66 research outputs found
Early emergence of CD19-negative human antibody secreting cells at the plasmablast to plasma cell transition
Long-lived human plasma cells (PCs) play central roles in immunity and autoimmunity and are enriched amongst the subpopulation of CD19-negative human PCs. However, whether human CD19-negative PCs are necessarily âłagedâł cells that have gradually lost CD19 expression is not known. Assessing peripheral blood samples at steady state and during the acute response to influenza vaccination in healthy donors we identify the presence of phenotypic CD19-negative plasmablasts, the proliferative precursor state to mature PCs, and demonstrate by ELISpot that these are antibody-secreting cells (ASCs). During the acute response to influenza vaccination CD19-positive, CD19-low and CD19-negative ASCs secrete vaccine-specific antibody and show linked IGHV repertoires. To address precursor/product relationships we employ in vitro models which mimic both T-dependent and T-independent differentiation finding that the CD19-negative state can be established at the plasmablast to PC transition, that CD19-negative PCs increase as a percentage of surviving PCs in vitro, and that CD19-negative and CD19-positive PCs can be maintained independently. These data provide proof-of-principle for the view that newly generated ASCs can acquire a mature PC phenotype accompanied by loss of CD19 expression at an early stage of differentiation and that âłagingâł is not an obligate requirement for a CD19-negative state to be established
Mineral concentrations in milk from cows fed seaweed (Saccharina latissima) under different basal protein supplementation
Sixteen multiparous Holstein cows in four blocks of 4 x 4 Latin square over 4-week experimental periods were used to study the effects of seaweed (Saccharina latissima) supplement (with/without) and protein source (rapeseed meal (RSM)/wheat distiller's grain (WDG)) on milk mineral concentrations. Dietary treatments did not affect milk production and basic composition. Feeding seaweed slightly decreased milk Ca and Cu concentrations; whilst increased (by 3.3-fold) milk iodine (I) concentration, due to a higher dietary I supply. Substitution of WDG with RSM increased feed-to-milk transfer of Ca, Na, and Se and decreased that of Mg, P, Fe, and Mn; but only reduced milk Mn and I concentrations (the latter by 27 % as a potential result of increased glucosinolate intake). Seaweed supplement can improve milk I content when cows' I supply/availability is limited, but care should be taken to avoid excess milk I contents that may pose nutritional risks for young children.Peer reviewe
Molecular redox species for next-generation batteries
This Tutorial Review describes how the development of dissolved redox-active molecules is beginning to unlock the potential of three of the most promising ânext-generationâ battery technologies â lithiumâair, lithiumâsulfur and redox-flow batteries. Redox-active molecules act as mediators in lithiumâair and lithiumâsulfur batteries, shuttling charge between electrodes and substrate systems and improving cell performance. In contrast, they act as the charge-storing components in flow batteries. However, in each case the performance of the molecular species is strongly linked to their solubility, electrochemical and chemical stability, and redox potentials. Herein we describe key examples of the use of redox-active molecules in each of these battery technologies and discuss the challenges and opportunities presented by the development and use of redox-active molecules in these applications. We conclude by issuing a âcall to armsâ to our colleagues within the wider chemical community, whose synthetic, computational, and analytical skills can potentially make invaluable contributions to the development of next-generation batteries and help to unlock of world of potential energy-storage applications
Integrative annotation and knowledge discovery of kinase post-translational modifications and cancer-associated mutations through federated protein ontologies and resources.
