RESUMO
OBJECTIVES: To analyze the records of the pregnancies of 2283 Australian women with epilepsy in the Australian Register of Antiepileptic Drugs in Pregnancy database to identify neurological factors relevant to the Cesarean sections carried out in these pregnancies. RESULTS: The Cesarean section rate in Australian women overall increased by an average of 0.59% annually over 20â¯years, from 26.0% to its calculated 2020 value of 37.3%. For the operations in women with epilepsy, the corresponding figures were 0.71% annually, and 34.4% and 48.7%. The average annual rate of increase for pre-labor operations was 0.89% to a 2020 value of 39.1%, the annual rate for operations during labor showing no statistically significant change. Multivariate regression analysis identified a number of characteristics of women with epilepsy that were statistically significantly associated with an increased likelihood of Cesarean section, but of these only seizures continuing to occur in the third trimester and having chronic illness, in particular migraine, were neurological ones. In 70 migraine-affected women, the Cesarean section rate was 51.4%, compared with 39% in the remaining pregnancies (Pâ¯<â¯0.05). CONCLUSIONS: Having seizures in the final trimester of pregnancy and having chronic neurological illness, especially migraine, favored Cesarean section being carried out in Australian women with epilepsy, but did not adequately account for the increasing rates of occurrence of the operation over the past 20â¯years.
Assuntos
Epilepsia , Transtornos de Enxaqueca , Austrália/epidemiologia , Cesárea/efeitos adversos , Epilepsia/complicações , Epilepsia/epidemiologia , Feminino , Humanos , Transtornos de Enxaqueca/epidemiologia , Gravidez , ConvulsõesRESUMO
The advent of costimulation blockade provides the prospect for targeted therapy with improved graft survival in transplant patients. Perhaps the most effective costimulation blockade in experimental models is the use of reagents to block the CD40/CD154 pathway. Unfortunately, successful clinical translation of anti-CD154 therapy has not been achieved. In an attempt to develop an agent that is as effective as previous CD154 blocking antibodies but lacks the risk of thromboembolism, we evaluated the efficacy and safety of a novel anti-human CD154 domain antibody (dAb, BMS-986004). The anti-CD154 dAb effectively blocked CD40-CD154 interactions but lacked crystallizable fragment (Fc) binding activity and resultant platelet activation. In a nonhuman primate kidney transplant model, anti-CD154 dAb was safe and efficacious, significantly prolonging allograft survival without evidence of thromboembolism (Median survival time 103 days). The combination of anti-CD154 dAb and conventional immunosuppression synergized to effectively control allograft rejection (Median survival time 397 days). Furthermore, anti-CD154 dAb treatment increased the frequency of CD4+ CD25+ Foxp3+ regulatory T cells. This study demonstrates that the use of a novel anti-CD154 dAb that lacks Fc binding activity is safe without evidence of thromboembolism and is equally as potent as previous anti-CD154 agents at prolonging renal allograft survival in a nonhuman primate preclinical model.
Assuntos
Anticorpos Monoclonais/farmacologia , Ligante de CD40/imunologia , Rejeição de Enxerto/prevenção & controle , Sobrevivência de Enxerto/imunologia , Imunoglobulina G/imunologia , Transplante de Rim/efeitos adversos , Animais , Taxa de Filtração Glomerular , Rejeição de Enxerto/etiologia , Sobrevivência de Enxerto/efeitos dos fármacos , Testes de Função Renal , Primatas , Fatores de Risco , Linfócitos T Reguladores/imunologia , Imunologia de TransplantesRESUMO
The International Knockout Mouse Consortium (IKMC) developed high throughput gene trapping and gene targeting pipelines that produced mostly conditional mutations of more than 18,500 genes in C57BL/6N mouse embryonic stem (ES) cells which have been archived and are freely available to the research community as a frozen resource. From this unprecedented resource more than 6,000 mutant mouse strains have been produced by the IKMC and mostly the International Mouse Phenotyping Consortium (IMPC). In addition, a cre-driver resource was established including 250 inducible cre-driver mouse strains in a C57BL/6 background. Complementing the cre-driver resource, a collection of comprising 27 cre-driver rAAVs has also been produced. The resources can be easily accessed at the IKMC/IMPC web portal (www.mousephenotype.org). The IKMC/IMPC resource is a standardized reference library of mouse models with defined genetic backgrounds that enables the analysis of gene-disease associations in mice of different genetic makeup and should therefore have a major impact on biomedical research.
