299 research outputs found

    Stalking influenza by vaccination with pre-fusion headless HA mini-stem.

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    Inaccuracies in prediction of circulating viral strain genotypes and the possibility of novel reassortants causing a pandemic outbreak necessitate the development of an anti-influenza vaccine with increased breadth of protection and potential for rapid production and deployment. The hemagglutinin (HA) stem is a promising target for universal influenza vaccine as stem-specific antibodies have the potential to be broadly cross-reactive towards different HA subtypes. Here, we report the design of a bacterially expressed polypeptide that mimics a H5 HA stem by protein minimization to focus the antibody response towards the HA stem. The HA mini-stem folds as a trimer mimicking the HA prefusion conformation. It is resistant to thermal/chemical stress, and it binds to conformation-specific, HA stem-directed broadly neutralizing antibodies with high affinity. Mice vaccinated with the group 1 HA mini-stems are protected from morbidity and mortality against lethal challenge by both group 1 (H5 and H1) and group 2 (H3) influenza viruses, the first report of cross-group protection. Passive transfer of immune serum demonstrates the protection is mediated by stem-specific antibodies. Furthermore, antibodies indudced by these HA stems have broad HA reactivity, yet they do not have antibody-dependent enhancement activity

    National protest agenda and the dimensionality of party politics: Evidence from four East-Central European democracies

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    Contemporary democracies show considerable differences in the issue composition of their protest politics, which tends to remain relatively stable over time. In countries like Germany or the Czech Republic, the vast majority of protests have been mobilised around sociocultural issues, such as human rights, peace, nuclear power or the environment, and only a tiny portion of protest has focused on economic issues. At the opposite extreme, protest in France or Poland usually has a strongly economic character and voices demands relating to material redistribution and social policy. What lies behind the cross-country differences in national protest agendas? In this article, the national protest agenda depends on what issues mainstream political parties are contesting: the content and strength of the master-issue dimension. In reference to the literature on the multidimensional political space and niche political parties, one should expect that there is a substitutive effect; where the stronger a specific master-issue dimension is in party politics, the less salient that issue dimension is in protest politics. This substitutive effect results from the tendency of electoral politics to reduce political conflict to a single-dimension equilibrium, which decreases the importance of other issues and relegates the contest over secondary, niche issues to the realm of policy-seeking strategies, with protest being a common type of this political strategy. In party systems where single-dimension equilibrium does not exist and the master-issue dimension is weaker, the same dynamics result in a more convergent relationship between party and protest politics and a greater similarity between the protest- and party-system agendas. To investigate this theory, the national protest agendas in four countries are examined. The Czech Republic, Hungary, Poland and Slovakia show four combinations of two crucial factors that are not available in the old Western democracies: the content and the strength of the master-issue dimension. The study draws on an original dataset of protest events organised in the four countries between 1993 and 2010, and on qualitative and quantitative data on issue dimensions of party politics obtained from studies on party politics and expert surveys. The results show that in the Czech Republic, where the master-issue dimension has remained strongly economic, protest has been predominantly sociocultural. In Poland between 1993 and 2001 and Hungary between 1993 and 2006, the master-issue dimensions are strongly sociocultural, while protest is predominantly economic. There is no single-dimension equilibrium in party politics in Slovakia or in post-2001 Poland and mainstream parties compete on both economic and sociocultural issues. Consequently, the substitutive dynamics between party and protest politics is weaker and the issue agendas in party and protest arenas are here more alike. <br/

    A pals-25 gain-of-function allele triggers systemic resistance against natural pathogens of C. elegans