Many bioinformatics resources with unique perspectives on the protein landscape are currently available. However, generating new knowledge from these resources requires interoperable workflows that support cross-resource queries. In this study, we employ federated queries linking information from the Protein Kinase Ontology, iPTMnet, Protein Ontology, neXtProt, and the Mouse Genome Informatics to identify key knowledge gaps in the functional coverage of the human kinome and prioritize understudied kinases, cancer variants and post-translational modifications (PTMs) for functional studies. We identify 32 functional domains enriched in cancer variants and PTMs and generate mechanistic hypotheses on overlapping variant and PTM sites by aggregating information at the residue, protein, pathway and species level from these resources. We experimentally test the hypothesis that S768 phosphorylation in the C-helix of EGFR is inhibitory by showing that oncogenic variants altering S768 phosphorylation increase basal EGFR activity. In contrast, oncogenic variants altering conserved phosphorylation sites in the \u27hydrophobic motif\u27 of PKCÎČII (S660F and S660C) are loss-of-function in that they reduce kinase activity and enhance membrane translocation. Our studies provide a framework for integrative, consistent, and reproducible annotation of the cancer kinomes. Sci Rep 2018 Apr 25; 8(1):6518
Minimal residual disease is an independent predictor for 10-year survival in CLL
Minimal residual disease (MRD) negativity, defined as <1 chronic lymphocytic leukemia (CLL) cell detectable per 10â000 leukocytes, has been shown to independently predict for clinical outcome in patients receiving combination chemoimmunotherapy in the frontline setting. However, the long-term prognostic value of MRD status in other therapeutic settings remains unclear. Here, we retrospectively analyzed, with up to 18 years follow-up, all patients at our institution who achieved at least a partial response (PR) with various therapies between 1996 and 2007, and received a bone marrow MRD assessment at the end of treatment according to the international harmonized approach. MRD negativity correlated with both progression-free survival (PFS) and overall survival (OS) independent of the type and line of treatment, as well as known prognostic factors including adverse cytogenetics. The greatest impact of achieving MRD negativity was seen in patients receiving frontline treatment, with 10-year PFS of 65% vs 10% and 10-year OS of 70% vs 30% for MRD-negative vs MRD-positive patients, respectively. Our results demonstrate the long-term benefit of achieving MRD negativity, regardless of the therapeutic setting and treatment modality, and support its use as a prognostic marker for long-term PFS and as a potential therapeutic goal in CLL
Self-similar propagation of optical pulses in fibers with positive quartic dispersion
We study the propagation of ultrashort pulses in optical fiber with gain and positive (or normal) quartic dispersion by self-similarity analysis of the modified nonlinear Schrödinger equation. We find an exact asymptotic solution, corresponding to a triangle-like, T^4/3 intensity profile, with a T^1/3 chirp, which is confirmed by numerical simulations. This solution follows different amplitude and width scaling compared to the conventional case with quadratic dispersion. We also suggest, and numerically investigate, a fiber laser consisting of components with positive quartic dispersion which emits quartic self-similar pulses
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Mineral concentrations in bovine milk from farms with contrasting grazing management
Thirty conventional and 24 organic dairy farms were divided into equal-number within system groups: high-pasture, standard-pasture and low-pasture groups. Milk samples were collected monthly for 12 consecutive months. Milk from high-pasture organic farms contained less fat and protein than standard- and low-pasture organic farms, but more lactose than low-pasture organic farms. Pasture, concentrate feeds intakes and the contribution of non-Holstein breeds were the key drivers for these changes. Milk Ca and P concentrations were lower in standard-pasture conven-tional farms than the other conventional groups. Milk from low-pasture organic farms contained less Ca than high- and standard-pasture organic farms, while high-pasture organic farms produced milk with the highest Sn concentration. Differences in mineral concentrations were driven by the contribution of non-Holstein breeds, feeding practices, and grazing activity; due to relatively low numerical differences the subsequent impact on consumersâ mineral intakes would be minor
Lysogeny with Shiga Toxin 2-Encoding Bacteriophages Represses Type III Secretion in Enterohemorrhagic Escherichia coli
