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Although fucoidan has potential use as an anti-inflammatory agent, the specific mechanisms by which it influences signaling and immunomodulatory pathways between gut microbiota and Peyer's patches remain unclear. Therefore, the aim of this study was to investigate the therapeutic potential of fucoidan in a dextran sulfate sodium (DSS)-induced mouse model of inflammatory bowel disease (IBD) by examining the effects on gut microbiota and the underlying anti-inflammatory mechanisms. Purified fucoidan, which upon characterization revealed structural fragments comprising →3)-β-D-Galp-(1→, →4)-α-L-Fucp-(1→, and →3)-α-L-Fucp-(1→ residues with a sulfation at position C2 was used. Treatment of the mice with fucoidan significantly alleviated the symptoms of IBD and restored the diversity of gut microbiota by enhancing the abundance of Bacteroidetes and reducing the proportion of Firmicutes. The administration of fucoidan also elevated levels of short-chain fatty acids while reducing the levels of pro-inflammatory cytokines, including interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ. Most importantly, fucoidan attenuated the expression of integrin α4β7/MAdCAM-1 and CCL25/CCR9, which are involved in homing intestinal lymphocytes within Peyer's patches. These findings indicate that fucoidan is a promising gut microbiota modulator and an anti-inflammatory agent for IBD., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Lentinan (LNT), a natural polysaccharide, has been reported to exhibit immunomodulatory effects in the intestine after oral administration. Herein, we aimed to investigate the lymphatic transport of LNT in Peyer's patches (PPs) by traceable fluorescent labeling and to explore whether/how LNT contacts related immune cells. Near-infrared imaging confirmed the absorption of LNT in the small intestinal segment and its accumulation within PPs after oral administration. Subsequently, tissue imaging confirmed that M cells are the main cells responsible for transporting LNT to PPs, and an M cell model was established to explore the involvement of Dectin-1 in the absorption process. Systematic in vitro and in vivo studies revealed that the Dectin-1 further mediates the uptake of LNT by mononuclear phagocytes in PPs. Moreover, LNT can promote the proliferation and differentiation of mononuclear phagocytes, thereby activating immune responses. In summary, this study elucidates the pharmacokinetic mechanisms by which LNT exerts oral immunomodulatory effects, providing a theoretical basis for the development and application of other polysaccharides., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest., (Copyright © 2024. Published by Elsevier Ltd.)

Nefecon, a targeted-release capsule formulation of budesonide approved for the reduction of proteinuria in adults with primary immunoglobulin A nephropathy, targets overproduction of galactose-deficient immunoglobulin A type 1 in the Peyer's patches at the gut mucosal level. To investigate whether the commercial formulation of Nefecon capsules reliably releases budesonide to the distal ileum, a human study was conducted with test capsules reproducing the delayed-release function of Nefecon capsules. Caffeine was included in the test capsules as a marker for capsule opening in the gut since it appears rapidly in saliva after release from orally administered dosage forms. Magnetic resonance imaging with black iron oxide was used to determine the capsule's position in the gut at the time caffeine was first measured in saliva and additionally to directly visualize dispersion of the capsule contents in the gut. In vitro dissolution results confirmed that the test capsules had the same delayed-release characteristics as Nefecon capsules. In 10 of 12 human volunteers, the capsule was demonstrated to open in the distal ileum; in the other two subjects, it opened just past the ileocecal junction. These results compared favorably with the high degree of variability seen in other published imaging studies of delayed-release formulations targeting the gut. The test capsules were shown to reliably deliver their contents to the distal ileum, the region with the highest concentration of Peyer's patches.

