223 research outputs found

    Nod Factors of Rhizobium leguminosarum bv. viciae and Their Fucosylated Derivatives Stimulate a Nod Factor Cleaving Activity in Pea Roots and Are Hydrolyzed In Vitro by Plant Chitinases at Different Rates

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    Nod factors (NFs) are rhizobial lipo-chitooligosaccharide signals that trigger root nodule development in legumes. Modifications of NF structures influence their biological activity and affect their degradation by plant chitinases. Nodulation of certain pea cultivars by Rhizobium leguminosarum by. viciae requires modification of NFs at the reducing end by either an O-acetyl or a fucosyl group. Fucosylated NFs were produced by an in vitro reaction with NodZ fucosyltransferase and purified. Their biological activity on pea was tested by measuring their capacity to stimulate the activity of a hydrolase that cleaves NFs, Nonmodified and fucosylated NFs displayed this activity at nano- to picomolar concentrations, while a sulfated NF from Sinorhizobium meliloti was inactive. In an additional series of experiments, the stability of non-modified and fucosylated NFs in the presence of purified tobacco chitinases was compared. The presence of the fucosyl group affected the degradation rates and the accessibility of specific cleavage sites on the chitooligosaccharide backbone. These results suggest that the fucosyl group in NFs also weakens the interaction of NFs with certain chitinases or chitinase-related proteins in pea roots.Microbial Biotechnolog

    Genome Wide Transcriptome Analysis of Dendritic Cells Identifies Genes with Altered Expression in Psoriasis

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    Activation of dendritic cells by different pathogens induces the secretion of proinflammatory mediators resulting in local inflammation. Importantly, innate immunity must be properly controlled, as its continuous activation leads to the development of chronic inflammatory diseases such as psoriasis. Lipopolysaccharide (LPS) or peptidoglycan (PGN) induced tolerance, a phenomenon of transient unresponsiveness of cells to repeated or prolonged stimulation, proved valuable model for the study of chronic inflammation. Thus, the aim of this study was the identification of the transcriptional diversity of primary human immature dendritic cells (iDCs) upon PGN induced tolerance. Using SAGESeq approach, a tag-based transcriptome sequencing method, we investigated gene expression changes of primary human iDCs upon stimulation or restimulation with Staphylococcus aureus derived PGN, a widely used TLR2 ligand. Based on the expression pattern of the altered genes, we identified non-tolerizeable and tolerizeable genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (Kegg) analysis showed marked enrichment of immune-, cell cycle- and apoptosis related genes. In parallel to the marked induction of proinflammatory mediators, negative feedback regulators of innate immunity, such as TNFAIP3, TNFAIP8, Tyro3 and Mer are markedly downregulated in tolerant cells. We also demonstrate, that the expression pattern of TNFAIP3 and TNFAIP8 is altered in both lesional, and non-lesional skin of psoriatic patients. Finally, we show that pretreatment of immature dendritic cells with anti-TNF-α inhibits the expression of IL-6 and CCL1 in tolerant iDCs and partially releases the suppression of TNFAIP8. Our findings suggest that after PGN stimulation/restimulation the host cell utilizes different mechanisms in order to maintain critical balance between inflammation and tolerance. Importantly, the transcriptome sequencing of stimulated/restimulated iDCs identified numerous genes with altered expression to date not associated with role in chronic inflammation, underlying the relevance of our in vitro model for further characterization of IFNprimed iDCs