Lytic or lysogenic infections by bacteriophages drive the evolution of enteric bacteria. Enterohemorrhagic Escherichia coli (EHEC) have recently emerged as a significant zoonotic infection of humans with the main serotypes carried by ruminants. Typical EHEC strains are defined by the expression of a type III secretion (T3S) system, the production of Shiga toxins (Stx) and association with specific clinical symptoms. The genes for Stx are present on lambdoid bacteriophages integrated into the E. coli genome. Phage type (PT) 21/28 is the most prevalent strain type linked with human EHEC infections in the United Kingdom and is more likely to be associated with cattle shedding high levels of the organism than PT32 strains. In this study we have demonstrated that the majority (90%) of PT 21/28 strains contain both Stx2 and Stx2c phages, irrespective of source. This is in contrast to PT 32 strains for which only a minority of strains contain both Stx2 and 2c phages (28%). PT21/28 strains had a lower median level of T3S compared to PT32 strains and so the relationship between Stx phage lysogeny and T3S was investigated. Deletion of Stx2 phages from EHEC strains increased the level of T3S whereas lysogeny decreased T3S. This regulation was confirmed in an E. coli K12 background transduced with a marked Stx2 phage followed by measurement of a T3S reporter controlled by induced levels of the LEE-encoded regulator (Ler). The presence of an integrated Stx2 phage was shown to repress Ler induction of LEE1 and this regulation involved the CII phage regulator. This repression could be relieved by ectopic expression of a cognate CI regulator. A model is proposed in which Stx2-encoding bacteriophages regulate T3S to co-ordinate epithelial cell colonisation that is promoted by Stx and secreted effector proteins
Ovine IgA-reactive proteins from Teladorsagia circumcincta infective larvae
AbstractInfection of small ruminants with Teladorsagia circumcincta has, until now, been controlled using a combination of pasture management and frequent anthelmintic treatments. Resistance to the commonly used anthelmintics has driven research into the development of a subunit vaccine, encouraged by the demonstration of development of protective immunity in sheep following exposure to this parasite. Local immune effectors in the abomasum, in particular IgA, are thought to play important roles in naturally- and experimentally-acquired immunity. L3s represent the first contact of this pathogen with the host immune system and, herein, the presence of L3 antigen-specific IgA was demonstrated in abomasal mucus from immune sheep. This antibody source was used to immunoaffinity purify and identify IgA-reactive molecules present in L3s. We identified 155 different proteins in this way, including a number of activation-associated secretory proteins, venom allergen-like-type proteins, detoxifying enzymes, galectins and a suite of other potential vaccine candidate molecules. Levels of immunoaffinity-enriched L3 antigen-specific IgA in gastric lymph from previously-infected sheep were statistically significantly higher (P=0.004) than those measured in helminth-free sheep and a statistically significant negative correlation (P=0.005, rs=â0.565) was identified between immunoaffinity-enriched L3 antigen-specific IgA levels in efferent gastric lymph and total T. circumcincta burden measured at necropsy. In addition, a statistically significant positive correlation (P=0.007, rs=0.534) was measured between immunoaffinity-enriched L3 antigen-specific IgA levels in efferent gastric lymph and the percentage of inhibited L4s enumerated at necropsy. These results indicate that the purified antigens contain components that could be strongly considered as vaccine candidates
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A horizon scan of issues affecting UK forest management within 50 years
Forests are in the spotlight: they are expected to play a pivotal role in our response to societyâs greatest challenges, such as the climate and biodiversity crises. Yet, the forests themselves, and the sector that manages them, face a range of interrelated threats and opportunities. Many of these are well understood, even if the solutions remain elusive. However, there are also emerging trends that are currently less widely appreciated. We report here the results of a horizon scan to identify developing issues likely to affect UK forest management within the next 50 years. These are issues that are presently under-recognized but have potential for significant impact across the sector and beyond. As the forest management sector naturally operates over long timescales, the importance of using good foresight is self-evident. We followed a tried-and-tested horizon scanning methodology involving a diverse Expert Panel to collate and prioritize a longlist of 180 issues. The top 15 issues identified are presented in the Graphical Abstract. The issues represent a diverse range of themes, within a spectrum of influences from environmental shocks and perturbations to changing political and socio-economic drivers, with complex emerging interactions between them. The most highly ranked issue was âCatastrophic forest ecosystem collapseâ, reflecting agreement that not only is such collapse a likely prospect but it would also have huge implications across the sector and wider society. These and many of the other issues are large scale, with far-reaching implications. We must be careful to avoid inaction through being overwhelmed, or indeed to merely focus on âeasy winsâ without considering broader ramifications. Our responses to each of the challenges and opportunities highlighted must be synergistic and coherent, involving landscape-scale planning. A more adaptive approach to forest management will be essential, encouraging continual innovation and learning. The 15 horizon scan issues presented here are a starting point on which to build further research, prompt debate and action, and develop evidence-based policy and practice. We hope that this stimulates greater recognition of how our forests and sector may need to change to be fit for the future. In some cases, these changes will need to be fundamental and momentous
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