RESUMEN
Alcohol use disorders (AUD) are among the most common and undertreated mental disorders in developed countries. The co-occurrence of psychiatric comorbidity and AUD has already been well documented. Moreover, alexithymia was found associated with heavy drinking and alcohol dependence. A large part of AUD individuals, between 45 and 67%, have been identified as alexithymics. Both psychiatric comorbidity and alexithymia can negatively impact the course of recovery from alcohol. Alcohol consumption has also been shown to significantly influence autonomic responses. Chronic use of alcohol may induce significant changes in heart rate variability, respiratory frequency, electrodermal activity and skin temperature. To date, only a few studies have comprehensively investigated the comorbidity of alexithymia in AUD individuals with dual diagnosis. Thus, the aim and also the novelty of the present investigation were to disclose in individuals with AUD the emotional and cognitive stress responses to selected physiological parameters measured by ProComp5 Infiniti™ encoder in AUD patients suffering alexithymia with or without concomitant dual diagnosis. Quite interestingly, in AUD subjects with concomitant dual diagnosis we found that the alexithymia elevated skin temperature, heart rate variability and decreased respiratory frequency. Alexithymia, if associated with the dual diagnosis condition in AUD individuals, can be considered as a further vulnerability factor to stressing factors, impacting psychosomatic processing and inducing alterations in physiological parameters. In this paper, we discuss the implications of these findings in the early treatment of alexithymic AUD individuals.
Asunto(s)
Síntomas Afectivos/psicología , Alcoholismo/psicología , Adulto , Síntomas Afectivos/complicaciones , Consumo de Bebidas Alcohólicas , Alcoholismo/complicaciones , Comorbilidad , Diagnóstico Dual (Psiquiatría) , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Treatment of pain has always been a major goal in the clinic, as it is related to several pathological conditions of inflammatory origin and surgical procedures, which are associated with inflammatory mediators. Understanding the molecular mechanisms underlying the association between inflammatory mediators and pain perception, from peripheral to central sensitization, can provide the basis for the development of new pharmacological treatments. Despite safety concerns, till date, the use of non-steroidal anti-inflammatory drugs (NSAIDs) has been shown to be efficacious, safe, and well tolerated by patients. Thus, choosing the appropriate administration route, developing new formulations and lowering the efficacious dose represent, currently, effective means of treating inflammation and relieving the pain, without inducing significant side effects.
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Mediadores de Inflamación/metabolismo , Percepción del Dolor/fisiología , Dolor/metabolismo , Animales , Antiinflamatorios no Esteroideos/farmacología , Antiinflamatorios no Esteroideos/uso terapéutico , Humanos , Inflamación/tratamiento farmacológico , Inflamación/metabolismo , Dolor/tratamiento farmacológicoRESUMEN
This study aimed to elucidate the genetic relatedness and epidemiology of 127 clinical and environmental Candida glabrata isolates from Europe and Africa using multilocus microsatellite analysis. Each isolate was first identified using phenotypic and molecular methods and subsequently, six unlinked microsatellite loci were analyzed using automated fluorescent genotyping. Genetic relationships were estimated using the minimum-spanning tree (MStree) method. Microsatellite analyses revealed the existence of 47 different genotypes. The fungal population showed an irregular distribution owing to the over-representation of genetically different infectious haplotypes. The most common genotype was MG-9, which was frequently found in both European and African isolates. In conclusion, the data reported here emphasize the role of specific C. glabrata genotypes in human infections for at least some decades and highlight the widespread distribution of some isolates, which seem to be more able to cause disease than others.
Asunto(s)
Candida glabrata/clasificación , Candida glabrata/genética , ADN de Hongos , Repeticiones de Microsatélite , Tipificación de Secuencias Multilocus , África , Alelos , Candida glabrata/aislamiento & purificación , Candidiasis/microbiología , Microbiología Ambiental , Europa (Continente) , Sitios Genéticos , Variación Genética , Genotipo , Haplotipos , HumanosRESUMEN
Fungal nosocomial infections continue to be a serious problem among hospitalized patients, decreasing quality of life and adding millions of euros to healthcare costs. The aim of this study was to describe the pattern of fungi associated with the hands of healthcare workers and to genotype Candida parapsilosis isolates in order to understand whether their high clinical prevalence stems from endemic nosocomial genotypes or from the real emergence of epidemiologically-unrelated strains. Approximately 39% (50/129) of healthcare workers were positive for yeasts and among 77 different fungal isolates recovered, C. parapsilosis was the most frequent (44/77; 57%). Twenty-seven diverse genotypes were obtained by microsatellite analysis of 42 selected blood and hand isolates. Most of the isolates from hands showed a new, unrelated, genotype, whereas a particular group of closely related genotypes prevailed in blood samples. Some of the latter genotypes were also found on the hands of healthcare workers, indicating a persistence of these clones within our hospital. C. parapsilosis genotypes from the hands were much more heterogeneous than clinical ones, thus reflecting a high genetic diversity among isolates, which is notably unusual and unexpected for this species.