RESUMO
Mutations in the lysosomal membrane protein CLN3 cause Juvenile Neuronal Ceroid Lipofuscinosis (JNCL). Activation of the lysosomal ion channel TRPML1 has previously been shown to be beneficial in several neurodegenerative disease models. Here, we tested whether TRPML1 activation rescues disease-associated phenotypes in CLN3-deficient retinal pigment epithelial (ARPE-19 CLN3-KO) cells. ARPE-19 CLN3-KO cells accumulate LAMP1 positive organelles and show lysosomal storage of mitochondrial ATPase subunit C (SubC), globotriaosylceramide (Gb3), and glycerophosphodiesters (GPDs), whereas lysosomal bis(monoacylglycero)phosphate (BMP/LBPA) lipid levels were significantly decreased. Activation of TRPML1 reduced lysosomal storage of Gb3 and SubC but failed to restore BMP levels in CLN3-KO cells. TRPML1-mediated decrease of storage was TFEB-independent, and we identified TRPML1-mediated enhanced lysosomal exocytosis as a likely mechanism for clearing storage including GPDs. Therefore, ARPE-19 CLN3-KO cells represent a human cell model for CLN3 disease showing many of the described core lysosomal deficits, some of which can be improved using TRPML1 agonists.
Assuntos
Lisossomos , Glicoproteínas de Membrana , Chaperonas Moleculares , Lipofuscinoses Ceroides Neuronais , Epitélio Pigmentado da Retina , Canais de Potencial de Receptor Transitório , Lisossomos/metabolismo , Humanos , Epitélio Pigmentado da Retina/metabolismo , Chaperonas Moleculares/metabolismo , Chaperonas Moleculares/genética , Glicoproteínas de Membrana/metabolismo , Glicoproteínas de Membrana/genética , Lipofuscinoses Ceroides Neuronais/metabolismo , Lipofuscinoses Ceroides Neuronais/genética , Lipofuscinoses Ceroides Neuronais/patologia , Canais de Potencial de Receptor Transitório/metabolismo , Canais de Potencial de Receptor Transitório/genética , Fenótipo , Linhagem Celular , Exocitose , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Lisofosfolipídeos , MonoglicerídeosRESUMO
Several genetic diseases are triggered by nonsense mutations leading to the formation of truncated and defective proteins. Aminoglycosides have the capability to mediate a bypass of stop mutations during translation thus resulting in a rescue of protein expression. So far no attention has been directed to obesity-associated stop mutations as targets for nonsense suppression. Herein, we focus on the characterization of the melanocortin-4-receptor (MC4R) nonsense allele W16X identified in obese subjects. Cell culture assays revealed a loss-of-function of Mc4r(X16) characterized by impaired surface expression and defect signaling. The aminoglycoside G-418 restored Mc4r(X16) function in vitro demonstrating that Mc4r(X16) is susceptible to nonsense suppression. For the evaluation of nonsense suppression in vivo, we generated a Mc4r(X16) knock-in mouse line by gene targeting. Mc4r(X16) knock-in mice developed hyperphagia, impaired glucose tolerance, severe obesity and an increased body length demonstrating that this new mouse model resembles typical characteristics of Mc4r deficiency. In a first therapeutic trial, the aminoglycosides gentamicin and amikacin induced no amelioration of obesity. Further experiments with Mc4r(X16) knock-in mice will be instrumental to establish nonsense suppression for Mc4r as an obesity-associated target gene expressed in the central nervous system.
