158 research outputs found

    Convergent evolution of venom gland transcriptomes across Metazoa.

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    Animals have repeatedly evolved specialized organs and anatomical structures to produce and deliver a mixture of potent bioactive molecules to subdue prey or predators-venom. This makes it one of the most widespread, convergent functions in the animal kingdom. Whether animals have adopted the same genetic toolkit to evolved venom systems is a fascinating question that still eludes us. Here, we performed a comparative analysis of venom gland transcriptomes from 20 venomous species spanning the main Metazoan lineages to test whether different animals have independently adopted similar molecular mechanisms to perform the same function. We found a strong convergence in gene expression profiles, with venom glands being more similar to each other than to any other tissue from the same species, and their differences closely mirroring the species phylogeny. Although venom glands secrete some of the fastest evolving molecules (toxins), their gene expression does not evolve faster than evolutionarily older tissues. We found 15 venom gland-specific gene modules enriched in endoplasmic reticulum stress and unfolded protein response pathways, indicating that animals have independently adopted stress response mechanisms to cope with mass production of toxins. This, in turn, activates regulatory networks for epithelial development, cell turnover, and maintenance, which seem composed of both convergent and lineage-specific factors, possibly reflecting the different developmental origins of venom glands. This study represents a first step toward an understanding of the molecular mechanisms underlying the repeated evolution of one of the most successful adaptive traits in the animal kingdom

    Serological response to 13-valent pneumococcal conjugate vaccine in children and adolescents with perinatally acquired HIV infection

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    BACKGROUND: Children with perinatally acquired HIV (paHIV) remain at an increased risk of pneumococcal infection despite highly active antiretroviral therapy (HAART). Beyond infancy, responses to pneumococcal conjugate vaccine (PCV) remain under-investigated. There are currently no published data on serological response to 13-valent PCV (PCV13) in the HIV-infected populations. METHODS: We measured pneumococcal serotype-specific IgG in 48 paHIV-infected child patients (CP), 27 young adult healthy controls (AHC) and 30 child healthy controls (CHC). Opsonophagocytic assay (OPA) titres for three PCV13-exclusive serotypes were measured in a subset of children. Serotype-specific IgG was repeated 1 and 6 months following PCV13 vaccination of CP and AHC groups. OPA titres for four serotypes were measured at the 1-month time-point. RESULTS: The majority of CP, CHC and AHC had serotype-specific IgG above 0.35 μg/ml at baseline, although OPA activity was undetectable for two of the three serotypes studied. Baseline IgG concentrations were significantly lower in CP than AHC for a proportion of serotypes and were strongly predictive of responses to vaccine. After adjusting for baseline, postvaccination IgG concentrations were comparable, although responses to some serotypes were impaired for CP. OPA correlated well with IgG after vaccination. Detectable HIV viral load was associated with significantly lower IgG concentration and OPA titre. CONCLUSION: Children with paHIV mount a robust serological response to PCV13 for most but not all vaccine serotypes. Viral load suppression with HAART and higher baseline IgG concentration are associated with higher postvaccination antibody levels. This has implications for HAART treatment and vaccination practices

    Urea Cycle Related Amino Acids Measured in Dried Bloodspots Enable Long-Term In Vivo Monitoring and Therapeutic Adjustment

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    BACKGROUND: Dried bloodspots are easy to collect and to transport to assess various metabolites, such as amino acids. Dried bloodspots are routinely used for diagnosis and monitoring of some inherited metabolic diseases. METHODS: Measurement of amino acids from dried blood spots by liquid chromatography-tandem mass spectrometry. RESULTS: We describe a novel rapid method to measure underivatised urea cycle related amino acids. Application of this method enabled accurate monitoring of these amino acids to assess the efficacy of therapies in argininosuccinate lyase deficient mice and monitoring of these metabolites in patients with urea cycle defects. CONCLUSION: Measuring urea cycle related amino acids in urea cycle defects from dried blood spots is a reliable tool in animal research and will be of benefit in the clinic, facilitating optimisation of protein-restricted diet and preventing amino acid deprivation

    Natural IgM antibodies in the immune defence against neoehrlichiosis

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    Background: Neoehrlichiosis is an infectious disease caused by the tick-borne bacterium “Candidatus Neoehrlichia mikurensis”. Splenectomy and rituximab therapies are risk factors for severe neoehrlichiosis. Our aim was to examine if neoehrlichiosis patients had low levels of natural IgM antibodies and/or were hypogammaglobulinemic, and if such deficiencies were associated with asplenia and vascular complications. Methods: Neoehrlichiosis patients (n = 9) and control subjects (n = 10) were investigated for serum levels of IgG, IgA, and IgM, and for levels of natural IgM antibodies to pneumococcal polysaccharides (6B, 14), and to the malondialdehyde acetaldehyde epitope of oxidized LDL. The multivariate method Projection to Latent Structures was used to analyze the data. Results: The levels of natural IgM antibodies of various specificities were decreased or not measurable in half of the studied patients with neoehrlichiosis. Only one patient and one control subject were hypogammaglobulinemic. An inverse relationship was noted between the levels of natural IgM antibodies and the development of deep vein thrombosis. Unexpectedly, no association was seen between having or not having a spleen and the levels of natural IgM antibody levels in the circulation. Conclusions: Neither hypogammaglobulinemia nor lack of natural IgM antibodies alone predisposes for severe neoehrlichiosis. The importance of the spleen in the immune defence against Ca. N. mikurensis probably lies in its capacity to generate or maintain specific antibodies

