ß-glucans from Agaricus bisporus mushroom products drive Trained Immunity.

Introduction: Macrofungi, such as edible mushrooms, have been used as a valuable medical resource for millennia as a result of their antibacterial and immuno-modulatory components. Mushrooms contain dietary fibers known as ß-glucans, a class of polysaccharides previously linked to the induction of Trained Immunity. However, little is known about the ability of mushroom-derived ß-glucans to induce Trained Immunity. Methods & results: Using various powdered forms of the white button mushroom (Agaricus bisporus), we found that mouse macrophages pre-treated with whole mushroom powder (WMP) displayed enhanced responses to restimulation with TLR ligands, being particularly sensitive to Toll-like receptor (TLR)-2 stimulation using synthetic lipopeptides. This trained response was modest compared to training observed with yeast-derived ß-glucans and correlated with the amount of available ß-glucans in the WMP. Enriching for ß-glucans content using either a simulated in-vitro digestion or chemical fractionation retained and boosted the trained response with WMP, respectively. Importantly, both WMP and digested-WMP preparations retained ß-glucans as identified by nuclear magnetic resonance analysis and both displayed the capacity to train human monocytes and enhanced responses to restimulation. To determine if dietary incorporation of mushroom products can lead to Trained Immunity in myeloid cells in vivo, mice were given a regimen of WMP by oral gavage prior to sacrifice. Flow cytometric analysis of bone-marrow progenitors indicated alterations in hematopoietic stem and progenitor cells population dynamics, with shift toward myeloid-committed multi-potent progenitor cells. Mature bone marrow-derived macrophages derived from these mice displayed enhanced responses to restimulation, again particularly sensitive to TLR2. Discussion: Taken together, these data demonstrate that ß-glucans from common macrofungi can train innate immune cells and could point to novel ways of delivering bio-available ß-glucans for education of the innate immune system.

Recognition of yeast ß-glucan particles triggers immunometabolic signaling required for trained immunity.

Fungal ß-glucans are major drivers of trained immunity which increases long-term protection against secondary infections. Heterogeneity in ß-glucan source, structure, and solubility alters interaction with the phagocytic receptor Dectin-1 and could impact strategies to improve trained immunity in humans. Using a panel of diverse ß-glucans, we describe the ability of a specific yeast-derived whole-glucan particle (WGP) to reprogram metabolism and thereby drive trained immunity in human monocyte-derived macrophages in vitro and mice bone marrow in vivo. Presentation of pure, non-soluble, non-aggregated WGPs led to the formation of the Dectin-1 phagocytic synapse with subsequent lysosomal mTOR activation, metabolic reprogramming, and epigenetic rewiring. Intraperitoneal or oral administration of WGP drove bone marrow myelopoiesis and improved mature macrophage responses, pointing to therapeutic and food-based strategies to drive trained immunity. Thus, the investment of a cell in a trained response relies on specific recognition of ß-glucans presented on intact microbial particles through stimulation of the Dectin-1 phagocytic response.

Maternal obesity: Perinatal implications.

Over the previous three decades, the prevalence and growth of overweight and obese status has risen relentlessly in both the general population and pregnant women. This rise is seen in both higher pre-pregnancy body mass index measurements along with excessive weight gain during pregnancy. Maternal obesity has been shown to exacerbate co-morbidities such as insulin resistance, pregnancy induced hypertension, and infectious states in parturient mothers. These changes have been shown to subsequently increase rates of fetal anomalies and affect fetal growth, as well as various aspects of the delivery such as rates of instrumented vaginal deliveries and an increase in delivery by cesarean section. Maternal obesity increases fetal birth weight, influences the delivery room resuscitation of the neonate by increasing the need for respiratory support, and increases the risk of neonatal hypoxic ischemic encephalopathy. This review also looks at recent studies revealing the strong association between maternal and offspring obesity and other long-term neurodevelopmental outcomes of offspring.

Negative Regulation of Innate Immune Signaling by Components of the Button Mushroom Agaricus bisporus.

SCOPE: Mushrooms are valued as an edible and medical resource for millennia. As macrofungi, they possess conserved molecular components recognized by innate immune cells like macrophages, yet unlike pathogenic fungi, they do not trigger the immune system in the same way. That these well-tolerated foods both avoid immuno-surveillance and have positive health benefits, highlights the dearth of information on the interactions of mushroom-derived products with the immune system. METHODS AND RESULTS: Using powders produced from the common white button mushroom, Agaricus bisporus, it is observed that pre-treatment of mouse and human macrophages with mushroom powders attenuates innate immune signaling triggered by microbial ligands like LPS and  ß-glucans, including NFκB activation and pro-inflammatory cytokine production. This effect of mushroom powders is observed at lower doses of TLR ligands, suggesting a model of competitive inhibition whereby mushroom compounds bind and occupy innate immune receptors, precluding activation by microbial stimuli. This effect is preserved following simulated digestion of the powders. Moreover, in vivo delivery of mushroom powders attenuates the development of colitis in a DSS-mouse model. CONCLUSION: This data highlights an important anti-inflammatory role for powdered A. bisporus mushrooms, which can be further utilized to develop complementary approaches to modulate chronic inflammation and disease.

