TGF-ß1 impairs IgA class switch recombination and production in porcine Peyer's patches B cells.

Secretory IgA is crucial for preventing the invasion of entero-pathogens via intestinal mucosa. While it is well-established that Transforming growth factor ß1 (TGF-ß1) regulates IgA production in human and mouse B cells, our previous investigation revealed different functions of TGF-ß1 in IgA generation in pigs compared with humans and mice, with the underlying mechanism remaining elusive. In this study, IgM+ B cells from porcine Peyer's patches (PPs) were isolated and stimulated with recombinant porcine TGF-ß1 to evaluate the effect of TGF-ß1 on pigs. The results showed that antibody production from B cells of PPs was impaired by TGF-ß1 ex vivo. Furthermore, TGF-ß1 treatment led to a decrease in the expression of germ-line transcript αand postswitch transcript α. Moreover, we observed that TGF-ß1 predominantly inhibited the phosphorylation of p38-mitogen-activated protein kinases (MAPK), confirming the involvement of the p38-MAPK pathway in porcine IgA generation and IgA class switch recombination. The application of p38-MAPK inhibitor resulted in decreased B-cell differentiation levels. Collectively, this study demonstrates that exogenous TGF-ß1 restrains the production and class switch recombination of IgA antibodies by inhibiting p38-MAPK signaling in porcine PPs B cells, which may constitute a component of TGF-ß1-mediated inhibition of B-cell activation.

Linoleic acid: a natural feed compound against porcine epidemic diarrhea disease.

IMPORTANCE: Porcine epidemic diarrhea virus (PEDV) is a pig coronavirus that causes severe diarrhea and high mortality in piglets, but as no effective drugs are available, this virus threatens the pig industry. Here, we found that the intestinal contents of specific pathogen-free pigs effectively blocked PEDV invasion. Through proteomic and metabolic analyses of the intestinal contents, we screened 10 metabolites to investigate their function and found that linoleic acid (LA) significantly inhibited PEDV replication. Further investigations revealed that LA inhibited viral replication and release mainly by binding with PEDV NSP5 to regulate the PI3K pathway and, in particular, inhibiting AKT phosphorylation. In vivo experiments illustrated that orally administered LA protected pigs from PEDV challenge and severe diarrhea. These findings provide strong support for exploring antiviral drugs for coronavirus treatment.

TGF-ß1 reduces the differentiation of porcine IgA-producing plasma cells by inducing IgM+ B cells apoptosis via Bax/Bcl2-Caspase3 pathway.

Transforming growth factor ß1 (TGF-ß1) performs a critical role in maintaining homeostasis of intestinal mucosa regulation and controls the survival, proliferation, and differentiation of many immune cells. In this study, we discovered that the infection of porcine epidemic diarrhea virus (PEDV), a coronavirus, upregulated TGF-ß1 expression via activating Tregs. Besides, recombinant porcine TGF-ß1 decreased the percentage of CD21+ B cells within the lymphocyte population in vitro. We further found that TGF-ß1 reduced the IgA-secreting B cell numbers and also inhibited plasma cell differentiation. Additional investigations revealed that TGF-ß1 induced the apoptosis of IgM+ B cells in both peyer's patches (PPs) and peripheral blood (PB) through the activation of the Bax/Bcl2-Caspase3 pathway. Conversely, the application of the TGF-ß1 signaling inhibitor SB431542 significantly antagonized the TGF-ß1-induced reduction of IgA secretion and B cell apoptosis and restored plasma cell differentiation. Collectively, TGF-ß1 plays an important role in regulating the survival and differentiation of porcine IgA-secreting B cells through the classical mitochondrial apoptosis pathway. These findings will facilitate future mucosal vaccine designs that target the regulation of TGF-ß1 for the control of enteric pathogens in the pig industry.

Soy Gly m 8 sIgE Has Limited Value in the Diagnosis of Soy Allergy in Peanut Ara h 2-Sensitized Adults.

