59 research outputs found
Risicobeheersing bij IKEA-projecten : een inventarisering van risico's en formulering van beheersingsmaatregelen bij renovatie, uitbreiding en nieuwbouw van IKEA-projecten
No full textEffectiviteit van het risicomanagement bij Design and Construct projecten van HBG Civiel
No full textDe inschatting van de totale projectkosten die door de caclulatieafdeling van HBG Civiel projecten en DMC voor D&C werken gemaakt wordt veel vaker dan verwacht overschreden. Het onvoldoende voorzien en beheersen van risico's wordt hiervoor als een van de hoofdzaken aangewezen. Binnen de HBG Civiel en specifiek op directieniveau, heerst twijfel over de uitkomsten van het risicoanalyse model. Wellicht komt de risicomodellering niet in voldoende mate overeen met de werkelijkheid, zodat uiteindelijk de financiele doelstellingen voor een project niet gehaald kunnen worden. Bovendien is deze situatie debet aan het vertrouwen in de kwantitatieve output van het risicoanalyse model. Dit vertrouwen is essentieel om beslissingen van het management omtrent het aanbesteden en onderhandelen op basis van deze output te laten geschieden. Doelstelling De doelstelling van dit afstudeeronderzoek is tweeledig: - Het evalueren van een aantal D&C werken waarbij het risicomanagement in het begrotingstraject wordt vergeleken met het behaalde financiele resultaat - Het doen van gefundeerde aanbevelingen die bij kunnen dragen aan de verbetering van de effectiviteit van het risicomanagement van HBG.Civil Engineering and Geoscience
Epitranscriptomic regulation in immunity and autoimmune disease: Unraveling novel implications of RNA modification m6A
No full textThe immune system protects the human body against pathogens such as viruses, bacteria, and parasites. It has innate and acquired components, which together recognize and eliminate these threats. When the immune system mistakes the body's own materials for pathogens, autoimmune diseases can occur. Immune cells, including T-helper cells (CD4+ T cells) and monocytes, play crucial roles in pathogen recognition, immune activation, and signaling molecule production. T-helper cells activate other immune cells through co-activation molecules like ICOS, CD28, and CD40L, while monocytes are involved in phagocytosis and regulating immune responses. RNA molecules labeled with m6A modification are key in regulating immune cell function. Proteins such as FTO and METTL3 modulate the presence of m6A on RNA, influencing gene expression and immune activation. m6A modifications impact the production and secretion of signaling molecules like TNF, which are critical in immune responses and autoimmune diseases. Research detailed in this thesis highlights the importance of m6A in: - Activating T-helper cells by regulating CD40L expression. - Modulating TNF production in T-helper cells and monocytes. - Controlling immune cell activation and antiviral responses against respiratory syncytial virus (RSV). - Influencing autoimmune diseases like juvenile idiopathic arthritis through altered expression of FTO and m6A labeling. These findings offer potential therapeutic targets for treating immune-related diseases and viral infections by manipulating m6A-regulating proteins
Conventional dendritic cells type 1 are strongly enriched, quiescent and relatively tolerogenic in local inflammatory arthritis
No full textINTRODUCTION: Dendritic cells (DC) are crucial for initiating and shaping immune responses. So far, little is known about the functional specialization of human DC subsets in (local) inflammatory conditions. We profiled conventional (c)DC1, cDC2 and monocytes based on phenotype, transcriptome and function from a local inflammatory site, namely synovial fluid (SF) from patients suffering from a chronic inflammatory condition, Juvenile Idiopathic Arthritis (JIA) as well as patients with rheumatoid arthritis (RA). METHODS: Paired PB and SF samples from 32 JIA and 4 RA patients were collected for mononuclear cell isolation. Flow cytometry was done for definition of antigen presenting cell (APC) subsets. Cell sorting was done on the FACSAria II or III. RNA sequencing was done on SF APC subsets. Proliferation assays were done on co-cultures after CD3 magnetic activated cell sorting (MACS). APC Toll-like receptor (TLR) stimulation was done using Pam3CSK4, Poly(I:C), LPS, CpG-A and R848. Cytokine production was measured by Luminex. RESULTS: cDC1, a relatively small DC subset in blood, are strongly enriched in SF, and showed a quiescent immune signature without a clear inflammatory profile, low expression of pathogen