Macrophage innate training induced by IL-4 and IL-13 activation enhances OXPHOS driven anti-mycobacterial responses.

Macrophages are a highly adaptive population of innate immune cells. Polarization with IFNγ and LPS into the 'classically activated' M1 macrophage enhances pro-inflammatory and microbicidal responses, important for eradicating bacteria such as Mycobacterium tuberculosis. By contrast, 'alternatively activated' M2 macrophages, polarized with IL-4, oppose bactericidal mechanisms and allow mycobacterial growth. These activation states are accompanied by distinct metabolic profiles, where M1 macrophages favor near exclusive use of glycolysis, whereas M2 macrophages up-regulate oxidative phosphorylation (OXPHOS). Here, we demonstrate that activation with IL-4 and IL-13 counterintuitively induces protective innate memory against mycobacterial challenge. In human and murine models, prior activation with IL-4/13 enhances pro-inflammatory cytokine secretion in response to a secondary stimulation with mycobacterial ligands. In our murine model, enhanced killing capacity is also demonstrated. Despite this switch in phenotype, IL-4/13 trained murine macrophages do not demonstrate M1-typical metabolism, instead retaining heightened use of OXPHOS. Moreover, inhibition of OXPHOS with oligomycin, 2-deoxy glucose or BPTES all impeded heightened pro-inflammatory cytokine responses from IL-4/13 trained macrophages. Lastly, this work identifies that IL-10 attenuates protective IL-4/13 training, impeding pro-inflammatory and bactericidal mechanisms. In summary, this work provides new and unexpected insight into alternative macrophage activation states in the context of mycobacterial infection.

Pyridoxine-Dependent Epilepsy as a Cause of Neonatal Seizures.

Pediatric seizures are a common reason for emergency department visits. The highest risk of seizures in children is during the neonatal period. A low index of suspicion is important to facilitate the early assessment, workup, and treatment of inborn errors of metabolism to optimize developmental outcomes. We present the rare case of a 9-day-old with seizures refractory to multiple anticonvulsant medications who was diagnosed with pyridoxine-dependent epilepsy. We review differences in the management of neonatal seizures from older patients, the utility of a trial of pyridoxine in refractory neonatal seizures, and the importance of preparing for emergent airway management given pyridoxine's ability to cause apnea and central nervous system depression.

Mycobacterium tuberculosis Limits Host Glycolysis and IL-1ß by Restriction of PFK-M via MicroRNA-21.

Increased glycolytic metabolism recently emerged as an essential process driving host defense against Mycobacterium tuberculosis (Mtb), but little is known about how this process is regulated during infection. Here, we observe repression of host glycolysis in Mtb-infected macrophages, which is dependent on sustained upregulation of anti-inflammatory microRNA-21 (miR-21) by proliferating mycobacteria. The dampening of glycolysis by miR-21 is mediated through targeting of phosphofructokinase muscle (PFK-M) isoform at the committed step of glycolysis, which facilitates bacterial growth by limiting pro-inflammatory mediators, chiefly interleukin-1ß (IL-1ß). Unlike other glycolytic genes, PFK-M expression and activity is repressed during Mtb infection through miR-21-mediated regulation, while other less-active isoenzymes dominate. Notably, interferon-γ (IFN-γ), which drives Mtb host defense, inhibits miR-21 expression, forcing an isoenzyme switch in the PFK complex, augmenting PFK-M expression and macrophage glycolysis. These findings place the targeting of PFK-M by miR-21 as a key node controlling macrophage immunometabolic function.

The circadian protein BMAL1 in myeloid cells is a negative regulator of allergic asthma.

Our body clock drives rhythms in the expression of genes that have a 24-h periodicity. The transcription factor BMAL1 is a crucial component of the molecular clock. A number of physiological processes, including immune function, are modulated by the circadian clock. Asthma, a disease with very strong clinical evidence demonstrating regulation by circadian variation, is of particular relevance to circadian control of immunity. Airway hypersensitivity and asthma attacks are more common at night in humans. The molecular basis for this is unknown, and there is no model of asthma in animals with genetic distortion of the molecular clock. We used mice lacking BMAL1 in myeloid cells (BMAL1-LysM-/-) to determine the role of BMAL1 in allergic asthma. Using the ovalbumin model of allergic asthma, we demonstrated markedly increased asthma features, such as increased lung inflammation, demonstrated by drastically higher numbers of eosinophils and increased IL-5 levels in the lung and serum, in BMAL1-LysM-/- mice. In vitro studies demonstrated increased proinflammatory chemokine and mannose receptor expression in IL-4- as well as LPS-treated macrophages from BMAL1-LysM-/- mice compared with wild-type controls. This suggests that Bmal1 is a potent negative regulator in myeloid cells in the context of allergic asthma. Our findings might explain the increase in asthma incidents during the night, when BMAL1 expression is low.