INTRODUCTION: Recently, specific IgE (sIgE) sensitization against Gly m 8 (soy 2S albumin) has been described as a good diagnostic marker for soy allergy (SA). The aim of this study was to evaluate the diagnostic value of Gly m 8 by determining the sensitization profiles based on the homologues soy allergens Bet v 1, Ara h 1, Ara h 2, and Ara h 3. METHODS: Thirty soy-allergic adults were included; sIgE to total soy extract, Gly m 8, Gly m 4, Gly m 5, Gly m 6, Bet v 1, Ara h 1, Ara h 2, and Ara h 3 were determined. Sensitization patterns were analyzed and determined. The clinical relevance of sIgE of Gly m 8 sensitization was measured by assessing its capacity to degranulate basophils in Gly m8-sensitized patients by an indirect basophil activation test (iBAT). RESULTS: Based on the sIgE patterns of sensitization, two groups of SA patients were identified: (i) peanut-associated SA group (all patients were sensitized to one or more of the peanut compounds) and (ii) non-peanut/PR-10-associated SA group (22 patients were sensitized to Gly m 4 and Bet v 1 but not to any of the peanut compounds). A high and significant correlation between total soy extract and Gly m 6 (R2 = 0.97), Gly m 5 (R2 = 0.85), and Gly m 8 (R2 = 0.78) was observed. A nonsignificant correlation was observed between the levels of sIgE of Gly m 8 versus Ara h2. The iBAT results showed that Gly m 8 did not induce basophil degranulation in any of the peanut-associated patients, indicating that the Gly m8 sensitizations were not clinically relevant. CONCLUSIONS: Gly m 8 was not a major allergen in the selected soy-allergic population. The iBAT results indicated that Gly m 8 was not able to induce basophil degranulation in sIgE Gly m 8-sensitized soy-allergic patients. Thus, Gly m 8 would have no added value in the diagnosis of SA in the present study population.

Extracellular flux analyses reveal differences in mitochondrial PBMC metabolism between high-fit and low-fit females.

Analyzing metabolism of peripheral blood mononuclear cells (PBMCs) can possibly serve as a cellular metabolic read-out for lifestyle factors and lifestyle interventions. However, the impact of PBMC composition on PBMC metabolism is not yet clear, neither is the differential impact of a longer-term lifestyle factor versus a short-term lifestyle intervention. We investigated the effect of aerobic fitness level and a recent exercise bout on PBMC metabolism in females. PBMCs from 31 young female adults divided into a high-fit (V̇o2peak ≥ 47 mL/kg/min, n = 15) and low-fit (V̇o2peak ≤ 37 mL/kg/min, n = 16) groups were isolated at baseline and overnight after a single bout of exercise (60 min, 70% V̇o2peak). Oxygen consumption rate (OCR) and glycolytic rate (GR) were measured using extracellular flux (XF) assays and PBMC subsets were characterized using fluorescence-activated cell sorting (FACS). Basal OCR, FCCP-induced OCR, spare respiratory capacity, ATP-linked OCR, and proton leak were significantly higher in high-fit than in low-fit females (all P < 0.01), whereas no significant differences in glycolytic rate (GR) were found (all P > 0.05). A recent exercise bout did not significantly affect GR or OCR parameters (all P > 0.05). The overall PBMC composition was similar between high-fit and low-fit females. Mitochondrial PBMC function was significantly higher in PBMCs from high-fit than from low-fit females, which was unrelated to PBMC composition and not impacted by a recent bout of exercise. Our study reveals a link between PBMC metabolism and levels of aerobic fitness, increasing the relevance of PBMC metabolism as a marker to study the impact of lifestyle factors on human health.NEW & NOTEWORTHY Mitochondrial metabolism was significantly higher in PBMCs from high-fit than from low-fit females. This was unrelated to PBMC composition and not impacted by a recent bout of exercise. Our study reveals a link between PBMC metabolism and levels of aerobic fitness, increasing the relevance of PBMC metabolism as a marker to study the impact of lifestyle factors on human health.

LF-EMF Compound Block Type Signal Activates Human Neutrophilic Granulocytes In Vivo.

This research aims to demonstrate in a randomized, placebo-controlled crossover design study that a nominal 5 µT low-frequency electromagnetic field (LF-EMF) signal for 30 min activates neutrophils in vivo in humans. Granularity of neutrophils was measured in blood samples of healthy human volunteers (n = 32) taken before and after exposure for both the exposure and control sessions. A significant decrease in the granularity, indicative of neutrophil activation, was observed both in the exposure measurements and the exposure minus control measurements. Earlier EMF publications show immune function increase in isolated cells and more effective immune responses in animals with infections. This result, therefore, supports the thesis that the exposure can activate the innate immune system in humans, speed up the innate immune response, and may have potential beneficial effects in infectious disease. © 2022 Bioelectromagnetics Society.