Assuntos
Códon sem Sentido , Receptor Tipo 4 de Melanocortina/genética , Receptor Tipo 4 de Melanocortina/metabolismo , Aminoglicosídeos/genética , Aminoglicosídeos/metabolismo , Animais , Composição Corporal/genética , Temperatura Corporal/genética , Peso Corporal/genética , Células COS , Linhagem Celular , Chlorocebus aethiops , Ingestão de Energia/genética , Expressão Gênica/genética , Células HEK293 , Humanos , Hipotálamo/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/genética , Obesidade/metabolismoRESUMO
BACKGROUND: Besides an improvement in quality of life, one of the major targets of rehabilitation programmes is to preserve the ability to work and to integrate the patient into working life again. Cancer in particular is often associated with a loss of employment and joblessness, frequently caused by incomplete rehabilitation. METHODS: The programme is aimed at young cancer patients aged between 18 and 40 years. In addition to medical rehabilitation, they undergo a specially developed programme which they complete in groups of no more than 5 persons. At baseline and at the end of the 3 weeks rehabilitation, tests on physical and mental capacity are conducted. During rehabilitation, different training programmes concerning mobility at work, fine motor skills and cognitive abilities are held, complemented by an intensive psycho-social training programme. Additionally, patients receive individual social counselling. RESULTS: So far, 34 patients with an average age of 31.8 years have participated in the programme, 65% of them suffering from malignant haematological diseases. The combination of a medical and a vocational rehabilitation programme was judged extremely positively by the participants, which remained the case 6 months after completion of the programme. The rehabilitation programme significantly reduced work incapacity periods: at baseline, only 6% of the participants had not experienced such periods, but after 3 and 6 months, this rate had increased to 61% and 62% respectively. This was accompanied by an increased health-related quality of life and reduced fatigue. CONCLUSION: With our pilot project we were able to show that such a programme is feasible, can be well integrated into clinical routine and is successful.
Assuntos
Avaliação da Deficiência , Neoplasias/reabilitação , Reabilitação Vocacional/psicologia , Adulto , Terapia Combinada , Fadiga/psicologia , Fadiga/reabilitação , Feminino , Seguimentos , Humanos , Masculino , Neoplasias/psicologia , Psicoterapia , Qualidade de Vida/psicologia , Adulto JovemRESUMO
The evidence-based review (EBR) process has been widely used to develop standards for medical decision-making and to explore complex clinical questions. This approach can be applied to genetic tests, such as chromosomal microarrays, in order to assist in the clinical interpretation of certain copy number variants (CNVs), particularly those that are rare, and guide array design for optimal clinical utility. To address these issues, the International Standards for Cytogenomic Arrays Consortium has established an EBR Work Group charged with building a framework to systematically assess the potential clinical relevance of CNVs throughout the genome. This group has developed a rating system enumerating the evidence supporting or refuting dosage sensitivity for individual genes and regions that considers the following criteria: number of causative mutations reported; patterns of inheritance; consistency of phenotype; evidence from large-scale case-control studies; mutational mechanisms; data from public genome variation databases; and expert consensus opinion. The system is designed to be dynamic in nature, with regions being reevaluated periodically to incorporate emerging evidence. The evidence collected will be displayed within a publically available database, and can be used in part to inform clinical laboratory CNV interpretations as well as to guide array design.
Assuntos
Variações do Número de Cópias de DNA/genética , Medicina Baseada em Evidências , Dosagem de Genes , Genoma Humano , Humanos , FenótipoRESUMO
It is notoriously difficult to grow membrane protein crystals and solve membrane protein structures. Improved detection and screening of membrane protein crystals are needed. We have shown here that second-order nonlinear optical imaging of chiral crystals based on second harmonic generation can provide sensitive and selective detection of two-dimensional protein crystalline arrays with sufficiently low background to enable crystal detection within the membranes of live cells. The method was validated using bacteriorhodopsin crystals generated in live Halobacterium halobium bacteria and confirmed by electron microscopy from the isolated crystals. Additional studies of alphavirus glycoproteins indicated the presence of localized crystalline domains associated with virus budding from mammalian cells. These results suggest that in vivo crystallization may provide a means for expediting membrane protein structure determination for proteins exhibiting propensities for two-dimensional crystal formation.