Asunto(s)
Candida/aislamiento & purificación , Infección Hospitalaria/epidemiología , Mano/microbiología , Personal de Salud , Sepsis/epidemiología , Candida/clasificación , Candida/genética , Infección Hospitalaria/microbiología , ADN de Hongos/genética , Transmisión de Enfermedad Infecciosa , Genotipo , Humanos , Epidemiología Molecular , Tipificación Molecular , Técnicas de Tipificación Micológica , Estudios Retrospectivos , Sepsis/microbiologíaRESUMEN
The thymus is the primary organ responsible for de novo generation of immunocompetent T cells that have a diverse repertoire of antigen recognition. During the developmental process, 98% of thymocytes die by apoptosis. Thus apoptosis is a dominant process in the thymus and occurs through either death by neglect or negative selection or through induction by stress/aging. Caspase activation is an essential part of the general apoptosis mechanism, and data suggest that caspases may have a role in negative selection; however, it seems more probable that caspase-8 activation is involved in death by neglect, particularly in glucocorticoid-induced thymocyte apoptosis. Caspase-8 is active in double-positive (DP) thymocytes in vivo and can be activated in vitro in DP thymocytes by T-cell receptor (TCR) crosslinking to induce apoptosis. Caspase-8 is a proapoptotic member of the caspase family and is considered an initiator caspase, which is activated upon stimulation of a death receptor (e.g., Fas), recruitment of the adaptor molecule FADD, and recruitment and subsequent processing of procaspase-8. The main role of caspase-8 seems to be pro-apoptotic and, in this review, we will discuss about the involvement of caspase-8 in (1) TCR-triggered thymic apoptosis; (2) death receptor-mediated thymic apoptosis; and (3) glucocorticoid-induced thymic apoptosis. Regarding TCR triggering, caspase-8 is active in medullary, semi-mature heat-stable antigen(hi) (HAS(hi) SP) thymocytes as a consequence of strong TCR stimulation. The death receptors Fas, FADD, and FLIP are involved upstream of caspase-8 activation in apoptosis; whereas, Bid and HDAC7 are involved downstream of caspase-8. Finally, caspase-8 is involved in glucocortocoid-induced thymocyte apoptosis through an activation loop with the protein GILZ. GILZ activates caspase-8, promoting GILZ sumoylation and its protection from proteasomal degradation.
Asunto(s)
Caspasa 8/metabolismo , Timo/enzimología , Timo/fisiología , Animales , HumanosRESUMEN
BACKGROUND: Hemophagocytic lymphohistiocytosis (HLH) is a rare syndrome that is often fatal despite treatment. It is caused by a dysregulation in natural killer T-cell function, resulting in activation and proliferation of histiocytes with uncontrolled hemophagocytosis and cytokines overproduction. The syndrome is characterized by fever, hepatosplenomegaly, cytopenias, liver dysfunction, and hyperferritinemia. HLH can be either primary, with a genetic aetiology, or secondary, associated with malignancies, autoimmune diseases, or infections. AIM: To focus on secondary HLH complicating zoonotic diseases. MATERIALS AND METHODS: PubMed search of human cases of HLH occurring during zoonotic diseases was performed combining the terms (haemophagocytic or haemophagocytosis or hemophagocytosis or hemophagocytic or erythrophagocytosis or macrophage activation syndrome) with each one of the etiological agents of zoonoses. RESULTS: Among bacterial diseases, most papers reported cases occurring during brucellosis, rickettsial diseases and Q fever. Regarding viral diseases, most of the cases were reported in patients with avian influenza A subtype H5N1. Among the protozoan zoonoses, most of the cases were reported in patients with visceral leishmaniasis. Regarding zoonotic fungi, most of the cases were reported in AIDS patient with histoplasmosis. No cases of secondary HLH were reported in patient with zoonotic helminthes. CONCLUSIONS: Zoonotic diseases are an important cause of HLH. Secondary HLH can delay the correct diagnosis of the zoonotic disease, and can contribute to an adverse outcome.
