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Key Points Mammalian target of rapamycin (mTOR) is an evolutionarily conserved serine/threonine kinase that is present in two complexes: mTORC1 and mTORC2. mTORC1 is the main energy and nutrient sensor of the cell: it senses the presence of amino acids, glucose, lipids and ATP to enable efficient activation of the network in response to growth factors, Toll-like receptor (TLR) ligands and cytokines. Activation of the mTOR pathway usually promotes an anabolic response that induces the synthesis of nucleic acids, proteins and lipids. In addition, it stimulates glycolysis and mitochondrial respiration. Emerging data suggest that this metabolic reconfiguration is required for specific effector functions in myeloid cells. Translational control of gene expression in myeloid immune cells has emerged as one way in which mTORC1 controls cellular processes such as migration, expression of type I interferon and pro-inflammatory or anti-inflammatory cytokines, and metabolic reprogramming. Counterintuitively, inhibition of mTORC1 during TLR triggering generally promotes interleukin-12 (IL-12) production and inhibits expression of IL-10 and type I interferon by dendritic cells (DCs); it also augments their T cell-stimulatory capacity. Inhibition of mTORC2 enhances a pro-inflammatory response and IL-12 production in DCs. Inhibition of mTORC1 in macrophages promotes autophagy, which is important for intracellular pathogen killing and clearance of ingested complex lipids such as low-density lipoprotein (LDL) cholesterol. mTORC2 is especially important for cell polarity and chemotaxis in neutrophils and mast cells. mTORC2 controls the leading edge as well as tail retraction during chemotactic migration. Activation of mTORC1 in NK cells by IL-15 triggers a glycolytic response, which is important for their proliferation and acquisition of cytotoxicity. The rapid response of innate immune cells requires metabolic reprogramming to support their specific effector functions. As discussed here, mTOR is a key regulator of this process: it senses the environmental and intracellular nutritional status of innate immune cells to dictate and optimize the inflammatory response. The innate immune system is central for the maintenance of tissue homeostasis and quickly responds to local or systemic perturbations by pathogenic or sterile insults. This rapid response must be metabolically supported to allow cell migration and proliferation and to enable efficient production of cytokines and lipid mediators. This Review focuses on the role of mammalian target of rapamycin (mTOR) in controlling and shaping the effector responses of innate immune cells. mTOR reconfigures cellular metabolism and regulates translation, cytokine responses, antigen presentation, macrophage polarization and cell migration. The mTOR network emerges as an integrative rheostat that couples cellular activation to the environmental and intracellular nutritional status to dictate and optimize the inflammatory response. A detailed understanding of how mTOR metabolically coordinates effector responses by myeloid cells will provide important insights into immunity in health and disease.

Macrophages are critical for granuloma formation, but the cell-intrinsic mechanisms remain unknown. Weichhart and colleagues demonstrate that chronic mTOR activity leads to macrophage-dependent granuloma formation, which may have relevance to sarcoidosis. The aggregation of hypertrophic macrophages constitutes the basis of all granulomatous diseases, such as tuberculosis or sarcoidosis, and is decisive for disease pathogenesis. However, macrophage-intrinsic pathways driving granuloma initiation and maintenance remain elusive. We found that activation of the metabolic checkpoint kinase mTORC1 in macrophages by deletion of the gene encoding tuberous sclerosis 2 ( Tsc2 ) was sufficient to induce hypertrophy and proliferation, resulting in excessive granuloma formation in vivo . TSC2-deficient macrophages formed mTORC1-dependent granulomatous structures in vitro and showed constitutive proliferation that was mediated by the neo-expression of cyclin-dependent kinase 4 (CDK4). Moreover, mTORC1 promoted metabolic reprogramming via CDK4 toward increased glycolysis while simultaneously inhibiting NF-κB signaling and apoptosis. Inhibition of mTORC1 induced apoptosis and completely resolved granulomas in myeloid TSC2-deficient mice. In human sarcoidosis patients, mTORC1 activation, macrophage proliferation and glycolysis were identified as hallmarks that correlated with clinical disease progression. Collectively, TSC2 maintains macrophage quiescence and prevents mTORC1-dependent granulomatous disease with clinical implications for sarcoidosis.

In imagining history, one must inevitably rely on its textual representations, whether fictitious or supposedly “objective”, yet always subject to the constraints and conventions of textuality. Still, it is precisely by exploiting and consciously relying on the textual in the presentation of the past that contemporary authors, including politicians and makers of history, strive to provide it with current significance, emotional impact and universal meaning. The study of such attempts benefits.