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    Regulation of immunity throughout an organism is critical for host defense. Previous studies in the nematode Caenorhabditis elegans have described an “ON/OFF” immune switch comprised of the antagonistic paralogs PALS-25 and PALS-22, which regulate resistance against intestinal and epidermal pathogens. Here, we identify and characterize a PALS-25 gain-of-function mutant protein with a premature stop (Q293*), which we find is freed from physical repression by its negative regulator, the PALS-22 protein. PALS-25(Q293*) activates two related gene expression programs, the Oomycete Recognition Response (ORR) against natural pathogens of the epidermis, and the Intracellular Pathogen Response (IPR) against natural intracellular pathogens of the intestine. A subset of ORR/IPR genes is upregulated in pals-25(Q293*) mutants, and they are resistant to oomycete infection in the epidermis, and microsporidia and virus infection in the intestine, but without compromising growth. Surprisingly, we find that activation of PALS-25 seems to primarily stimulate the downstream bZIP transcription factor ZIP-1 in the epidermis, with upregulation of gene expression in both the epidermis and in the intestine. Interestingly, we find that PALS-22/25-regulated epidermal-to-intestinal signaling promotes resistance to the N. parisii intestinal pathogen, demonstrating cross-tissue protective immune induction from one epithelial tissue to another in C. elegans

    Between Apprehension and Support: Social Dialogue, Democracy, and Industrial Restructuring in Central and Eastern Europe

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    This article explores the attitudes of trade union organizations to restructuring and privatization of their enterprises to strategic foreign investors in Central and Eastern Europe\u27s biggest steel producers: Poland, Czech Republic, Romania, and Slovakia. Contrary to advocates of insulating technocratic decision-makers from social partners, this article argues that higher quality of democracy and concomitant social dialogue carried out at the level of the sector with union organizations that are autonomous of the government in power (as was the case in the Czech Republic and Poland), are associated with greater restructuring and with support for privatization to strategic foreign investors. In these circumstances, the unions actually pressure reluctant governments to accelerate the privatization process. By contrast, politically motivated capture of individual enterprise-level unions and splitting them from sectoral-level organizations, as occurred in countries with lower quality of democracy (Romania and Slovakia), weakens the autonomous sectoral-level organizations, which are generally supportive of restructuring. Conversely, captured unions remain far more resistant to reform than their counterparts belonging to autonomous sectoral organizations. Thus, higher quality of democracy and concomitant vibrant social dialogue safeguard industrial restructuring

    Resveratrol-Based Nanoformulations as an Emerging Therapeutic Strategy for Cancer

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    Resveratrol is a polyphenolic stilbene derivative widely present in grapes and red wine. Broadly known for its antioxidant effects, numerous studies have also indicated that it exerts anti-inflammatory and antiaging abilities and a great potential in cancer therapy. Regrettably, the oral administration of resveratrol has pharmacokinetic and physicochemical limitations such as hampering its effects so that effective administration methods are demanding to ensure its efficiency. Thus, the present review explores the published data on the application of resveratrol nanoformulations in cancer therapy, with the use of different types of nanodelivery systems. Mechanisms of action with a potential use in cancer therapy, negative effects, and the influence of resveratrol nanoformulations in different types of cancer are also highlighted. Finally, the toxicological features of nanoresveratrol are also discussed.CR would like to acknowledge the UID/EQU/00511/2020 Project—Laboratory of Process Engineering, Environment, Biotechnology and Energy (LEPABE), financed by national funds through FCT/MCTES (PIDDAC). NC-M acknowledges the Portuguese Foundation for Science and Technology under the Horizon 2020 Program (PTDC/PSI-GER/28076/2017). Some of the components of the illustrations are taken from freepik and flaticon

    Cross-Neutralizing Antibodies to Pandemic 2009 H1N1 and Recent Seasonal H1N1 Influenza A Strains Influenced by a Mutation in Hemagglutinin Subunit 2