Asunto(s)
Linfohistiocitosis Hemofagocítica/etiología , Zoonosis/transmisión , Animales , Comorbilidad , Humanos , Linfohistiocitosis Hemofagocítica/terapiaRESUMEN
The leaves of Artocarpus tonkinensis are used in Vietnamese traditional medicine for treatment of arthritis, and the compound maesopsin 4-O-ß-D-glucoside (TAT-2), isolated from them, inhibits the proliferation of activated T cells. Our goal was to test the anti-proliferative activity of TAT-2 on the T-cell leukemia, Jurkat, and on the acute myeloid leukemia, OCI-AML. TAT-2 inhibited the growth of OCI-AML (and additional acute myeloid leukemia cells) but not Jurkat cells. Growth inhibition was shown to be due to inhibition of proliferation rather than increase in cell death. Analysis of cytokine release showed that TAT-2 stimulated the release of TGF-ß, yet TGF-ß neutralization did not reverse the maesopsin-dependent effect. Gene expression profiling determined that maesopsin modulated 19 identifiable genes. Transcription factor CP2 was the gene most significantly modulated. Real-time PCR validated that up-regulation of sulphiredoxin 1 homolog (SRXN1), hemeoxygenase 1 (HMOX1), and breast carcinoma amplified sequence 3 (BCAS3) were consistently modulated.
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Benzofuranos/farmacología , Glucósidos/farmacología , Hemo-Oxigenasa 1/genética , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/genética , Proteínas de Neoplasias/genética , Oxidorreductasas actuantes sobre Donantes de Grupos Sulfuro/genética , Artocarpus/química , Muerte Celular/efectos de los fármacos , Procesos de Crecimiento Celular/efectos de los fármacos , Línea Celular Tumoral , Proteínas de Unión al ADN/genética , Relación Dosis-Respuesta a Droga , Expresión Génica/efectos de los fármacos , Perfilación de la Expresión Génica/métodos , Células HL-60 , Hemo-Oxigenasa 1/biosíntesis , Humanos , Células Jurkat , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patología , Leucemia de Células T/tratamiento farmacológico , Leucemia de Células T/genética , Leucemia de Células T/metabolismo , Leucemia de Células T/patología , Masculino , Persona de Mediana Edad , Proteínas de Neoplasias/biosíntesis , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Oxidorreductasas actuantes sobre Donantes de Grupos Sulfuro/biosíntesis , Linfocitos T/efectos de los fármacos , Factores de Transcripción/genética , Factor de Crecimiento Transformador beta/metabolismo , Células U937 , Regulación hacia Arriba/efectos de los fármacosRESUMEN
In this study, we evaluated the possible cross-talk between glucocorticoid (GC)-induced leucine zipper (Gilz) and caspase-8 in dexamethasone (Dex)-treated thymocytes. We determined that expression of Dex-induced Gilz protein was reduced when caspase-8 activity was inhibited, and this effect was not partially due to altered Gilz mRNA expression. Inhibition of the proteasome abrogated this reduction in Gilz expression, suggesting that Dex-induced caspase-8 activation protects Gilz from degradation. We hypothesized that the caspase-8-dependent protection of Gilz could be due to caspase-8-driven sumoylation. As a putative small ubiquitin-like modifier (SUMO)-binding site was identified in the Gilz sequence, we assessed whether SUMO-1 interacted with Gilz. We identified a 30-kDa protein that was compatible with the size of a Gilz-SUMO-1 complex and was recognized by the anti-SUMO-1 and anti-Gilz antibodies. In addition, Gilz bound to SUMO ubiquitin-conjugating (E2)-conjugating enzyme Ube21 (Ubc9), the specific SUMO-1 E2-conjugating enzyme, in vitro and coimmunoprecipitated with Ubc9 in vivo. Furthermore, Gilz coimmunoprecipitated with SUMO-1 both in vitro and in vivo, and this interaction depended on caspase-8 activation. This requirement for caspase-8 was further evaluated in caspase-8-deficient thymocytes and lymphocytes in which Gilz expression was reduced. In summary, our results suggest that caspase-8 activation protects Gilz from proteasomal degradation and induces its binding to SUMO-1 in GC-treated thymocytes.