Chronic stress has become a predominant factor associated with a variety of psychiatric disorders, such as depression and anxiety, in both human and animal models. Although multiple studies have looked at transcriptional changes after social defeat stress, these studies primarily focus on bulk tissues, which might dilute important molecular signatures of social interaction in activated cells. In this study, we employed the Arc-GFP mouse model in conjunction with chronic social defeat (CSD) to selectively isolate activated nuclei (AN) populations in the ventral hippocampus (vHIP) and prefrontal cortex (PFC) of resilient and susceptible animals. Nuclear RNA-seq of susceptible vs. resilient populations revealed distinct transcriptional profiles linked predominantly with neuronal and synaptic regulation mechanisms. In the vHIP, susceptible AN exhibited increased expression of genes related to the cytoskeleton and synaptic organization. At the same time, resilient AN showed upregulation of cell adhesion genes and differential expression of major glutamatergic subunits. In the PFC, susceptible mice exhibited upregulation of synaptotagmins and immediate early genes (IEGs), suggesting a potentially over-amplified neuronal activity state. Our findings provide a novel view of stress-exposed neuronal activation and the molecular response mechanisms in stress-susceptible vs. resilient animals, which may have important implications for understanding mental resilience.

Invasin and intimin are major virulence factors of enteropathogenic Yersiniae and Escherichia coli, mediating invasion into and intimate adherence to host cells, respectively. Several studies have hinted that extracellular portion of these homologous proteins might be exported via an autotransport mechanism, but rigorous experimental proof has been lacking. Here, we present a topology model for invasin and intimin, consistent with the hypothesis that the N-terminal β-barrel domain acts as a translocation pore to secrete the C-terminal passenger domain. We confirmed this topology model by inserting epitope tags into the loops of the β-barrel. We further show that obstructing the pore of β-barrel hinders the export of the passenger domain. As for classical autotransport, the biogenesis of invasin and intimin is dependent on the Bam complex and the periplasmic chaperone SurA, whereas the chaperone/protease DegP is involved in quality control. However, compared to classical autotransporters (Type Va secretion), the domain structure of intimin and invasin is inverted. We conclude that proteins of the intimin and invasin family constitute a novel group of autotransported proteins, and propose that this class of autotransporters be termed Type Ve secretion.

Ionic liquids (ILs) have gained considerable attention due to their versatile and designable properties. ILs show great potential as antibacterial agents, but understanding the mechanism of attack on bacterial cells is essential to ensure the optimal design of IL-based biocides. The final aim is to achieve maximum efficacy while minimising toxicity and preventing resistance development in target organisms. In this study, we examined a dose–response analysis of ILs’ antimicrobial activity against two pathogenic bacteria with different Gram types in terms of molecular responses on a cellular level using Fourier-transform infrared (FTIR) spectroscopy. In total, 18 ILs with different antimicrobial active motifs were evaluated on the Gram-negative enteropathogenic Escherichia coli (EPEC) and Gram-positive methicillin-resistant Staphylococcus aureus (MRSA). The results showed that most ILs impact bacterial proteins with increasing concentration but have a minimal effect on cellular membranes. Dose–response spectral analysis revealed a distinct ante-mortem response against certain ILs for MRSA but not for EPEC. We found that at sub-lethal concentrations, MRSA actively changed their membrane composition to counteract the damaging effect induced by the ILs. This suggests a new adaptive mechanism of Gram-positive bacteria against ILs and demonstrates the need for a better understanding before using such substances as novel antimicrobials.

Cereals, in addition to being a major ingredient in daily meals, also play a role in the preparation of foodstuffs for ritual purposes. This paper deals with finds that may correspond to such ritual preparations retrieved from the hillfort site of Stillfried an der March. The site, spreading across an area of ca. 23 ha, held a very important position among settlements of Late Urnfield period (particularly during the 10th- 9th c. BCE), acting as a central place where large scale storage of grain as well as textile and metal production took place under the control of local elites. Three incomplete ring-shaped charred organic objects, found together with 14 rings and ring fragments made of clay were discovered in a secondary filled silo pit, excavated among a total of about 100 pits of this kind at the site. The overall good state of preservation of the organic ring fragments suggests that they were deposited intact on the bottom of the pit and covered well so that no re-deposition or damage occurred. This could be indicate their intentional placement in this position. Light and scanning electron microscopy revealed that the charred organic rings are cereal products containing hulled barley and a wheat species. Indications that the objects were shaped from a wet cereal mixture and had been subsequently dried without baking are discussed, as well as the possible significance of the find assemblage. The annular objects are put in context with the contemporary cereal spectrum as well as other cereal preparations from Stillfried, outlining their different chaînes opératoires for handling cereal food.

