排序方式: 共有15条查询结果,搜索用时 15 毫秒
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Adrian Egli Deanna M. Santer Daire O'Shea Khaled Barakat Mohammedyaseen Syedbasha Madeleine Vollmer Aliyah Baluch Rakesh Bhat Jody Groenendyk Michael A. Joyce Luiz F. Lisboa Brad S. Thomas Manuel Battegay Nina Khanna Thomas Mueller D. Lorne J. Tyrrell Michael Houghton Atul Humar Deepali Kumar 《PLoS pathogens》2014,10(12)
Influenza is a major cause of morbidity and mortality in immunosuppressed persons, and vaccination often confers insufficient protection. IL-28B, a member of the interferon (IFN)-λ family, has variable expression due to single nucleotide polymorphisms (SNPs). While type-I IFNs are well known to modulate adaptive immunity, the impact of IL-28B on B- and T-cell vaccine responses is unclear. Here we demonstrate that the presence of the IL-28B TG/GG genotype (rs8099917, minor-allele) was associated with increased seroconversion following influenza vaccination (OR 1.99 p = 0.038). Also, influenza A (H1N1)-stimulated T- and B-cells from minor-allele carriers showed increased IL-4 production (4-fold) and HLA-DR expression, respectively. In vitro, recombinant IL-28B increased Th1-cytokines (e.g. IFN-γ), and suppressed Th2-cytokines (e.g. IL-4, IL-5, and IL-13), H1N1-stimulated B-cell proliferation (reduced 70%), and IgG-production (reduced>70%). Since IL-28B inhibited B-cell responses, we designed antagonistic peptides to block the IL-28 receptor α-subunit (IL28RA). In vitro, these peptides significantly suppressed binding of IFN-λs to IL28RA, increased H1N1-stimulated B-cell activation and IgG-production in samples from healthy volunteers (2-fold) and from transplant patients previously unresponsive to vaccination (1.4-fold). Together, these findings identify IL-28B as a key regulator of the Th1/Th2 balance during influenza vaccination. Blockade of IL28RA offers a novel strategy to augment vaccine responses. 相似文献
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Adrian Egli Moacyr Silva Jr Daire O'Shea Leticia E. Wilson Aliyah Baluch Luiz F. Lisboa Luis G. Hidalgo Deepali Kumar Atul Humar 《PloS one》2012,7(11)
Background
CMV-specific T-cells are crucial to control CMV-replication post-transplant. Regulatory T-cells (T-regs) are associated with a tolerant immune state and may contribute to CMV-replication. However, T-cell subsets such as T-regs and IL-17 producing T-cells (Th-17) are not well studied in this context. We explored T-regs and Th-17 frequencies during CMV-replication after transplantation.Methods
We prospectively evaluated 30 transplant patients with CMV-viremia. We quantified CMV-specific CD4+ and CD8+ T-cells, T-regs (CD4+CD25+FoxP3+) and Th-17 frequencies using flow-cytometry and followed patients requiring anti-viral treatment. Two subsets were compared: anti-viral treatment requirement (n = 20) vs. spontaneous clearance of viremia (n = 10).Results
Higher initial CMV-specific CD4+ T-cells and lower T-regs were observed in patients with spontaneous clearance (p = 0.043; p = 0.021 respectively). Using a ratio of CMV-specific CD4+ T-cells to T-regs allowed prediction of viral clearance with 80% sensitivity and 90% specificity (p = 0.001). One month after stop of treatment, the same correlation was observed in patients protected from CMV-relapse. The ratio of CMV-specific CD4+ T-cells to T-regs allowed prediction of relapse with 85% sensitivity and 86% specificity (p = 0.004). Th-17 responses were not correlated with virologic outcomes.Conclusions
This study provides novel insights into T-regs and Th-17 subpopulations during CMV-replication after transplantation. These preliminary data suggest that measurement of CMV-specific CD4+ T-cells together with T-regs has value in predicting spontaneous clearance of viremia and relapse. 相似文献4.