Asunto(s)
Caspasa 8/metabolismo , Dexametasona/farmacología , Glucocorticoides/farmacología , Complejo de la Endopetidasa Proteasomal/metabolismo , Proteína SUMO-1/metabolismo , Glándula Tiroides/metabolismo , Factores de Transcripción/metabolismo , Secuencia de Aminoácidos , Animales , Anticuerpos/inmunología , Sitios de Unión , Caspasa 8/genética , Caspasa 8/fisiología , Células Cultivadas , Ratones , Datos de Secuencia Molecular , Unión Proteica , Sumoilación , Glándula Tiroides/citología , Factores de Transcripción/química , Factores de Transcripción/genética , Enzimas Ubiquitina-Conjugadoras/metabolismoRESUMEN
We used transgenic mice to investigate the effect of IL-2 stimulation on T lymphocyte functions of GILZ-overexpressing splenic T cells. When compared to their controls, T cells from transgenic mice underwent normal activation after stimulation with anti-CD3 plus anti-CD28 monoclonal antibodies, as evaluated by CD25 expression, CD2 up-regulation and proliferation. IL-10, IL-13 and IFN-gamma increased more consistently in CD3/CD28-triggered TG compared to WT splenic CD4(+)cells. Analysis of the CD4(+)and CD8(+)T cells demonstrated a decreased CD4(+)/CD8(+)T-cell ratio (1:1 instead of 1:2) in response to IL-2 stimulation, possibly due to an unresponsiveness of IL-2 receptor beta and/or gamma chains. Finally, the total number of T cells was significantly increased in aged mice and this was due to the augmentation of CD4(+)T cells. These results support the hypothesis that GILZ regulates, at least in part, peripheral T-cell functions by influencing their responsiveness to IL-2.
Asunto(s)
Linfocitos T CD4-Positivos/metabolismo , Linfocitos T CD8-positivos/metabolismo , Interleucina-2/metabolismo , Factores de Transcripción/metabolismo , Envejecimiento/inmunología , Animales , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Citocinas/biosíntesis , Ensayo de Inmunoadsorción Enzimática , Citometría de Flujo , Interleucina-2/inmunología , Activación de Linfocitos/fisiología , Ratones , Ratones Transgénicos , Bazo/citología , Bazo/inmunología , Factores de Transcripción/genética , Factores de Transcripción/inmunologíaRESUMEN
Cladophialophora bantiana is an uncommon fungus related to the black yeasts which causes, if untreated, mostly fatal cerebral infections in immunosuppressed and competent patients. We report a case of a patient who survived a recurrent cerebral abscess caused by C. bantiana despite delayed and apparently inappropriate therapy.
Asunto(s)
Absceso Encefálico/microbiología , Cladosporium/aislamiento & purificación , Adulto , Antifúngicos/farmacología , Antifúngicos/uso terapéutico , Absceso Encefálico/diagnóstico , Absceso Encefálico/tratamiento farmacológico , Infecciones Fúngicas del Sistema Nervioso Central/diagnóstico , Infecciones Fúngicas del Sistema Nervioso Central/tratamiento farmacológico , Cladosporium/clasificación , Humanos , MasculinoRESUMEN
The lethal effects occurring in neonatal (< 24-h old) BALB/c mice after challenge with E. coli lipopolysaccharide (LPS) were significantly counteracted by pretreatment with antibacterial peptide PR-39. Neonatal mice protection was probably related to the depressive effect of PR-39 on production of TNF-alpha known to be the major mediator of the lethal effects of neonatal endotoxic shock. Indeed, TNF-alpha plasmatic levels were consistently lower in pups pretreated with PR-39 compared with controls. Administration 24 h after challenge was no longer effective. Although PR-39 and anti-TNF-alpha doses were ineffective alone, when combined at different ratios protected neonatal mice. The present experiments show the potential use of peptide PR-39 in preventing neonatal endotoxic shock.