The Otago program (OP) is evidence-based and focuses on fall prevention in older people. The feasibility and usability of a short-term digital program modeled after the principles of the OP in the setting of early geriatric rehabilitation (EGR) are unclear. This study investigated the feasibility and usability of an additional technology-based fall prevention program (FPP) in the setting of EGR. We performed a feasibility study in the setting of EGR. A sample of 30 patients (mobility at least by walker; mini-mental status test score >17) was recruited between March and June 2024 and compared with a retrospective cohort (n=30, former EGR patients). All patients in the intervention group (IG) received a supervised, OP-modified FPP thrice/week for 20 minutes using a technology-based platform called \"Pixformance.\" The device is a digital trainer and enables real-time corrections. The primary end point was the feasibility (given when 80% of the IG participated in 6 trainings within 2 weeks). Secondary outcomes were usability (patients' and facilitators' perspective; ≥75%), risk of falls (Berg Balance Scale), mobility (Timed Up and Go Test), functional independence (Functional Independence Measure), and activities of daily living (Barthel Index). Several further exploratory end points were analyzed including anxiety and depression (Four-Item Patient Health Questionnaire; PH-Q4). Data were accessed at entry to EGR and after 2 weeks prior to discharge. To analyze the pre-posttest results, the dependent Student t test and the Wilcoxon test were applied. A mixed ANOVA with repeated measurements was used for statistical analyses of time-, group-, and interaction-related changes. A cohort of 60 patients (mean 80.2, SD 6.1 y; 58% females, 35/60) was analyzed. The main indication for EGR was stroke (9/60, 15%). Patients were recruited into a prospective IG (n=30) and a retrospective control group (n=30). Of the 30 patients in the prospective IG, 11 patients (37%) completed 6 training sessions within 2 weeks. Reasons why participants did not complete 6 training sessions were diagnostic appointments (33%), pain/discomfort (33%), or fatigue (17%). EGR patients rated FPP usability at 84% and facilitators at 65% out of 100%. Pre-posttest analysis of the standard assessments showed a significant interaction in Berg Balance Scale (<.01). In both groups, a significant improvement over time was found in the Timed Up and Go Test (<.01), Barthel Index (<.01), and Functional Independence Measure (<.01). Likewise, in the IG, the PH-Q4 score (.02) improved. While the technology-based FPP in the EGR setting was generally well-accepted by patients, with high usability ratings, its feasibility was limited. Only 37% of participants completed the required additional training sessions. Further studies should test the technology-based FPP as an integrated part of the EGR complex therapy concept. Our findings suggest potential benefits of incorporating technology-based FPPs in EGR, but further refinement is needed to enhance participation and feasibility.

Phenotypic diversity is an important trait of bacterial populations and can enhance fitness of the existing genotype in a given environment. To characterize different subpopulations, several studies have analyzed differential gene expression using fluorescent reporters. These studies visualized either single or multiple genes within single cells using different fluorescent proteins. However, variable maturation and folding kinetics of different fluorophores complicate the study of dynamics of gene expression. Here, we present a proof-of-principle study for an alternative gene expression system in a wbaP mutant of Salmonella Typhimurium (S. Tm) lacking the O-sidechain of the lipopolysaccharide. We employed the hemagglutinin (HA)-tagged inverse autotransporter invasin (invAHA) as a transcriptional reporter for the expression of the type three secretion system 1 (T1) in S. Tm. Using a two-reporter approach with GFP and the InvAHA in single cells, we verify that this reporter system can be used for T1 gene expression analysis, at least in strains lacking the O-antigen (wbaP), which are permissive for detection of the surface-exposed HA-epitope. When we placed the two reporters gfp and invAHA under the control of either one or two different promoters of the T1 regulon, we were able to show correlative expression of both reporters. We conclude that the invAHA reporter system is a suitable tool to analyze T1gene expression in S. Tm and propose its applicability as molecular tool for gene expression studies within single cells.