Conversion of rutin, a prevalent dietary flavonol, by the human gut microbiota

The gut microbiota plays a pivotal role in the conversion of dietary flavonoids, which can affect their bioavailability and bioactivity and thereby their health-promoting properties. The ability of flavonoids to stimulate the activity of the microbiota has, however, not been systematically evaluated. In the present study, we used a fluorescence-based single-cell activity measure [biorthogonal non-canonical ammino acid-tagging (BONCAT)] combined with fluorescence-activated cell-sorting (FACS) to determine which microorganisms are stimulated by the flavonoid rutin. We performed anaerobic incubations of human fecal microbiota amended with rutin and in the presence of the cellular activity marker L-Azidohomoalanine (AHA) to detect rutin-stimulated cells. We found that 7% of cells in the gut microbiota were active after a 6 h incubation and 23% after 24 h. We then sorted BONCAT-positive cells and observed an enrichment of Lachnospiraceae (Lachnoclostridium, and Eisenbergiella), Enterobacteriaceae, Tannerellaceae and Erysipelotrichaceae species in the rutin-responsive fraction of the microbiota. There was marked inter-individual variability in the appearance of rutin conversion products after incubation with rutin. Consistent with this, there was substantial variability in the abundance of rutin-responsive microbiota among different individuals. Specifically, we observed that Enterobacteriaceae were associated with conversion of rutin into quercetin-3-glucoside and Lachnospiraceae were associated with quercetin production. This suggests that individual microbiotas differ in their ability to metabolize rutin and utilize different conversion pathways

Integrative transcriptome analysis deciphers mechanisms of nickel contact dermatitis

Background Nickel-induced allergic contact dermatitis (nACD) remains a major occupational skin disorder, significantly impacting the quality of life of suffering patients. Complex cellular compositional changes and associated immunological pathways are partly resolved in humans; thus, the impact of nACD on human skin needs to be further elucidated. Methods To decipher involved immunological players and pathways, human skin biopsies were taken at 0, 2, 48, and 96 hours after nickel patch test in six nickel-allergic patients. Gene expression profiles were analyzed via microarray. Results Leukocyte deconvolution of nACD-affected skin identified major leukocyte compositional changes at 48 and 96 hours, including natural killer (NK) cells, macrophage polarization, and T-cell immunity. Gene set enrichment analysis mirrored cellular-linked functional pathways enriched over time. NK cell infiltration and cytotoxic pathways were uniquely found in nACD-affected skin compared to sodium lauryl sulfate-induced irritant skin reactions. Conclusion These results highlight key immunological leukocyte subsets as well as associated pathways in nACD, providing insights into pathophysiology with the potential to unravel novel therapeutic targets.Peer reviewe

Integrative Transcriptomics Reveals Activation of Innate Immune Responses and Inhibition of Inflammation During Oral Immunotherapy for Egg Allergy in Children

We previously reported the results of a randomized, open-label trial of egg oral immunotherapy (OIT) in 50 children where 44% were desensitized and 46% were partially desensitized after 8 months of treatment. Here we focus on cell-mediated molecular mechanisms driving desensitization during egg OIT. We sought to determine whether changes in genome-wide gene expression in blood cells during egg OIT correlate with humoral responses and the clinical outcome. The blood cell transcriptome of 50 children receiving egg OIT was profiled using peripheral blood mononuclear cell (PBMC) samples obtained at baseline and after 3 and 8 months of OIT. We identified 467 differentially expressed genes (DEGs) after 3 or 8 months of egg OIT. At 8 months, 86% of the DEGs were downregulated and played a role in the signaling of TREM1, IL-6, and IL-17. In correlation analyses, Gal d 1-4-specific IgG4 antibodies associated positively with DEGs playing a role in pathogen recognition and antigen presentation and negatively with DEGs playing a role in the signaling of IL-10, IL-6, and IL-17. Desensitized and partially desensitized patients had differences in their antibody responses, and although most of the transcriptomic changes were shared, both groups had also specific patterns, which suggest slower changes in partially desensitized and activation of NK cells in the desensitized group. OIT for egg allergy in children inhibits inflammation and activates innate immune responses regardless of the clinical outcome at 8 months. Changes in gene expression patterns first appear as posttranslational protein modifications, followed by more sustained epigenetic gene regulatory functions related to successful desensitization.Peer reviewe

Bet v 1 triggers antiviral-type immune signalling in birch-pollen-allergic individuals