Asunto(s)
Péptidos Catiónicos Antimicrobianos/farmacología , Péptidos Catiónicos Antimicrobianos/uso terapéutico , Choque Séptico/prevención & control , Animales , Animales Recién Nacidos , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Modelos Animales de Enfermedad , Escherichia coli/química , Lipopolisacáridos/aislamiento & purificación , Lipopolisacáridos/toxicidad , Ratones , Ratones Endogámicos BALB C , Análisis de Supervivencia , Factor de Necrosis Tumoral alfa/análisisRESUMEN
Antigenic stimuli increase ROS that influence T-cell activation by interfering with the oxidant-antioxidant balance. Oxidative stress takes place when excess of ROS production is not counterbalanced by antioxidant mechanisms and bcl-2 gene product that inhibits apoptosis by interacting with mitochondrial superoxide dismutase. ROS Excess induces apoptosis both by activation of NF-kB-dependent genes and DNA damage. The latter has been shown to elicit the activation of poly-ADP-ribose transferase and the accumulation of p53, thus determining apoptosis. Additionally, oxidative stress may induce formation of cell membrane oxidized lipids, potent inducers of apoptosis. Oxidative stress is also involved in immune diseases. In AIDS, ROS excess and deficiency of antioxidants lead to apoptosis and virus activation. ROS produced at sites of chronic inflammation, have genotoxic effects. As a consequence, abnormalities of the p53 genes might explain the conversion from an inflammatory phase into autonomous progression of rheumatoid arthritis or other chronic inflammatory disorders.
RESUMEN
To investigate the role of MHC class I on in vitro differentiation of natural killer (NK) cells, a CD44low/-CD2-classlow population was isolated from mouse bone marrow. This population, which lacked expression of NK-1.1, Ly49A, Ly49C/I, and Ly49G, generated populations of NK-1.1+ NK cells expressing Ly49A, Ly49C/I, or Ly49G when cocultured for 13 days with syngeneic supportive stromal cells in the presence of interleukin 2. Ly49A and Ly49C/I were absent on the progeny of progenitors tested after 7 days of culture but were expressed as a late event together with low-level expression of NK-1.1, from day 8 of culture. The addition of anti-H-2b monoclonal antibody to cultures at day 0 inhibited proliferation of progenitors supported by either syngeneic, allogeneic, or H-2b-deficient stromal cells, thus suggesting that the effect was not exerted on stromal cells. Additional analyses demonstrated that class Ilow progenitors generated class I+ cells on which the anti-H-2b monoclonal antibody exerted its inhibitory effect.
Asunto(s)
Anticuerpos Monoclonales/metabolismo , Antígenos Ly , Células de la Médula Ósea/metabolismo , Células Asesinas Naturales/metabolismo , Glicoproteínas de Membrana/metabolismo , Animales , Diferenciación Celular , Células Cultivadas , Técnicas de Cocultivo , Citometría de Flujo , Genes MHC Clase I , Interleucina-2/farmacología , Lectinas Tipo C , Magnetismo , Glicoproteínas de Membrana/inmunología , Ratones , Ratones Endogámicos C3H , Ratones Endogámicos C57BL , Subfamilia A de Receptores Similares a Lectina de Células NK , Fenotipo , Receptores Similares a Lectina de Células NK , Factores de TiempoRESUMEN
To investigate the role of major histocompatibility complex class I and bone marrow stromal cells on in vitro differentiation of natural killer cells, a CD44(low/-) CD2- population was isolated from mouse bone marrow. This NK-1.1- CD3- LFA-3+ B220+ population, when stimulated with IL-2 and co-cultured with supportive syngeneic stromal cells, generated populations of NK-1.1+ Ly49A+ Ly49C/I+ CD3- mature natural killer cells. The effect of anti-H-2b monoclonal antibodies (mAbs) on this phenomenon was assayed. Pre-adhesion of anti-H-2b mAbs to the stromal cells did not exert any effect, whereas when the same mAbs were pre-adhered to progenitors, there was a inhibition of natural killer cell generation that was maximum when the mAbs were added directly to cultures. In addition, the anti-H-2b mAbs did not inhibit the IL-2-induced proliferation of mature natural killer cells. Allogeneic but not H-2b-deficient stromal cells decreased the expression of Ly-49C/I but not Ly49A, thus suggesting that stromal cell haplotypes qualitatively influence the expression of Ly49s repertoire.
