Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Más filtros










Tipo de estudio
Intervalo de año de publicación
1.
Sci Rep ; 9(1): 16614, 2019 11 12.
Artículo en Inglés | MEDLINE | ID: mdl-31719632

RESUMEN

Premature ovarian insufficiency (POI) is a significant complication of cytotoxic treatments due to extreme ovarian sensitivity to chemotherapy and radiation. POI is particularly devastating for young girls reaching puberty, because it irreversibly affects their physical and cognitive development. Changes occurring during puberty determine their height, bone health, insulin responsiveness, lipid metabolism, cardiovascular health and cognition. The only available treatment for POI during puberty is hormone replacement therapy (HRT), which delivers non-physiological levels of estrogen, lacks other ovarian hormones and pulsatility, and is not responsive to feedback regulation. Here we report that ovarian allografts encapsulated in a hydrogel-based capsule and implanted in ovariectomized mice restore ovarian endocrine function in immune competent mice. Ovarian tissue from BALB/c mice was encapsulated in poly(ethylene-glycol) (PEG) hydrogels, with a proteolytically degradable core and a non-degradable shell. The dual capsules were implanted subcutaneously in immune competent ovariectomized C57BL/6 mice for a period of 60 days. As expected, non-encapsulated ovarian allografts implanted in a control group sensitized the recipients as confirmed with donor-specific IgG in the serum, which increased 26-fold in the 3 weeks following transplantation (p = 0.02) and infiltration of the graft with CD8 T cells consistent with allo-immunity. In contrast, encapsulation in the Dual PEG capsules prevented sensitization to the allograft in all the recipients with no evidence of lymphocytic infiltration. In summary, the approach of hydrogel-based immunoisolation presents a minimally invasive and robust cell-therapy to restore hormonal balance in ovarian insufficiency. This report is the first to demonstrate the application of a tunable PEG-based hydrogel as an immunoisolator of allogeneic ovarian tissue to restore endocrine function in ovariectomized mice and prevent cell-mediated immune rejection in immune competent mice.

2.
PLoS Negl Trop Dis ; 11(7): e0005754, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28715406

RESUMEN

The pathways that trigger exacerbated immune reactions in leprosy could be determined by genetic variations. Here, in a prospective approach, both genetic and non-genetic variables influencing the amount of time before the development of reactional episodes were studied using Kaplan-Meier survival curves, and the genetic effect was estimated by the Cox proportional-hazards regression model. In a sample including 447 leprosy patients, we confirmed that gender (male), and high bacillary clinical forms are risk factors for leprosy reactions. From the 15 single nucleotide polymorphisms (SNPs) at the 8 candidate genes genotyped (TNF/LTA, IFNG, IL10, TLR1, NOD2, SOD2, and IL6) we observed statistically different survival curves for rs751271 at the NOD2 and rs2069845 at the IL6 genes (log-rank p-values = 0.002 and 0.023, respectively), suggesting an influence on the amount of time before developing leprosy reactions. Cox models showed associations between the SNPs rs751271 at NOD2 and rs2069845 at IL6 with leprosy reactions (HRGT = 0.45, p = 0.002; HRAG = 1.88, p = 0.0008, respectively). Finally, IL-6 and IFN-γ levels were confirmed as high, while IL-10 titers were low in the sera of reactional patients. Rs751271-GT genotype-bearing individuals correlated (p = 0.05) with lower levels of IL-6 in sera samples, corroborating the genetic results. Although the experimental size may be considered a limitation of the study, the findings confirm the association of classical variables such as sex and clinical forms with leprosy, demonstrating the consistency of the results. From the results, we conclude that SNPs at the NOD2 and IL6 genes are associated with leprosy reactions as an outcome. NOD2 also has a clear functional pro-inflammatory link that is coherent with the exacerbated responses observed in these patients.