    The Porto European Cancer Research Summit 2021

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    Key stakeholders from the cancer research continuum met in May 2021 at the European Cancer Research Summit in Porto to discuss priorities and specific action points required for the successful implementation of the European Cancer Mission and Europe's Beating Cancer Plan (EBCP). Speakers presented a unified view about the need to establish high-quality, networked infrastructures to decrease cancer incidence, increase the cure rate, improve patient's survival and quality of life, and deal with research and care inequalities across the European Union (EU). These infrastructures, featuring Comprehensive Cancer Centres (CCCs) as key components, will integrate care, prevention and research across the entire cancer continuum to support the development of personalized/precision cancer medicine in Europe. The three pillars of the recommended European infrastructures – namely translational research, clinical/prevention trials and outcomes research – were pondered at length. Speakers addressing the future needs of translational research focused on the prospects of multiomics assisted preclinical research, progress in Molecular and Digital Pathology, immunotherapy, liquid biopsy and science data. The clinical/prevention trial session presented the requirements for next-generation, multicentric trials entailing unified strategies for patient stratification, imaging, and biospecimen acquisition and storage. The third session highlighted the need for establishing outcomes research infrastructures to cover primary prevention, early detection, clinical effectiveness of innovations, health-related quality-of-life assessment, survivorship research and health economics. An important outcome of the Summit was the presentation of the Porto Declaration, which called for a collective and committed action throughout Europe to develop the cancer research infrastructures indispensable for fostering innovation and decreasing inequalities within and between member states. Moreover, the Summit guidelines will assist decision making in the context of a unique EU-wide cancer initiative that, if expertly implemented, will decrease the cancer death toll and improve the quality of life of those confronted with cancer, and this is carried out at an affordable cost.Where authors are identified as personnel of the International Agency for Research on Cancer/World Health Organization, the authors alone are responsible for the views expressed in this article and they do not necessarily represent the decisions, policy or views of the International Agency for Research on Cancer/World Health Organization. JT reports personal financial interest in form of scientific consultancy role for Array Biopharma, AstraZeneca, Avvinity, Bayer, Boehringer Ingelheim, Chugai, DaiichiSankyo, F. Hoffmann‐La Roche Ltd, Genentech Inc, HalioDX SAS, Hutchison MediPharma International, Ikena Oncology, IQVIA, Lilly, Menarini, Merck Serono, Merus, MSD, Mirati, Neophore, Novartis, Orion Biotechnology, Peptomyc, Pfizer, Pierre Fabre, Samsung Bioepis, Sanofi, Seattle Genetics, Servier, Taiho, Tessa Therapeutics and TheraMyc. And also educational collaboration with Imedex, Medscape Education, MJH Life Sciences, PeerView Institute for Medical Education and Physicians Education Resource (PER). JT also declares institutional financial interest in form of financial support for clinical trials or contracted research for Amgen Inc, Array Biopharma Inc, AstraZeneca Pharmaceuticals LP, BeiGene, Boehringer Ingelheim, Bristol Myers Squibb, Celgene, Debiopharm International SA, F. Hoffmann‐La Roche Ltd, Genentech Inc, HalioDX SAS, Hutchison MediPharma International, Janssen‐Cilag SA, MedImmune, Menarini, Merck Health KGAA, Merck Sharp & Dohme, Merus NV, Mirati, Novartis Farmacéutica SA, Pfizer, Pharma Mar, Sanofi Aventis Recherche & Développement, Servier, Taiho Pharma USA Inc, Spanish Association Against Cancer Scientific Foundation and Cancer Research UK. MB has received funding for his research projects and for educational grants to the University of Dresden by Bayer AG (2016‐2018), Merck KGaA (2014‐open) and Medipan GmbH (2014‐2018). He is on the supervisory board of HI‐STEM GmbH (Heidelberg) for the German Cancer Research Center (DKFZ, Heidelberg) and also member of the supervisory body of the Charité University Hospital, Berlin. As former chair of OncoRay (Dresden) and present CEO and Scientific