Patchouli Essential Oil (PEO) has been used as a scent for various healing purposes since the ancient Egyptian period. The primary source of the oil is Pogostemon cablin (PC), a medicinal plant for treating gastrointestinal symptoms. However, the pharmacological function has not been addressed. Here, we report the cancer prevention and gut microbiota (GM) modulating property of PEO and its derivatives patchouli alcohol (PA) and pogostone (PO) in the Apc Min /+ colorectal cancer mice model. We found that PEO, PA, and PO significantly reduced the tumor burden. At the same time, it strengthened the epithelial barrier, evidenced by substantially increasing the number of the goblet and Paneth cells and upregulation of tight junction and adhesion molecules. In addition, PEO, PA, and PO shifted M1 to M2 macrophage phenotypes and remodeled the inflammatory milieu of Apc Min /+ mice. We also found suppression of CD4 + CD25 + and stimulation CD4 + CD8 + cells in the spleen, blood, mesenteric lymph nodes (MLNs), and Peyer's patches (PPs) of the treated mice. The composition of the gut microbiome of the drug-treated mice was distinct from the control mice. The drugs stimulated the short-chain fatty acids (SCFAs)-producers and the key SCFA-sensing receptors (GPR41, GPR43, and GPR109a). The activation of SCFAs/GPSs also triggered the alterations of PPAR-γ, PYY, and HSDCs signaling mediators in the treated mice. Our work showed that PEO and its derivatives exert potent anti-cancer effects by modulating gut microbiota and improving the intestinal microenvironment of the ApcM min /+ mice., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Fumonisin B1 (FB1) is a widespread mycotoxin produced by fungal Fusarium species-mainly in maize, one of the plants most commonly used for food and feed. Pigs and horses are the animal species most susceptible to this mycotoxin. FB1 exposure can cause highly diverse clinical symptoms, including hepatotoxicity, immunotoxicity, and intestinal barrier function disturbance. Inhibition of ceramide synthetase is a well-understood ubiquitous molecular mechanism of FB1 toxicity, but other more tissue-specific effects remain to be elucidated. To investigate the effects of FB1 in different exposed tissues, we cross-analyzed the transcriptomes of fours organs: liver, jejunum, jejunal Peyer's patches, and spleen. During a four-week study period, pigs were fed a control diet or a FB1-contaminated diet (10 mg/kg feed). In response to oral FB1 exposure, we observed common biological processes in the four organs, including predominant and recurrent processes (extracellular matrix organization, integrin activation, granulocyte chemotaxis, neutrophil migration, and lipid and sterol homeostasis), as well as more tissue-specific processes that appeared to be related to lipid outcomes (cell cycle regulation in jejunum, and gluconeogenesis in liver).

Muscarinic-acetylcholine-receptors (mAChRs) modulate intestinal homeostasis, but their role in inflammation is unclear; thus, this issue was the focus of this study. BALB/c mice were treated for 7 days with muscarine (mAChR/agonist), atropine (mAChR/antagonist) or saline. Small-intestine samples were collected for histology and cytofluorometric assays in Peyer's patches (PP) and lamina propria (LP) cell-suspensions. In LP, goblet-cells/leukocytes/neutrophils/MPO + cells and MPO/activity were increased in the muscarine group. In PP, IFN-γ + /CD4 + T or IL-6 + /CD4 + T cell numbers were higher in the muscarine or atropine groups, respectively. In LP, TNF-α + /CD4 + T cell number was higher in the muscarine group and lower in the atropine., (Copyright © 2021. Published by Elsevier B.V.)

Viral infections increase the risk of developing allergies in childhood, and disruption of mucosal homeostasis is presumed to be involved. However, no study has reported a role for viral infections in such disruption. In this study, we clarified the mechanism of immunoglobulin A (IgA) overproduction in viral infections. Autopsies were performed on 33 pediatric cases, IgA and interferon (IFN)β levels were measured, and histopathological and immunohistochemical examinations were conducted. Furthermore, we cultured human cells and measured IFNβ and IgA levels to examine the effect of viral infections on IgA production. Blood IgA levels in viral infections were higher than in bacterial infections. Moreover, IFNβ levels in most viral cases were below the detection limit. Cell culture revealed increased IgA in gastrointestinal lymph nodes, especially in Peyer's patches, due to enhanced IFNβ after viral stimulation. Conversely, respiratory regional lymph nodes showed enhanced IgA with no marked change in IFNβ. Overproduction of IgA, identified as an aberration of the immune system and resulting from excessive viral infection-induced IFNβ was observed in the intestinal regional lymph nodes, particularly in Peyer's patches. Further, increased IgA without elevated IFNβ in the respiratory system suggested the possibility of a different mechanism from the gastrointestinal system.