Asunto(s)
Predisposición Genética a la Enfermedad , Inflamación/patología , Interleucina-6/genética , Lepra/patología , Proteína Adaptadora de Señalización NOD2/genética , Polimorfismo de Nucleótido Simple , Adulto , Estudios de Cohortes , Femenino , Humanos , Inflamación/genética , Lepra/genética , Masculino , Persona de Mediana Edad , Factores de Riesgo
3.
PLoS Pathog ; 13(1): e1006103, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-28056107

RESUMEN

Leprosy is a chronic infectious disease that may present different clinical forms according to the immune response of the host. Levels of IFN-γ are significantly raised in paucibacillary tuberculoid (T-lep) when compared with multibacillary lepromatous (L-lep) patients. IFN-γ primes macrophages for inflammatory activation and induces the autophagy antimicrobial mechanism. The involvement of autophagy in the immune response against Mycobacterium leprae remains unexplored. Here, we demonstrated by different autophagic assays that LC3-positive autophagosomes were predominantly observed in T-lep when compared with L-lep lesions and skin-derived macrophages. Accumulation of the autophagic receptors SQSTM1/p62 and NBR1, expression of lysosomal antimicrobial peptides and colocalization analysis of autolysosomes revealed an impairment of the autophagic flux in L-lep cells, which was restored by IFN-γ or rapamycin treatment. Autophagy PCR array gene-expression analysis revealed a significantly upregulation of autophagy genes (BECN1, GPSM3, ATG14, APOL1, and TPR) in T-lep cells. Furthermore, an upregulation of autophagy genes (TPR, GFI1B and GNAI3) as well as LC3 levels was observed in cells of L-lep patients that developed type 1 reaction (T1R) episodes, an acute inflammatory condition associated with increased IFN-γ levels. Finally, we observed increased BCL2 expression in L-lep cells that could be responsible for the blockage of BECN1-mediated autophagy. In addition, in vitro studies demonstrated that dead, but not live M. leprae can induce autophagy in primary and lineage human monocytes, and that live mycobacteria can reduce the autophagy activation triggered by dead mycobacteria, suggesting that M. leprae may hamper the autophagic machinery as an immune escape mechanism. Together, these results indicate that autophagy is an important innate mechanism associated with the M. leprae control in skin macrophages.


Asunto(s)
Autofagia/fisiología , Lepra/inmunología , Piel/microbiología , Adulto , Anciano , Western Blotting , Ensayo de Inmunoadsorción Enzimática , Femenino , Técnica del Anticuerpo Fluorescente , Humanos , Inmunohistoquímica , Interferón gamma/inmunología , Lepra/patología , Macrófagos/inmunología , Masculino , Microscopía Electrónica de Transmisión , Persona de Mediana Edad , Mycobacterium leprae/inmunología , Reacción en Cadena de la Polimerasa , Piel/inmunología , Piel/patología , Transcriptoma , Adulto Joven
4.
s.l; Elsevier; 2017. 10 p. tab, graf.
No convencional en Inglés | Sec. Est. Saúde SP, HANSEN, SESSP-ILSLPROD, Sec. Est. Saúde SP, SESSP-ILSLACERVO, Sec. Est. Saúde SP | ID: biblio-1052567

RESUMEN

Our previous study has demonstrated that IL-10 may modulate both indoleamine 2,3-dioxygenase (IDO) and CD163 expression in lepromatous leprosy (LL) cells, favoring Mycobacterium leprae persistence through induction of regulatory pathways and iron storage. Here, we observed that in LL lesion cells there is an increase in the expression of proteins involved in iron metabolism such as hemoglobin (Hb), haptoglobin, heme oxygenase 1 and transferrin receptor 1 (TfR1) when compared to tuberculoid leprosy (BT) cells. We also found increased iron deposits and diminished expression of the iron exporter ferroportin 1 in LL lesion cells. Hemin, but not FeSO stimulation, was able to enhance M. leprae viability by a mechanism that involves IDO. Analysis of cell phenotype in lesions demonstrated a predominance of M2 markers in LL when compared with BT lesion cells. A positive correlation between CD163 and PPARG with the bacillary index (BI) was observed. In contrast, TNF, STAT1 and CSF2 presented a negative correlation with the BI. In summary, this study demonstrates that iron may regulate IDO expression by a mechanism that involves IL-10, which may contribute for the predominance of M2-like phenotype in LL lesions that favors the phagocytosis and maintenance of M. leprae in host cells.


