1,691 research outputs found
Detection of a novel intracellular microbiome hosted in arbuscular mycorrhizal fungi
No full textArbuscular mycorrhizal fungi (AMF) are important members of the plant microbiome. They are obligate biotrophs that colonize the roots of most land plants and enhance host nutrient acquisition. Many AMF themselves harbor endobacteria in their hyphae and spores. Two types of endobacteria are known in Glomeromycota: rod-shaped Gram-negative Candidatus Glomeribacter gigasporarum, CaGg, limited in distribution to members of the Gigasporaceae family, and coccoid Mollicutes-related endobacteria, Mre, widely distributed across different lineages of AMF. The goal of the present study is to investigate the patterns of distribution and coexistence of the two endosymbionts, CaGg and Mre, in spore samples of several strains of Gigaspora margarita. Based on previous observations, we hypothesized that some AMF could host populations of both endobacteria. To test this hypothesis, we performed an extensive investigation of both endosymbionts in G. margarita spores sampled from Cameroonian soils as well as in the Japanese G. margarita MAFF520054 isolate using different approaches (molecular phylotyping, electron microscopy, fluorescence in situ hybridization and quantitative real-time PCR). We found that a single AMF host can harbour both types of endobacteria, with Mre population being more abundant, variable and prone to recombination than the CaGg one. Both endosymbionts seem to retain their genetic and lifestyle peculiarities regardless of whether they colonize the host alone or together. These findings show for the first time that fungi support an intracellular bacterial microbiome, in which distinct types of endobacteria coexist in a single cell
PDZ-mediated interactions retain the epithelial GABA transporter on the basolateral surface of polarized epithelial cells
No full textThe PDZ target motifs located in the C-terminal end of many receptors and ion channels mediate protein–protein interactions by binding to specific
PDZ-containing proteins. These interactions are involved in the localization of surface proteins on specialized membrane domains of neuronal and epithelial cells. However, the molecular mechanism responsible for this PDZ protein-dependent polarized localization is still unclear. This study first demonstrated
that the epithelial g-aminobutyric acid (GABA)transporter (BGT-1) contains a PDZ target motif that mediates the interaction with the PDZ protein LIN-7 in Madin–Darby canine kidney (MDCK) cells, and then investigated the role of this interaction in
the basolateral localization of the transporter. It was found that although the transporters from which the PDZ target motif was deleted were still targeted to
the basolateral surface, they were not retained but internalized in an endosomal recycling compartment.Furthermore, an interfering BGT peptide determined
the intracellular relocation of the native transporter. These data indicate that interactions with PDZ proteins determine the polarized surface localization of target proteins by means of retention and not
targeting mechanisms. PDZ proteins may, therefore, act as a sort of membrane protein sorting machinery which, by recognizing retention signals (the PDZtarget sequences), prevents protein internalization
Optimización de la enseñanza de la ciencia matemática aplicada a la economía
No full textEl objetivo general del proyecto consiste en desarrollar estrategias metodológicas necesarias para la optimización de la enseñanza de la
ciencia matemática, buscando modelos flexibles a los cambios y utilizando la informática como herramienta. Este trabajo se fundamenta en el concepto de calidad en el ámbito de la educación y en la transmisión de procesos propios de la matemática más que en la mera transferencia de contenidos. Siendo el medio la herramienta informática, tratando de lograr la familiarización de docente y alumno con software que los asistan y que potencie el trabajo de ambos.Fil: Sillitti, Raimundo. Universidad Nacional de La Matanza; Argentina.Fil: Gimeno, Claudio Joaquín. Universidad Nacional de La Matanza; Argentina.Fil: Barreta, Jorge. Universidad Nacional de La Matanza; Argentina.Fil: Hrynkiewicz, Alberto. Universidad Nacional de La Matanza; Argentina.Fil: Kaech, Aníbal. Universidad Nacional de La Matanza; Argentina
Optimización de la enseñanza de la ciencia matemática aplicada a la economía
No full textEl objetivo general del proyecto consiste en desarrollar estrategias metodológicas necesarias para la optimización de la enseñanza de la
ciencia matemática, buscando modelos flexibles a los cambios y utilizando la informática como herramienta. Este trabajo se fundamenta en el concepto de calidad en el ámbito de la educación y en la transmisión de procesos propios de la matemática más que en la mera transferencia de contenidos. Siendo el medio la herramienta informática, tratando de lograr la familiarización de docente y alumno con software que los asistan y que potencie el trabajo de ambos.Fil: Sillitti, Raimundo. Universidad Nacional de La Matanza; Argentina.Fil: Gimeno, Claudio Joaquín. Universidad Nacional de La Matanza; Argentina.Fil: Barreta, Jorge. Universidad Nacional de La Matanza; Argentina.Fil: Hrynkiewicz, Alberto. Universidad Nacional de La Matanza; Argentina.Fil: Kaech, Aníbal. Universidad Nacional de La Matanza; Argentina
Abstract IA03: Anti-tumor T cells: You are what you eat
No full textAbstract
Activated T cells engage aerobic glycolysis and anabolic metabolism for growth, proliferation, and effector functions. In contrast, resting memory CD8 T cells depend less on high rates of glycolysis and more on fatty acid oxidation to persist, self-renew and respond to secondary infection. This talk will discuss the concept of metabolic checkpoints for immune cells in tumors, referring to the idea that the nutrients utilized by different types of T cells can affect both their energetic demands and their functionality. In particular, the metabolic state of exhausted T cells found in tumors is only recently starting to be studied. Our data in mouse models of cancer suggest that a glucose-poor, fatty acid-rich tumor microenvironment limits aerobic glycolysis, but promotes fatty acid uptake in tumor-infiltrating T cells, which suppresses tumoricidal effector functions and increases PD-1 expression. This talk will discuss recent analyses of the signaling pathways that respond to these nutrient alterations in T cells in tumors and how this may relate to new modalities of treatment in combination with checkpoint blockade.