Ganoderma lucidum is a legendary traditional Chinese medicine with various bioactivities. This study was conducted (a) to explore the in vitro fermentation of the water extracts of G. lucidum fruiting body with Lactobacillus acidophilus and Bifidobacterium breve and (b) to investigate the effect of fermentation broth (GLFB) on dexamethasone (DEX)-induced immunosuppressed mice. Our results demonstrated that probiotic fermentation of G. lucidum fruiting body extracts underwent structural changing of major ganoderic acid components, such as ganoderic acid A (GA) into GC2, and this fermentation process involves changing of several metabolic pathways in the probiotic strains. GLFB could significantly improve the immunity, intestinal integrity, and gut microbiota dysbiosis in DEX-treated mice, and the immunostimulatory activity of GLFB was found closely related to its direct regulation on the expansion of CD4 + T cells in Peyer's patches of mice. These data implied that probiotic fermentation of G. lucidum fruiting body extracts promoted its immunostimulatory activity via biotransformation of components such as GA. This research provides a theoretical support for the development and application of G. lucidum fermentation by probiotics., (Copyright © 2021 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Intestinal microfold cells (M cells) are a dynamic lineage of epithelial cells that initiate mucosal immunity in the intestine. They are responsible for the uptake and transcytosis of microorganisms, pathogens, and other antigens in the gastrointestinal tract. A mature M cell expresses a receptor Gp2 which binds to pathogens and aids in the uptake. Due to the rarity of these cells in the intestine, their development and differentiation remain yet to be fully understood. We recently demonstrated that polycomb repressive complex 2 (PRC2) is an epigenetic regulator of M cell development, and 12 novel transcription factors including Atoh8 were revealed to be regulated by the PRC2. Here, we show that Atoh8 acts as a regulator of M cell differentiation; the absence of Atoh8 led to a significant increase in the number of Gp2+ mature M cells and other M cell-associated markers such as Spi-B and Sox8. In vitro organoid analysis of RankL treated organoid showed an increase of mature marker GP2 expression and other M cell-associated markers. Atoh8 null mice showed an increase in transcytosis capacity of luminal antigens. An increase in M cell population has been previously reported to be detrimental to mucosal immunity because some pathogens like orally acquired prions have been able to exploit the transcytosis capacity of M cells to infect the host; mice with an increased population of M cells are also susceptible to Salmonella infections. Our study here demonstrates that PRC2 regulated Atoh8 is one of the factors that regulate the population density of intestinal M cell in the Peyer's patch.