Asunto(s)
Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Immunoblotting , Lepra Lepromatosa/metabolismo , Lepra Lepromatosa/microbiología , Técnicas para Inmunoenzimas , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Indolamina-Pirrol 2,3,-Dioxigenasa/fisiología , Indolamina-Pirrol 2,3,-Dioxigenasa/metabolismo , Hierro/fisiología , Hierro/metabolismo , Mycobacterium leprae/fisiología , Mycobacterium leprae/metabolismo
5.
PLoS Negl Trop Dis ; 10(8): e0004955, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27556927

RESUMEN

Erythema Nodosum Leprosum (ENL) is an immune reaction in leprosy that aggravates the patient´s clinical condition. ENL presents systemic symptoms of an acute infectious syndrome with high leukocytosis and intense malaise clinically similar to sepsis. The treatment of ENL patients requires immunosuppression and thus needs to be early and efficient to prevent both disabilities and permanent nerve damage. Some patients experience multiple episodes of ENL and prolonged use of immunosuppressive drugs may lead to serious adverse effects. Thalidomide treatment is extremely effective at ameliorating ENL symptoms. Several mechanisms have been proposed to explain the efficacy of thalidomide in ENL, including the inhibition of TNF production. Given its teratogenicity, thalidomide is prohibitive for women of childbearing age. A rational search for molecular targets during ENL episodes is essential to better understand the disease mechanisms involved, which may also lead to the discovery of new drugs and diagnostic tests. Previous studies have demonstrated that IFN-γ and GM-CSF, involved in the induction of CD64 expression, increase during ENL. The aim of the present study was to investigate CD64 expression during ENL and whether thalidomide treatment modulated its expression. Leprosy patients were allocated to one of five groups: (1) Lepromatous leprosy, (2) Borderline leprosy, (3) Reversal reaction, (4) ENL, and (5) ENL 7 days after thalidomide treatment. The present study demonstrated that CD64 mRNA and protein were expressed in ENL lesions and that thalidomide treatment reduced CD64 expression and neutrophil infiltrates-a hallmark of ENL. We also showed that ENL blood neutrophils exclusively expressed CD64 on the cell surface and that thalidomide diminished overall expression. Patient classification based on clinical symptoms found that severe ENL presented high levels of neutrophil CD64. Collectively, these data revealed that ENL neutrophils express CD64, presumably contributing to the immunopathogenesis of the disease.


Asunto(s)
Eritema Nudoso/inmunología , Leprostáticos/uso terapéutico , Neutrófilos/efectos de los fármacos , Neutrófilos/inmunología , Receptores de IgG/genética , Talidomida/uso terapéutico , Adolescente , Adulto , Anciano , Biopsia , Eritema Nudoso/diagnóstico , Eritema Nudoso/tratamiento farmacológico , Eritema Nudoso/microbiología , Femenino , Humanos , Lepra Dimorfa/tratamiento farmacológico , Lepra Dimorfa/inmunología , Lepra Dimorfa/microbiología , Lepra Lepromatosa/tratamiento farmacológico , Lepra Lepromatosa/inmunología , Lepra Lepromatosa/microbiología , Masculino , Persona de Mediana Edad , Receptores de IgG/inmunología , Piel/microbiología , Piel/patología , Adulto Joven
6.
Expert Rev Clin Immunol ; 11(3): 391-407, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25666357

RESUMEN

Type 1 reaction (T1R) or reversal reaction is the leading cause of physical disabilities and deformities in leprosy. Leprosy patients, even after being considered cured and released from treatment, may suffer from reactional episodes for long periods of time. Early diagnosis is a great challenge for effectively treating and managing T1R. There is an urgent need to identify the most significant biomarkers to prevent recurrent T1R and to differentiate late T1R from relapse. T1R continues to be treated with corticosteroids and complications due to iatrogenic treatment remain frequent. This review aims to provide a framework from which to approach the great challenges that still persist in T1R management and debate key issues in order to reduce the distance between basic research and the clinic.