Chair of the German Cancer Research Center (DKFZ, Heidelberg), he has been or is responsible for collaborations with a multitude of companies and institutions, worldwide. In this capacity, he has discussed potential projects and signed contracts for research funding and/or collaborations with industry and academia for his institute(s) and staff, including but not limited to pharmaceutical companies such as Bayer, Boehringer Ingelheim, Bosch, Roche and other companies such as Siemens, IBA, Varian, Elekta, Bruker, etc. In this role, he was/is also responsible for the commercial technology transfer activities of his institute(s), including the creation of start‐ups and licensing. This includes the DKFZ‐PSMA617 related patent portfolio [WO2015055318 (A1), ANTIGEN (PSMA)] and similar IP portfolios. MB confirms that, to the best of his knowledge, none of the above funding sources were involved in the preparation of this paper. BB has received research funding from 4D Pharma, Abbvie, Amgen, Aptitude Health, AstraZeneca, BeiGene, Blueprint Medicines, BMS, Boehringer Ingelheim, Celgene, Cergentis, Cristal Therapeutics, Daiichi‐Sankyo, Eli Lilly, GSK, Inivata, Janssen, Onxeo, OSE immunotherapeutics, Pfizer, Roche‐Genentech, Sanofi, Takeda, Tolero Pharmaceuticals. FC declares consultancy role for: Amgen, Astellas/Medivation, AstraZeneca, Celgene, Daiichi‐Sankyo, Eisai, GE Oncology, Genentech, GlaxoSmithKline, Macrogenics, Medscape, Merck‐Sharp, Merus BV, Mylan, Mundipharma, Novartis, Pfizer, Pierre‐Fabre, prIME Oncology, Roche, Sanofi, Samsung Bioepis, Seagen, Teva. SF is a consulting or advisory board member at Bayer, Illumina, Roche; has received honoraria from Amgen, Eli Lilly, PharmaMar, Roche; has received research funding from AstraZeneca, Pfizer, PharmaMar, Roche; has received sponsorship of travel or accommodation expenses by Amgen, Eli Lilly, Illumina, PharmaMar, Roche. SG owns AstraZeneca stock and is a full‐time employee of AstraZeneca. PN has had an advisory role at Bayer, MSD Oncology, has received honoraria from Bayer, Novartis and MSD Oncology, and has had travel expenses paid by Novartis. JO has been an advisory board member at Roche, Novartis, Bayer, Merck, Eisai, Astrazeneca, Pierre Fabre Medicament and Bristol‐Myers Squibb. He has also received research funding by IPO Porto, Astrazeneca, Fundação para a Ciencia e a Tecnologia (FCT) and Liga Portuguesa Contra o Cancro (LPCC). AR is an employee of European Federation of Pharmaceutical Industries and Associations, Brussels, MSD International Business GmbH, Kriens, Switzerland[CvG1], and Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ USA, who may own stock and/or hold stock options in the Company.RS serves as principal investigator of the ASCO TAPUR study. ASCO receives research grants from the following companies in support of the study: Astra‐Zeneca, Bayer, Boehringer‐Ingelheim, Bristol Myers Squibb, Genentech, Lilly, Merck, Pfizer, Seattle Genetics. Dr. Schilsky serves as a member of the managing board of Clariifi and as a consultant to Bryologyx, Cellworks Group, EQRx, and Scandion Oncology. The Netherlands Cancer Institute receives research support via EV from Roche, Astrazeneca, Eisai, Novartis, GSK, Clovis, BMS, MSD, Pfizer, Amgen, Bayer, Lilly, Janssen and Seagen. LZ is founder of everImmune, member of the board of directors of Transgene, member of the scientific advisory board of Transgene, EpiVax, Lytix Biopharma. LZ has also had research contracts with: Merus, Roche, Tusk, Kaleido, GSK, BMS, Incyte, Pileje, Innovate Pharma, and Transgene and has received honoraria by Transgene. All other authors have no conflicts of interest to declare. Regarding the design of innovative and adaptive clinical trials, two examples were illustrated: the first European multimodular, two‐part academic CCE‐endorsed Basket of Baskets (BoB) study, and the recently launched CCE Building Data Rich Clinical Trials (DART) Consortium, which is supported by EU’s Horizon 2020 research and innovation programme (Box 13 ). We are grateful for the support by Carolina Espina, International Agency for Research on Cancer; Christina von Gertten, European Academy of Cancer Sciences; Ana Augusta Silva, Portuguese Oncology Institute of Porto; and Teresa Tavares, Ministry of Science, Technology and Higher Education, Portugal for their excellent cooperation. Carmen Jeronimo, Portuguese Oncology Institute of Porto, collaborated in the presentation of Porto Comprehensive Cancer Center by Raquel Seruca

