosuppression. Inhibition of PGE2 production represents an attractive target to improve innate immune response against secondary infection in the immunocompromised host.
Asunto(s)
Antiinflamatorios no Esteroideos/efectos adversos , Dinoprostona/inmunología , Tolerancia Inmunológica/efectos de los fármacos , Cetoprofeno/efectos adversos , Sepsis/inmunología , Animales , Antiinflamatorios no Esteroideos/farmacología , Citocinas/inmunología , Modelos Animales de Enfermedad , Cetoprofeno/farmacología , Macrófagos/inmunología , Macrófagos/patología , Ratones , Ratones Endogámicos BALB C , Fagocitosis/efectos de los fármacos , Fagocitosis/inmunología , Subtipo EP4 de Receptores de Prostaglandina E/inmunología , Sepsis/tratamiento farmacológico , Índice de Severidad de la EnfermedadRESUMEN
Helminths are known to elicit a wide range of immunomodulation characterized by dominant Th2-type immune responses. Our group previously showed that a DNA vaccine encoding the mycobacterial 65-kDa heat shock protein (DNA-hsp65) showed immunomodulatory properties. We also showed, using a helminth-tuberculosis (TB) co-infection model, that the DNA-hsp65 vaccine protected mice against TB. We next investigated the mechanistic role of the vaccine during helminth-TB co-infection. Clinically, helminth infection causes type 2 granulomas in the lung. Mice were immunized with DNA-hsp65 while they were submitted to the type 2 granuloma induction protocol by Schistosoma mansoni eggs infusion. In this work we investigated the effects of DNA-hsp65 on the pathology and immune response during the development of type 2 granuloma induced by S. mansoni eggs. Histologic analyses of lung parenchyma showed that the DNA-hsp65 vaccine protected mice against exacerbated fibrosis induced by Schistosoma eggs, and decreased the size of the granulomas. These changes were correlated with a reduction in the number of T cells specific for the egg antigens in the lung and also with modulation of Th2 cytokine expression. Taken together, our results showed that the adjuvant properties of the DNA-hsp65 vaccine regulated the immune response in this Th2 model, and resulted in a preserved lung parenchyma.
Asunto(s)
Movimiento Celular , Citocinas/metabolismo , Fibrosis/prevención & control , Granuloma/prevención & control , Miofibroblastos/patología , Esquistosomiasis mansoni/prevención & control , Vacunas de ADN/uso terapéutico , Animales , Western Blotting , Proliferación Celular , Femenino , Fibrosis/inmunología , Fibrosis/metabolismo , Técnica del Anticuerpo Fluorescente , Granuloma/inmunología , Granuloma/metabolismo , Pulmón/inmunología , Pulmón/metabolismo , Pulmón/patología , Ratones , Ratones Endogámicos C57BL , Miofibroblastos/inmunología , Miofibroblastos/metabolismo , Óvulo/inmunología , Óvulo/metabolismo , ARN Mensajero/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Schistosoma mansoni/genética , Schistosoma mansoni/inmunología , Esquistosomiasis mansoni/inmunología , Esquistosomiasis mansoni/metabolismo , Linfocitos T/inmunología , Linfocitos T/metabolismo , Linfocitos T/patología , Células Th2/inmunología , Células Th2/metabolismo , Células Th2/patologíaRESUMEN
BACKGROUND: Helminthiasis and tuberculosis (TB) coincide geographically and there is much interest in exploring how concurrent worm infections might alter immune responses against bacilli and might necessitate altered therapeutic approaches. A DNA vaccine that codifies heat shock protein Hsp65 from M. leprae (DNAhsp65) has been used in therapy during experimental tuberculosis. This study focused on the impact of the co-existence of worms and TB on the therapeutic effects of DNAhsp65. METHODOLOGY/PRINCIPAL FINDINGS: Mice were infected with Toxocara canis or with Schistosoma mansoni, followed by coinfection with M. tuberculosis and treatment with DNAhsp65. While T. canis infection did not increase vulnerability to pulmonary TB, S. mansoni enhanced susceptibility to TB as shown by higher numbers of bacteria in the lungs and spleen, which was associated with an increase in Th2 and regulatory cytokines. However, in coinfected mice, the therapeutic effect of DNAhsp65 was not abrogated, as indicated by colony forming units and analysis of histopathological changes. In vitro studies indicated that Hsp65-specific IFN-gamma production was correlated with vaccine-induced protection in coinfected mice. Moreover, in S. mansoni-coinfected mice, DNA treatment inhibited in vivo TGF-beta and IL-10 production, which could be associated with long-term protection. CONCLUSIONS/SIGNIFICANCE: We have demonstrated that the therapeutic effects of DNAhsp65 in experimental TB infection are persistent in the presence of an unrelated Th2 immune response induced by helminth infections.
Asunto(s)
Esquistosomiasis mansoni/microbiología , Toxocariasis/microbiología , Vacunas contra la Tuberculosis/inmunología , Tuberculosis/parasitología , Vacunas de ADN/inmunología , Análisis de Varianza , Animales , Proteínas Bacterianas/genética , Chaperonina 60/genética , Modelos Animales de Enfermedad , Femenino , Helmintos , Interferón gamma , Interleucinas/metabolismo , Pulmón/metabolismo , Ratones , Ratones Endogámicos BALB C , Nitritos/metabolismo , Schistosoma mansoni , Esquistosomiasis mansoni/inmunología , Células TH1/metabolismo , Toxocara canis , Tuberculosis/tratamiento farmacológico , Tuberculosis/inmunología , Tuberculosis/prevención & control , Vacunas contra la Tuberculosis/farmacología , Vacunas de ADN/farmacologíaRESUMEN
Despite an increase in the knowledge of mechanisms and mediators involved in pulmonary fibrosis, there are no successful therapeutics available. Lipoxins (LX) and their 15-epimers, aspirin-triggered LX (ATL), are endogenously produced eicosanoids with potent anti-inflammatory and proresolution effects. To date, few studies have been performed regarding their effect on pulmonary fibrosis. In the present study, using C57BL/6 mice, we report that bleomycin (BLM)-induced lung fibrosis was prevented by the concomitant treatment with an ATL synthetic analog, ATLa, which reduced inflammation and matrix deposition. ATLa inhibited BLM-induced leukocyte accumulation and alveolar collapse as evaluated by histology and morphometrical analysis. Moreover, Sirius red staining and lung hydroxyproline content showed an increased collagen deposition in mice receiving BLM alone that was decreased upon treatment with the analog. These effects resulted in benefits to pulmonary mechanics, as ATLa brought to normal levels both lung resistance and compliance. Furthermore, the analog improved mouse survival, suggesting an important role for the LX pathway in the control of disease establishment and progression. One possible mechanism by which ATLa restrained fibrosis was suggested by the finding that BLM-induced myofibroblast accumulation/differentiation in the lung parenchyma was also reduced by both simultaneous and posttreatment with the analog (alpha-actin immunohistochemistry). Interestingly, ATLa posttreatment (4 days after BLM) showed similar inhibitory effects on inflammation and matrix deposition, besides the TGF-beta level reduction in the lung, reinforcing an antifibrotic effect. In conclusion, our findings show that LX and ATL can be considered as promising therapeutic approaches to lung fibrotic diseases.