389 research outputs found

    Effective targeting of DC-sign by α-fucosylamide functionalized gold nanoparticles

    Get PDF
    Dendritic Cells (DCs), the most potent antigenpresenting cells, play a critical role in the detection of invading pathogens, which are recognized also by multiple carbohydrate-specific receptors. Among them, DC-SIGN is one of the best characterized, with high-mannose and Lewis-type glycan specificity. In this study, we present a potent DC-SIGN targeting device developed using gold nanoparticles functionalized with \u3b1-fucosyl-\u3b2-alanyl amide. The nanoparticles bound to cellular DC-SIGN and induced internalization as effectively as similar particles coated with comparable amounts of LewisX oligosaccharide. They were found to be neutral toward dendritic cell maturation and IL-10 production, thus envisaging a possible use as targeted imaging tools and antigen delivery devices

    Propiedades antioxidantes y antiinflamatorias de huauzontle (Chenopodium berlandieri subsp. nuttalliae, Chenopodiaceae) fermentado por Lactiplantibacillus plantarum Lp22

    Get PDF
    Background and Aims: Huauzontle (Chenopodium berlandieri subsp. nuttalliae) is a pseudocereal native to Mexico and is part of its culinary tradition. This pseudocereal is recognized for its high nutritional value and components that are associated with beneficial health effects. However, there is currently no literature on the impact that the fermentation process would have on its bioactive properties. Therefore, the aim of this research was to evaluate the effect of fermentation by Lactiplantibacillus plantarum Lp22 in huauzontle seeds suspended in water on their antioxidant and anti-inflammatory properties in vitro. Methods: Huauzontle seeds were suspended in water (0.3%, w/v), inoculated with L. plantarum Lp22 (1%, v/v) at 108 CFU/ml, and allowed to ferment for 24 h at 37 °C. Then, seeds were recovered by filtration, grounded and aqueous extract was obtained. The antioxidant activity of the extracts was determined by the ABTS and ORAC methods. Moreover, the inhibition of the enzymes lipoxygenase (LOX) and trypsin was evaluated and the total phenolic compounds in methanolic extract (Folin-Ciocalteu method) were also determined. Key results: The antioxidant activity represented as mM of Trolox equivalents was 812.50 and 927.50 by ABTS and 1384.32 and 3391.11 for ORAC, for unfermented and fermented huauzontle, respectively (p<0.05). The inhibition of LOX activity was 40.06% and 37.24% for unfermented and fermented huauzontle, respectively, while for trypsin it was 12.53% and 14.38% (p>0.05). Besides, total phenol content was 7.49 and 20.24 mg/ml (p<0.05), respectively. Conclusions: Our findings evidence that fermentation of huauzontle improves the antioxidant and anti-inflammatory properties, which may be associated with increased phenol content. Therefore, its consumption could enhance the antioxidant and immune system of the human organism.Antecedentes y Objetivos: El huauzontle (Chenopodium berlandieri subsp. nuttalliae) es un pseudocereal nativo de México y forma parte de su tradición culinaria. Este pseudocereal es reconocido por su alto valor nutricional y componentes que se asocian a efectos benéficos a la salud. Sin embargo, al momento no se cuenta con literatura sobre el impacto que tendría el proceso de fermentación sobre sus propiedades bioactivas. Por ello, el objetivo de la presente investigación fue evaluar el efecto de la fermentación por Lactiplantibacillus plantarum Lp22, en semillas de huauzontle suspendidas en agua, sobre sus propiedades antioxidantes y antiinflamatorias in vitro. Métodos: Semillas de huauzontle se suspendieron en agua (0.3% p/v), se inocularon con L. plantarum Lp22 (1% v/v) a una concentración de 108 UFC/ml y se fermentaron por 24 h a 37 °C. Finalmente, las semillas fueron recuperadas por filtración, se molieron y del extracto acuoso se determinó la actividad antioxidante por los métodos de ABTS y ORAC. Además, se evaluó la inhibición de las enzimas lipooxigenasa (LOX) y tripsina y se determinó la concentración de fenoles totales (método de Folin-Ciocalteu) en extractos metanólicos. Resultados clave: La actividad antioxidante representada como mM de equivalentes Trolox fue de 812.50 y 927.50 por ABTS, y 1384.32 y 3391.11, para ORAC, para huauzontle no fermentado y fermentado, respectivamente (p<0.05). La inhibición de la actividad de LOX fue de 40.06% y 37.24%, y para tripsina fue de 12.53% y 14.38% (p>0.05), para no fermentado y fermentado, respectivamente, mientras que el contenido de fenoles totales fue de 7.49 y 20.24 mg/ml (p<0.05), respectivamente. Conclusiones: Estos hallazgos indican que la fermentación del huauzontle mejora las propiedades antioxidantes y antiinflamatorias, y que pueden estar asociados con el incremento en el contenido de fenoles, por lo que su consumo podría fortalecer el mecanismo antioxidante y sistema inmune del organismo humano

    Distinct antigen uptake receptors route to the same storage compartments for cross-presentation in dendritic cells