Background In allergic patients, clinical symptoms caused by pollen remind of symptoms triggered by viral respiratory infections, which are also the main cause of asthmatic exacerbations. In patients sensitized to birch pollen, Bet v 1 is the major symptom-causing allergen. Immune mechanisms driving Bet v 1-related responses of human blood cells have not been fully characterized. Objective To characterize the immune response to Bet v 1 in peripheral blood in patients allergic to birch pollen. Methods The peripheral blood mononuclear cells of birch-allergic (n = 24) and non-allergic (n = 47) adolescents were stimulated ex-vivo followed by transcriptomic profiling. Systems-biology approaches were employed to decipher disease-relevant gene networks and deconvolution of associated cell populations. Results Solely in birch-allergic patients, co-expression analysis revealed activation of networks of innate immunity and antiviral signalling as the immediate response to Bet v 1 stimulation. Toll-like receptors and signal transducer transcription were the main drivers of gene expression patterns. Macrophages and dendritic cells were the main cell subsets responding to Bet v 1. Conclusions and clinical relevance In birch-pollen-allergic patients, the activated innate immune networks seem to be, in part, the same as those activated during viral infections. This tendency of the immune system to read pollens as viruses may provide new insight to allergy prevention and treatment.Peer reviewe

An optimized, robust and reproducible protocol to generate well-differentiated primary nasal epithelial models from extremely premature infants

Extremely premature infants are prone to severe respiratory infections, and the mechanisms underlying this exceptional susceptibility are largely unknown. Nasal epithelial cells (NEC) represent the first-line of defense and adult-derived ALI cell culture models show promising results in mimicking in vivo physiology. Therefore, the aim of this study was to develop a robust and reliable protocol for generating well-differentiated cell culture models from NECs of extremely premature infants. Nasal brushing was performed in 13 extremely premature infants at term corrected age and in 11 healthy adult controls to obtain NECs for differentiation at air-liquid interface (ALI). Differentiation was verified using imaging and functional analysis. Successful isolation and differentiation was achieved for 5 (38.5%) preterm and 5 (45.5%) adult samples. Preterm and adult ALI-cultures both showed well-differentiated morphology and ciliary function, however, preterm cultures required significantly longer cultivation times for acquiring full differentiation (44 +/- 3.92 vs. 23 +/- 1.83 days; p <0.0001). Moreover, we observed that recent respiratory support may impair successful NECs isolation. Herewithin, we describe a safe, reliable and reproducible method to generate well-differentiated ALI-models from NECs of extremely premature infants. These models provide a valuable foundation for further studies regarding immunological and inflammatory responses and respiratory disorders in extremely premature infants.Peer reviewe

Transcriptomic analysis identifies lactoferrin-induced quiescent circuits in neonatal macrophages

IntroductionUpon birth, a hitherto naïve immune system is confronted with a plethora of microbial antigens due to intestinal bacterial colonization. To prevent excessive inflammation and disruption of the epithelial barrier, physiological mechanisms must promote immune-anergy within the neonatal gut. As high concentrations of human lactoferrin (hLF), a transferrin glycoprotein shown to modulate macrophage function, are frequently encountered in colostrum, its direct interaction with intestinal macrophages may satisfy this physiological need. Thus, the primary objective of this study was to investigate transcriptional changes induced by human lactoferrin in neonatal monocyte-derived macrophages.MethodsCord blood-derived monocytes were differentiated with M-CSF in presence or absence of 500 µg/mL hLF for 7 days and afterwards stimulated with 1 ng/mL LPS or left untreated. RNA was then isolated and subjected to microarray analysis.ResultsDifferentiation of cord blood-derived monocytes in presence of hLF induced a distinct transcriptional program defined by cell cycle arrest in the G2/M phase, induction of IL-4/IL-13-like signaling, altered extracellular matrix interaction, and enhanced propensity for cell-cell interaction. Moreover, near-complete abrogation of transcriptional changes induced by TLR4 engagement with LPS was observed in hLF-treated samples.DiscussionThe global transition towards an M2-like homeostatic phenotype and the acquisition of quiescence elegantly demonstrate the ontogenetical relevance of hLF in attenuating pro-inflammatory signaling within the developing neonatal intestine. The marked anergy towards proinflammatory stimuli such as LPS further underlines the glycoprotein’s potential therapeutic relevance

Machine-learning-driven biomarker discovery for the discrimination between allergic and irritant contact dermatitis

Contact dermatitis tremendously impacts the quality of life of suffering patients. Currently, diagnostic regimes rely on allergy testing, exposure specification, and follow-up visits; however, distinguishing the clinical phenotype of irritant and allergic contact dermatitis remains challenging. Employing integrative transcriptomic analysis and machine-learning approaches, we aimed to decipher disease-related signature genes to find suitable sets of biomarkers. A total of 89 positive patch-test reaction biopsies against four contact allergens and two irritants were analyzed via microarray. Coexpression network analysis and Random Forest classification were used to discover potential biomarkers and selected biomarker models were validated in an independent patient group. Differential gene-expression analysis identified major gene-expression changes depending on the stimulus. Random Forest classification identified CD47, BATF, FASLG, RGS16, SYNPO, SELE, PTPN7, WARS, PRC1, EXO1, RRM2, PBK, RAD54L, KIFC1, SPC25, PKMYT, HISTH1A, TPX2, DLGAP5, TPX2, CH25H, and IL37 as potential biomarkers to distinguish allergic and irritant contact dermatitis in human skin. Validation experiments and prediction performances on external testing datasets demonstrated potential applicability of the identified biomarker models in the clinic. Capitalizing on this knowledge, novel diagnostic tools can be developed to guide clinical diagnosis of contact allergies.Peer reviewe

