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BACKGROUND: The significant annual burden caused by seasonal influenza has led to global calls for increased influenza vaccination coverage rates (VCRs). We aimed to estimate the proportion of the German population at high risk of serious illness from influenza due to chronic conditions and to estimate age-specific VCRs of people with/without chronic conditions.; METHODS: Using health insurance claims data covering nine influenza seasons (2010-2019), we assessed up to 7 million insured individuals per season across all German regions. Individuals were classified according to age and presence of chronic health conditions. VCRs were estimated using outpatient healthcare utilization documentation.; RESULTS: In the 2018-2019 influenza season, 47.3% of individuals had ≥1 chronic condition. Most common were circulatory disorders, accounting for more than a third of individuals with ≥1 condition. Prevalence of chronic diseases, and therefore the proportion of high-risk individuals, increased slightly over time across most age groups. A downward trend in influenza VCRs was observed in all age groups until the 2017-2018 season, followed by a noticeable increase in the 2018-2019 season. Highest VCRs occurred among individuals of ≥60years, with a 38.5% VCR for this age group in the 2018-2019 season. Several factors, including age, chronic condition type, and geographical location, affected VCRs.; CONCLUSIONS: Influenza VCRs in individuals at high risk of severe complications from influenza infection are insufficient. Our results suggest that intensified public health efforts are necessary to reach the World Health Organization vaccination coverage target of 75%. © 2022 The Authors. Influenza and Other Respiratory Viruses published by John Wiley & Sons Ltd.

Although it is well-known that limited local mutations of enzymes, such as matrix metalloproteinases (MMPs), may change enzyme activity by orders of magnitude as well as its stability, the completely rational design of proteins is still challenging. These local changes alter the electrostatic potential and thus local electrostatic fields, which impacts the dynamics of water molecules close the protein surface. Here we show by a combined computational design, experimental, and molecular dynamics (MD) study that local mutations have not only a local but also a global effect on the solvent: In the specific case of the matrix metalloprotease MMP14, we found that the nature of local mutations, coupled with surface morphology, have the ability to influence large patches of the water hydrogen-bonding network at the protein surface, which is correlated with stability. The solvent contribution can be experimentally probed via terahertz (THz) spectroscopy, thus opening the door to the exciting perspective of rational protein design in which a systematic tuning of hydration water properties allows manipulation of protein stability and enzymatic activity.

Formation of biomolecular condensates through liquid-liquid phase separation (LLPS) has emerged as a pervasive principle in cell biology, allowing compartmentalization and spatiotemporal regulation of dynamic cellular processes. Proteins that form condensates under physiological conditions often contain intrinsically disordered regions with low-complexity domains. Among them, the RNA-binding proteins FUS and TDP-43 have been a focus of intense investigation because aberrant condensation and aggregation of these proteins is linked to neurodegenerative diseases such as amyotrophic lateral sclerosis and frontotemporal dementia. LLPS occurs when protein-rich condensates form surrounded by a dilute aqueous solution. LLPS is per se entropically unfavorable. Energetically favorable multivalent protein-protein interactions are one important aspect to offset entropic costs. Another proposed aspect is the release of entropically unfavorable preordered hydration water into the bulk. We used attenuated total reflection spectroscopy in the terahertz frequency range to characterize the changes in the hydrogen bonding network accompanying the FUS enrichment in liquid-liquid phase-separated droplets to provide experimental evidence for the key role of the solvent as a thermodynamic driving force. The FUS concentration inside LLPS droplets was determined to be increased to 2.0 mM independent of the initial protein concentration (5 or 10 μM solutions) by fluorescence measurements. With terahertz spectroscopy, we revealed a dewetting of hydrophobic side chains in phase-separated FUS. Thus, the release of entropically unfavorable water populations into the bulk goes hand in hand with enthalpically favorable protein-protein interaction. Both changes are energetically favorable, and our study shows that both contribute to the thermodynamic driving force in phase separation.

Immunosuppressive Interleukin (IL)-10 production by pro-inflammatory CD4(+) T cells is a central self-regulatory function to limit aberrant inflammation. Still, the molecular mediators controlling IL-10 expression in human CD4(+) T cells are largely undefined. Here, we identify a Notch/STAT3 signaling-module as a universal molecular switch to induce IL-10 expression across human naïve and major effector CD4(+) T cell subsets. IL-10 induction was transient, jointly controlled by the transcription factors Blimp-1/c-Maf and accompanied by upregulation of several co-inhibitory receptors, including LAG-3, CD49b, PD-1, TIM-3 and TIGIT. Consistent with a protective role of IL-10 in inflammatory bowel diseases (IBD), effector CD4(+) T cells from Crohn's disease patients were defective in Notch/STAT3-induced IL-10 production and skewed towards an inflammatory Th1/17 cell phenotype. Collectively, our data identify a Notch/STAT3-Blimp-1/c-Maf axis as a common anti-inflammatory pathway in human CD4(+) T cells, which is defective in IBD and thus may represent an attractive therapeutic target.