Trouvelot S Varnier AL Allègre M Mercier L Baillieul F Arnould C Gianinazzi-Pearson V Klarzynski O Joubert JM Pugin A Daire X 《Molecular plant-microbe interactions : MPMI》2008,21(2):232-243
Sulfated laminarin (PS3) has been shown previously to be an elicitor of plant defense reactions in tobacco and Arabidopsis and to induce protection against tobacco mosaic virus. Here, we have demonstrated the efficiency of PS3 in protecting a susceptible grapevine cultivar (Vitis vinifera cv. Marselan) against downy mildew (Plasmopara viticola) under glasshouse conditions. This induced resistance was associated with potentiated H2O2 production at the infection sites, upregulation of defense-related genes, callose and phenol depositions, and hypersensitive response-like cell death. Interestingly, similar responses were observed following P. viticola inoculation in a tolerant grapevine hybrid cultivar (Solaris). A pharmacological approach led us to conclude that both callose synthesis and jasmonic acid pathway contribute to PS3-induced resistance. 相似文献
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Dr. Abdessamad Seddas Raymonde Meignoz Xavier Daire Elisabeth Boudon-Padieu Antoine Caudwell 《Current microbiology》1993,27(4):229-236
To date MLO (Mycoplasma-like organism) remain non-culturable organisms and are difficult to extract in good conditions of purity and conservation from infected hosts (plants or leafhopper vectors). An immunoaffinity procedure that permits the purification of large quantities of Grapevine Flavescence dorée MLO (FD-MLO) is described, with covalently bound and oriented IgG molecules of a previously obtained anti-FD-MLO monoclonal antibody and elution of antigens in alkaline conditions. Evidence for purity and integrity of the eluted MLO is presented. The two main antigenic components detected by rabbit polyclonal antibodies to FD-MLO were shown to be different proteins and to contain different epitopes with the use of different monoclonal antibodies. DNA extracted from the purified FD-MLO fraction hybridized with an FD-MLO DNA-specific probe. 相似文献
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Vanessa Daire Julien Giustiniani Ingrid Leroy-Gori M��lanie Quesnoit St��phanie Drevensek Ariane Dimitrov Franck Perez Christian Po��s 《The Journal of biological chemistry》2009,284(46):31992-32001
In the kinesin family, all the molecular motors that have been implicated in the regulation of microtubule dynamics have been shown to stimulate microtubule depolymerization. Here, we report that kinesin-1 (also known as conventional kinesin or KIF5B) stimulates microtubule elongation and rescues. We show that microtubule-associated kinesin-1 carries the c-Jun N-terminal kinase (JNK) to allow its activation and that microtubule elongation requires JNK activity throughout the microtubule life cycle. We also show that kinesin-1 and JNK promoted microtubule rescues to similar extents. Stimulation of microtubule rescues by the kinesin-1/JNK pathway could not be accounted for by the rescue factor CLIP-170. Indeed only a dual inhibition of kinesin-1/JNK and CLIP-170 completely blocked rescues and led to extensive microtubule loss. We propose that the kinesin-1/JNK signaling pathway is a major regulator of microtubule dynamics in living cells and that it is required with the rescue factor CLIP-170 to allow cells to build their interphase microtubule network. 相似文献
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Enhancing the diversity of breeding invertebrates within field margins of intensively managed grassland: Effects of alternative management practices
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Rochelle A. Fritch Helen Sheridan John A. Finn Stephen McCormack Daire Ó hUallacháin 《Ecology and evolution》2017,7(22):9763-9774
Severe declines in biodiversity have been well documented for many taxonomic groups due to intensification of agricultural practices. Establishment and appropriate management of arable field margins can improve the diversity and abundance of invertebrate groups; however, there is much less research on field margins within grassland systems. Three grassland field margin treatments (fencing off the existing vegetation “fenced”; fencing with rotavation and natural regeneration “rotavated” and; fencing with rotavation and seeding “seeded”) were compared to a grazed control in the adjacent intensively managed pasture. Invertebrates were sampled using emergence traps to investigate species breeding and overwintering within the margins. Using a manipulation experiment, we tested whether the removal of grazing pressure and nutrient inputs would increase the abundance and richness of breeding invertebrates within grassland field margins. We also tested whether field margin establishment treatments, with their different vegetation communities, would change the abundance and richness of breeding invertebrates in the field margins. Exclusion of grazing and nutrient inputs led to increased abundance and richness in nearly all invertebrate groups that we sampled. However, there were more complex effects of field margin establishment treatment on the abundance and richness of invertebrate taxa. Each of the three establishment treatments supported a distinct invertebrate community. The removal of grazing from grassland field margins provided a greater range of overwintering/breeding habitat for invertebrates. We demonstrate the capacity of field margin establishment to increase the abundance and richness in nearly all invertebrate groups in study plots that were located on previously more depauperate areas of intensively managed grassland. These results from grassland field margins provide evidence to support practical actions that can inform Greening (Pillar 1) and agri‐environment measures (Pillar 2) of the Common Agricultural Policy (CAP). Before implementing specific management regimes, the conservation aims of agri‐environment measures should be clarified by defining the target species or taxonomic groups. 相似文献
