116 research outputs found

    Manipulating adenovirus hexon hypervariable loops dictates immune neutralisation and coagulation factor X-dependent cell interaction in vitro and in vivo

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    Adenoviruses are common pathogens, mostly targeting ocular, gastrointestinal and respiratory cells, but in some cases infection disseminates, presenting in severe clinical outcomes. Upon dissemination and contact with blood, coagulation factor X (FX) interacts directly with the adenovirus type 5 (Ad5) hexon. FX can act as a bridge to bind heparan sulphate proteoglycans, leading to substantial Ad5 hepatocyte uptake. FX “coating” also protects the virus from host IgM and complement-mediated neutralisation. However, the contribution of FX in determining Ad liver transduction whilst simultaneously shielding the virus from immune attack remains unclear. In this study, we demonstrate that the FX protection mechanism is not conserved amongst Ad types, and identify the hexon hypervariable regions (HVR) of Ad5 as the capsid proteins targeted by this host defense pathway. Using genetic and pharmacological approaches, we manipulate Ad5 HVR interactions to interrogate the interplay between viral cell transduction and immune neutralisation. We show that FX and inhibitory serum components can co-compete and virus neutralisation is influenced by both the location and extent of modifications to the Ad5 HVRs. We engineered Ad5-derived HVRs into the rare, native non FX-binding Ad26 to create Ad26.HVR5C. This enabled the virus to interact with FX at high affinity, as quantified by surface plasmon resonance, FX-mediated cell binding and transduction assays. Concomitantly, Ad26.HVR5C was also sensitised to immune attack in the absence of FX, a direct consequence of the engineered HVRs from Ad5. In both immune competent and deficient animals, Ad26.HVR5C hepatic gene transfer was mediated by FX following intravenous delivery. This study gives mechanistic insight into the pivotal role of the Ad5 HVRs in conferring sensitivity to virus neutralisation by IgM and classical complement-mediated attack. Furthermore, through this gain-of-function approach we demonstrate the dual functionality of FX in protecting Ad26.HVR5C against innate immune factors whilst determining liver targeting

    The European Association for Haemophilia and Allied Disorders (EAHAD) Coagulation Factor Variant Databases: Important resources for haemostasis clinicians and researchers

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    Haemophilia published by John Wiley & Sons Ltd Introduction: Advances in genomic sequencing have facilitated the sequencing of genes associated with disorders of haemostasis. The identification of variants within genes and access to curated data incorporating structural, functional, evolutionary as well as phenotypic data has become increasingly important in order to ascribe pathogenicity. Aim: The European Association for Haemophilia and Allied Disorders (EAHAD) Coagulation Factor Variant Database Project aims to provide a single port of entry to a web-accessible resource for variants in genes involved in clinical bleeding disorders. Results: New databases have evolved from previously developed single gene variant coagulation database projects, incorporating new data, new analysis tools and a new common database architecture with new interfaces and filters. These new databases currently present information about the genotype, phenotype (laboratory and clinical) and structural and functional effects of variants described in the genes of factor (F) VII (F7), FVIII (F8), FIX (F9) and von Willebrand factor (VWF). Conclusion: The project has improved the quality and quantity of information available to the haemostasis research and clinical communities, thereby enabling accurate classification of disease severity in order to make assessments of likely pathogenicity

    The EAHAD blood coagulation factor VII variant database

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    Hereditary blood coagulation factor VII (FVII) deficiency is a rare autosomal recessive bleeding disorder resulting from variants in the gene encoding FVII (F7 ). Integration of genetic variation with functional consequences on protein function is essential for the interpretation of the pathogenicity of novel variants. Here, we describe the integration of previous locus‐specific databases for F7 into a single curated database with enhanced features. The database provides access to in silico analyses that may be useful in the prediction of variant pathogenicity as well as cross‐species sequence alignments, structural information, and functional and clinical severity described for each variant, where appropriate. The variant data is shared with the F7 Leiden Open Variation Database. The updated database now includes 221 unique variants, representing gene variants identified in 728 individuals. Single nucleotide variants are the most common type (88%) with missense representing 74% of these variants. A number of variants are found with relatively high minor allele frequencies that are not pathogenic but contribute significantly to the likely pathogenicity of coinherited variants due to their effect on FVII plasma levels. This comprehensive collection of curated information significantly aids the assessment of pathogenicity

    Database Evaluation for Muscle and Nerve Diseases - DEMAND: An academic neuromuscular coding system