recognition receptors (PRRs), chemokine and cytokine receptors, and poor induction of T cell proliferation and cytokine production, but selective production of IFNλ upon polyinosinic:polycytidylic acid exposure. In stark contrast, cDC2 and monocytes from the same environment, showed a pro-inflammatory transcriptional profile, high levels of (spontaneous) pro-inflammatory cytokine production, and strong induction of T cell proliferation and cytokine production, including IL-17. Although the cDC2 and monocytes showed an overlapping transcriptional core profile, there were clear differences in the transcriptional landscape and functional features, indicating that these cell types retain their lineage identity in chronic inflammatory conditions. DISCUSSION: Our findings suggest that at the site of inflammation, there is specific functional programming of human DCs, especially cDC2. In contrast, the enriched cDC1 remain relatively quiescent and seemingly unchanged under inflammatory conditions, pointing to a potentially more regulatory role
The Epigenetic and Epitranscriptomic Regulation of Immune Activation
No full textGene expression in immune cells is regulated by intricate mechanisms that contribute to the immune response. Precise control of this expression is crucial for achieving well-timed and finely tuned expression of genes and pathways associated with inflammation. Disruption of this delicate balance can lead to severe complications, such as infections, auto-inflammatory disorders, or autoimmune diseases. This thesis elucidates the role of histone regulation and post-transcriptional regulation via m6A modification in both the adaptive and innate immune systems. Chapter 1 provides a general introduction, setting the stage for the detailed investigations that follow. Chapter 2 delves into the impact of histone regulation on CD4+ T cell activation by inhibiting key co-activators and HAT proteins P300/CBP. The potential of targeted inhibition of P300/CBP through BET inhibition is explored as a therapeutic approach for treating Juvenile Idiopathic Arthritis (JIA). In Chapter 3, the focus shifts to the role of m6A modification in monocyte activation. Following monocyte activation, differential expression of multiple m6A-associated proteins is uncovered, leading to elevated m6A levels. m6A methylation is identified on numerous genes within the TNF signaling via the NFkB pathway, including TNF itself. The m6A reader YTHDC1 binds to m6A-modified TNF, promoting TNF protein expression by facilitating the nuclear export of TNF mRNA. Chapter 4 elaborates on the increased expression of WTAP observed in monocyte activation. An alternative WTAP promoter is identified, which increases expression of a specific WTAP mRNA isoform in monocyte activation under the regulation of NFkB. Chapter 5 returns to JIA, demonstrating expression differences of m6A-associated proteins and increased m6A levels in monocytes derived from the inflamed joint of JIA patients. Decreased expression of the m6A eraser FTO can be induced by environmental cues from the synovial fluid of the inflamed joint. Chapter 6 examines the role of m6A in host immunity against Respiratory Syncytial Virus (RSV) infection. m6A modifications are detected on respiratory viruses, including RSV, which enhances viral replication and immune evasion. On host transcripts, the m6A reader YTHDC1 negatively regulates RSV entry by reducing the expression of the RSV entry receptor CX3CR1. The role of m6A in adaptive immunity and CD4+ T cell activation is discussed in Chapter 7 and Chapter 8, particularly in regulating stability of CD40L and TNF mRNA via m6A reader protein YTHDF2. Chapter 9 provides a general discussion, summarizing the findings of the thesis. Both histone regulation and m6A modification emerge as critical mechanisms for precisely modulating gene expression in different components of the immune system. This chapter explores the intricate interplay between these mechanisms, highlighting factors such as timing, transcript specificity, and reader specificity for m6A modifications. Furthermore, the potential implications of BET inhibition and m6A protein inhibition are underscored as promising therapeutic strategies for addressing autoimmune diseases. Overall, this thesis provides novel insights into how distinct forms of gene regulation orchestrate the immune response. Epigenetic and epitranscriptomic mechanisms, such as histone regulation and m6A modifications, exhibit multifaceted roles in T cell and monocyte activation
NRF2/Itaconate Axis Regulates Metabolism and Inflammatory Properties of T Cells in Children with JIA
