21 research outputs found

    The poverty of journal publishing

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    The article opens with a critical analysis of the dominant business model of for-profit, academic publishing, arguing that the extraordinarily high profits of the big publishers are dependent upon a double appropriation that exploits both academic labour and universities’ financial resources. Against this model, we outline four possible responses: the further development of open access repositories, a fair trade model of publishing regulation, a renaissance of the university presses, and, finally, a move away from private, for-profit publishing companies toward autonomous journal publishing by editorial boards and academic associations. </jats:p

    Stage-Specific Inhibition of MHC Class I Presentation by the Epstein-Barr Virus BNLF2a Protein during Virus Lytic Cycle

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    gamma-herpesvirus Epstein-Barr virus (EBV) persists for life in infected individuals despite the presence of a strong immune response. During the lytic cycle of EBV many viral proteins are expressed, potentially allowing virally infected cells to be recognized and eliminated by CD8+ T cells. We have recently identified an immune evasion protein encoded by EBV, BNLF2a, which is expressed in early phase lytic replication and inhibits peptide- and ATP-binding functions of the transporter associated with antigen processing. Ectopic expression of BNLF2a causes decreased surface MHC class I expression and inhibits the presentation of indicator antigens to CD8+ T cells. Here we sought to examine the influence of BNLF2a when expressed naturally during EBV lytic replication. We generated a BNLF2a-deleted recombinant EBV (ΔBNLF2a) and compared the ability of ΔBNLF2a and wild-type EBV-transformed B cell lines to be recognized by CD8+ T cell clones specific for EBV-encoded immediate early, early and late lytic antigens. Epitopes derived from immediate early and early expressed proteins were better recognized when presented by ΔBNLF2a transformed cells compared to wild-type virus transformants. However, recognition of late antigens by CD8+ T cells remained equally poor when presented by both wild-type and ΔBNLF2a cell targets. Analysis of BNLF2a and target protein expression kinetics showed that although BNLF2a is expressed during early phase replication, it is expressed at a time when there is an upregulation of immediate early proteins and initiation of early protein synthesis. Interestingly, BNLF2a protein expression was found to be lost by late lytic cycle yet ΔBNLF2a-transformed cells in late stage replication downregulated surface MHC class I to a similar extent as wild-type EBV-transformed cells. These data show that BNLF2a-mediated expression is stage-specific, affecting presentation of immediate early and early proteins, and that other evasion mechanisms operate later in the lytic cycle

    Varicellovirus UL49.5 Proteins Differentially Affect the Function of the Transporter Associated with Antigen Processing, TAP

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    Cytotoxic T-lymphocytes play an important role in the protection against viral infections, which they detect through the recognition of virus-derived peptides, presented in the context of MHC class I molecules at the surface of the infected cell. The transporter associated with antigen processing (TAP) plays an essential role in MHC class I–restricted antigen presentation, as TAP imports peptides into the ER, where peptide loading of MHC class I molecules takes place. In this study, the UL49.5 proteins of the varicelloviruses bovine herpesvirus 1 (BHV-1), pseudorabies virus (PRV), and equine herpesvirus 1 and 4 (EHV-1 and EHV-4) are characterized as members of a novel class of viral immune evasion proteins. These UL49.5 proteins interfere with MHC class I antigen presentation by blocking the supply of antigenic peptides through inhibition of TAP. BHV-1, PRV, and EHV-1 recombinant viruses lacking UL49.5 no longer interfere with peptide transport. Combined with the observation that the individually expressed UL49.5 proteins block TAP as well, these data indicate that UL49.5 is the viral factor that is both necessary and sufficient to abolish TAP function during productive infection by these viruses. The mechanisms through which the UL49.5 proteins of BHV-1, PRV, EHV-1, and EHV-4 block TAP exhibit surprising diversity. BHV-1 UL49.5 targets TAP for proteasomal degradation, whereas EHV-1 and EHV-4 UL49.5 interfere with the binding of ATP to TAP. In contrast, TAP stability and ATP recruitment are not affected by PRV UL49.5, although it has the capacity to arrest the peptide transporter in a translocation-incompetent state, a property shared with the BHV-1 and EHV-1 UL49.5. Taken together, these results classify the UL49.5 gene products of BHV-1, PRV, EHV-1, and EHV-4 as members of a novel family of viral immune evasion proteins, inhibiting TAP through a variety of mechanisms

    Radiotherapy for Prostate Cancer: is it ‘what you do’ or ‘the way that you do it’? A UK Perspective on Technique and Quality Assurance

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    The putative reentrant loop domain of ANO1 facilitates channel activation

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    The calcium-activated chloride channel ANO1 (TMEM16A) regulates multiple physiological processes, including fluid secretion, smooth muscle constriction and neuronal excitability. However, little is known about the processes leading to activation of the channel. Here we report the results of an unbiased approach to investigate the structure-function relationship of ANO1. By using high-throughput, random mutagenesis we generated and functionally characterized a library of ~6000 mutants of ANO1. Our data indicate a critical role of residues AA 736-742 in the regulation of the calcium sensitivity and activation of ANO1. Our newly identified Furthermore, we report mutations affecting the intracellular trafficking and localization of ANO1. Our data provides novel insight in the functional composition of the quaternary structure of ANO1 and is consistent with ANO1 forming a dimer with two independent pores. In summary, our data provides the first, unbiased and comprehensive study of the structure-function relationship of ANO1. Our newly identified mutants of ANO1 exhibiting diverse functional characteristic provide a new tool to study ANO1 function in biological systems and pave the path for a better understanding of the function of anoctamins and their role in diseases

    Specific changes in the Arabidopsis proteome in response to bacterial challenge: differentiating basal and R-gene mediated resistance

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    Alterations in the proteome of Arabidopsis thaliana leaves during early responses to challenge by Pseudomonas syringae pv. tomato DC3000 (DC3000) were analysed using two-dimensional (2D) gel electrophoresis. Protein changes characteristic of the establishment of basal resistance and R-gene mediated resistance were examined by comparing responses to DC3000, a hrp mutant and DC3000 expressing avrRpm1 respectively. The abundance of selected transcripts was also analysed in GeneChip experiments. Here we present data from the soluble fraction of leaf protein, highlighting changes in two antioxidant enzyme groups; the glutathione S-transferases (GSTs F2, F6, F7 and F8) and peroxiredoxins (PrxA, B and IIE). Members of both enzyme groups showed signs of specific post-translational modifications, represented by multiple spots on gels. We suggest that oxidation of specific residues is responsible for some of the spot shifts. All forms of the GST proteins identified here increased following inoculation with bacteria. GSTF8 showed particularly dynamic responses to pathogen challenge, the corresponding transcript was significantly up-regulated by 2 h after inoculation, and the protein showed post-translational modifications specific to an incompatible interaction. Differential changes were observed with the peroxiredoxin proteins; PrxIIE and to a lesser extent PrxB, no change was observed with PrxA, but a truncated form PrxA-L was greatly reduced in abundance following bacterial challenges. Our data suggest that bacterial challenge generally induces Prxs and the antioxidants GSTs, however individual members of these families may be specifically modified dependent upon the virulence of the DC3000 strain and outcome of the interaction. Finally, proteomic and transcriptomic data derived from the same inoculation system are compared and the advantages offered by 2D gel analysis discussed in light of our results
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