28 research outputs found

    ClgR regulation of chaperone and protease systems is essential for Mycobacterium tuberculosis parasitism of the macrophage

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    Chaperone and protease systems play essential roles in cellular homeostasis and have vital functions in controlling the abundance of specific cellular proteins involved in processes such as transcription, replication, metabolism and virulence. Bacteria have evolved accurate regulatory systems to control the expression and function of chaperones and potentially destructive proteases. Here, we have used a combination of transcriptomics, proteomics and targeted mutagenesis to reveal that the clp gene regulator (ClgR) of Mycobacterium tuberculosis activates the transcription of at least ten genes, including four that encode protease systems (ClpP1/C, ClpP2/C, PtrB and HtrA-like protease Rv1043c) and three that encode chaperones (Acr2, ClpB and the chaperonin Rv3269). Thus, M. tuberculosis ClgR controls a larger network of protein homeostatic and regulatory systems than ClgR in any other bacterium studied to date. We demonstrate that ClgR-regulated transcriptional activation of these systems is essential for M. tuberculosis to replicate in macrophages. Furthermore, we observe that this defect is manifest early in infection, as M. tuberculosis lacking ClgR is deficient in the ability to control phagosome pH 1 h post-phagocytosis

    Erratum. Blood and Islet Phenotypes Indicate Immunological Heterogeneity in Type 1 Diabetes. Diabetes 2014;63:3835–3845

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    The article to which this is the erratum is available in ORE at: http://hdl.handle.net/10871/17968In the article, there are two errors in the research design and methods section. In the section with the heading “Studies on Islet-Infiltrating Leukocytes,” the antibody listed as #M0701 should be attributed to Dako and not to Abcam and the Abcam rabbit anti-CD8 catalogue number should read #ab4055 and not #GR404-4. The online version reflects these changes

    XIV Colóquio Internacional de Psicologia e Educação - Atas

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    Realizou-se no ISPA – Instituto Universitário, o XIV Colóquio Internacional de Psicologia e Educação, subordinado ao tema geral “Educar Hoje: Diálogos entre Psicologia, Educação e Currículo”, nos dias 9 e 10 de julho de 2018 realizou-se em Lisboa. A organização do evento esteve a cabo do Departamento de Psicologia da Educação e o Centro de Investigação em Educação do ISPA-Instituto Universitário (CIE-ISPA). Foram objetivos deste Colóquio: a) promover o encontro entre profissionais da Psicologia e da Educação no âmbito da investigação e da intervenção, desde a educação de infância ao ensino superior, b) promover trocas interdisciplinares que levassem à partilha de conhecimento e à divulgação de práticas em contextos educativos, formais ou informais. Este Livro de Atas conta com contribuições de especialistas de várias partes do mundo, e explora uma variedade de temas, nomeadamente: Avaliação em Contexto Educativo, Contextos Educativos e Comportamentos, Contextos sociais e Desenvolvimento, Diversidade e Educação, Educação, Família(s) e Comunidade, Ensinar e Aprender, Interculturalidade e Educação, Literacia e Educação, Motivação e Emoções e Problemáticas do Currículo, que examinam novas sinergias, na procura do alargamento e partilha de conhecimentos e práticas. Com a divulgação deste volume espera-se disponibilizar informação que possa contribuir para um aprofundamento da reflexão das temáticas abordadas, sendo que os conteúdos apresentados são da responsabilidade dos seus autores. Agradecemos a todos aqueles que tornaram possível a realização deste Colóquio Internacional, em particular aos participantes e oradores convidados. Agradecemos ao ISPA-Instituto Universitário pelo apoio institucional bem como ao CIE-ISPA pelo suporte científico e organizativo. Agradecemos ainda a todos os colaboradores do ISPA, estudantes e professores que nos ajudaram a realizar com sucesso este evento. Com a colaboração deste leque diversificado de pessoas e estruturas, a quem renovamos o agradecimento, foi possível atingir o nosso objetivo também traduzido neste Livro de Atas A Coordenação do XIV Colóquio Internacional de Psicologia e Educaçãoinfo:eu-repo/semantics/publishedVersio

    Differential Impact of the Pinewood Nematode on Pinus Species Under Drought Conditions