Assuntos
Bacteriorodopsinas/química , Halobacterium salinarum/química , Halobacterium salinarum/citologia , Animais , Linhagem Celular , Sobrevivência Celular , Cristalização , Halobacterium salinarum/crescimento & desenvolvimento , Fótons , Membrana Purpúrea/metabolismo , Espectrometria de FluorescênciaRESUMO
STUDY OBJECTIVES: To compare the pharmacokinetics (PK) of tobramycin in patients with cystic fibrosis (CF) before and after bilateral lung transplantation, in order to evaluate optimal dosing practices post transplant. DESIGN: Retrospective, single-center, chart review study, in which tobramycin concentrations from CF patients were used to calculate PK parameters, including elimination rate constant, half-life, volume of distribution (Vd), area under the curve (AUC), and clearance before and after lung transplantation. SETTING: Medical school-affiliated teaching hospital. PATIENTS: Eight patients with CF, who received a bilateral lung transplant from January 1, 2005 through August 1, 2009 (4 males, 4 females; mean age 26.3 years). INTERVENTIONS: None. MAIN RESULTS: Sixty-nine sets of pre- (n=52) and post transplant (n=17) tobramycin concentrations were available. PK parameters were significantly altered post transplant. Elimination rate constant decreased 38% from 0.26±0.1 to 0.16±0.1 h(-1) (P<0.001), with a related increase of 200% in half-life from 2.8±0.8 to 8.4±8.7 h (P<0.001). Clearance decreased 25% post transplant from 67.3±32.3 to 50.2±15.9 mL/min (P=0.04). No statistically significant change occurred in AUC or Vd after transplant, although a trend was seen toward increased Vd. Dosage requirements after transplantation were significantly lower, 10.7±2.5 and 7.6±1.6 mg/kg/day, pre and post transplant, respectively (P<0.001). Concentrations were also evaluated in 2 time periods: 0-3 weeks and ≥6 weeks post transplant, based on available data. Clearance and Vd ≥6 weeks post transplant did not significantly differ from pre-transplant values (P=0.28 and 0.54, respectively), suggesting that these changes may be temporary. CONCLUSIONS: The results suggest that tobramycin PK are altered in patients with CF after bilateral lung transplantation, although no clear trend was seen owing to inter-patient variability. We propose that PK parameters should be reassessed during each treatment course post transplant.
Assuntos
Antibacterianos/farmacocinética , Fibrose Cística/tratamento farmacológico , Fibrose Cística/cirurgia , Transplante de Pulmão/fisiologia , Tobramicina/farmacocinética , Adulto , Antibacterianos/administração & dosagem , Feminino , Hospitais de Ensino , Humanos , Masculino , Estudos Retrospectivos , Tobramicina/administração & dosagemRESUMO
The UCSC Genome Browser Database (GBD, http://genome.ucsc.edu) is a publicly available collection of genome assembly sequence data and integrated annotations for a large number of organisms, including extensive comparative-genomic resources. In the past year, 13 new genome assemblies have been added, including two important primate species, orangutan and marmoset, bringing the total to 46 assemblies for 24 different vertebrates and 39 assemblies for 22 different invertebrate animals. The GBD datasets may be viewed graphically with the UCSC Genome Browser, which uses a coordinate-based display system allowing users to juxtapose a wide variety of data. These data include all mRNAs from GenBank mapped to all organisms, RefSeq alignments, gene predictions, regulatory elements, gene expression data, repeats, SNPs and other variation data, as well as pairwise and multiple-genome alignments. A variety of other bioinformatics tools are also provided, including BLAT, the Table Browser, the Gene Sorter, the Proteome Browser, VisiGene and Genome Graphs.