Asunto(s)
Antígenos Ly , Antineoplásicos/farmacología , Antígenos H-2/inmunología , Interleucina-2/farmacología , Células Asesinas Naturales/fisiología , Glicoproteínas de Membrana/inmunología , Animales , Células de la Médula Ósea , Técnicas de Cultivo de Célula , Diferenciación Celular , División Celular , Regulación de la Expresión Génica , Lectinas Tipo C , Ratones , Ratones Endogámicos C57BL , Subfamilia A de Receptores Similares a Lectina de Células NK , Receptores Similares a Lectina de Células NK , Células del Estroma/inmunologíaAsunto(s)
Empalme Alternativo , Variación Genética , ARN Mensajero/genética , Receptores de Factor de Crecimiento Nervioso/genética , Receptores del Factor de Necrosis Tumoral/genética , Secuencia de Aminoácidos , Exones , Proteína Relacionada con TNFR Inducida por Glucocorticoide , Humanos , Intrones , Datos de Secuencia Molecular , Señales de Clasificación de Proteína/química , Receptores de Factor de Crecimiento Nervioso/química , Receptores del Factor de Necrosis Tumoral/química , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Linfocitos T/metabolismoRESUMEN
The immune T-cell compartment maintains the capability to respond to a wide variety of antigens (Ag). This whole process is regulated by lymphocyte apoptosis (programmed cell death, PCD) and involves the coordinated expression of a great number of genes including those coding for cytokines and their receptors, such as for example IL-2/IL-2R and the Fas/FasL systems and those coding for transcription factors, including the NF-kB complex, involved in T-cell activation and apoptosis in that they simultaneously activate cell suicide and an anti-death programme. This binary effect, PCD activation and inhibition, is due on one hand to GCH-induced activation of the caspases cascade and on the other to the induction of expression of a new gene that we have named GILZ. In fact, GILZ over-expression in transfected cells inhibits the sequential increase of NF-kB/DNA-binding activity, IL-2 production and IL-2R expression, and transcription of the Fas/FasL complex that follows TCR triggering and plays an important role in the control of T-lymphocyte apoptosis. These results indicate a new mechanism responsible for the GCH-mediated inhibition of T-cell death and activation that could contribute to anti-inflammatory and immunosuppressive efficacy.
Asunto(s)
Apoptosis/fisiología , Muerte Celular/fisiología , Glucocorticoides/fisiología , Animales , Humanos , Linfocitos T/fisiologíaRESUMEN
Long-term bone marrow cultures were used to investigate the effect of IL-2, a cytokine widely used in immunotherapy, on natural killer cell differentiation. Specifically, the role of MHC was evaluated by comparing normal B6 and class I-deficient TAP-1-/- mice. The number of cells generated after a 13-day culture was the same in cell cultures from TAP-1-/- or B6 mice but the relative number of natural killer cells, identified as NK-1.1+CD3- cells by flow cytometry analysis, was increased in TAP-1-/- compared to B6 cultures (74.4% and 63.9%, respectively). Addition of an anti-class I mAb determined a strong inhibition of natural killer cell generation in B6 cultures, and its effect was specific since no effect was seen in TAP-1-/- cell cultures. TAP-1-/- natural killer cells or the few natural killer cells escaping the inhibitory effect of anti-class I mAb, were less cytotoxic than total B6 natural killer cells against target cell lines of different haplotype.
Asunto(s)
Células de la Médula Ósea/efectos de los fármacos , Genes MHC Clase I , Interleucina-2/farmacología , Células Asesinas Naturales/efectos de los fármacos , Transportador de Casetes de Unión a ATP, Subfamilia B, Miembro 2 , Transportadoras de Casetes de Unión a ATP/genética , Animales , Células de la Médula Ósea/citología , Recuento de Células , Diferenciación Celular/efectos de los fármacos , Células Cultivadas , Citometría de Flujo , Células Asesinas Naturales/citología , Ratones , Ratones Endogámicos C57BL , Ratones Mutantes , Microglobulina beta-2/genéticaRESUMEN
GITR is a type I transmembrane protein that belongs to the tumor necrosis factor/nerve growth factor receptor (TNF/NGFR) family. This receptor is preferentially expressed in activated T lymphocytes and may function as signaling molecule during T-cell development. In the present study, we examined the genomic organization of the entire mouse GITR (mGITR) gene. The gene spans a 2543-bp region and consists of five exons (with a length ranging from 88 bp to 395 bp) and four introns (67 bp to 778 bp). In agreement with GITR expression in activated T cells, consensus elements for transcription factors involved in T-cell development and activation were identified in the 5' flanking region, including a consensus element for NF-kappaB. Two highly significant binding sites for MyoD and one binding site for myogenin were also found, suggesting involvement of GITR in muscle development. The mGITR gene contains 17 transcription initiation sites distributed over a 76-bp region, all used with the same frequency. We localized mGITR to the murine chromosome 4 (E region), where other 4 TNF/NGFR members localize, including m4-1BB and mOX40. These results further indicate that GITR shares several features with OX40, 4-1BB, and CD27, suggesting the existence of a new subfamily of the TNFR family, as also confirmed by the similarity of their cytoplasmic domains.