Citation Format: Guoliang Cui, Ping-Chih Ho, Robert Amezquita, Susan M. Kaech. Anti-tumor T cells: You are what you eat. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2016 Oct 20-23; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2017;5(3 Suppl):Abstract nr IA03.</jats:p
IL-7 plays a critical role for the homeostasis of allergen-specific memory CD4 T cells in the lung and airways
No full textMemory T cells respond rapidly to repeated antigen exposure and can maintain their population for extended periods through self-renewal. These characteristics of memory T cells have mainly been studied during viral infections, whereas their existence and functions in allergic diseases have been studied incompletely. Since allergic patients can suffer repeated relapses caused by intermittent allergen exposure, we hypothesized that allergen- specific memory Th2 cells are present and the factors necessary for the maintenance of these cells are provided by the lung and airways. Using a murine model of airway inflammation, we found that allergen-specific CD4 T cells survived longer than 70 days in the lung and airways in an IL-7 dependent fashion. These T cells showing homeostatic proliferation were largely found in the mediastinal lymph node (mLN), rather than the airways; however, cells residing in the lung and airways developed recall responses successfully. We also found that CD4 T cells exhibited differential phenotypes in the mLN and in the lung. Altogether, we believe that allergen-specific memory T cells reside and function in the lung and airways, while their numbers are replenished through homeostatic turnover in the mLNs. Furthermore, we determined that IL-7 signaling is important for the homeostasis of these cells.
Immigration in science
No full textThe advance of science is dependent upon collaboration, which does not have a visa attached to it. Indeed, over 40% of all American-based Nobel Prize winners are immigrants, and data from the National Science Foundation show that 49% of postdocs and 29% of science and engineering faculty in the US are foreign-born. However, restrictive new immigration policies in the US have left many scientists deeply concerned about their future and many American-based laboratories worried about attracting the best talent. At JEM, we're celebrating immigration by sharing the experiences of immigrant and nonimmigrant scientists on our editorial board. Alexander Rudensky and Jean-Laurent Casanova give their firsthand perspective on immigrating to the US, while Jedd Wolchok, Carl Nathan, David Holtzman, Susan Kaech, Lewis Lanier, and David Tuveson reflect on how immigration has affected their laboratories
Author Correction: A portrait of the Higgs boson by the CMS experiment ten years after the discovery
No full textIn the version of this article initially published, CMS Collaboration author names, affiliations and acknowledgements were omitted and have now been included in the HTML and PDF versions of the articl
Word Stress and Phrasal Intonation in Addis Ababa Amharic
No full textAnalyses of word-level stress in Amharic have been inconsistent since early grammars of the language were written, with little consensus amongst the authors. While some claim that there is no consistent and systematic assignment of stress, others propose weight-based analyses. Data were collected from a native Amharic speaker who was presented with words and sentences in English; acoustic measurements were performed to evaluate pitch. This study presents a proposal of word-level stress in Addis Ababa Amharic based on phonetic analysis that directly contests the analyses of previous authors to varying degrees. The findings show that there is word-level stress, and that it may be predictably assigned based on the shape and category of a word. This study also proposes a model of intonational phonology of Amharic declarative phrases based on the Autosegmental-Metrical framework. The data show that although Amharic has lexical stress, it patterns with Farasani Arabic in that declarative phrases show no pitch accent; the role of stress in these phrasal contexts is suppressed. As such, in neutral focus, most words constitute an Accentual Phrase (AP), demarcated by a low tone (L) on the left edge, and a high tone (Ha) on the right edge
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