Dynamic imaging of dendritic cell extension into the small bowel lumen in response to epithelial cell TLR engagement

Cells lining the gastrointestinal tract serve as both a barrier to and a pathway for infectious agent entry. Dendritic cells (DCs) present in the lamina propria under the columnar villus epithelium of the small bowel extend processes across this epithelium and capture bacteria, but previous studies provided limited information on the nature of the stimuli, receptors, and signaling events involved in promoting this phenomenon. Here, we use immunohistochemical as well as dynamic explant and intravital two-photon imaging to investigate this issue. Analysis of CD11c–enhanced green fluorescent protein (EGFP) or major histocompatibility complex CII-EGFP mice revealed that the number of trans-epithelial DC extensions, many with an unusual “balloon” shape, varies along the length of the small bowel. High numbers of such extensions were found in the proximal jejunum, but only a few were present in the terminal ileum. The extensions in the terminal ileum markedly increased upon the introduction of invasive or noninvasive Salmonella organisms, and chimeric mouse studies revealed the key role of MyD88-dependent Toll-like receptor (TLR) signaling by nonhematopoietic (epithelial) elements in the DC extension response. Collectively, these findings support a model in which epithelial cell TLR signaling upon exposure to microbial stimuli induces active DC sampling of the gut lumen at sites distant from organized lymphoid tissues

Coordination of hydraulic and morphological traits across dominant grasses in eastern Australia

Leaf hydraulic traits characterize plant drought tolerance and responses to climate change. Yet, plant hydraulics are biased towards northern hemisphere woody species. We collected rhizomes of several perennial grass species along a precipitation gradient in eastern Australia and grew them in an experimental pot study to investigate potential trade-offs between drought tolerance and plant morphology. We measured the following leaf hydraulic traits: the leaf water potential (Ψleaf) at 50% and 88% loss of leaf hydraulic conductance (P50Kleaf and P88Kleaf), the Ψleaf at 50% loss of stomatal conductance (P50gs), leaf turgor loss point (TLP), leaf dry matter content (LDMC), leaf modulus of elasticity (ε), and the slope of the relationship between predawn and midday Ψleaf. We also measured basal area, tiller density, seed head density, root collar diameter, plant height, and aboveground biomass of each individual. As expected, grass species varied widely in leaf-level drought tolerance, with loss of 88% hydraulic conductance occurring at a Ψleaf ranging from −1.52 to −4.01 MPa. However, all but one species lost leaf turgor, and most reached P50gs before this critical threshold. Taller more productive grass species tended to have drought vulnerable leaves characterized by low LDMC and less negative P88Kleaf. Species with greater tiller production experienced stomatal closure and lost turgor at more negative Ψleaf. Although our sample size was limited, we found no relationships between these species' traits and their climate of origin. Overall, we identified important hydraulic and morphological trade-offs in Australian grasses that were surprisingly similar to those observed for woody plants: (1) xylem of taller species was less drought tolerant and (2) turgor loss occurs and stomatal closure begins before significant loss of Kleaf. These data build upon a small yet growing field of grass hydraulics and may be informative of species responses to further drought intensification in Australia. Read the free Plain Language Summary for this article on the Journal blog

The Importance of Cooperation and Relative's Involvement in Combined Treatment for Eating Disorders: a Case Report

Introduction: The importance of combined treatment of EDs is widely acknowledged. We describe the good outcome of a combined treatment in a 43 year old woman, affected by severe Anorexia Nervosa \u2013 Binge Purging (BMI 9.1), since early adolescence. She sought treatment only after giving birth to her second-born when she became aware of her illness. Despite intensive treatment (as an inpatient in hospitals and specialized rehabilitation centres, and in Day Hospital facilities), her condition gradually worsened, and her personal, social, working and family functioning was severely compromised (Global Assessment of Functioning Scale 35), Methods: A multidisciplinary team including psychiatrist, psychotherapist, family psychotherapist, nutritionist, dietician, nurses was involved in treatment, working together to a common treatment strategy. The Psychiatrists role (psicopharmacology, therapeutic process, helping acknowledging and avoiding manipulation) and the nurses role (establishing a therapeutic relationship with the patient, assisting her during meals and supporting the overall therapeutic process), are discussed. Results: A gradual psychopathologic and somatic improvement occurred across a 12-months period: she spent two months in a Psychiatry ward, four more months in a rehab centre and six months in an ED therapeutic community. She gained weight (BMI 21.4) and regained an excellent personal, social and family functioning. She returned to her husband (they previously separated), and the relationship with her daughters, who previously rejected her, improved (GAF 90). Conclusions: The cooperation of the multidisciplinary equipe and the involvement of the patient\u2019s relatives succeeded in reducing anxiety, depression, dysmorphophobia and interrupting the manipulating attitudes typical of the illness