Bovine lactoferrin (bLf), a component of milk and a dietary supplement, modulates intestinal immunity at effector and inductor sites. Considering the regional difference in intestinal compartments and the dynamics of local cytokine-producing cells in the gut across time, the aim of this work was to characterize the effects of bLf on the proximal small intestine in a BALB/c murine model of oral administration. Male BALB/c mice were treated with oral bLf vs. saline control as mock by buccal deposition for 28 days. Intestinal secretions were obtained at different time points and cells were isolated from Peyer's patches (PP) and lamina propria (LP) of the proximal small intestine as representative inductor and effector sites, respectively. Total and specific anti-bLF IgA and IgM were determined by enzyme-immuno assay; the percentages of IgA + and IgM + plasma cells (PC) and cytokine-producing CD4 + T cells of PP and LP were analyzed by flow cytometry. We found that total and bLf-specific IgA and IgM levels were increased in the intestinal secretions of the bLf group in comparison to mock group and day 0. LP IgA + PC and IgM + PC presented an initial elevation on day 7 and day 21, respectively, followed by a decrease on day 28 in comparison to mock. Higher percentages of CD4 + T cells in LP were found in the bLf group. Cytokines-producing CD4 + T cells populations presented a pattern of increases and decreases in the bLf group in both LP and PP. Transforming growth factor beta (TGF-β) + CD4 + T cells showed higher percentages after bLf administration with a marked peak at day 21 in both LP and PP in comparison to mock-treated mice. Oral bLf exhibits complex immune properties in the proximal small intestine, where temporal monitoring of the inductor and effector compartments reveals patterns of rises and falls of different cell populations. Exceptionally, TGF-β + CD4 + T cells show consistent higher numbers after bLf intervention across time. Our work suggests that isolated measurements do not show the complete picture of the modulatory effects of oral bLf in immunological sites as dynamic as the proximal small intestine.

The complement fragment C5a is closely associated with adaptive immune induction in the mucosa. However, the mechanisms that control CD8 + T cell responses by C5a have not been extensively explored. This study reveals that C5/C5a in the Peyer's patch (PP) subepithelial dome increases upon oral Listeria infection. We hypothesize that C5aR + PP cells play an important role in the induction of antigen-specific T cell immunity. Using single-cell RNA sequencing, we identify C5aR- and lysozyme-expressing dendritic cells (C5aR + LysoDCs) in PP and examine their role in CD8 + T cell immune induction. Stimulation of C5aR + LysoDCs by C5a increases reactive oxygen species levels, leading to efficient antigen cross-presentation, which elicits an antigen-specific CD8 + T cell response. In C5-deficient mice, oral co-administration of C5a and Listeria enhances Listeria-specific cytotoxic T cell levels. Collectively, these findings suggest a role of the complement system in intestinal T cell immunity., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2021 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Gegen Qinlian decoction (GQ) is a traditional Chinese herbal prescription that has been widely used for the treatment of bacterial dysentery and enteric typhoid fever. Recently, GQ has been clinically reported to be a potential candidate for the treatment of ulcerative colitis (UC). However, the immunoregulatory function of GQ in the treatment of UC has not been fully elucidated., Purpose: This study focused on the role of immune imbalance in the pathogenesis of UC and the immunomodulatory effect of GQ in the treatment of UC., Methods: The UC model was established by treating female mice with 3.0% dextran sulfate sodium (DSS) for 7 days, and GQ was orally administered at dosages of 1.5 and 7.5 g/kg/day. Inflammatory factors were detected by ELISA and qRT-PCR. Treg and Th17 cell dysregulation was analyzed by qRT-PCR, immunohistochemistry and flow cytometry. Proteins related to IL-6/JAK2/STAT3 signaling were detected by western blotting., Results: GQ significantly alleviated the symptoms of UC mice and suppressed the activity of myeloperoxidase (MPO). Furthermore, the production of proinflammatory factors, such as IL-1β, TNF-α and IL-6, was dramatically reduced after GQ administration. Furthermore, GQ improved the infiltration of Treg and Th17 cells into the colons and decreased the expression of inflammatory factors, such as TGF-β1 and IL-17. The frequencies of Treg and Th17 cells in the Peyer's patches and spleen were reduced by GQ administration; however, GQ had no significant regulatory effect on normal mice. The western blotting results showed that GQ markedly suppressed the phosphorylation of JAK2 and STAT3 and decreased the transcription function of phosphorylated STAT3., Conclusions: Taken together, these results indicated that GQ alleviated DSS-induced UC by suppressing IL-6/JAK2/STAT3 signaling to restore Treg and Th17 cell homeostasis in colonic tissue., (Copyright © 2021. Published by Elsevier GmbH.)

Ethnopharmacological Relevance: Coptis chinensis Franch is one of the most widely used traditional Chinese herbs in China and was firstly recorded in "Shennong's Classic of Materia Medica" in the Han Dynasty. The medical records in past thousands years have fully confirmed the clinical efficacies of Coptis chinensis Franch against intestinal diseases. The polysaccharides in herbal medicines can be digested by the flora and uptaken by the Peyer's patches (PPs) in intestine. It can be reasonably presumed that the polysaccharides in Coptis chinensis Franch (CCP) should be one of the critical element in the regulation of intestinal microenvironment., Aim of the Study: This study intended to explore the dynamic regulation of CCP on intestinal microenvironment from the perspective of the intestinal mucosal immunity and the intestinal flora, in order to provide a new research perspective for the pharmacological mechanism of Coptis chinensis Franch., Materials and Methods: The absorption and distribution of CCP in intestinal tissues were observed after the perfusion of FITC labeled CCP. The influences of CCP on intestinal flora were evaluated by the 16sRNA gene illumina-miseq sequencing after gavage. The regulations of CCP on intestinal mucosal immunity were evaluated by the immunohistochemical analysis of the interferon-γ (IFN-γ), interleukin-4 (IL-4), interleukin-17 (IL-17) and transforming growth factor-β (TGF-β) secretion in PPs and intestinal epithelial tissue., Results: With the self-aggregation into particles morphology, CCP can be up-taken by PPs and promote the IFN-γ, IL-4, IL-17 and TGF-β secretion in PPs in a dose-dependent manner. The CCP can also be utilized by the intestinal flora and dynamically regulate the diversity, composition and distribution of the intestinal flora. The temporal regulations of CCP on IFN-γ, IL-4, IL-17 and TGF-β secretions in intestinal epithelial tissues are consistent with the variation tendency of intestinal flora., Conclusion: CCP can provide effective, dynamical and dose-dependent regulations on intestinal microenvironment, not only the intestinal flora but also the PPs and intestinal epithelium related immune response. These may be involved in the multiple biological activities of Coptis chinensis Franch., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Interleukin-2 (IL-2) has both pro- and anti-inflammatory properties that have been harnessed clinically and that are used experimentally to modulate leukocyte subsets in vivo. In mice, the bioavailability and half-life of IL-2 in vivo can be increased by complexing recombinant IL-2 with different clones of anti-IL-2 monoclonal antibodies that differentially target the cytokine to cells expressing different kinds of IL-2 receptors. While the impacts of systemic IL-2: anti-IL-2 antibody complex (IL-2C) administration are well-defined in the spleen and peripheral lymph nodes, how immune cells in the gut and gut-associated lymphoid tissues respond to IL-2C is not well characterized. Here, we analyze how major leukocyte populations in these tissues respond to IL-2C. We find that IL-2C targeting cells expressing IL-2 receptor beta cause an acute decrease in cellularity of Peyer's Patches while cell numbers in the lamina propria and intraepithelial lymphocytes are unaffected. Cell contraction in Peyer's Patches is associated with the apoptosis of multiple B cell subsets. Our results are important to consider for understanding off-target impacts of IL-2C regimes in experimental models and for considering how IL-2 may contribute to the etiology or severity of gut-associated conditions such as Crohn's Disease.

The aim of the present study was to determine the effect of zearalenone (ZEN), administered per os to gilts at doses equivalent to 50%, 100%, and 150% of no-observed-adverse-effect level (NOAEL) values for 14, 28, and 42 days during weaning, on changes in the parameters of the oxidoreductive balance, cytokine secretion, and basal metabolism in ileal Payer's patches. Immunoenzymatic ELISA tests and biochemical methods were used to measure the concentrations of interleukin 1α, interleukin 1β, interleukin 12/23p40, interleukin 2, interferon γ, interleukin 4, interleukin 6, interleukin 8, tumor necrosis factor α, interleukin 10, transforming growth factor β, malondialdehyde, sulfhydryl groups, fructose, glucose, and proline, as well as the activity of peroxidase, superoxide dismutase and catalase. The study demonstrated that ZEN doses corresponding to 50%, 100%, and 150% of NOAEL values, i.e., 5 µg, 10 µg, and 15 µg ZEN/kg BW, respectively, have proinflammatory properties, exacerbate oxidative stress responses, and disrupt basal metabolism in ileal Payer's patches in gilts.