Is There a Role for Elective Early Upper Gastrointestinal Contrast Study in Neurologically Impaired Children following Laparoscopic Nissen Fundoplication?

Assessment of discomfort as a sign for early postoperative complications in neurologically impaired (NI) children is challenging. The necessity of early routine upper gastrointestinal (UGI) contrast studies following laparoscopic Nissen fundoplication in NI children is unclear. We aimed to evaluate the role of scheduled UGI contrast studies to identify early postoperative complications following laparoscopic Nissen fundoplication in NI children. Data for laparoscopic Nissen fundoplications performed in NI children between January 2004 and June 2021 were reviewed. A total of 103 patients were included, with 60 of these being boys. Mean age at initial operation was 6.51 (0.11–18.41) years. Mean body weight was 16.22 (3.3–62.5) kg. Mean duration of follow up was 4.15 (0.01–16.65 years) years. Thirteen redo fundoplications (12.5%) were performed during the follow up period; eleven had one redo and two had 2 redos. Elective postoperative UGI contrast studies were performed in 94 patients (91%). Early postoperative UGI contrast studies were able to identify only one complication: an intrathoracal wrap herniation on postoperative day five, necessitating a reoperation on day six. The use of early UGI contrast imaging following pediatric laparoscopic Nissen fundoplication is not necessary as it does not identify a significant number of acute postoperative complications requiring re-intervention

Scientific Reports / Increased nurse workload is associated with bloodstream infections in very low birth weight infants

Neonatal sepsis is a major cause of morbidity and mortality in very low birth weight infants (VLBWI). Nurse workload considerably affects infection rates in intensive care units. However, data concerning the impact of staff workload on bloodstream infections (BSI) in VLBWI are scarce. The aim of the study was to examine the association between nurse workload and BSI in VLBWI. VLBWI admitted to our neonatal intensive care unit during 20162017 were retrospectively analysed. Association between nurse workload, determined by a standardized nursing score, and the BSI occurrence was investigated. A higher nurse workload was significantly associated with higher occurrence of BSI (p=0.0139) in VLBWI. An assumed workload of 120% or higher, representing the need for additional nurses in our NICU setting, is associated with an elevated risk for BSI in this vulnerable population OR 2.32 (95% CI: 1.423.8, p=0.0005). In conclusion, nurse understaffing is associated with a higher risk for BSI in VLBWI.(VLID)493353

Cobalt nanoparticles cause allergic contact dermatitis in humans

Background: Cobalt (Co) causes allergic contact dermatitis (ACD) and the emerging use of Co nanoparticles (CoNPs) warrants gaining further insight into its potential to elicit ACD in sensitized individuals. Objectives: The aims of the study were to clarify to what extent CoNPs may elicit ACD responses in participants with Co contact allergy, and to evaluate whether the nanoparticles cause a distinct immune response compared with cobalt chloride (CoCl2) in the skin reactions. Methods: Fourteen individuals with Co contact allergy were exposed to CoNPs, CoCl2, a Co-containing hard-metal disc (positive control), and an empty test chamber (negative control) by patch testing. Allergic responses were evaluated clinically by a dermatologist at Days 2, 4 and 7. At Day 2, patch-test chambers were removed, and remaining test-substance and skin-wipe samples were collected for inductive-coupled plasma mass spectrometry (ICP-MS) analysis. Additionally, skin biopsies were taken from patch-test reactions at Day 4 for quantitative real-time polymerase chain reaction analysis, histopathology and ICP-MS analysis of Co skin penetration. Results: Patch testing with CoNPs elicited allergic reactions in Co-sensitized individuals. At all timepoints, clinical assessment revealed significantly lower frequencies of positive patch-test reactions to CoNPs compared with CoCl2 or to the positive control. CoNPs elicited comparable immune responses to CoCl2. Chemical analysis of Co residues in patch-test filters, and on skin, shows lower doses for CoNPs compared with CoCl2. Conclusions: CoNPs potently elicit immune responses in Co-sensitized individuals. Even though patch testing with CoNPs resulted in a lower skin dose than CoCl2, identical immunological profiles were present. Further research is needed to identify the potential harm of CoNPs to human health