Asunto(s)
Corticoesteroides/uso terapéutico , Inmunosupresores/uso terapéutico , Leprostáticos/uso terapéutico , Lepra/terapia , Mycobacterium leprae/inmunología , Animales , Ensayos Clínicos como Asunto , Humanos , Interferón gamma/antagonistas & inhibidores , Leprostáticos/farmacología , Lepra/inmunología , Factor de Crecimiento Transformador beta/antagonistas & inhibidores
7.
Rio de Janeiro; s.n; 2012. xx,97 p. graf, tab, ilus, mapas.
Tesis en Portugués | LILACS | ID: lil-695546

RESUMEN

A forma lepromatosa da Hanseníase caracteriza-se pela baixa ou ausente resposta imune específica aos antígenos do Mycobacterium leprae e intensa proliferação bacilar. Dentre as células hospedeiras, os macrófagos parecem ter um papel crucial no direcionamento do perfil de resposta ao M. leprae. Muitas das vias de imunossupressão da resposta imune celular parecem estar envolvidas com o metabolismo do ferro e seus carreadores, como a expressão aumentada de IDO em macrófagos lepromatosos e de heme-oxigenase 1 em macrófagos M2. Anteriormente, o nosso grupo demonstrou que macrófagos de pacientes lepromatosos apresentam uma maior expressão do receptor scavenger CD163, quando comparados aos tuberculóides. O CD163 reconhece o complexo Hemoglobina-Haptoglobina e nós hipotetizamos que o M. leprae adaptou-se para aumentara expressão de CD163, a fim de aumentar estoques de ferro em macrófagos, contribuindo para sua persistência. Assim, o objetivo do presente trabalho foi investigar o envolvimento de ferro na imunopatogênese da hanseníase. Nós observamos que biópsias de lesão de pele de pacientes lepromatosos apresentam uma maior expressão de proteínas relacionadas à captação e metabolismo de ferro, assim como uma maior deposição de ferro na forma de ferritina e hemossiderina nos macrófagos espumosos, onde se localizam os bacilos. A adição de ferro exógeno, na forma de tratamento com sulfato ferroso, foi capaz de reduzir a expressão e atividade de indoleamina 2,3-dioxigenase induzida pelo M. leprae em monócitos de doadores saudáveis. A adição de ferro livre também foi capaz de modular a produção de citocinas, aumentando a produção de IL-12p70 e IL-10 em culturas de monócitos, e de IL-6 em culturas de células mononucleares do sangue periférico. O aumento dos receptores CD163 e receptor de transferrina 1 em macrófagos lepromatosos foram associados com o aumento dos estoques de ferro em biópsias de pele de pacientes lepromatosos. Em adição, o tratamento com ferro livre foi capaz aumentar vias proinflamatórias em leucócitos estimulados com M. leprae. Isto indica que a homeostase do ferro no hospedeiro no momento da infecção é importante para a definição do desfecho da Hanseníase, e que o ferro pode ter um papel duplo dependendo do momento e da forma que este está apresentado, podendo criar um ambiente favorável para a micobactéria ou induzindo a produção de citocinas próinflamatórias que podem contribuir para ativação de vias antimicrobianas em macrófagos.


Asunto(s)
Enfermedades Transmisibles , Inmunidad , Hierro , Trastornos del Metabolismo del Hierro , Lepra , Mycobacterium leprae , Parásitos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA