60 research outputs found

    Cross-protective immunity to Leishmania amazonensis is mediated by CD4+and CD8+epitopes of Leishmania donovani nucleoside hydrolase terminal domains

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    The nucleoside hydrolase (NH) of Leishmania donovani (NH36) is a phylogenetic marker of high homology among Leishmania parasites. in mice and dog vaccination, NH36 induces a CD4+ T cell-driven protective response against Leishmania chagasi infection directed against its C-terminal domain (F3). the C-terminal and N-terminal domain vaccines also decreased the footpad lesion caused by Leishmania amazonensis. We studied the basis of the crossed immune response using recombinant generated peptides covering the whole NH36 sequence and saponin for mice prophylaxis against L. amazonensis. the F1 (amino acids 1-103) and F3 peptide (amino acids 199-314) vaccines enhanced the IgG and IgG2a anti-NH36 antibodies to similar levels. the F3 vaccine induced the strongest DTH response, the highest proportions of NH36-specific CD4+ and CD8+ T cells after challenge and the highest expression of IFN-gamma and TNF-alpha. the F1 vaccine, on the other hand, induced a weaker but significant DTH response and a mild enhancement of IFN-gamma and TNF-alpha levels. the in vivo depletion with anti-CD4 or CD8 monoclonal antibodies disclosed that cross-protection against L. amazonensis infection was mediated by a CD4+ T cell response directed against the C-terminal domain (75% of reduction of the size of footpad lesion) followed by a CD8+T cell response against the N-terminal domain of NH36 (57% of reduction of footpad lesions). Both vaccines were capable of inducing long-term cross-immunity. the amino acid sequence of NH36 showed 93% identity to the sequence of the NH A34480 of L amazonensis, which also showed the presence of completely conserved predicted epitopes for CD4+ and CD8+ T cells in F1 domain, and of CD4+ epitopes differing by a single amino acid, in F1 and F3 domains. the identification of the C-terminal and N-terminal domains as the targets of the immune response to NH36 in the model of L. amazonensis infection represents a basis for the rationale development of a bivalent vaccine against leishmaniasis.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)Univ Fed Rio de Janeiro, Inst Microbiol Paulo Goes, Dept Microbiol Geral, Lab Biol & Bioquim Leishmania, BR-21941902 Rio de Janeiro, RJ, BrazilUniv Fed Rio de Janeiro, Inst Microbiol Paulo Goes, Lab Imunol, BR-21941902 Rio de Janeiro, RJ, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, São Paulo, BrazilUniv Fed Minas Gerais, Inst Ciencias Biol, Dept Biol Geral, Belo Horizonte, MG, BrazilUniv Fed Rio de Janeiro, Fac Med, Programa Pos Grad Clin Med, BR-21941902 Rio de Janeiro, RJ, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Ctr Terapia Celular & Mol, Dept Microbiol Imunol & Parasitol, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Ctr Terapia Celular & Mol, Dept Microbiol Imunol & Parasitol, São Paulo, BrazilCNPq: 301215-2007-3CNPq: 302039/2010-4CNPq: 559756/2010-0CNPq: 404400/2012-4FAPERJ: 102733/2008FAPERJ: 102957/2011FAPERJ: E-26/102415/2010FAPERJ: E-26/110535/2010Web of Scienc

    Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

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    In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field

    Leishmania donovani Nucleoside Hydrolase terminal domains in cross-protective immunotherapy against Leishmania amazonensis murine infection

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    Nucleoside hydrolases of the Leishmania genus are vital enzymes for the replication of the DNA and conserved phylogenetic markers of the parasites. Leishmania donovani Nucleoside hydrolase (NH36) induced a main CD4+ T cell driven protective response against Leishmania chagasi infection in mice which is directed against its C-terminal domain. In this study, we used the three recombinant domains of NH36: N-terminal domain (F1, amino acids 1-103), central domain (F2 aminoacids 104-198) and C-terminal domain (F3 amino acids 199-314) in combination with saponin and assayed their immunotherapeutic effect on Balb/c mice previously infected with L. amazonensis. We identified that the F1 and F3 peptides determined strong cross-immunotherapeutic effects, reducing the size of footpad lesions to 48% and 64%, and the parasite load in footpads to 82.6% and 81%, respectively. The F3 peptide induced the strongest anti-NH36 antibody response and intradermal response (IDR) against L. amazonenis and a high secretion of IFN-γ and TNF-α with reduced levels of IL-10. The F1 vaccine, induced similar increases of IgG2b antibodies and IFN-γ and TNF-α levels, but no IDR and no reduction of IL-10. The multiparameter flow cytometry analysis was used to assess the immune response after immunotherapy and disclosed that the degree of the immunotherapeutic effect is predicted by the frequencies of the CD4+ and CD8+ T cells producing IL-2 or TNF-α or both. Total frequencies and frequencies of double-cytokine CD4 T cell producers were enhanced by F1 and F3 vaccines. Collectively, our multifunctional analysis disclosed that immunotherapeutic protection improved as the CD4 responses progressed from 1+ to 2+, in the case of the F1 and F3 vaccines, and as the CD8 responses changed qualitatively from 1+ to 3+, mainly in the case of the F1 vaccine, providing new correlates of immunotherapeutic protection against cutaneous leishmaniasis in mice based on T-helper TH1 and CD8+ mediated immune responses

    The adjuvanticity of Chiococca alba saponins increases with the length and hydrophilicity of their sugar chains

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    The saponins of Chiococca alba are triterpene bidesmosides that contain glycidic moieties attached to the C-3 and C-28 carbon of their aglycone. We describe that their adjuvant potential increases in direct relationship to the length and hydrophilicity of the C-28 attached sugar chain which contains: arabinose-rhamnose in the CA2, arabinose-rhamnose-xylose in the CA3X; arabinose-rhamnose-apiose in the CA3 and arabinose-rhamnose-apiose-apiose in the CA4 saponin. the hydrophile/lipophile balance calculated for CA2 was 12.7, for CA3 and CA3X was 15.8 and for CA4 19.9. All saponins were formulated with the FML antigen for mice prophylaxis against visceral leishmaniasis. the immune response was studied using an ELISA-antibody assay and monitoring of the intradermal response (IDR) to Leishmania antigens, the cytokine expression in supernatants and the intracellular staining of in vitro cultured splenocytes. After challenge, significant increases of IgG and IgG2a antibodies were noted only in the CA4 vaccinated mice that showed extended IDR, higher IFN-gamma production by CD8+ and TNF-alpha production by CD4+ T cells, higher TNF-alpha secretion and the highest reduction of the parasite load (78%). the increases in IDR, CD4-TNF-alpha,CD8-IFN-gamma and CD8-TNF-alpha by the CA4 vaccine were strong correlates of protection and were significantly correlated to the decrease of parasite load (p=-0.007). Protection generated by the CA4 vaccine was mainly mediated by a CD4+ T cell and a TNF-alpha driven response with a lower contribution of CD8+ T cells, as confirmed by an in vivo depletion with monoclonal antibodies and by vaccination assays in TNF-alpha-receptor knock-out mice. Our results confirm that the superiority of the CA4 saponin is related to the higher hydrophilicity of its longer carbohydrate chain. C. alba saponins were non-toxic and only the xylose-containing saponin CA3X was hemolytic (HD50 = 87 mu g/ml). the increase in sugar units of the saponins is positively correlated to the increase of IDR and to the decrease of parasite load. (C) 2012 Elsevier B.V. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)Univ Fed Rio de Janeiro, Inst Microbiol Paulo Goes, CCS, Ilha Fundao,Dept Microbiol Geral, BR-21941902 Rio de Janeiro, BrazilUniv Fed Rio de Janeiro, Nucleo Pesquisas Prod Nat, BR-21941902 Rio de Janeiro, BrazilUFRJ, Hosp Univ Clementino Fraga Filho, Fac Med, BR-21941913 Rio de Janeiro, BrazilUniversidade Federal de São Paulo UNIFESP, Ctr Interdisciplinar Terapia Genica, BR-04044010 São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP, Ctr Interdisciplinar Terapia Genica, BR-04044010 São Paulo, BrazilCNPq: 500992/2008-8FAPERJ: E-26/110305/2007FAPERJ: E-26/110132/2007FAPERJ: E-26/100416/2007FAPERJ: E-22/102733/2008Web of Scienc

    Sleep deprivation abolishes the locomotor stimulant effect of ethanol in mice

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    The present study aimed to investigate the effects of sleep deprivation (SD) on the dose-dependent stimulant effect of ethanol (ETOH) on the open-field behavior of female and male mice. Sleep-deprived (48 h, multiple platforms method) or home-cage control female mice were treated with saline (SAL) or 1.4, 1.8 or 2.2 g/kg ETOH 5 min before behavioral testing. ETOH produced a dose-dependent increase in open-field locomotor behavior. This locomotor stimulant effect did not reflect a general stimulation in motor activity, since it was accompanied by a simultaneous decrease in rearing frequency as well as by no modification in immobility duration. the effects of ETOH on these three behavioral parameters were specifically modified by SD: the locomotor stimulant effect was abolished, the rearing inhibitory effect was potentiated and the lack of effect on immobility was changed to increase in immobility. Similar results were obtained for male mice although the effects of SD had a lower magnitude. the present findings demonstrate that the acute effect of ETOH on mice's motor activity are behaviorally complex and can be specifically modulated by SD. (c) 2006 Elsevier Inc. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundo de Auxílio ao Docente e Aluno da UNIFESP (FADA)Associação Fundo de Incentivo à Psicofarmacologia (AFIP)Universidade Federal de São Paulo, Dept Farmacol, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Psicobiol, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Farmacol, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Psicobiol, BR-04023062 São Paulo, BrazilWeb of Scienc

    Defining the scope of the European Antimicrobial Resistance Surveillance network in Veterinary medicine (EARS-Vet): a bottom-up and One Health approach