Assuntos
Bases de Dados de Ácidos Nucleicos , Genômica , Animais , Mapeamento Cromossômico , Gráficos por Computador , Expressão Gênica , Variação Genética , Humanos , RNA Mensageiro/química , Software , Interface Usuário-ComputadorRESUMO
Interleukin 4 (IL-4) is essential for the induction of immunoglobulin E (IgE) responses in mice. Recent in vitro studies have suggested that IL-4 derived from non T helper (Th) cells, in particular from mast cells and basophils, may be essential for triggering of IL-4 expression in Th cells and may directly contribute to IgE isotype switch induction. Here, we have generated mice carrying a functional IL-4 gene only in Th cells or non-Th cells, respectively, by reconstitution of IL-4-deficient mice (IL-4T mice) with CD4+ or CD4- spleen cells from congenic wild-type animals. In mice in which only CD4+ cells are able to express IL-4, antigen-specific IgE is produced in a T cell-dependent immune response. Thus, induction of IL-4 expression in Th cells can occur in the absence of IL-4 from non-Th cells, which suggests that at least some Th cells can express IL-4 in response to another signal which has yet to be identified. No IgE is detectable, however, in mice in which only CD4- cells can express IL-4, suggesting that Th cells are the primary, if not the only source of IL-4 for initial induction of IgE synthesis.
Assuntos
Interleucina-4/biossíntese , Linfócitos T Auxiliares-Indutores/metabolismo , Linfócitos T/metabolismo , Animais , Regulação da Expressão Gênica , Imunoglobulina E/biossíntese , Interleucina-4/genética , Camundongos , Camundongos Endogâmicos C57BLRESUMO
We have examined the role of endogenously produced interleukin (IL) 4 and IL-10 in the regulation of inflammatory and immune reactions in the skin. In these experiments, irritant and contact hypersensitivity (CH) responses were elicited in mice with targeted disruptions of the IL-4 (IL-4T) or IL-10 (IL-10T) gene. Our study showed that IL-4T and wild-type (wt) mice exhibited equivalent responses to the irritant croton oil. In contrast, the response of IL-10T mice challenged with croton oil was abnormally increased. When IL-10T mice were exposed to a higher dose of irritant, irreversible tissue damage occurred. By comparison, any treatment of wt mice with croton oil resulted in far less tissue damage and resolution of inflammation. Neutralizing antibody studies demonstrated that the necrosis that occurred in IL-10T mice was due to the overproduction of tumor necrosis factor. The anti-tumor necrosis factor antibody treatment of IL-10T mice did not significantly reduce the edema or the influx of inflammatory cells, suggesting that these changes were due to the uncontrolled production of other proinflammatory cytokines. T cell-dependent immune responses were also evaluated using the contact sensitizer oxazolone. The response of IL-4T mice did not differ from wt mice. In contrast, IL-10T mice mounted an exaggerated CH response, increased in both magnitude and duration as compared with wt mice. Based on these studies, we have concluded that IL-10, but not IL-4, is a natural suppressant of irritant responses and of CH, and it limits immunopathologic damage in the skin.