    Comparative immunogenicity of 7 and 13-valent pneumococcal conjugate vaccines and the development of functional antibodies to cross-reactive serotypes

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    Protection against disease or colonization from serotypes related to those in pneumococcal conjugate vaccines (i.e. cross-protection) vary by serotype; the basis for this variation is not understood. The 13-valent pneumococcal conjugate vaccine (PCV13) replaced 7-valent conjugate (PCV7) in the USA in 2010 allowing assessment of PCV7 and PCV13 immunogenicity and functional cross-protection in vitro

    The new COST Action European Venom Network (EUVEN)—synergy and future perspectives of modern venomics

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    Venom research is a highly multidisciplinary field that involves multiple subfields of biology, informatics, pharmacology, medicine, and other areas. These different research facets are often technologically challenging and pursued by different teams lacking connection with each other. This lack of coordination hampers the full development of venom investigation and applications. The COST Action CA19144–European Venom Network was recently launched to promote synergistic interactions among different stakeholders and foster venom research at the European level

    Direct Comparison of Immunogenicity Induced by 10-or 13-Valent Pneumococcal Conjugate Vaccine around the 11-Month Booster in Dutch Infants

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    BACKGROUND & AIMS: Since 2009/10, a 10- and a 13-valent pneumococcal conjugate vaccine (PCV) are available, but only the 10-valent vaccine is now being used for the children in the Netherlands. As the vaccines differ in number of serotypes, antigen concentration, and carrier proteins this study was designed to directly compare quantity and quality of the antibody responses induced by PCV10 and PCV13 before and after the 11-month booster. METHODS: Dutch infants (n = 132) were immunized with either PCV10 or PCV13 and DTaP-IPV-Hib-HepB at the age of 2, 3, 4 and 11 months. Blood samples were collected pre-booster and post-booster at one week and one month post-booster for quantitative and qualitative immunogenicity against 13 pneumococcal serotypes, as well as quantitative immunogenicity against diphtheria, tetanus, pertussis and Haemophilus influenzae type b. We compared immunogenicity induced by PCV13 and PCV10 for their ten shared serotypes. RESULTS: One month post-booster, pneumococcal serotype-specific IgG geometric mean concentrations (GMCs) for the PCV13 group were higher compared with the PCV10 group for six serotypes, although avidity was lower. Serotype 19F showed the most distinct difference in IgG and, in contrast to other serotypes, its avidity was higher in the PCV13 group. One week post-booster, opsonophagocytosis for serotype 19F did not differ significantly between the PCV10- and the PCV13 group. CONCLUSION: Both PCV10 and PCV13 were immunogenic and induced a booster response. Compared to the PCV10 group, the PCV13 group showed higher levels for serotype 19F GMCs and avidity, pre- as well as post-booster, although opsonophagocytosis did not differ significantly between groups. In our study, avidity is not correlated to opsonophagocytotic activity (OPA) and correlations between IgG and OPA differ per serotype. Therefore, besides assays to determine IgG GMCs, assays to detect opsonophagocytotic activity, i.e., the actual killing of the pneumococcus, are important for PCV evaluation. How differences between the two vaccines relate to long-term protection requires further investigation. TRIAL REGISTRATION: www.trialregister.nl NTR3069

    Modern venomics – Current insights, novel methods and future perspectives in biological and applied animal venom research

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    Venoms have evolved >100 times in all major animal groups, and their components, known as toxins, have been fine-tuned over millions of years into highly effective biochemical weapons. There are many outstanding questions on the evolution of toxin arsenals, such as how venom genes originate, how venom contributes to the fitness of venomous species, and which modifications at the genomic, transcriptomic, and protein level drive their evolution. These questions have received particularly little attention outside of snakes, cone snails, spiders, and scorpions. Venom compounds have further become a source of inspiration for translational research using their diverse bioactivities for various applications. We highlight here recent advances and new strategies in modern venomics and discuss how recent technological innovations and multi-omic methods dramatically improve research on venomous animals. The study of genomes and their modifications through CRISPR and knockdown technologies will increase our understanding of how toxins evolve and which functions they have in the different ontogenetic stages during the development of venomous animals. Mass spectrometry imaging combined with spatial transcriptomics, in situ hybridization techniques, and modern computer tomography gives us further insights into the spatial distribution of toxins in the venom system and the function of the venom apparatus. All these evolutionary and biological insights contribute to more efficiently identify venom compounds, which can then be synthesized or produced in adapted expression systems to test their bioactivity. Finally, we critically discuss recent agrochemical, pharmaceutical, therapeutic, and diagnostic (so-called translational) aspects of venoms from which humans benefit
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