No full textBackground: CD4+ T cells critically contribute to the initiation and perturbation of inflammation. When CD4+ T cells enter inflamed tissues, they adapt to hypoxia and oxidative stress conditions, and to a reduction in nutrients. We aimed to investigate how this distinct environment regulates T cell responses within the inflamed joints of patients with childhood rheumatism (JIA) by analyzing the behavior of NRF2—the key regulator of the anti-oxidative stress response—and its signaling pathways. Methods: Flow cytometry and quantitative RT-PCR were used to perform metabolic profiling of T cells and to measure the production of inflammatory cytokines. Loss of function analyses were carried out by means of siRNA transfection experiments. NRF2 activation was induced by treatment with 4-octyl-Itaconate (4-OI). Results: Flow cytometry analyses revealed a high metabolic status in CD4+ T cells taken from synovial fluid (SF) with greater mitochondrial mass, and increased glucose and fatty acid uptake. This resulted in a heightened oxidative status of SF CD4+ T cells. Despite raised ROS levels, expression of NRF2 and its target gene NQO1 were lower in CD4+ T cells from SF than in those from blood. Indeed, NRF2 activation of CD4+ T cells downregulated oxidative stress markers, altered the metabolic phenotype and reduced secretion of IFN-γ. Conclusion: NRF2 could be a potential regulator in CD4+ T cells during chronic inflammation and could instigate a drift toward disease progression or regression, depending on the inflammatory environment
Update on research and clinical translation on specific clinical areas from biology to bedside: Unpacking the mysteries of juvenile idiopathic arthritis pathogenesis
No full textLong-term efficacy and safety of canakinumab in patients with mevalonate kinase deficiency: results from the randomised Phase 3 CLUSTER trial
No full textItem does not contain fulltextOBJECTIVES: To evaluate the long-term efficacy and safety of canakinumab in patients with mevalonate kinase deficiency during the open label extension (weeks 41-113) of the randomized controlled CLUSTER trial. METHODS: During a 72-week period, patients received open-label canakinumab 150 or 300 mg, every 4 or 8 weeks. The disease activity was evaluated every 8 weeks using physician global assessment and counting the number of flares. Concentrations of CRP and serum amyloid A protein were measured. The safety was studied by determination and classification of observed adverse events. The safety and efficacy were analysed separately in three subgroups of patients receiving a cumulative dose of less than 90% reporting minimal disease activity or none at all. Median CRP concentrations were consistently equal or lower than 10 mg/l, while median serum amyloid A concentrations remained only slightly above the normal range of 10 mg/l. The study showed no new or unexpected adverse events. CONCLUSION: Canakinumab proved effective to control disease activity and prevent flares in mevalonate kinase deficiency during the 72-week study period. No new safety concerns were reported. TRIAL REGISTRATION: NCT02059291. https://clinicaltrials.gov
Share – Workpackage 4: addressing the need for health care for paediatric rheumatic diseases throughout europe
No full textGlycolytic reprogramming shapes the histone acetylation profile of activated CD4+ T cells in juvenile idiopathic arthritis
No full textJuvenile idiopathic arthritis (JIA) is an autoimmune disease characterized by accumulation of activated CD4+ T cells in the synovial fluid (SF) of affected joints. JIA CD4+ T cells exhibit a unique inflammation-associated epigenomic signature, but the underlying mechanisms remain unclear. We demonstrate that CD4+ T cells from JIA SF display heightened glycolysis upon activation and JIA-specific H3K27 acetylation, driving transcriptional reprogramming. Pharmacological inhibition of glycolysis altered the expression of genes associated with these acetylated regions. Healthy CD4+ T cells exposed to JIA SF exhibited increased glycolytic activity and transcriptomic changes marked by heightened histone 3 lysine 27 acetylation (H3K27ac) at JIA-specific genes. Elevated H3K27ac was dependent on glycolytic flux, while inhibiting glycolysis or pyruvate dehydrogenase (PDH) impaired transcription of SF-driven genes. These findings demonstrate a key role of glycolysis in JIA-specific gene expression, offering potential therapeutic targets for modulating inflammation in JIA
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