Differences in growth of Trypanoplasma borreli in carp serum is dependent on transferrin genotype.

Kinetoplastid parasites require transferrin (Tf), being the main source of iron, for growth and multiplication. This group of parasites developed a unique receptor-mediated system for acquiring host Tf which bears no structural homology with the host transferrin receptor. Trypanoplasma borreli, a blood parasite of common carp, probably uses a similar mechanism to sequester iron from host transferrin. In this study, we demonstrate a critical role of Tf for parasite growth. For in vitro studies we isolated and purified Tf from carp homozygous for the D or G allele of Tf. We obtained Tf-depleted serum using specific antibodies to carp Tf and studied gene expression in vivo during T. borreli infection with Real Time-quantitative PCR. We demonstrate that T. borreli cannot survive in medium supplemented with Tf-depleted serum while reconstitution with Tf restores normal growth. The critical role of Tf for parasite survival was shown in incomplete medium (medium without serum): addition of purified Tf significantly increased parasite survival. We also demonstrate that Tf polymorphism has a significant impact on T. borreli multiplication. Cultured parasites die more quickly in an environment containing D-typed Tf, as compared to medium with G-typed Tf. Gene expression during T. borreli infection in carp did not show an acute phase response. We could, however, observe an increased transcription of Tf in the head kidney, which may be associated with an immunological function of the Tf protein.

TPH1 gene polymorphism rs211105 is associated with serotonin and tryptophan hydroxylase 1 concentrations in acute pancreatitis patients.

BACKGROUND: The role of serotonin and its metabolic pathway in proper functioning of the pancreas has not been thoroughly investigated yet in acute pancreatitis (AP) patients. Tryptophan hydroxylase (TPH) as the rate-limiting enzyme of serotonin synthesis has been considered for possible associations in various diseases. Single-nucleotide polymorphisms (SNPs) in TPH genes have been already described in associations with psychiatric and digestive system disorders. This study aimed to explore the association of a rs211105 (T/G) polymorphism in TPH1 gene with tryptophan hydroxylase 1 concentrations in blood serum in a population of acute pancreatitis patients, and to investigate this association with acute pancreatitis susceptibility. RESULTS: Our data showed an association between the presence of the T allele at the position rs211105 (OR = 2.47, 95 % CI 0.94-6.50, p = 0.06) under conditions of a decreased AP incidence. For TT and GT genotypes in the control group, the lowest concentration of TPH was associated with higher serotonin levels (TT: Rs = - 0.415, p = 0.0018; GT: Rs = - 0.457, p = 0.0066), while for the AP group the highest levels of TPH among the TT genotype were associated with lower levels of serotonin (TT: Rs = - 0.749, p < 0.0001, and in the GG genotype higher levels of TPH were associated with higher levels of serotonin (GG: Rs = - 0.738, p = 0.037). CONCLUSIONS: Here, a new insight in the potential role of a selected genetic factor in pancreatitis development was shown. Not only the metabolic pathway of serotonin, but also factors affecting serotonin synthesis may be interesting and important points in acute pancreatitis.

Asthma-Associated Long TSLP Inhibits the Production of IgA.

Thymic stromal lymphopoietin (TSLP) contributes to asthmatic disease. The concentrations of protective IgA may be reduced in the respiratory tract of asthma patients. We investigated how homeostatic short TSLP (shTSLP) and asthma-associated long TSLP (loTSLP) regulate IgA production. B cells from healthy donors were stimulated in the presence or absence of shTSLP or loTSLP; the concentrations of IgA, IgM, IgE, and IgG antibodies were determined in cell culture supernatants; and B cells were analyzed by flow cytometry. LoTSLP, but not shTSLP, suppressed the secretion of IgA but not of IgE. The type 2 cytokine IL-4, which in addition to loTSLP contributes to asthmatic disease, did not affect the production of IgA or the frequency of IgA+ B cells. Instead, IL-4 increased IgG production, especially of the subclasses IgG2 and IgG4. LoTSLP inhibited IgA secretion by sorted memory B cells but not by naïve B cells. Although loTSLP inhibited IgA production, the vitamin A metabolite retinoic acid promoted the secretion of IgA, also in the presence of loTSLP, suggesting that vitamin A may promote IgA production in asthma. Our data demonstrate that asthma-associated loTSLP negatively regulates the secretion of IgA, which may negatively impact the surveillance of mucosal surfaces in asthma.