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Mapeo Cromosómico , Receptores de Factor de Crecimiento Nervioso/genética , Receptores del Factor de Necrosis Tumoral/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , ADN , Exones , Proteína Relacionada con TNFR Inducida por Glucocorticoide , Hibridación Fluorescente in Situ , Ratones , Datos de Secuencia Molecular , Regiones Promotoras Genéticas , ARN Mensajero/genética , Homología de Secuencia de Aminoácido , Transcripción GenéticaRESUMEN
The Fas/FasL system mediates apoptosis in several different cell types, including T lymphocytes. Fas ligand (FasL), a 40-kD type II membrane protein also expressed in activated T cells, belongs to the tumor necrosis factor ligand family. We describe a new alternative splicing of mouse FasL, named FasL short (FasLs), cloned by reverse transcriptase-polymerase chain reaction. FasLs is encoded by part of exon 1 and part of exon 4 of FasL gene. The protein encoded by FasLs mRNA has a putative initiation code at position 756 and preserves the same reading frame as FasL, resulting in a short molecule lacking the intracellular, the transmembrane, and part of the extracellular domains. RNase protection and immunoprecipitation analysis showed that FasLs is expressed in nonactivated normal spleen cells and in hybridoma T cells and that it is upregulated upon activation by anti-CD3 monoclonal antibody (MoAb). Moreover, FasLs-transfected cells expressed soluble FasLs in the supernatant and became resistant to apoptosis induced by agonist anti-Fas MoAb. Thus, FasLs, a new alternative splicing of FasL, is involved in the regulation of Fas/FasL-mediated cell death.
Asunto(s)
Glicoproteínas de Membrana/genética , Receptor fas/metabolismo , Empalme Alternativo , Secuencia de Aminoácidos , Animales , Apoptosis , Secuencia de Bases , Complejo CD3/inmunología , Células Cultivadas , Clonación Molecular , ADN Complementario/metabolismo , Proteína Ligando Fas , Hibridomas , Glicoproteínas de Membrana/metabolismo , Glicoproteínas de Membrana/fisiología , Ratones , Datos de Secuencia Molecular , ARN Mensajero/metabolismo , Bazo/citología , Bazo/metabolismo , Linfocitos T/patología , Linfocitos T/fisiología , Transfección , Regulación hacia Arriba , Receptor fas/genéticaRESUMEN
This study was undertaken to test the hypothesis that altered IL-10 production plays a role in the increased susceptibility of neonates to listeriosis. Plasma IL-10 levels were measured in neonatal and adult mice at various times after infection with Listeria monocytogenes. Relative to adults, neonatal mice had markedly increased IL-10 levels early in the course of infection with Listeria using a 90% lethal dose. Higher neonatal IL-10 responses were also observed after injecting adults and pups with equal doses of killed organisms. Splenic macrophages from neonates produced higher IL-10 levels than those of adults after in vitro stimulation with killed bacteria, confirming in vivo observations. Moreover, IL-10 blockade had differential effects in neonates and adults infected with live Listeria. In adult mice, anti-IL-10 Abs decreased bacterial burden early in the course of infection, but were no longer effective at 6 days or later after challenge. In the pups, however, the same treatment had beneficial effects both early and late during infection and resulted in increased survival. Collectively, our data suggest that an overproduction of IL-10 by macrophages may at least partially explain the increased susceptibility of neonates to listeriosis, and provide further evidence that cytokine production is different in adults and neonates.