Human exposure to persistent, nonbiological nanoparticles and microparticles via the oral route is continuous and large scale (10 12 -10 13 particles per day per adult in Europe). Whether this matters or not is unknown but confirmed health risks with airborne particle exposure warns against complacency. Murine models of oral exposure will help to identify risk but, to date, lack validation or relevance to humans. This work addresses that gap. It reports i) on a murine diet, modified with differing concentrations of the common dietary particle, food grade titanium dioxide (fgTiO 2 ), an additive of polydisperse form that contains micro- and nano-particles, ii) that these diets deliver particles to basal cells of intestinal lymphoid follicles, exactly as is reported as a "normal occurrence" in humans, iii) that confocal reflectance microscopy is the method of analytical choice to determine this, and iv) that food intake, weight gain, and Peyer's patch immune cell profiles, up to 18 weeks of feeding, do not differ between fgTiO 2 -fed groups or controls. These findings afford a human-relevant and validated oral dosing protocol for fgTiO 2 risk assessment as well as provide a generalized platform for application to oral exposure studies with nano- and micro-particles., (© 2020 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The immunomodulatory activity of a few Lactobacillus exopolysaccharides (EPS) has been reported. However, whether Lactobacillus EPS can promote the differentiation of CD4 T lymphocytes (CD4 + T) cells into T-helper 17 cells (Th17 cells) in the Peyer's Patches (PPs) of mice has not been addressed. In this study, we found the molecular weight ( M w ) of the purified EPS from L. casei ranged from 2.7 × 10 6 Da to 1.7 × 10 7 Da, and the average M w was approximately 8.4 × 10 6 Da. In healthy BALB/c mice, EPS elevated the numbers of Th17 cells and levels of Th17-related cytokines. In vitro, EPS induced BMDCs to stimulate the differentiation of CD4 + T cells of PPs into Th17 cells and the related cytokine secretions. Results suggest that L. casei EPS can effectively induce and promote the differentiation of CD4 + T cells of PPs into Th17 cells in healthy mice and has the potential ability to improve intestinal mucosa immunity.

Paeoniflorin shows distinct anti-arthritis and immunoregulatory activities, but its rather low bioavailability via oral administration greatly challenges its known mechanism of in vivo activity. Our data showed that oral administration, instead of intraperitoneal injection, of paeoniflorin significantly reduced the polyarthritis index by 44.4%, reduced paw swelling by 18.4% and delayed the onset of arthritis in collagen-induced arthritis (CIA) mice. Oral paeoniflorin treatment also downregulated the systemic pro-inflammatory cytokines IL-6 (by 52.2%), TNF-α (by 57.7%) and IL-1β (by 34.1%). A pharmacokinetic study revealed that the maximal plasma concentration of paeoniflorin after oral administration was 4.8 ± 1.9 μM in the CIA mice, much lower than the effective concentration in vitro (30 μM). In contrast, paeoniflorin was highly concentrated in the gut content, intestine and Peyer's patches. T cell analysis showed that paeoniflorin markedly reduced transcription factors of Th1 and Th17, inhibited Th1 by 22.2% and 23.1% and Th17 by 43.2% and 25.4% (p < 0.05) in the mesenteric lymph node and Peyer's patches, respectively. Paeoniflorin did not have a significant impact on Th1 and Th17 in the spleen. For the first time, these data suggest that paeoniflorin accumulates in the intestine and primarily modulates Th1 and Th17 responses in the mesenteric lymph nodes and Peyer's patches, rather than in the spleen, to exert anti-arthritis effects.