IgE cross-reactivity measurement of cashew nut, hazelnut and peanut using a novel IMMULITE inhibition method.

Background Tree nut-allergic individuals are often sensitised towards multiple nuts and seeds. The underlying cause behind a multi-sensitisation for cashew nut, hazelnut, peanut and birch pollen is not always clear. We investigated whether immunoglobulin E antibody (IgE) cross-reactivity between cashew nut, hazelnut and peanut proteins exists in children who are multi-allergic to these foods using a novel IMMULITE®-based inhibition methodology, and investigated which allergens might be responsible. In addition, we explored if an allergy to birch pollen might play a role in this co-sensitisation for cashew nut, hazelnut and peanut. Methods Serum of five children with a confirmed cashew nut allergy and suffering from allergic symptoms after eating peanut and hazelnut were subjected to inhibition immunoassays using the IMMULITE® 2000 XPi. Serum-specific IgE (sIgE) to seed storage allergens and pathogenesis-related protein 10 (PR10) allergens were determined and used for molecular multicomponent allergen correlation analyses with observed clinical symptoms and obtained inhibition data. Results IgE cross-reactivity was observed in all patients. Hazelnut extract was a strong inhibitor of cashew nut sIgE (46.8%), while cashew nut extract was less able to inhibit hazelnut extract (22.8%). Peanut extract showed the least inhibition potency. Moreover, there are strong indications that a birch pollen sensitisation to Bet v 1 might play a role in the observed symptoms provoked upon ingestion of cashew nut and hazelnut. Conclusions By applying an adjusted working protocol, the IMMULITE® technology can be used to perform inhibition assays to determine the risk of sIgE cross-reactivity between very different food components.

Vitamin D Binding Protein (VDBP) and Its Gene Polymorphisms-The Risk of Malignant Tumors and Other Diseases.

Vitamin D is an important component of the endocrine system that controls calcium homeostasis and bone mineralization. Because of the very short half-life of free serum vitamin D it is stabilized and transported to target tissues by being bound to the vitamin D binding protein (VDBP). The most common polymorphisms: rs4588 and rs7041 in the vitamin D binding protein gene may correlate with differences in vitamin D status in the serum. This review presents data that relate to the presence of genetic variants in the VDBP gene in correlation with certain diseases, mostly concerning cancers (breast, prostate, pancreatic, lung, colorectal, basal cell carcinoma cancer and cutaneous melanoma) or other related diseases (thyroid autoimmunity disorders, obesity, diabetes mellitus, bone metabolism, rheumatoid arthritis, ankylosing spondylitis, asthma, chronic obstructive pulmonary disease, tuberculosis and coronary artery diseases).

Binding of CML-Modified as Well as Heat-Glycated ß-lactoglobulin to Receptors for AGEs Is Determined by Charge and Hydrophobicity.

Intake of dietary advanced glycation end products (AGEs) is associated with inflammation-related health problems. Nε-carboxymethyl lysine (CML) is one of the best characterised AGEs in processed food. AGEs have been described as ligands for receptors present on antigen presenting cells. However, changes in protein secondary and tertiary structure also induce binding to AGE receptors. We aimed to discriminate the role of different protein modifications in binding to AGE receptors. Therefore, ß-lactoglobulin was chemically modified with glyoxylic acid to produce CML and compared to ß-lactoglobulin glycated with lactose. Secondary structure was monitored with circular dichroism, while hydrophobicity and formation of ß-sheet structures was measured with ANS-assay and ThT-assay, respectively. Aggregation was monitored using native-PAGE. Binding to sRAGE, CD36, and galectin-3 was measured using inhibition ELISA. Even though no changes in secondary structure were observed in all tested samples, binding to AGE receptors increased with CML concentration of CML-modified ß-lactoglobulin. The negative charge of CML was a crucial determinant for the binding of protein bound CML, while binding of glycated BLG was determined by increasing hydrophobicity. This shows that sRAGE, galectin-3, and CD36 bind to protein bound CML and points out the role of negatively charged AGEs in binding to AGE receptors.

BAFF augments IgA2 and IL-10 production by TLR7/8 stimulated total peripheral blood B cells.