Assuntos
Óleo de Cróton/toxicidade , Dermatite Alérgica de Contato/patologia , Toxidermias/patologia , Interleucina-10/fisiologia , Interleucina-4/fisiologia , Irritantes/toxicidade , Oxazolona/toxicidade , Animais , Anticorpos Monoclonais/farmacologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Citocinas/biossíntese , Dermatite Alérgica de Contato/imunologia , Toxidermias/imunologia , Edema/induzido quimicamente , Interleucina-10/genética , Interleucina-4/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Necrose , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Fator de Necrose Tumoral alfa/imunologia , Fator de Necrose Tumoral alfa/fisiologiaRESUMO
Leishmania major promastigotes were found to avoid activation of mouse bone marrow-derived macrophages (BMM0) in vitro for production of cytokines that are typically induced during infection with other intracellular pathogens. Coexposure of BMM0 to the parasite and other microbial stimuli resulted in complete inhibition of interleukin (IL) 12 (p40) mRNA induction and IL-12 release. In contrast, mRNA and protein levels for IL-1(alpha), IL-1(beta), tumor necrosis factor (TNF) alpha, and inducible NO synthase (iNOS) were only partially reduced, and signals for IL-10 and monocyte chemoattractant protein (MCP-1/JE) were enhanced. The parasite could provide a detectable trigger for TNF-alpha and iNOS in BMM0 primed with interferon (IFN) gamma, but still failed to induce IL-12. Thus IL-12 induction is selectively impaired after infection, whereas activation pathways for other monokine responses remain relatively intact. Selective and complete inhibition of IL-12(p40) induction was observed using BMM0 from either genetically susceptible or resistant mouse strains, as well as IL-10 knockout mice, and was obtained using promastigotes from cutaneous, visceral, and lipophosphoglycan-deficient strains of Leishmania. The impaired production of the major physiological inducer of IFN-gamma is suggested to underlie the relatively prolonged interval of parasite intracellular survival and replication that is typically associate with leishmanial infections, including those producing self-limiting disease.
Assuntos
Medula Óssea/imunologia , Regulação da Expressão Gênica , Interleucina-12/biossíntese , Leishmania/imunologia , Macrófagos/imunologia , Animais , Sequência de Bases , Células da Medula Óssea , Citocinas/biossíntese , Predisposição Genética para Doença , Imunidade Inata/genética , Interleucina-12/genética , Leishmania donovani/imunologia , Leishmania major/imunologia , Lipopolissacarídeos/imunologia , Ativação de Macrófagos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Mycobacterium tuberculosis/imunologia , RNA Mensageiro/análiseRESUMO
Immunoglobulin (Ig) class switching in B cells is regulated by stimuli transduced by cytokines and cell-cell contact. Among these stimuli, interleukin (IL)-4 has been considered an absolute prerequisite for class switching to IgE in the mouse. Here we report that IL-4-deficient (IL-4-/-) and wildtype mice had comparably elevated serum IgE levels during the course of a murine retrovirus-induced immunodeficiency syndrome, MAIDS. IgE switching in IL-4-/- mice was also induced by injection of anti-IgD antibody. Treatment with anti-IgD induced germline epsilon (g epsilon) transcripts with comparable efficiency in IL-4-/- mice and controls, but the levels of productive epsilon transcripts (p epsilon) were lower by a factor of 200 and serum IgE levels were lower by a factor of 300 in IL-4-/- mice as compared with controls. Induction of g epsilon after anti-IgD treatment of IL-4-/- mice was unaffected by simultaneous treatment with monoclonal antibodies to IL-4 and IL-4 receptor alpha chain. Infection of IL-4-/- mice with Nippostrongylus brasiliensis, a potent stimulus for IgE production, resulted in induction of g epsilon transcripts; however, p epsilon transcripts were barely detectable and serum IgE was not detected. These findings establish a novel IL-4-independent pathway for IgE switching in the mouse that is strongly activated in retroviral infection but weakly in nematode infection. This pathway appears to be dependent on distinct factors that separately control induction of g epsilon transcription and switch recombination to p epsilon.