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Laminarin elicits defense responses in grapevine and induces protection against Botrytis cinerea and Plasmopara viticola 总被引:2,自引:0,他引:2
Aziz A Poinssot B Daire X Adrian M Bézier A Lambert B Joubert JM Pugin A 《Molecular plant-microbe interactions : MPMI》2003,16(12):1118-1128
Grapevine (Vitis vinifera L.) is susceptible to many pathogens, such as Botrytis cinerea, Plasmopara viticola, Uncinula necator, and Eutypa lata. Phytochemicals are used intensively in vineyards to limit pathogen infections, but the appearance of pesticide-resistant pathogen strains and a desire to protect the environment require that alternative strategies be found. In the present study, the beta-1,3-glucan laminarin derived from the brown algae Laminaria digitata was shown both to be an efficient elicitor of defense responses in grapevine cells and plants and to effectively reduce B. cinerea and P. viticola development on infected grapevine plants. Defense reactions elicited by laminarin in grapevine cells include calcium influx, alkalinization of the extracellular medium, an oxidative burst, activation of two mitogen-activated protein kinases, expression of 10 defense-related genes with different kinetics and intensities, increases in chitinase and beta-1,3-glucanase activities, and the production of two phytoalexins (resveratrol and epsilon-viniferin). Several of these effects were checked and confirmed in whole plants. Laminarin did not induce cell death. When applied to grapevine plants, laminarin reduced infection by B. cinerea and P. viticola by approximately 55 and 75%, respectively. Our data describing a large set of defense reactions in grapevine indicate that the activation of defense responses using elicitors could be a valuable strategy to protect plants against pathogens. 相似文献
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Allègre M Daire X Héloir MC Trouvelot S Mercier L Adrian M Pugin A 《The New phytologist》2007,173(4):832-840
In grapevine, the penetration and sporulation of Plasmopara viticola occur via stomata, suggesting functional relationships between guard cells and the pathogen. This assumption was supported by our first observation that grapevine (Vitis vinifera cv. Marselan) cuttings infected by P. viticola wilted more rapidly than healthy ones when submitted to water starvation. Here, complementary approaches measuring stomatal conductance and infrared thermographic and microscopic observations were used to investigate stomatal opening/closure in response to infection. In infected leaves, stomata remained open in darkness and during water stress, leading to increased transpiration. This deregulation was restricted to the colonized area, was not systemic and occurred before the appearance of symptoms. Cytological observations indicated that stomatal lock-open was not related to mechanical forces resulting from the presence of the pathogen in the substomatal cavity. In contrast to healthy leaves, stomatal closure in excised infected leaves could not be induced by a water deficit or abscisic acid (ABA) treatment. However, ABA induced stomatal closure in epidermal peels from infected leaves, indicating that guard cells remained functional. These data indicate that the oomycete deregulates guard cell functioning, causing significant water losses. This effect could be attributed to a nonsystemic compound, produced by the oomycete or by the infected plant, which inhibits stomatal closure or induces stomatal opening; or a reduction of the back-pressure exerted by surrounding epidermal cells. Both hypotheses are under investigation. 相似文献
10.
Audrey Dumont Emmanuel Boucrot Stéphanie Drevensek Vanessa Daire Jean‐Pierre Gorvel Christian Poüs David W. Holden Stéphane Méresse 《Traffic (Copenhagen, Denmark)》2010,11(7):899-911
In Salmonella‐infected cells, the bacterial effector SifA forms a functional complex with the eukaryotic protein SKIP (SifA and kinesin‐interacting protein). The lack of either partner has important consequences on the intracellular fate and on the virulence of this pathogen. In addition to SifA, SKIP binds the microtubule‐based motor kinesin‐1. Yet the absence of SifA or SKIP results in an unusual accumulation of kinesin‐1 on the bacterial vacuolar membrane. To understand this apparent contradiction, we investigated the interaction between SKIP and kinesin‐1 and the function of this complex. We show that the C‐terminal RUN (RPIP8, UNC‐14 and NESCA) domain of SKIP interacted specifically with the tetratricopeptide repeat (TPR) domain of the kinesin light chain. Overexpression of SKIP induced a microtubule‐ and kinesin‐1‐dependent anterograde movement of late endosomal/lysosomal compartments. In infected cells, SifA contributed to the fission of vesicles from the bacterial vacuole and the SifA/SKIP complex was required for the formation and/or the anterograde transport of kinesin‐1‐enriched vesicles. These observations reflect the role of SKIP as a linker and/or an activator for kinesin‐1. 相似文献