Class-switching of B cells to IgA can be induced via both T-cell-dependent and T-cell-independent mechanisms. IgA is most predominantly produced mucosally and is important for combating infections and allergies. In contrast to mice, humans have two forms of IgA; IgA1 and IgA2 with diverse tissue distribution. In early life, IgA levels might be sub-optimal especially during the fall season when bacterial and viral infections are more common. Therefore, we investigated using human B cells whether T-cell-independent factors -promoting cell survival, class switching and immunoglobulin secretion- BAFF, APRIL, IL-10 and retinoic acid can boost IgA production in the context of viral or bacterial infection. To this end total and naive peripheral blood B cells were stimulated with these factors for 6 days in the presence or absence of TLR7/8 agonist R848 (mimicking viral infection) or TLR9 agonist CpG-ODN (mimicking bacterial infection). We show that BAFF significantly augments IgA2 production in TLR7/8 stimulated mature, but not naïve B cells. In addition, BAFF augments IL-10 production and viability in TLR7/8 and TLR9 stimulated mature B cells. These data warrant further investigation of its role in immune regulation both in the periphery and mucosal tissues in early life or during disease.

The Basophil Activation Test reduces the need for a food challenge test in children suspected of IgE-mediated cow's milk allergy.

BACKGROUND: The gold standard for the diagnosis of cow's milk allergy is the Double-Blind Placebo-Controlled Food Challenge (DBPCFC) test. However, disadvantages of the DBPCFC are the potential risk of anaphylactic reactions, the time-consuming procedure and high costs. OBJECTIVE: The aim of this study was to determine the reliability of the Basophil Activation Test (BAT) both for the initial diagnosis of cow's milk allergy in children and for the determination of tolerance in children with cow's milk allergy. METHODS: Ninety-seven BATs and cow's milk-specific IgE (sIgE) tests were performed in 86 infants/young children, suspected of (persistent) cow's milk allergy, who were qualified for an in-hospital DBPCFC. The BAT was performed with cow's milk extract and the purified major allergens casein, α-lactalbumin, ß-lactoglubulin. Basophil activation was determined by CD63 upregulation measured by flow cytometry. The BAT results were compared to the DBPCFC outcomes. RESULTS: Based on unequivocal DBPCFC and BAT result combinations (80%), the BAT had a sensitivity and specificity of 100% (CI: 86%-100% and 68%-100%, respectively) in IgE-sensitized children (41% of the tested children). All non-IgE-sensitized children (59%) had a negative DBPCFC and BAT, except for five patients. These latter showed delayed and relatively mild symptoms in the DBPCFC with a negative BAT, supporting a non-IgE-mediated allergy in these children. CONCLUSIONS AND CLINICAL RELEVANCE: The BAT seems reliable and cost-effective to diagnose patients with an IgE-mediated cow's milk allergy. In IgE-sensitized patients, a BAT might replace a DBPCFC. For non-IgE-sensitized patients presenting with mild symptoms, we propose to consider a (double-blind) extended (time) challenge test at home.

IgE Cross-Reactivity of Cashew Nut Allergens.

BACKGROUND: Allergic sensitisation towards cashew nut often happens without a clear history of eating cashew nut. IgE cross-reactivity between cashew and pistachio nut is well described; however, the ability of cashew nut-specific IgE to cross-react to common tree nut species and other Anacardiaceae, like mango, pink peppercorn, or sumac is largely unknown. OBJECTIVES: Cashew nut allergic individuals may cross-react to foods that are phylogenetically related to cashew. We aimed to determine IgE cross-sensitisation and cross-reactivity profiles in cashew nut-sensitised subjects, towards botanically related proteins of other Anacardiaceae family members and related tree nut species. METHOD: Sera from children with a suspected cashew nut allergy (n = 56) were assessed for IgE sensitisation to common tree nuts, mango, pink peppercorn, and sumac using dot blot technique. Allergen cross-reactivity patterns between Anacardiaceae species were subsequently examined by SDS-PAGE and immunoblot inhibition, and IgE-reactive allergens were identified by LC-MS/MS. RESULTS: From the 56 subjects analysed, 36 were positive on dot blot for cashew nut (63%). Of these, 50% were mono-sensitised to cashew nuts, 19% were co-sensitised to Anacardiaceae species, and 31% were co-sensitised to tree nuts. Subjects co-sensitised to Anacardiaceae species displayed a different allergen recognition pattern than subjects sensitised to common tree nuts. In pink peppercorn, putative albumin- and legumin-type seed storage proteins were found to cross-react with serum of cashew nut-sensitised subjects in vitro. In addition, a putative luminal binding protein was identified, which, among others, may be involved in cross-reactivity between several Anacardiaceae species. CONCLUSIONS: Results demonstrate the in vitro presence of IgE cross-sensitisation in children towards multiple Anacardiaceae species. In this study, putative novel allergens were identified in cashew, pistachio, and pink peppercorn, which may pose factors that underlie the observed cross-sensitivity to these species. The clinical relevance of this widespread cross-sensitisation is unknown.