    Get PDF
    An exclusive feature of dendritic cells (DCs) is their capacity to present exogenous antigens by MHC class I molecules, called cross-presentation. Here, we show that protein antigen can be conserved in mature murine DCs for several days in a lysosome-like storage compartment, distinct from MHC class II and early endosomal compartments, as an internal source for the supply of MHC class I ligands. Using two different uptake routes via Fc gamma receptors and C-type lectin receptors, we could show that antigens were routed towards the same endolysosomal compartments after 48 h. The antigen-containing compartments lacked co-expression of molecules involved in MHC class I processing and presentation including TAP and proteasome subunits as shown by single-cell imaging flow cytometry. Moreover, we observed the absence of cathepsin S but selective co-localization of active cathepsin X with protein antigen in the storage compartments. This indicates cathepsin S-independent antigen degradation and a novel but yet undefined role for cathepsin X in antigen processing and cross-presentation by DCs. In summary, our data suggest that these antigen-containing compartments in DCs can conserve protein antigens from different uptake routes and contribute to long-lasting antigen cross-presentation.Microscopic imaging and technolog

    Open Education as a threshold concept in Teacher Education: a theoretical framework for further research

    Get PDF
    * Threshold concept framework: A threshold concept can be considered as akin to a portal, opening up a new and previously inaccessible way of thinking about something. It represents a transformed way of understanding, or interpreting, or viewing something without which the learner cannot progress. As a consequence of comprehending a threshold concept there may thus be a transformed internal view of subject matter, subject landscape, or even worldview (Meyer and Land, 2003). Threshold concepts have been explored in many disciplines (Bradbeer, 2006) and may have a key role for the transformation of the students’ learning experience (Cousin, 2006). Since open education has implications for innovation and change (Peter and Deimann, 2013), we suggest exploring it as a threshold concept. There are five main attributes defined originally by Meyer and Land (2003) and three more have also been listed stemming from comments made by the authors (UCL, 2013): transformative, troublesome, irreversible, integrative, bounded, discursive, reconstitutive and liminal. * Openness as a threshold concept: 1. Transformative Is openness transformative for students involved in open educational practices? 2. Troublesome What difficulties do students face when being involved in open educational practices? 3. Irreversible How do students’ perceptions change when being involved in open educational practices? How do these changes impact visions of their own future professional careers? 4. Liminality How can the progressive change towards the open movement be scaffolded? How can feedback help in the construction of authentic open educational practices? 5. Discursive What kind of narrative do students involved in open educational practices develop? Does it reflect authentic construction of the open movement understanding? This is the theoretical framework for future research about openness as a threshold concept. More research is needed to obtain data that would throw light on how to address each particular attribute. This is an open call to those interested in going further in this line of research

    Genome of the Avirulent Human-Infective Trypanosome—Trypanosoma rangeli

    Get PDF
    Background: Trypanosoma rangeli is a hemoflagellate protozoan parasite infecting humans and other wild and domestic mammals across Central and South America. It does not cause human disease, but it can be mistaken for the etiologic agent of Chagas disease, Trypanosoma cruzi. We have sequenced the T. rangeli genome to provide new tools for elucidating the distinct and intriguing biology of this species and the key pathways related to interaction with its arthropod and mammalian hosts.  Methodology/Principal Findings: The T. rangeli haploid genome is ,24 Mb in length, and is the smallest and least repetitive trypanosomatid genome sequenced thus far. This parasite genome has shorter subtelomeric sequences compared to those of T. cruzi and T. brucei; displays intraspecific karyotype variability and lacks minichromosomes. Of the predicted 7,613 protein coding sequences, functional annotations could be determined for 2,415, while 5,043 are hypothetical proteins, some with evidence of protein expression. 7,101 genes (93%) are shared with other trypanosomatids that infect humans. An ortholog of the dcl2 gene involved in the T. brucei RNAi pathway was found in T. rangeli, but the RNAi machinery is non-functional since the other genes in this pathway are pseudogenized. T. rangeli is highly susceptible to oxidative stress, a phenotype that may be explained by a smaller number of anti-oxidant defense enzymes and heatshock proteins.  Conclusions/Significance: Phylogenetic comparison of nuclear and mitochondrial genes indicates that T. rangeli and T. cruzi are equidistant from T. brucei. In addition to revealing new aspects of trypanosome co-evolution within the vertebrate and invertebrate hosts, comparative genomic analysis with pathogenic trypanosomatids provides valuable new information that can be further explored with the aim of developing better diagnostic tools and/or therapeutic targets

    N-glycans of Human Protein C Inhibitor: Tissue-Specific Expression and Function

    Get PDF
    Protein C inhibitor (PCI) is a serpin type of serine protease inhibitor that is found in many tissues and fluids in human, including blood plasma, seminal plasma and urine. This inhibitor displays an unusually broad protease specificity compared with other serpins. Previous studies have shown that the N-glycan(s) and the NH2-terminus affect some blood-related functions of PCI. In this study, we have for the first time determined the N-glycan profile of seminal plasma PCI, by mass spectrometry. The N-glycan structures differed markedly compared with those of both blood-derived and urinary PCI, providing evidence that the N-glycans of PCI are expressed in a tissue-specific manner. The most abundant structure (m/z 2592.9) had a composition of Fuc3Hex5HexNAc4, consistent with a core fucosylated bi-antennary glycan with terminal Lewisx. A major serine protease in semen, prostate specific antigen (PSA), was used to evaluate the effects of N-glycans and the NH2-terminus on a PCI function related to the reproductive tract. Second-order rate constants for PSA inhibition by PCI were 4.3±0.2 and 4.1±0.5 M−1s−1 for the natural full-length PCI and a form lacking six amino acids at the NH2-terminus, respectively, whereas these constants were 4.8±0.1 and 29±7 M−1s−1 for the corresponding PNGase F-treated forms. The 7–8-fold higher rate constants obtained when both the N-glycans and the NH2-terminus had been removed suggest that these structures jointly affect the rate of PSA inhibition, presumably by together hindering conformational changes of PCI required to bind to the catalytic pocket of PSA
    corecore