Assuntos
Switching de Imunoglobulina , Imunoglobulina E/biossíntese , Interleucina-4/deficiência , Síndrome de Imunodeficiência Adquirida Murina/imunologia , Animais , Dinoprostona/biossíntese , Imunoglobulina D/imunologia , Imunoglobulina E/genética , Interferon gama/biossíntese , Interleucina-4/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , RNA Mensageiro/biossíntese , Recombinação Genética , Infecções por Strongylida/imunologiaRESUMO
Mice rendered deficient in the production of interleukin 10 (IL-10-/-) develop a chronic inflammatory bowel disease (IBD) that predominates in the colon and shares histopathological features with human IBD. Our aim was to identify which cell type(s) can mediate colitis in IL-10-/- mice. We detected an influx of immunoglobulin-positive cells into the colon and the presence of colon-reactive antibodies in the serum of IL-10-/- mice. To assess a pathogenic role for B cells, we generated a B cell-deficient (B-/-) strain of IL-10-/- mice. B-/-IL-10-/- mice acquired a severe colitis analogous to that IL-10-/- mice, implying that B cells were not the primary mediator of IBD in this model. A series of cell transfer experiments was performed to assess a pathogenic role for T cells. When IL-10-/- T cell-enriched lamina propria lymphocytes (LPL) or intraepithelial lymphocytes (IEL) were transferred into immunodeficient recombinase-activating gene (RAG)-2-/- recipients, a mild to severe colitis developed, depending on the cell number transferred. Lymphocytes recovered from the colon of transplanted RAG-2-/- mice with colitis were predominantly alpha beta TCR+CD4+, including a large proportion of CD4+CD8 alpha + cells. These cells were also CD45RB-/low and CD44+, indicative of an activated/memory population. Individual populations of CD4+CD8 alpha-, CD4+CD8 alpha + and CD4-CD8 alpha + T cells were then isolated from the lamina propria compartment of IL-10-/- mice and transferred into RAG-2-/- recipients. Only IL-10-/- CD4-expressing LPL, including both the CD4+CD8 alpha- and CD4+CD8 alpha + populations, induced colitis in recipient mice. Interferon-gamma, but little to no IL-4, was produced by CD4+CD8 alpha- and CD4+CD8 alpha + LPL recovered from the inflamed colons of RAG-2-/- recipients implicating alpha T helper cell 1 (TH1)-mediated response. We thus conclude that colitis in IL-10-/- mice is predominantly mediated by TH1-type alpha beta TCR+ T cells expressing CD4 alone, or in combination with the CD8 alpha molecule.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Colite/imunologia , Proteínas de Ligação a DNA , Doenças Inflamatórias Intestinais/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Animais , Linfócitos T CD8-Positivos/imunologia , Colo/imunologia , Citocinas/biossíntese , Imunização Passiva , Doenças Inflamatórias Intestinais/genética , Interleucina-10/deficiência , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas/fisiologia , Receptores de Antígenos de Linfócitos T alfa-beta/análise , Subpopulações de Linfócitos T/imunologiaRESUMO
Serine/threonine phosphorylation of the nonstructural protein 5 (NS5) is a conserved feature of flaviviruses, but the kinase(s) responsible and function(s) remain unknown. Mass spectrometry was used to compare the phosphorylation sites of the NS5 proteins of yellow fever virus (YFV) and dengue virus (DENV), two flaviviruses transmitted by mosquitoes. Seven DENV phosphopeptides were identified, but only one conserved phosphoacceptor site (threonine 449 in DENV) was identified in both viruses. This site is predicted to be a protein kinase G (PKG) recognition site and is a strictly conserved serine/threonine phosphoacceptor site in mosquito-borne flaviviruses. In contrast, in tick-borne flaviviruses, this residue is typically a histidine. A DENV replicon engineered to have the tick-specific histidine residue at this position is replication defective. We show that DENV NS5 purified from Escherichia coli is a substrate for PKG in vitro and facilitates the autophosphorylation of PKG as seen with cellular substrates. Phosphorylation in vitro by PKG also occurs at threonine 449. Activators and inhibitors of PKG modulate DENV replication in cell culture but not replication of the tick-borne langat virus. Collectively, these data argue that PKG mediates a conserved serine/threonine phosphorylation event specifically for flaviviruses spread by mosquitoes.