The toxicity of dietary E 171, a food grade titanium dioxide was evaluated. A recent study reported rats receiving E 171 in water developed inflammation and aberrant crypt foci (ACF) in the gastrointestinal tract. Here, rats received food containing E 171 (7 or 100 days). The 100-day study included feeding E 171 after dimethylhydrazine (DMH) or vehicle only pretreatment. Food consumption was similar between treatment groups with maximum total cumulative E 171 exposure being 2617 mg/kg in 7 days and 29,400 mg/kg in 100 days. No differences were observed due to E 171 in the percentage of dendritic, CD4 + T or T reg cells within Peyer's patches or the periphery, or in cytokine production in plasma, sections of jejunum, and colon in 7- or 100-day E 171 alone fed rats. Differences were observed for IL-17A in colon (400 ppm E 171 + DMH) and IL-12p70 in plasma (40 ppm E 171 + DMH). E 171 had no effect on histopathologic evaluations of small and large intestines, liver, spleen, lungs, or testes, and no effects on ACF, goblet cell numbers, or colonic gland length. Dietary E 171 administration (7- or 100-day), even at high doses, produced no effect on the immune parameters or tissue morphology., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

In this study, an acidic polysaccharide from Codonopsis pilosula Nannf. var. modesta (Nannf.) L. T. Shen (WCP-I) and its main fragment, WCP-Ia, obtained after pectinase digestion, were structurally elucidated and found to consist of a rhamnogalacturonan I (RG-I) region containing both arabinogalactan type I (AG-I) and type II (AG-II) as sidechains. They both expressed immunomodulating activity against Peyer's patch cells. Endo-1,4-β-galactanase degradation gave a decrease of interleukine 6 (IL-6) production compared with native WCP-I and WCP-Ia, but exo-α-l-arabinofuranosidase digestion showed no changes in activity. This demonstrated that the stimulation activity partly disappeared with removal of β-d-(1→4)-galactan chains, proving that the AG-I side chain plays an important role in immunoregulation activity. WCP-Ia had a better promotion effect than WCP-I in vivo, shown through an increased spleen index, higher concentrations of IL-6, transforming growth factor-β (TGF-β), and tumor necrosis factor-α (TNF-α) in serum, and a slight increment in the secretory immunoglobulin A (sIgA) and CD4 + /CD8 + T lymphocyte ratio. These results suggest that β-d-(1→4)-galactan-containing chains in WCP-I play an essential role in the expression of immunomodulating activity. Combining all the results in this and previous studies, the intestinal immune system might be the target site of WCP-Ia.

Lentinan (LNT), a polysaccharide isolated from Lentinus edodes, has been shown to stimulate immune response. Despite its widespread use owing to its health benefits, epidemiologic and experimental studies that address the biological activities of LNT after oral administration to animals or humans are rare. In this study, the effects of LNT on the intestinal mucosal immune system of immunosuppressed mice were investigated. The number and size of the Peyer's patches (PPs), proliferation ability of PP lymphocytes, T and B lymphocyte percentage, and T-cell activation proportion, as well as the number of M-like cells in PPs, were determined. The antigen transfer ability of M-like cells and intestinal secretory immunoglobulin A (IgA) levels were also detected. After oral administration of LNT for 7 days, the number of PPs, lymphocytes in PPs, and the level of intestinal soluble IgA in immunosuppressed mice were increased. LNT maintained the percentage of T and B lymphocytes and upregulated the proportion of activated T cells in PPs. Furthermore, the number of M-like cells, which were differentiated from intestinal epithelial cells, and their antigen transfer ability were enhanced. These results indicate that orally administered LNT can improve the immune status of the intestinal mucosa in immunosuppressed mice., (Copyright © 2019. Published by Elsevier B.V.)