Preschoolers Flexibly Adapt to Linguistic Input in a Noisy Channel.

Because linguistic communication is inherently noisy and uncertain, adult language comprehenders integrate bottom-up cues from speech perception with top-down expectations about what speakers are likely to say. Further, in line with the predictions of ideal-observer models, past results have shown that adult comprehenders flexibly adapt how much they rely on these two kinds of cues in proportion to their changing reliability. Do children also show evidence of flexible, expectation-based language comprehension? We presented preschoolers with ambiguous utterances that could be interpreted in two different ways, depending on whether the children privileged perceptual input or top-down expectations. Across three experiments, we manipulated the reliability of both their perceptual input and their expectations about the speaker's intended meaning. As predicted by noisy-channel models of speech processing, results showed that 4- and 5-year-old-but perhaps not younger-children flexibly adjusted their interpretations as cues changed in reliability.

Length of stay of pediatric mental health emergency department visits in the United States.

OBJECTIVE: To compare pediatric mental health emergency department visits to other pediatric emergency department visits, focusing on length of stay. METHOD: We analyzed data from the National Hospital Ambulatory Medical Care Survey, a nationally representative sample of US emergency department visits from 2001 to 2008, for patients aged ≤18 years (n = 73,015). Visits with a principal diagnosis of a mental disorder (n = 1,476) were compared to visits (n = 71,539) with regard to patient and hospital characteristics, treatment, and length of stay. Predictors of prolonged mental health visits were identified. RESULTS: Mental health visits were more likely than other visits to arrive by ambulance (21.8% versus 6.3%, p < .001), to be triaged to rapid evaluation (27.9% versus 14.9%, p < .001), and to be admitted (16.4% versus 7.6%, p < .001) or transferred (15.7% versus 1.5%, p < .001). The median length of stay for mental health visits (169 minutes) significantly exceeded that of other visits (108 minutes). The odds of extended stay beyond 4 hours for mental health visits was almost twice that for other visits (adjusted odds ratio 1.9, 95% CI = 1.5-2.4) and was not explained by observed differences in evaluation, treatment, or disposition. Among mental health visits, advancing calendar year of study, intentional self-injury, age 6-13 years, Northeastern, Southern, and metropolitan hospital location, use of laboratory studies, and patient transfer all predicted extended stays. CONCLUSIONS: Compared with other pediatric emergency visits, mental health visits are longer, are more frequently triaged to urgent evaluation, and more likely to result in patient admission or transfer, thereby placing distinctive burdens on US emergency departments.

Coalescence of low-viscosity fluids in air.

An electrical method is used to study the early stages of coalescence of two low-viscosity drops. A drop of aqueous NaCl solution is suspended in air above a second drop of the same solution, which is grown until the drops touch. At that point a rapidly widening bridge forms between them. By measuring the resistance and capacitance of the system during this coalescence event, one can obtain information about the time dependence of the characteristic bridge radius and its characteristic height. At early times, a new asymptotic regime is observed that is inconsistent with previous theoretical predictions. The measurements at several drop radii and approach velocities are consistent with a model in which the two liquids coalesce with a slightly deformed interface.

Coalescence in low-viscosity liquids.

The expected universal dynamics associated with the initial stage of droplet coalescence are difficult to study visually due to the rapid motion of the liquid and the awkward viewing geometry. Here we employ an electrical method to study the coalescence of two low-viscosity droplets at early times. We measure the growth dynamics of the bridge connecting the two droplets and observe a new asymptotic regime inconsistent with previous theoretical predictions. The measurements are consistent with a model in which the two liquids coalesce with a slightly deformed interface.

Spout states in the selective withdrawal of immiscible fluids through a nozzle suspended above a two-fluid interface.

In selective withdrawal, fluid is withdrawn through a nozzle suspended above the flat interface separating two immiscible, density-separated fluids of viscosities nu(upper) and nu(lower) = lambda nu(upper). At low withdrawal rates, the interface gently deforms into a hump. At a transition withdrawal rate, a spout of the lower fluid becomes entrained with the flow of the upper one into the nozzle. When lambda=0.005, the spouts at the transition are very thin with features that are over an order of magnitude smaller than any observed in the humps. When lambda=20, there is an intricate pattern of hysteresis and a spout appears which is qualitatively different from those seen at lower lambda. No corresponding qualitative difference is seen in the hump shapes.