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    Background: Building the European Antimicrobial Resistance Surveillance network in Veterinary medicine (EARS-Vet) was proposed to strengthen the European One Health antimicrobial resistance (AMR) surveillance approach. Objectives: To define the combinations of animal species/production types/age categories/bacterial species/specimens/antimicrobials to be monitored in EARS-Vet. Methods: The EARS-Vet scope was defined by consensus between 26 European experts. Decisions were guided by a survey of the combinations that are relevant and feasible to monitor in diseased animals in 13 European countries (bottom-up approach). Experts also considered the One Health approach and the need for EARS-Vet to complement existing European AMR monitoring systems coordinated by the ECDC and the European Food Safety Authority (EFSA). Results: EARS-Vet plans to monitor AMR in six animal species [cattle, swine, chickens (broilers and laying hens), turkeys, cats and dogs], for 11 bacterial species (Escherichia coli, Klebsiella pneumoniae, Mannheimia haemolytica, Pasteurella multocida, Actinobacillus pleuropneumoniae, Staphylococcus aureus, Staphylococcus pseudintermedius, Staphylococcus hyicus, Streptococcus uberis, Streptococcus dysgalactiae and Streptococcus suis). Relevant antimicrobials for their treatment were selected (e.g. tetracyclines) and complemented with antimicrobials of more specific public health interest (e.g. carbapenems). Molecular data detecting the presence of ESBLs, AmpC cephalosporinases and methicillin resistance shall be collected too. Conclusions: A preliminary EARS-Vet scope was defined, with the potential to fill important AMR monitoring gaps in the animal sector in Europe. It should be reviewed and expanded as the epidemiology of AMR changes, more countries participate and national monitoring capacities improve

    NEOTROPICAL CARNIVORES: a data set on carnivore distribution in the Neotropics

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    Mammalian carnivores are considered a key group in maintaining ecological health and can indicate potential ecological integrity in landscapes where they occur. Carnivores also hold high conservation value and their habitat requirements can guide management and conservation plans. The order Carnivora has 84 species from 8 families in the Neotropical region: Canidae; Felidae; Mephitidae; Mustelidae; Otariidae; Phocidae; Procyonidae; and Ursidae. Herein, we include published and unpublished data on native terrestrial Neotropical carnivores (Canidae; Felidae; Mephitidae; Mustelidae; Procyonidae; and Ursidae). NEOTROPICAL CARNIVORES is a publicly available data set that includes 99,605 data entries from 35,511 unique georeferenced coordinates. Detection/non-detection and quantitative data were obtained from 1818 to 2018 by researchers, governmental agencies, non-governmental organizations, and private consultants. Data were collected using several methods including camera trapping, museum collections, roadkill, line transect, and opportunistic records. Literature (peer-reviewed and grey literature) from Portuguese, Spanish and English were incorporated in this compilation. Most of the data set consists of detection data entries (n = 79,343; 79.7%) but also includes non-detection data (n = 20,262; 20.3%). Of those, 43.3% also include count data (n = 43,151). The information available in NEOTROPICAL CARNIVORES will contribute to macroecological, ecological, and conservation questions in multiple spatio-temporal perspectives. As carnivores play key roles in trophic interactions, a better understanding of their distribution and habitat requirements are essential to establish conservation management plans and safeguard the future ecological health of Neotropical ecosystems. Our data paper, combined with other large-scale data sets, has great potential to clarify species distribution and related ecological processes within the Neotropics. There are no copyright restrictions and no restriction for using data from this data paper, as long as the data paper is cited as the source of the information used. We also request that users inform us of how they intend to use the data

    The DUNE Far Detector Vertical Drift Technology, Technical Design Report

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    International audienceDUNE is an international experiment dedicated to addressing some of the questions at the forefront of particle physics and astrophysics, including the mystifying preponderance of matter over antimatter in the early universe. The dual-site experiment will employ an intense neutrino beam focused on a near and a far detector as it aims to determine the neutrino mass hierarchy and to make high-precision measurements of the PMNS matrix parameters, including the CP-violating phase. It will also stand ready to observe supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector implements liquid argon time-projection chamber (LArTPC) technology, and combines the many tens-of-kiloton fiducial mass necessary for rare event searches with the sub-centimeter spatial resolution required to image those events with high precision. The addition of a photon detection system enhances physics capabilities for all DUNE physics drivers and opens prospects for further physics explorations. Given its size, the far detector will be implemented as a set of modules, with LArTPC designs that differ from one another as newer technologies arise. In the vertical drift LArTPC design, a horizontal cathode bisects the detector, creating two stacked drift volumes in which ionization charges drift towards anodes at either the top or bottom. The anodes are composed of perforated PCB layers with conductive strips, enabling reconstruction in 3D. Light-trap-style photon detection modules are placed both on the cryostat's side walls and on the central cathode where they are optically powered. This Technical Design Report describes in detail the technical implementations of each subsystem of this LArTPC that, together with the other far detector modules and the near detector, will enable DUNE to achieve its physics goals
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