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    Background: A database which documents the diagnosis of neuromuscular patients is useful for determining the types of patients referred to academic centers and for identifying participants for clinical trials and other studies. The ICD-9 or ICD-10 numeric systems are insufficiently detailed for this purpose. Objective: To develop a database for neuromuscular diagnoses Methods: We developed a detailed diagnostic coding system for neuromuscular diseases called DEMAND: Database Evaluation for Muscle and Nerve Diseases that has been adopted by neuromuscular clinics at University of Texas Health Science Center San Antonio (UTHSCSA), Ohio State University (OSU), University of Kansas Medical Center (KUMC), and University of Texas Southwestern (UTSW). At the initial visit, patients are assigned a diagnostic code which can be revised later if appropriate. Fields include patient’s name, date of birth, and diagnostic code. The neuromuscular database consisted of 457 codes. Each code has a prefix (MUS or PNS) followed by a three-digit number. Depending on whether muscle or nerve is primarily involved, there are eight broad groups: motor neuron disease (MUS codes 100-139); neuromuscular junction disorders (MUS 200-217); acquired and hereditary myopathies (MUS 300-600s); acquired and hereditary polyneuropathies (PNS 100-400); mononeuropathies (PNS 500s); plexopathies (PNS 600s); radiculopathies (PNS 700s); and mononeuritis multiplex (PNS 800s). Results: During a period of 10 years, 17,163 of patients were entered (1,752 at UTHSCSA, 1,840 at OSU, 3,699 at KUMC, 9,872 at UTSW). The number of patients in several broad categories are: 3,080 motor neuron disease; 1,575 neuromuscular junction disease; 1,851 muscular dystrophies; 633 inflammatory myopathies; 1,090 hereditary neuropathies; 1,001 immune-mediated polyneuropathies; 620 metabolic/toxic polyneuropathies; 535 mononeuropathies; 296 plexopathies; and 769 radiculopathies. Conclusion: A detailed diagnostic neuromuscular database can be utilized at multiple academic centers. The database should be simple without too many fields to complete, to ensure compliance during busy clinic operations. This database has been very useful in identifying groups of patients for retrospective, observational studies and for prospective treatment studies including trials for Amyotrophic Lateral Sclerosis (ALS), Muscular Dystrophies (MD), Myasthenia Gravis (MG), and retrospective studies of Primary Lateral Sclerosis (PLS), chronic inflammatory demyelinating neuropathy (CIDP), etc

    Lactobacillus rhamnosus GG soluble mediators ameliorate early life stress-induced visceral hypersensitivity and changes in spinal cord gene expression

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    peer-reviewedVisceral hypersensitivity is a hallmark of many functional and stress-related gastrointestinal disorders, and there is growing evidence that the gut microbiota may play a role in its pathophysiology. It has previously been shown that early life stress-induced visceral sensitivity is reduced by various probiotic strains of bacteria (including Lactobacillus rhamnosus GG (LGG)) alone or in combination with prebiotic fibres in rat models. However, the exact mechanisms underpinning such effects remain unresolved. Here, we investigated if soluble mediators derived from LGG can mimic the bacteria’s effects on visceral hypersensitivity and the microbiota–gut–brain axis. Rats were exposed to maternal separation (MS) from postnatal days 2–12. From weaning onwards both non-separated (NS) and MS offspring were provided drinking water with or without supplementation of standardized preparations of the LGG soluble mediators (LSM). Our results show that MS led to increased visceral sensitivity and exaggerated corticosterone plasma levels following restraint stress in adulthood, and both of these effects were ameliorated through LSM supplementation. Differential regulation of various genes in the spinal cord of MS versus NS rats was observed, 41 of which were reversed by LSM supplementation. At the microbiota composition level MS led to changes in beta diversity and abundance of specific bacteria including parabacteroides, which were ameliorated by LSM. These findings support probiotic soluble mediators as potential interventions in the reduction of symptoms of visceral hypersensitivity

    Decreased Pre-existing Ad5 Capsid and Ad35 Neutralizing Antibodies Increase HIV-1 Infection Risk in the Step Trial Independent of Vaccination

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    <div><h3>Background</h3><p>The Step trial raised the possibility that uncircumcised men with pre-existing Ad5 neutralizing antibodies carried an increased risk of HIV infection after vaccination. Thus, understanding Ad seropositivity in humans is important to the development of an AIDS vaccine. Here, we analyze the impact of different Ad5-specific neutralizing antibodies on immune function and clinical outcome.</p> <h3>Methods and Findings</h3><p>Ad seropositivity in the Step trial volunteers was analyzed using chimeric rAd5/35 vectors to characterize their specificity for Ad5 fiber and non-fiber external (capsid) proteins. Immune responses and HIV seropositivity were correlated with the specificity of Ad5-neutralizing antibodies. Neutralizing antibodies induced by the vaccine in Ad5 seronegative subjects were directed preferentially to Ad5 capsid proteins, although some fiber-neutralizing antibodies could be detected. Pre-vaccination Ad5 serostatus did not affect the capsid-directed response after three vaccinations. In contrast, anti-fiber antibody titers were significantly higher in volunteers who were Ad5 seropositive prior to vaccination. Those Ad5 seropositive subjects who generated anti-capsid responses showed a marked reduction in vaccine-induced CD8 responses. Unexpectedly, anti-vector immunity differed qualitatively in Ad5 seropositive participants who became HIV-1 infected compared to uninfected case controls; Ad5 seropositive participants who later acquired HIV had lower neutralizing antibodies to capsid. Moreover, Ad35 seropositivity was decreased in HIV-infected subjects compared with uninfected case controls, while seroprevalence for other serotypes including Ad14, Ad28 and Ad41 was similar in both groups.</p> <h3>Conclusions</h3><p>Together, these findings suggest that the case subjects were less immunologically responsive prior to infection. Subjects infected during the Step trial had qualitative differences in immunity that increased their risk of HIV-1 infection independent of vaccination.</p> </div

