310 research outputs found

    Asparaginyl endopeptidase (Legumain) supports human Th1 induction via cathepsin L-mediated intracellular C3 activation

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    Autocrine activation of the complement receptors C3aR and CD46 by complement activation components C3a and C3b produced through C3 cleavage by the protease cathepsin L (CTSL) during T cell stimulation is a requirement for IFN-Îł production and Th1 induction in human CD4+ T cells. Thus, lack of autocrine CD46 activation, such as in CD46-deficient patients, is associated with defective Th1 responses and recurrent infections. We have identified LGMN [the gene coding for legumain, also known as asparaginyl endopeptidase (AEP)] as one of the key genes induced by CD46 co-stimulation during human CD4+ T cell activation. AEP processes and activates a range of proteins, among those α1-thymosin and CTSL, which both drive intrinsically Th1 activity—but has so far not been described to be functionally active in human T cells. Here we found that pharmacological inhibition of AEP during activation of human CD4+ T cells reduced CTSL activation and the CTSL-mediated generation of intracellular C3a. This translated into a specific reduction of IFN-Îł production without affecting cell proliferation or survival. In line with these findings, CD4+ T cells isolated from Lgmn−/− mice also displayed a specific defect in IFN-Îł secretion and Th1 induction. Furthermore, we did not observe a role for AEP-driven autocrine α1-thymosin activation in T cell-derived IFN-Îł production. These data suggest that AEP is an “upstream” activator of the CTSL-C3-IFN-Îł axis in human CD4+ T cells and hence an important supporter of human Th1 induction

    Replications of software engineering experiments

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    There are many open issues that must be addressed before the replication process can be successfully formalized in empirical software engineering research. We define replication as the deliberate repetition of the same empirical study for the purpose of determining whether the results of the first experiment can be reproduced. This definition would appear at first glance to be good. However, it needs several clarifications that have not yet been forthcoming in software engineering: – What is the exact meaning of the same empirical study? Namely how similar should an experiment be to the baseline study for it to be considered a replication? What is the exact meaning of a result being reproduced? Namely how similar does a result have to be to the result of the baseline study for it to be considered reproduced? These and other methodological questions need to be researched and tailored for empirical software engineering

    FOOT PRONATION AND STRESS FRACTURES OF THE FEMUR AND TIBIA: A PROSPECTIVE BIOMECHANICAL STUDY

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    The relation between foot pronation and stress fractures has been suggested. However, evidence based literature is lacking and contradictory. The purpose of this study was to examine whether dynamic parameters of foot pronation are related to the development of stress fractures of the femur and tibia. 2 weeks prior to beginning of 14 weeks of basic military training, 473 infantry recruits were inrolled into the study. 2D analysis was performed to measure foot pronation during treadmill walking. The soldiers were examined during the training course at two weeks intervals for stress fractures. The odds ratio was calculated for each dynamic pronation parameter in relation to the stress fractures. 10% of the 405 soldiers who finished the training were diagnosed with stress fractures of the femur and tibia. Longer pronation time was related to risk reduction for the development of stress fractures and may have a protective effect during an extended period of training

    Proteomic Identification of Potential Target Proteins of Cathepsin W for Its Development as a Drug Target for Influenza

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    Influenza A virus (IAV) coopts numerous host factors for efficient replication. The cysteine protease cathepsin W (CTSW) has been identified as one host factor required for IAV entry, specifically for the escape of IAVs from late endosomes. However, the substrate specificity of CTSW and the proviral mechanism are thus far unknown. Here, we show that intracellular but not secreted CTSW promotes viral entry. We reveal 79 potential direct and 31 potential indirect cellular target proteins of CTSW using the high-throughput proteomic approach terminal amine isotopic labeling of substrates (TAILS) and determine the cleavage motif shared by the substrates of CTSW. Subsequent integration with data from RNA interference (RNAi) screens for IAV host factors uncovers first insights into the proviral function of CTSW. Notably, CTSW-deficient mice display a 25% increase in survival and a delay in mortality compared to wild-type mice upon IAV infection. Altogether, these findings support the development of drugs targeting CTSW as novel host-directed antiviral therapies. IMPORTANCE Influenza viruses are respiratory pathogens and pose a constant threat to human health. Although antiviral drugs are available for influenza, the emergence and spread of drug-resistant viruses is cause for concern. Therefore, the development of new antivirals with lower chances of their target viruses acquiring resistance is urgently needed to reduce the high morbidity and mortality caused by influenza. Promising alternatives to drugs targeting viral proteins are those directed against host factors required for viral replication. The cysteine protease cathepsin W (CTSW) is an important host factor for IAV replication, and its proteolytic activity is required for fusion of viral and endosomal membranes. In this work, we identify a number of hitherto unknown CTSW substrates, providing new insights into virus-host interactions, and reveal that CTSW might also play a proviral role in an in vivo model. These results support the development of CTSW as a drug target for next-generation antivirals against influenza

    Proteomic identification of potential target proteins of cathepsin W for its development as a drug target for influenza