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    Pandemic 2009 H1N1 influenza A virus (2009 H1N1) differs from H1N1 strains that circulated in the past 50 years, but resembles the A/New Jersey/1976 H1N1 strain used in the 1976 swine influenza vaccine. We investigated whether sera from persons immunized with the 1976 swine influenza or recent seasonal influenza vaccines, or both, neutralize 2009 H1N1. Using retroviral pseudovirions bearing hemagglutinins on their surface (HA-pseudotypes), we found that 77% of the sera collected in 1976 after immunization with the A/New Jersey/1976 H1N1 swine influenza vaccine neutralized 2009 H1N1. Forty five percent also neutralized A/New Caledonia/20/1999 H1N1, a strain used in seasonal influenza vaccines during the 2000/01–2006/07 seasons. Among adults aged 48–64 who received the swine influenza vaccine in 1976 and recent seasonal influenza vaccines during the 2004/05–2008/09 seasons, 83% had sera that neutralized 2009 H1N1. However, 68% of age-matched subjects who received the same seasonal influenza vaccines, but did not receive the 1976 swine influenza vaccine, also had sera that neutralized 2009 H1N1. Sera from both 1976 and contemporary cohorts frequently had cross-neutralizing antibodies to 2009 H1N1 and A/New Caledonia/20/1999 that mapped to hemagglutinin subunit 2 (HA2). A conservative mutation in HA2 corresponding to a residue in the A/Solomon Islands/3/2006 and A/Brisbane/59/2007 H1N1 strains that circulated in the 2006/07 and 2007/08 influenza seasons, respectively, abrogated this neutralization. These findings highlight a cross-neutralization determinant influenced by a point mutation in HA2 and suggest that HA2 may be evolving under direct or indirect immune pressure

    Mimotopes selected with neutralizing antibodies against multiple subtypes of influenza A

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    <p>Abstract</p> <p>Background</p> <p>The mimotopes of viruses are considered as the good targets for vaccine design. We prepared mimotopes against multiple subtypes of influenza A and evaluate their immune responses in flu virus challenged Balb/c mice.</p> <p>Methods</p> <p>The mimotopes of influenza A including pandemic H1N1, H3N2, H2N2 and H1N1 swine-origin influenza virus were screened by peptide phage display libraries, respectively. These mimotopes were engineered in one protein as multi- epitopes in Escherichia coli (E. coli) and purified. Balb/c mice were immunized using the multi-mimotopes protein and specific antibody responses were analyzed using hemagglutination inhibition (HI) assay and enzyme-linked immunosorbent assay (ELISA). The lung inflammation level was evaluated by hematoxylin and eosin (HE).</p> <p>Results</p> <p>Linear heptopeptide and dodecapeptide mimotopes were obtained for these influenza virus. The recombinant multi-mimotopes protein was a 73 kDa fusion protein. Comparing immunized infected groups with unimmunized infected subsets, significant differences were observed in the body weight loss and survival rate. The antiserum contained higher HI Ab titer against H1N1 virus and the lung inflammation level were significantly decreased in immunized infected groups.</p> <p>Conclusions</p> <p>Phage-displayed mimotopes against multiple subtypes of influenza A were accessible to the mouse immune system and triggered a humoral response to above virus.</p

    The type VII secretion system of <i>Staphylococcus aureus</i> secretes a nuclease toxin that targets competitor bacteria

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    The type VII protein secretion system (T7SS) plays a critical role in the virulence of human pathogens including Mycobacterium tuberculosis and Staphylococcus aureus. Here we report that the S. aureus T7SS secretes a large nuclease toxin, EsaD. The toxic activity of EsaD is neutralised during its biosynthesis through complex formation with an antitoxin, EsaG, which binds to its C-terminal nuclease domain. The secretion of EsaD is dependent upon a further accessory protein, EsaE, that does not interact with the nuclease domain, but instead binds to the EsaD N-terminal region. EsaE has a dual cytoplasmic/membrane localization and membrane-bound EsaE interacts with the T7SS secretion ATPase, EssC, implicating EsaE in targeting the EsaDG complex to the secretion apparatus. EsaD and EsaE are co-secreted whereas EsaG is found only in the cytoplasm and may be stripped off during the secretion process. Strain variants of S. aureus that lack esaD encode at least two copies of EsaG-like proteins most likely to protect themselves from the toxic activity of EsaD secreted by esaD(+) strains. In support of this, a strain overproducing EsaD elicits significant growth inhibition against a sensitive strain. We conclude that T7SSs may play unexpected and key roles in bacterial competitiveness
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