    A genome-wide association study of myasthenia gravis

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    IMPORTANCE: Myasthenia gravis is a chronic, autoimmune, neuromuscular disease characterized by fluctuating weakness of voluntary muscle groups. Although genetic factors are known to play a role in this neuroimmunological condition, the genetic etiology underlying myasthenia gravis is not well understood. OBJECTIVE: To identify genetic variants that alter susceptibility to myasthenia gravis, we performed a genome-wide association study. DESIGN, SETTING, AND PARTICIPANTS: DNA was obtained from 1032 white individuals from North America diagnosed as having acetylcholine receptor antibody–positive myasthenia gravis and 1998 race/ethnicity-matched control individuals from January 2010 to January 2011. These samples were genotyped on Illumina OmniExpress single-nucleotide polymorphism arrays. An independent cohort of 423 Italian cases and 467 Italian control individuals were used for replication. MAIN OUTCOMES AND MEASURES: We calculated P values for association between 8114394 genotyped and imputed variants across the genome and risk for developing myasthenia gravis using logistic regression modeling. A threshold P value of 5.0 × 10(−8) was set for genome-wide significance after Bonferroni correction for multiple testing. RESULTS: In the over all case-control cohort, we identified association signals at CTLA4 (rs231770; P = 3.98 × 10(−8); odds ratio, 1.37; 95% CI, 1.25–1.49), HLA-DQA1 (rs9271871; P = 1.08 × 10(−8); odds ratio, 2.31; 95% CI, 2.02 – 2.60), and TNFRSF11A (rs4263037; P = 1.60 × 10(−9); odds ratio, 1.41; 95% CI, 1.29–1.53). These findings replicated for CTLA4 and HLA-DQA1 in an independent cohort of Italian cases and control individuals. Further analysis revealed distinct, but overlapping, disease-associated loci for early- and late-onset forms of myasthenia gravis. In the late-onset cases, we identified 2 association peaks: one was located in TNFRSF11A (rs4263037; P = 1.32 × 10(−12); odds ratio, 1.56; 95% CI, 1.44–1.68) and the other was detected in the major histocompatibility complex on chromosome 6p21 (HLA-DQA1; rs9271871; P = 7.02 × 10(−18); odds ratio, 4.27; 95% CI, 3.92–4.62). Association within the major histocompatibility complex region was also observed in early-onset cases (HLA-DQA1; rs601006; P = 2.52 × 10(−11); odds ratio, 4.0; 95% CI, 3.57–4.43), although the set of single-nucleotide polymorphisms was different from that implicated among late-onset cases. CONCLUSIONS AND RELEVANCE: Our genetic data provide insights into aberrant cellular mechanisms responsible for this prototypical autoimmune disorder. They also suggest that clinical trials of immunomodulatory drugs related to CTLA4 and that are already Food and Drug Administration approved as therapies for other autoimmune diseases could be considered for patients with refractory disease

    The human DEK oncogene regulates DNA damage response signaling and repair

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    The human DEK gene is frequently overexpressed and sometimes amplified in human cancer. Consistent with oncogenic functions, Dek knockout mice are partially resistant to chemically induced papilloma formation. Additionally, DEK knockdown in vitro sensitizes cancer cells to DNA damaging agents and induces cell death via p53-dependent and -independent mechanisms. Here we report that DEK is important for DNA double-strand break repair. DEK depletion in human cancer cell lines and xenografts was sufficient to induce a DNA damage response as assessed by detection of γH2AX and FANCD2. Phosphorylation of H2AX was accompanied by contrasting activation and suppression, respectively, of the ATM and DNA-PK pathways. Similar DNA damage responses were observed in primary Dek knockout mouse embryonic fibroblasts (MEFs), along with increased levels of DNA damage and exaggerated induction of senescence in response to genotoxic stress. Importantly, Dek knockout MEFs exhibited distinct defects in non-homologous end joining (NHEJ) when compared to their wild-type counterparts. Taken together, the data demonstrate new molecular links between DEK and DNA damage response signaling pathways, and suggest that DEK contributes to DNA repair

    The predictive moment: reverie, connection and predictive processing

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    According to the theory of predictive processing, understanding in the present involves non-consciously representing the immediate future, based on probabilistic inference shaped by learning from the past. This paper suggests links between this neuroscientific theory and the psychoanalytic concept of reverie – an empathic, containing attentional state – and considers implications for the ways therapists intuit implicit material in their clients. Using findings from a study about therapists’ experiences of this state, we propose that reverie can offer practitioners from diverse theoretical backgrounds a means to enter the predictive moment deeply, making use of its subtle contents to connect with clients
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