48 research outputs found

    The outcomes of a sport-based intervention on risky sexual behaviours among rural school-going adolescents

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    The spread of HIV infection in sexually active adolescents and young adults has been attributed to the increasing risky sexual behaviours including early sexual activity, multiple sexual partnership, and irregular condoms use in this population. There are increasing calls to scale up youth-friendly HIV prevention programmes to assist youth in adopting safe sexual behaviours. The objective of this study was to assess the effectiveness of a 12-week sports-based HIV prevention programme on the HIV-risk reduction outcomes among rural high school learners. Participants are 430 learners representing 250 learners in the intervention school and 180 learners in the control school respectively. The intervention was delivered in school using the Grassroot Soccer generation skills curriculum consisting of soccer-themed HIV prevention activities including knowledge about HIV risks, self-efficacy to be abstinent and resist peer pressure. A one-way repeated measures ANOVA conducted to compare risk behaviour reduction outcomes at Time 1 (prior to the intervention), Time 2 (following the 12-week intervention) and Time 3 (four-month follow up) showed improvement in HIV knowledge [F (2) = 72.57, p = 0.000], self-efficacy [F (2) = 6.63, p = 0.002] and negotiation skills [F (2) = 4.07, p = 0.02]. Logistic regression analysis comparing risk reduction outcomes between intervention and control group showed statistically significant difference only on self-efficacy scores [ÎČ = 1.43 (95% CI: 1.07-1.92); p = 0.018]. There were no significant findigns regarding effect of sport-based HIV prevention programmes on risky sexual behaviours in rural school-going adolescents. The potential effect of the intervention on improvement of HIV knowledge, self-efficacy to refuse sex and negotiation skills for safe sex indicated that sport-based HIV prevention programmes could be used to modify risky sexual behaviours in South African adolescents and young adults.DHE

    The Fab region of IgG impairs the internalization pathway of FcRn upon Fc engagement

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    Binding to the neonatal Fc receptor (FcRn) extends serum half-life of IgG, and antagonizing this interaction is a promising therapeutic approach in IgG-mediated autoimmune diseases. Fc-MST-HN, designed for enhanced FcRn binding capacity, has not been evaluated in the context of a full-length antibody, and the structural properties of the attached Fab regions might affect the FcRn-mediated intracellular trafficking pathway. Here we present a comprehensive comparative analysis of the IgG salvage pathway between two full-size IgG1 variants, containing wild type and MST-HN Fc fragments, and their Fc-only counterparts. We find no evidence of Fab-regions affecting FcRn binding in cell-free assays, however, cellular assays show impaired binding of full-size IgG to FcRn, which translates into improved intracellular FcRn occupancy and intracellular accumulation of Fc-MST-HN compared to full size IgG1-MST-HN. The crystal structure of Fc-MST-HN in complex with FcRn provides a plausible explanation why the Fab disrupts the interaction only in the context of membrane-associated FcRn. Importantly, we find that Fc-MST-HN outperforms full-size IgG1-MST-HN in reducing IgG levels in cynomolgus monkeys. Collectively, our findings identify the cellular membrane context as a critical factor in FcRn biology and therapeutic targeting

    Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

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    © 2024 The Authors. Journal of Extracellular Vesicles, published by Wiley Periodicals, LLC on behalf of the International Society for Extracellular Vesicles. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly.Peer reviewe

    Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

    Get PDF
    Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its ‘Minimal Information for Studies of Extracellular Vesicles’, which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly

    De totale O&O-uitgaven in Vlaanderen: GERD

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    no isbnedition: 2015status: publishe

    Structural basis of human IL-18 sequestration by the decoy receptor IL-18 binding protein in inflammation and tumor immunity

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    Human Interleukin-18 (IL-18) is an omnipresent proinflammatory cytokine of the IL-1 family with central roles in autoimmune and inflammatory diseases and serves as a staple biomarker in the evaluation of inflammation in physiology and disease, including the inflammatory phase of COVID-19. The sequestration of IL-18 by its soluble decoy receptor IL-18-Binding Protein (IL-18BP) is critical to the regulation of IL-18 activity. Since an imbalance in expression and circulating levels of IL-18 is associated with disease, structural insights into how IL-18BP outcompetes binding of IL-18 by its cognate cell-surface receptors are highly desirable; however, the structure of human IL-18BP in complex with IL-18 has been elusive. Here, we elucidate the sequestration mechanism of human IL-18 mediated by IL-18BP based on the crystal structure of the IL-18:IL-18BP complex. These detailed structural snapshots reveal the interaction landscape leading to the ultra-high affinity of IL-18BP toward IL-18 and identify substantial differences with respect to previously characterized complexes of IL-18 with IL-18BP of viral origin. Furthermore, our structure captured a fortuitous higher-order assembly between IL-18 and IL-18BP coordinated by a disulfide-bond distal to the binding surface connecting IL-18 and IL-18BP molecules from different complexes, resulting in a novel tetramer with 2:2 stoichiometry. This tetrapartite assembly was found to restrain IL-18 activity more effectively than the canonical 1:1 complex. Collectively, our findings provide a framework for innovative, structure-driven therapeutic strategies and further functional interrogation of IL-18 in physiology and disease

    Structural basis of human IL-18 sequestration by the decoy receptor IL-18 binding protein in inflammation and tumor immunity

    No full text
    Human Interleukin-18 (IL-18) is an omnipresent proinflammatory cytokine of the IL-1 family with central roles in autoimmune and inflammatory diseases and serves as a staple biomarker in the evaluation of inflammation in physiology and disease, including the inflammatory phase of COVID-19. The sequestration of IL-18 by its soluble decoy receptor IL-18-Binding Protein (IL-18BP) is critical to the regulation of IL-18 activity. Since an imbalance in expression and circulating levels of IL-18 is associated with disease, structural insights into how IL-18BP outcompetes binding of IL-18 by its cognate cell-surface receptors are highly desirable; however, the structure of human IL-18BP in complex with IL-18 has been elusive. Here, we elucidate the sequestration mechanism of human IL-18 mediated by IL-18BP based on the crystal structure of the IL-18:IL-18BP complex. These detailed structural snapshots reveal the interaction landscape leading to the ultra-high affinity of IL-18BP toward IL-18 and identify substantial differences with respect to previously characterized complexes of IL-18 with IL-18BP of viral origin. Furthermore, our structure captured a fortuitous higher-order assembly between IL-18 and IL-18BP coordinated by a disulfide-bond distal to the binding surface connecting IL-18 and IL-18BP molecules from different complexes, resulting in a novel tetramer with 2:2 stoichiometry. This tetrapartite assembly was found to restrain IL-18 activity more effectively than the canonical 1:1 complex. Collectively, our findings provide a framework for innovative, structure-driven therapeutic strategies and further functional interrogation of IL-18 in physiology and disease
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