Systematic Comparison of Zwitterionic and Non-Zwitterionic Antifouling Polymer Brushes on a Bead-Based Platform.

Nonspecific adsorption of biomolecules to solid surfaces, a process called biofouling, is a major concern in many biomedical applications. Great effort has been made in the development of antifouling polymer coatings that are capable of repelling the nonspecific adsorption of proteins, cells, and micro-organisms. In this respect, we herein contribute to understanding the factors that determine which polymer brush results in the best antifouling coating. To this end, we compared five different monomers: two sulfobetaines, a carboxybetaine, a phosphocholine, and a hydroxyl acrylamide. The antifouling coatings were analyzed using our previously described bead-based method with flow cytometry as the read-out system. This method allows for the quick and automated analysis of thousands of beads per second, enabling fast analysis and good statistics. We report the first direct comparison made between a sulfobetaine with opposite charges separated by two and three methylene groups and a carboxybetaine bearing two separating methylene groups. It was concluded that both the distance between opposite charges and the nature of the anionic groups have a distinct effect on the antifouling performance. Phosphocholines and simple hydroxyl acrylamides are not often compared with the betaines. However, here we found that they perform equally well or even better, yielding the following overall antifouling ranking: HPMAA ≥ PCMA-2 ≈ CBMAA-2 > SBMAA-2 > SBMAA-3 ≫ nonmodified beads (HPMAA being the best).

Akkermansia muciniphila ameliorates the age-related decline in colonic mucus thickness and attenuates immune activation in accelerated aging Ercc1 -/Δ7 mice.

BACKGROUND: The use of Akkermansia muciniphila as potential therapeutic intervention is receiving increasing attention. Health benefits attributed to this bacterium include an improvement of metabolic disorders and exerting anti-inflammatory effects. The abundance of A. muciniphila is associated with a healthy gut in early mid- and later life. However, the effects of A. muciniphila on a decline in intestinal health during the aging process are not investigated yet. We supplemented accelerated aging Ercc1 -/Δ7 mice with A. muciniphila for 10 weeks and investigated histological, transcriptional and immunological aspects of intestinal health. RESULTS: The thickness of the colonic mucus layer increased about 3-fold after long-term A. muciniphila supplementation and was even significantly thicker compared to mice supplemented with Lactobacillus plantarum WCFS1. Colonic gene expression profiles pointed towards a decreased expression of genes and pathways related to inflammation and immune function, and suggested a decreased presence of B cells in colon. Total B cell frequencies in spleen and mesenteric lymph nodes were not altered after A. muciniphila supplementation. Mature and immature B cell frequencies in bone marrow were increased, whereas B cell precursors were unaffected. These findings implicate that B cell migration rather than production was affected by A. muciniphila supplementation. Gene expression profiles in ileum pointed toward a decrease in metabolic- and immune-related processes and antimicrobial peptide production after A. muciniphila supplementation. Besides, A. muciniphila decreased the frequency of activated CD80+CD273- B cells in Peyer's patches. Additionally, the increased numbers of peritoneal resident macrophages and a decrease in Ly6Cint monocyte frequencies in spleen and mesenteric lymph nodes add evidence for the potentially anti-inflammatory properties of A. muciniphila. CONCLUSIONS: Altogether, we show that supplementation with A. muciniphila prevented the age-related decline in thickness of the colonic mucus layer and attenuated inflammation and immune-related processes at old age. This study implies that A. muciniphila supplementation can contribute to a promotion of healthy aging.

Oxidative stress and immune aberrancies in attention-deficit/hyperactivity disorder (ADHD): a case-control comparison.