Assuntos
Chlorocebus aethiops/virologia , Proteínas Quinases Dependentes de GMP Cíclico/metabolismo , Flavivirus/química , Proteínas não Estruturais Virais/metabolismo , Animais , Vírus da Dengue , Histidina/genética , Espectrometria de Massas , Fosforilação , Serina/metabolismo , Treonina/metabolismo , Carrapatos/virologia , Replicação Viral , Vírus da Febre AmarelaRESUMO
Flavivirus assembles into an inert particle that requires proteolytic activation by furin to enable transmission to other hosts. We previously showed that immature virus undergoes a conformational change at low pH that renders it accessible to furin (I. M. Yu, W. Zhang, H. A. Holdaway, L. Li, V. A. Kostyuchenko, P. R. Chipman, R. J. Kuhn, M. G. Rossmann, and J. Chen, Science 319:1834-1837, 2008). Here we show, using cryoelectron microscopy, that the structure of immature dengue virus at pH 6.0 is essentially the same before and after the cleavage of prM. The structure shows that after cleavage, the proteolytic product pr remains associated with the virion at acidic pH, and that furin cleavage by itself does not induce any major conformational changes. We also show by liposome cofloatation experiments that pr retention prevents membrane insertion, suggesting that pr is present on the virion in the trans-Golgi network to protect the progeny virus from fusion within the host cell.
Assuntos
Vírus da Dengue/fisiologia , Furina/metabolismo , Montagem de Vírus , Internalização do Vírus , Animais , Linhagem Celular , Microscopia Crioeletrônica , Culicidae , Vírus da Dengue/ultraestrutura , Concentração de Íons de Hidrogênio , Processamento de Imagem Assistida por Computador , Modelos Biológicos , Modelos MolecularesRESUMO
The University of California, Santa Cruz, Genome Browser Database (GBD) provides integrated sequence and annotation data for a large collection of vertebrate and model organism genomes. Seventeen new assemblies have been added to the database in the past year, for a total coverage of 19 vertebrate and 21 invertebrate species as of September 2007. For each assembly, the GBD contains a collection of annotation data aligned to the genomic sequence. Highlights of this year's additions include a 28-species human-based vertebrate conservation annotation, an enhanced UCSC Genes set, and more human variation, MGC, and ENCODE data. The database is optimized for fast interactive performance with a set of web-based tools that may be used to view, manipulate, filter and download the annotation data. New toolset features include the Genome Graphs tool for displaying genome-wide data sets, session saving and sharing, better custom track management, expanded Genome Browser configuration options and a Genome Browser wiki site. The downloadable GBD data, the companion Genome Browser toolset and links to documentation and related information can be found at: http://genome.ucsc.edu/.
Assuntos
Bases de Dados de Ácidos Nucleicos , Genômica , Animais , Gráficos por Computador , Variação Genética , Humanos , Internet , Invertebrados/genética , Alinhamento de Sequência , Interface Usuário-Computador , Vertebrados/genéticaRESUMO
Mice infected with trypanosoma cruzi or stimulated with poly(inosinic.cytodylic acid) were found to possess splenic and peritoneal exudate cells with enhanced cytotoxic activity against epimastigote and trypomastigote forms of Trypanosoma cruzi. By use of specific alloantiserums it was determined that the effector cells responsible for this cytotoxic activity were typical natural killer cells.
Assuntos
Doença de Chagas/imunologia , Células Matadoras Naturais/imunologia , Trypanosoma cruzi/imunologia , Animais , Líquido Ascítico/citologia , Citotoxicidade Imunológica , Feminino , Camundongos , Camundongos Endogâmicos , Poli I-C/farmacologia , Baço/citologiaRESUMO
A method of gene targeting that allows the inducible inactivation of a target gene in mice is presented. The method uses an interferon-responsive promoter to control the expression of Cre recombinase. Here, Cre was used to delete a segment of the DNA polymerase beta gene flanked by IoxP recombinase recognition sites. Deletion was complete in liver and nearly complete in lymphocytes within a few days, whereas partial deletion was obtained in other tissues. This method can be used for the inducible inactivation of any other gene in vivo.