    BOLITA, an Arabidopsis AP2/ERF-like transcription factor that affects cell expansion and proliferation/differentiation pathways

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    The BOLITA (BOL) gene, an AP2/ERF transcription factor, was characterized with the help of an activation tag mutant and overexpression lines in Arabidopsis and tobacco. The leaf size of plants overexpressing BOL was smaller than wild type plants due to a reduction in both cell size and cell number. Moreover, severe overexpressors showed ectopic callus formation in roots. Accordingly, global gene expression analysis using the overexpression mutant reflected the alterations in cell proliferation, differentiation and growth through expression changes in RBR, CYCD, and TCP genes, as well as genes involved in cell expansion (i.e. expansins and the actin remodeling factor ADF5). Furthermore, the expression of hormone signaling (i.e. auxin and cytokinin), biosynthesis (i.e. ethylene and jasmonic acid) and regulatory genes was found to be perturbed in bol-D mutant leave

    Conserved CDC20 Cell Cycle Functions Are Carried out by Two of the Five Isoforms in Arabidopsis thaliana

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    The CDC20 and Cdh1/CCS52 proteins are substrate determinants and activators of the Anaphase Promoting Complex/Cyclosome (APC/C) E3 ubiquitin ligase and as such they control the mitotic cell cycle by targeting the degradation of various cell cycle regulators. In yeasts and animals the main CDC20 function is the destruction of securin and mitotic cyclins. Plants have multiple CDC20 gene copies whose functions have not been explored yet. In Arabidopsis thaliana there are five CDC20 isoforms and here we aimed at defining their contribution to cell cycle regulation, substrate selectivity and plant development.Studying the gene structure and phylogeny of plant CDC20s, the expression of the five AtCDC20 gene copies and their interactions with the APC/C subunit APC10, the CCS52 proteins, components of the mitotic checkpoint complex (MCC) and mitotic cyclin substrates, conserved CDC20 functions could be assigned for AtCDC20.1 and AtCDC20.2. The other three intron-less genes were silent and specific for Arabidopsis. We show that AtCDC20.1 and AtCDC20.2 are components of the MCC and interact with mitotic cyclins with unexpected specificity. AtCDC20.1 and AtCDC20.2 are expressed in meristems, organ primordia and AtCDC20.1 also in pollen grains and developing seeds. Knocking down both genes simultaneously by RNAi resulted in severe delay in plant development and male sterility. In these lines, the meristem size was reduced while the cell size and ploidy levels were unaffected indicating that the lower cell number and likely slowdown of the cell cycle are the cause of reduced plant growth.The intron-containing CDC20 gene copies provide conserved and redundant functions for cell cycle progression in plants and are required for meristem maintenance, plant growth and male gametophyte formation. The Arabidopsis-specific intron-less genes are possibly "retrogenes" and have hitherto undefined functions or are pseudogenes

    Endoreplication Controls Cell Fate Maintenance

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    Cell-fate specification is typically thought to precede and determine cell-cycle regulation during differentiation. Here we show that endoreplication, also known as endoreduplication, a specialized cell-cycle variant often associated with cell differentiation but also frequently occurring in malignant cells, plays a role in maintaining cell fate. For our study we have used Arabidopsis trichomes as a model system and have manipulated endoreplication levels via mutants of cell-cycle regulators and overexpression of cell-cycle inhibitors under a trichome-specific promoter. Strikingly, a reduction of endoreplication resulted in reduced trichome numbers and caused trichomes to lose their identity. Live observations of young Arabidopsis leaves revealed that dedifferentiating trichomes re-entered mitosis and were re-integrated into the epidermal pavement-cell layer, acquiring the typical characteristics of the surrounding epidermal cells. Conversely, when we promoted endoreplication in glabrous patterning mutants, trichome fate could be restored, demonstrating that endoreplication is an important determinant of cell identity. Our data lead to a new model of cell-fate control and tissue integrity during development by revealing a cell-fate quality control system at the tissue level
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