Feeling Through the Body: Alexithymia and Eating Disorders

INTRODUCTION Alexithymia is characterized by difficulties identifying and communicating feelings, and problems differentiating between feelings and bodily sensations; its concrete cognitive style focused on the external environment is typical of psychosomatic patients. Patients with eating disorders (EDs) have high levels of alexithymia, particularly difficulties identifying and describing their feelings. OBJECTIVE The aims of our study are (1) to assess the alexythimia, emotional empathy, facial emotion identification skills and social inference abilities in a sample of ED patients; (2) to compare these variables between ED patients and healthy controls (HC); and (3) to correlate levels of alexithymia with the severity of the ED as measured by the Eating Disorder Inventory-3 (EDI-3) EDRC score in the ED group. METHODS ED (N=42) and HC (N=42) were tested with the Toronto Alexithymia Scale (TAS-20), Eating Disorder Inventory (EDI-3), Facial Emotion Identification Test (FEIT), The Awareness of Social Inference Test (TASIT) and Interpersonal Reactivity Index (IRI). RESULTS Data collection is being completed and the results’ analysis is ongoing. We expect the ED sample to show greater alexythimia and a poorer performance at FEIT and TASIT than HCs. We expect to find a linear correlation between the TAS-20 and EDRC score. CONCLUSION A better understanding of the role of alexithymia in ED etiology and maintenance might allow the development of targeted treatment approaches to help patients improve their skills in identifying and expressing emotions

Diet influences the functions of the human intestinal microbiome

Gut microbes programme their metabolism to suit intestinal conditions and convert dietary components into a panel of small molecules that ultimately affect host physiology. To unveil what is behind the effects of key dietary components on microbial functions and the way they modulate host\u2013microbe interaction, we used for the first time a multi-omic approach that goes behind the mere gut phylogenetic composition and provides an overall picture of the functional repertoire in 27 fecal samples from omnivorous, vegan and vegetarian volunteers. Based on our data, vegan and vegetarian diets were associated to the highest abundance of microbial genes/proteins responsible for cell motility, carbohydrate- and protein-hydrolyzing enzymes, transport systems and the synthesis of essential amino acids and vitamins. A positive correlation was observed when intake of fiber and the relative fecal abundance of flagellin were compared. Microbial cells and flagellin extracted from fecal samples of 61 healthy donors modulated the viability of the human (HT29) colon carcinoma cells and the host response through the stimulation of the expression of Toll-like receptor 5, lectin RegIII\u3b1 and three interleukins (IL-8, IL-22 and IL-23). Our findings concretize a further and relevant milestone on how the diet may prevent/mitigate disease risk

Diet influences the functions of the human intestinal microbiome

Gut microbes programme their metabolism to suit intestinal conditions and convert dietary components into a panel of small molecules that ultimately affect host physiology. To unveil what is behind the effects of key dietary components on microbial functions and the way they modulate host\u2013microbe interaction, we used for the first time a multi-omic approach that goes behind the mere gut phylogenetic composition and provides an overall picture of the functional repertoire in 27 fecal samples from omnivorous, vegan and vegetarian volunteers. Based on our data, vegan and vegetarian diets were associated to the highest abundance of microbial genes/proteins responsible for cell motility, carbohydrate- and protein-hydrolyzing enzymes, transport systems and the synthesis of essential amino acids and vitamins. A positive correlation was observed when intake of fiber and the relative fecal abundance of flagellin were compared. Microbial cells and flagellin extracted from fecal samples of 61 healthy donors modulated the viability of the human (HT29) colon carcinoma cells and the host response through the stimulation of the expression of Toll-like receptor 5, lectin RegIII\u3b1 and three interleukins (IL-8, IL-22 and IL-23). Our findings concretize a further and relevant milestone on how the diet may prevent/mitigate disease risk

Biogeography of arbuscular mycorrhizal fungal spore traits along an aridity gradient, and responses to experimental rainfall manipulation

peer-reviewedSpore size, colour and melanin content are hypothesised to be functional in relation to environmental stress. Here, we studied AM fungal spores in arid environments of Australia and in an experimental platform simulating altered rainfall. We used microscopy and image analysis to measure spore colour and size, and a quantitative colorimetric assay to estimate melanin content in spores. In arid sites, melanin content tended to increase with increasing aridity. We observed a large range of spore colours at all sites but found a higher proportion of both dark and light spores, and fewer intermediate colours, in drier sites. Spore abundance and size varied among sites, but neither were related to aridity. In the experimental platform established in a grassland, we found no evidence that altered rainfall influenced spore traits. This study identifies traits associated with environmental stress to inform future work into AM fungal life history and assembly processes

To respond or not to respond - a personal perspective of intestinal tolerance

For many years, the intestine was one of the poor relations of the immunology world, being a realm inhabited mostly by specialists and those interested in unusual phenomena. However, this has changed dramatically in recent years with the realization of how important the microbiota is in shaping immune function throughout the body, and almost every major immunology institution now includes the intestine as an area of interest. One of the most important aspects of the intestinal immune system is how it discriminates carefully between harmless and harmful antigens, in particular, its ability to generate active tolerance to materials such as commensal bacteria and food proteins. This phenomenon has been recognized for more than 100 years, and it is essential for preventing inflammatory disease in the intestine, but its basis remains enigmatic. Here, I discuss the progress that has been made in understanding oral tolerance during my 40 years in the field and highlight the topics that will be the focus of future research