ObjectivesThe aim was to evaluate the safety and effectiveness of sarilumab in RA patients after inadequate response (IR) to janus kinase inhibitors (JAKi) and tocilizumab.MethodsThe prospective, observational, 24-month single-arm PROSARA study (SARILL08661) is currently running in Germany at 96 sites. RA patients were prospectively selected at the physician’s discretion according to label. This interim analysis included 536 patients over a treatment course of ≤6 months. Patients were stratified in four groups according to pretreatment before the start of sarilumab therapy: last prior treatment JAKi (JAKi-IR); last prior treatment tocilizumab (tocilizumab-IR); any other biological DMARD (bDMARD) in treatment history (bDMARD TH); and patients who had not received any bDMARDs or targeted synthetic (ts) DMARDs (b/tsDMARD naive) before.ResultsFor this preplanned interim analysis, 536 patients were included in the baseline population, of whom 502 patients had at least one corresponding post-baseline effectiveness assessment documented (main analysis population). In all analysed cohorts, safety was consistent with the anticipated profile of sarilumab, without new safety signals. Six months of sarilumab treatment attenuated disease activity in JAKi-IR, tocilizumab-IR, bDMARD TH and b/tsDMARD-naive patients to a very similar extent. Physical function did not change substantially over the course of treatment. Rates of premature study discontinuation were comparable between cohorts.ConclusionSarilumab treatment was effective in patients with IR to JAKi and tocilizumab, with an expectable safety profile and drug retention over 6 months. Confirmation of these promising results should encourage further studies on this treatment sequence, which is of high practical relevance.Study registrationPaul-Ehrlich-Institut—Federal Institute for Vaccine and Biomedics, SARILL08661.

Immunosuppressive Interleukin (IL)-10 production by pro-inflammatory CD4

In cells, proteins are embedded in a crowded environment that controls their properties via manifold avenues including weak protein-macromolecule interactions. A molecular level understanding of these quinary interactions and their contribution to protein stability, function, and localization in the cell is central to modern structural biology. Using a mutational analysis to quantify the energetic contributions of single amino acids to the stability of the ALS related protein superoxide dismutase I (SOD1) in mammalian cells, we show that quinary interactions destabilize SOD1 by a similar energetic offset for most of the mutants, but there are notable exceptions: Mutants that alter its surface properties can even lead to a stabilization of the protein in the cell as compared to the test tube. In conclusion, quinary interactions can amplify and even reverse the mutational response of proteins, being a key aspect in pathogenic protein misfolding and aggregation.

The transcriptional regulator Blimp-1 is absolutely required for IL-10 production in Th1 cells and limits inflammatory effector T cell responses downstream of IL-12 and IL-27., Secretion of the immunosuppressive cytokine interleukin (IL) 10 by effector T cells is an essential mechanism of self-limitation during infection. However, the transcriptional regulation of IL-10 expression in proinflammatory T helper (Th) 1 cells is insufficiently understood. We report a crucial role for the transcriptional regulator Blimp-1, induced by IL-12 in a STAT4-dependent manner, in controlling IL-10 expression in Th1 cells. Blimp-1 deficiency led to excessive inflammation during Toxoplasma gondii infection with increased mortality. IL-10 production from Th1 cells was strictly dependent on Blimp-1 but was further enhanced by the synergistic function of c-Maf, a transcriptional regulator of IL-10 induced by multiple factors, such as the Notch pathway. We found Blimp-1 expression, which was also broadly induced by IL-27 in effector T cells, to be antagonized by transforming growth factor (TGF) β. While effectively blocking IL-10 production from Th1 cells, TGF-β shifted IL-10 regulation from a Blimp-1–dependent to a Blimp-1–independent pathway in IL-27–induced Tr1 (T regulatory 1) cells. Our findings further illustrate how IL-10 regulation in Th cells relies on several transcriptional programs that integrate various signals from the environment to fine-tune expression of this critical immunosuppressive cytokine.