    Get PDF
    Influenza A virus (IAV) coopts numerous host factors for efficient replication. The cysteine protease cathepsin W (CTSW) has been identified as one host factor required for IAV entry, specifically for the escape of IAVs from late endosomes. However, the substrate specificity of CTSW and the proviral mechanism are thus far unknown. Here, we show that intracellular but not secreted CTSW promotes viral entry. We reveal 79 potential direct and 31 potential indirect cellular target proteins of CTSW using the high-throughput proteomic approach terminal amine isotopic labeling of substrates (TAILS) and determine the cleavage motif shared by the substrates of CTSW. Subsequent integration with data from RNA interference (RNAi) screens for IAV host factors uncovers first insights into the proviral function of CTSW. Notably, CTSW-deficient mice display a 25% increase in survival and a delay in mortality compared to wild-type mice upon IAV infection. Altogether, these findings support the development of drugs targeting CTSW as novel host-directed antiviral therapies

    First-Response ABCDE Management of Status Epilepticus: A Prospective High-Fidelity Simulation Study

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    Respiratory infections following status epilepticus (SE) are frequent, and associated with higher mortality, prolonged ICU stay, and higher rates of refractory SE. Lack of airway protection may contribute to respiratory infectious complications. This study investigates the order and frequency of physicians treating a simulated SE following a systematic Airways-Breathing-Circulation-Disability-Exposure (ABCDE) approach, identifies risk factors for non-adherence, and analyzes the compliance of an ABCDE guided approach to SE with current guidelines. We conducted a prospective single-blinded high-fidelity trial at a Swiss academic simulator training center. Physicians of different affiliations were confronted with a simulated SE. Physicians (; n; = 74) recognized SE and performed a median of four of the five ABCDE checks (interquartile range 3-4). Thereof, 5% performed a complete assessment. Airways were checked within the recommended timeframe in 46%, breathing in 66%, circulation in 92%, and disability in 96%. Head-to-toe (exposure) examination was performed in 15%. Airways were protected in a timely manner in 14%, oxygen supplied in 69%, and antiseizure drugs (ASDs) administered in 99%. Participants' neurologic affiliation was associated with performance of fewer checks (regression coefficient -0.49;; p; = 0.015). We conclude that adherence to the ABCDE approach in a simulated SE was infrequent, but, if followed, resulted in adherence to treatment steps and more frequent protection of airways

    The 6 May 1976 Friuli earthquake: re-evaluating and consolidating

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    The aim of this paper is to propose the creation, in terms of European Macroseismic Scale (EMS-98), of the entire macroseismic fi eld of the 6 May 1976 Friuli earthquake. Only forty odd years have passed, and nothwithsatnding that there is a huge quantity of existing data, it was still disturbing to fi nd that much of the original data are missing and probably lost forever Efforts have therefore been made to fi nd additional and still unknown primary data. For the majority of the collected national data sets, a reevaluation was then possible. This study presents the comprehensive macroseismic data set for 14 European countries. It is, to our knowledge, one of the largest European data sets, consisting of 3423 intensity data points (IDPs). The earthquake was felt from Rome to the Baltic Sea, and from Belgium to Warsaw. The maximum intensity 10 EMS-98 was reached in eight localities in Friuli (Italy). Compared to previous studies, the Imax values have changed from country to country, in some cases being lowered due to methodological differences, but in the case of three among the most hit countries, Imax is now higher than in the previous studies, mainly due to the new data.Published417-4444T. SismicitĂ  dell'ItaliaJCR Journa

    Isokinetic moment curve abnormalities are associated with articular knee lesions

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    The aim of this study was to test whether lesions of the medial meniscus (MM) and of the anterior cruciate ligament (ACL) are associated with specific abnormalities of isokinetic moment curves (IMCs). Fifty-four young adults (20 active healthy people, and 34 patients with unilateral knee injuries) were assessed through knee extensor and flexor isokinetic tests at 60\ub0/s. Qualitative IMC analysis was performed using a novel classification system which identified three distinct abnormal shapes. The chi-squared (\u3c72) test was used to determine the inter-individual and intra-individual differences between the groups. Quantitative IMC inter-group comparisons were performed by a one-way analysis of variance (ANOVA). Knees with MM and ACL lesions were consistently associated with IMC shape irregularities (p<0.001) and with abnormal quantitative scores (p<0.001). More specifically, knees with isolated ACL lesions and knees with combined ACL and MM lesions presented similar distribution of knee extensor and flexor IMC irregularities, which was not present in knees with isolated MM lesions. A possible association between specific knee pathologies and IMC irregularities was identified (all p<0.05). In conclusion, different knee pathologies may be associated with different qualitative IMCs, which could be used as an additional presentation tool in clinical settings

    IFITM3 incorporation sensitizes influenza A virus to antibody-mediated neutralization

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    The disease severity of influenza is highly variable in humans, and one genetic determinant behind these differences is the IFITM3 gene. As an effector of the interferon response, IFITM3 potently blocks cytosolic entry of influenza A virus (IAV). Here, we reveal a novel level of inhibition by IFITM3 in vivo: We show that incorporation of IFITM3 into IAV particles competes with incorporation of viral hemagglutinin (HA). Decreased virion HA levels did not reduce infectivity, suggesting that high HA density on IAV virions may be an antagonistic strategy used by the virus to prevent direct inhibition. However, we found that IFITM3-mediated reduction in HA content sensitizes IAV to antibody-mediated neutralization. Mathematical modeling predicted that this effect decreases and delays peak IAV titers, and we show that, indeed, IFITM3-mediated sensitization of IAV to antibody-mediated neutralization impacts infection outcome in an in vivo mouse model. Overall, our data describe a previously unappreciated interplay between the innate effector IFITM3 and the adaptive immune response
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