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    The pinewood nematode (PWN), Bursaphelenchus xylophilus, responsible for the pine wilt disease (PWD), is a major threat to pine forests worldwide. Since forest mortality due to PWN might be exacerbated by climate, the concerns regarding PWD in the Mediterranean region are further emphasized by the projected scenarios of more drought events and higher temperatures. In this context, it is essential to better understand the pine species vulnerability to PWN under these conditions. To achieve that, physiological responses and wilting symptoms were monitored in artificially inoculated Pinus pinaster (P. pinaster), Pinus pinea (P. pinea), and Pinus radiata (P. radiata) saplings under controlled temperature (25/30°C) and water availability (watered/water stressed). The results obtained showed that the impact of PWN is species-dependent, being infected P. pinaster and P. radiata more prone to physiological and morphological damage than P. pinea. For the more susceptible species (P. pinaster and P. radiata), the presence of the nematode was the main driver of photosynthetic responses, regardless of their temperature or water regime conditions. Nevertheless, water potential was revealed to be highly affected by the synergy of PWN and the studied abiotic conditions, with higher temperatures (P. pinaster) or water limitation (P. radiata) increasing the impact of nematodes on trees' water status. Furthermore, water limitation had an influence on nematodes density and its allocation on trees' structures, with P. pinaster revealing the highest nematode abundance and inner dispersion. In inoculated P. pinea individuals, nematodes' population decreased significantly, emphasizing this species resistance to PWN. Our findings revealed a synergistic impact of PWN infection and stressful environmental conditions, particularly on the water status of P. pinaster and P. radiata, triggering disease symptoms and mortality of these species. Our results suggest that predicted drought conditions might facilitate proliferation and exacerbate the impact of PWN on these two species, through xylem cavitation, leading to strong changes in pine forests of the Mediterranean regions

    The Stress-Response Factor SigH Modulates the Interaction between Mycobacterium tuberculosis and Host Phagocytes

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    The Mycobacterium tuberculosis stress response factor SigH plays a crucial role in modulating the pathogen's response to heat, oxidative-stress, envelope damage and hypoxia. We hypothesized that the lack of this key stress response factor would alter the interaction between the pathogen and its host cells. We compared the interaction of Mtb, Mtb:Δ-sigH and a strain where the mutation had been genetically complemented (Mtb: Δ-sigH:CO) with primary rhesus macaque bone marrow derived macrophages (Rh-BMDMs). The expression of numerous inducible and homeostatic (CCL) β-chemokines and several apoptotic markers was induced to higher levels in the cells infected with Mtb:Δ-sigH, relative to Mtb or the complemented strain. The differential expression of these genes manifested into functional differences in chemotaxis and apoptosis in cells infected with these two strains. The mutant strain also exhibited reduced late-stage survival in Rh-BMDMs. We hypothesize that the product of one or more SigH-dependent genes may modulate the innate interaction of Mtb with host cells, effectively reducing the chemokine-mediated recruitment of immune effector cells, apoptosis of infected monocytes and enhancing the long-term survival and replication of the pathogen in this milieu The significantly higher induction of Prostaglandin Synthetase 2 (PTGS2 or COX2) in Rh-BMDMs infected with Mtb relative to Mtb: Δ-sigH may explain reduced apoptosis in Mtb-infected cells, as PTGS2 is known to inhibit p53-dependent apoptosis.The SigH-regulon modulates the innate interaction of Mtb with host phagocytes, perhaps as part of a strategy to limit its clearance and prolong its survival. The SigH regulon appears to be required to modulate innate immune responses directed against Mtb

    ClgR regulation of chaperone and protease systems is essential for Mycobacterium tuberculosis parasitism of the macrophage

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    Chaperone and protease systems play essential roles in cellular homeostasis and have vital functions in controlling the abundance of specific cellular proteins involved in processes such as transcription, replication, metabolism and virulence. Bacteria have evolved accurate regulatory systems to control the expression and function of chaperones and potentially destructive proteases. Here, we have used a combination of transcriptomics, proteomics and targeted mutagenesis to reveal that the clp gene regulator (ClgR) of Mycobacterium tuberculosis activates the transcription of at least ten genes, including four that encode protease systems (ClpP1/C, ClpP2/C, PtrB and HtrA-like protease Rv1043c) and three that encode chaperones (Acr2, ClpB and the chaperonin Rv3269). Thus, M. tuberculosis ClgR controls a larger network of protein homeostatic and regulatory systems than ClgR in any other bacterium studied to date. We demonstrate that ClgR-regulated transcriptional activation of these systems is essential for M. tuberculosis to replicate in macrophages. Furthermore, we observe that this defect is manifest early in infection, as M. tuberculosis lacking ClgR is deficient in the ability to control phagosome pH 1 h post-phagocytosis
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