The objective of this study is to compare oxidative stress and immune biomarkers between attention-deficit/hyperactivity disorder (ADHD) patients and controls without ADHD. A case-control comparison between 57 paediatric (6-12 years) untreated ADHD patients from the Antwerp University Hospital and 69 controls without ADHD from random schools in Flanders, Belgium, was conducted. Erythrocyte glutathione (GSH) and plasma lipid-soluble antioxidants (retinol, α-tocopherol, γ-tocopherol, retinyl palmitate, ß-carotene, and co-enzyme Q10) were determined by HPLC with electrochemical detection, plasma malondialdehyde (MDA) by HPLC with fluorescence detection, plasma cytokines (interleukin (IL)-1ß, IL-5, IL-6, IL-8, IL-10, tumour necrosis factor (TNF) and interferon (INF)-γ) and immunoglobulins (IgE, IgG and IgM) by flow cytometry and urinary 8-hydroxy-2'deoxyguanosine (8-OHdG) levels by ELISA assay. Dietary habits were determined by a food frequency questionnaire. Plasma MDA levels were on average 0.031 µM higher in patients than in controls (p < 0.05), and a trend for higher urinary 8-OHdG was observed. Erythrocyte GSH and plasma retinyl palmitate levels, as well as IgG and IgE levels, were higher in patients than in controls as well (on average 93.707 µg/ml, 0.006 µg/ml, 301.555 µg/ml and 125.004 µg/ml, resp., p < 0.05). Finally, a trend for lower plasma IL-5 levels was observed. After Bonferroni correction for multiple testing, the difference in GSH levels remained statistically significant (nominally significant for retinyl palmitate), while significance was lost for MDA, IgG and IgE levels. Dietary habits do not appear to cause the observed differences. These results point at the potential involvement of slight oxidative stress and immune disturbances in ADHD.

Induction of human tolerogenic dendritic cells by 3'-sialyllactose via TLR4 is explained by LPS contamination.

The human milk oligosaccharide 3'-sialyllactose (3'SL) has previously been shown to activate murine dendritic cells (DC) in a Toll-like receptor (TLR) 4-mediated manner ex vivo. In this study we aimed to investigate whether 3'SL has similar immunomodulatory properties on human DC. 3'SL was shown to induce NF-κB activation via human TLR4. However, LPS was detected in the commercially obtained 3'SL from different suppliers. After the removal of LPS from 3'SL, we studied its ability to modify DC differentiation in vitro. In contrast to LPS and 3'SL, LPS-free 3'SL did not induce functional and phenotypical changes on immature DC (iDC). iDC that were differentiated in the presence of LPS or 3'SL showed a semi-mature phenotype (i.e., fewer CD83+CD86+ DC), produced IL-10 and abrogated IL-12p70 and tumor necrosis factor-alpha levels upon stimulation with several TLR ligands. Differentiation into these tolerogenic DC was completely abrogated by LPS removal from 3'SL. In contrast to previous reports in mice, we found that LPS-free 3'SL does not activate NF-κB via human TLR4. In conclusion, removing LPS from (oligo)saccharide preparations is necessary to study their potential immunomodulatory function.

Aged mice display altered numbers and phenotype of basophils, and bone marrow-derived basophil activation, with a limited role for aging-associated microbiota.

BACKGROUND: The influence of age on basophils is poorly understood, as well as the effect of aging-associated microbiota on basophils. Therefore, we studied the influence of aging and aging-associated microbiota on basophil frequency and phenotype, and differentiation from basophil precursors. RESULTS: Basophils became more abundant in bone marrow (BM) and spleens of 19-month-old mice compared with 4-month-old mice. Aged basophils tended to express less CD200R3 and more CD123, both in BM and spleen. Differences in microbiota composition with aging were confirmed by 16S sequencing. Microbiota transfers from young and old mice to germ-free recipients revealed that CD11b tended to be lowered on splenic basophils by aging-associated microbiota. Furthermore, abundance of Alistipes, Oscillibacter, Bacteroidetes RC9 gut group, and S24-7 family positively correlated and CD123 expression, whereas Akkermansia abundance negatively correlated with basophils numbers.Subsequently, we purified FcεRIα+CD11c-CD117- BM-derived basophils and found that those from aged mice expressed lower levels of CD11b upon stimulation. Higher frequencies of IL-4+ basophils were generated from basophil precursors of aged mice, which could be reproduced in basophils derived from germ-free recipients of aging-associated microbiota. CONCLUSIONS: Collectively, these results show the influence of aging on basophils. Furthermore, this study shows that aging-associated microbiota altered activation of BM-derived basophils in a similar fashion as observed in BM-derived basophils from aged mice.