Objective: Dimethyl fumarate (DMF) exerts immunomodulatory and neuroprotective effects in the animal model of experimental autoimmune neuritis (EAN) in the Lewis rat. DMF has been shown to modulate gut microbiota in veterinary medicine, however the effects of oral DMF on the gut-associated lymphoid tissue (GALT) remain unknown. Methods: Lewis rats were treated orally twice daily with DMF up to day 10 after immunization with immunogenic P2 peptide. Histological, flow cytometric and RT-PCR analyses of the GALT (intraepithelial layer, lamina propria, and Peyer patches) in duodenum, jejunum, and ileum were performed ex vivo . Moreover, cell transfer experiments were used to examine the protective effects of GALT regulatory T cells of the Peyer patches. Results: In the upper layers of duodenum, DMF induced a reduction of the toll-like receptor 4 (TLR4) mRNA expression. This was combined by a decrease of the pro-inflammatory lamina propria IFN-γ mRNA expression. In the ileum, we detected an immunoregulatory phenotype characterized by an increase of FoxP3 mRNA expression and of the nuclear factor (erythroid-derived-2)- like 2 (Nrf2) downstream molecule heme oxygenase-1 (HO-1) mRNA. Finally, CD4 + CD25 + regulatory T cells were increased in the Peyer patches. In vivo , the protective effect of these regulatory cells was verified by cell transfer into recipient EAN rats. Conclusions: Our results identified a novel immunomodulatory effect of DMF through the different regions and layers of the small intestine, which led to an increase of regulatory T cells, exerting a protective role in experimental neuritis.

The aim of the present study was chemical clarification of in vitro Peyer's patch-immunomodulating polysaccharides in sugar cane molasses, and evaluation of in vivo modulating activity on immune function of T lymphocytes in Peyer's patches and on microenvironment of hemopoietic system. Five kinds of glucans, comprising of dextranase-sensitive and activity-related d-glucosyl moieties, were purified as in vitro Peyer's patch-immunomodulating polysaccharides from the molasses. Oral administration of a glucan-enriched subfraction induced IL-2 and GM-CSF-producing T lymphocytes in Peyer's patches, resulting in enhancement of IL-6 production in a hemopoietic microenvironment to boost neutrophil numbers in the peripheral blood stream. Oral administration of purified glucan or glucan-enrich sub-fraction of sugar cane reduced the number of Plasmodium berghei- or P. yoelii-infected erythrocytes in a murine infection model, using polysaccharide alone or via co-administration with the antimalarial drug, artesunate. These results suggested that Peyer's patch-immunomodulating glucans enhanced protective immunity through axis of Peyer's patches-hemopoietic system., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Objective: Exposure to lethal doses of radiation has severe effects on normal tissues. Exposed individuals experience a plethora of symptoms in different organ systems including the gastrointestinal (GI) tract, summarized as Acute Radiation Syndrome (ARS). There are currently no approved drugs for mitigating GI-ARS. A recent high-throughput screen performed at the UCLA Center for Medical Countermeasures against Radiation identified compounds containing sulfonylpiperazine groups with radiation mitigation properties to the hematopoietic system and the gut. Among these 1-[(4-Nitrophenyl)sulfonyl]-4-phenylpiperazine (Compound #5) efficiently mitigated gastrointestinal ARS. However, the mechanism of action and target cells of this drug is still unknown. In this study we examined if Compound #5 affects gut-associated lymphoid tissue (GALT) with its subepithelial domes called Peyer's patches., Methods: C3H mice were irradiated with 0 or 12 Gy total body irradiation (TBI). A single dose of Compound #5 or solvent was administered subcutaneously 24 h later. 48 h after irradiation the mice were sacrificed, and the guts examined for changes in the number of visible Peyer's patches. In some experiments the mice received 4 daily injections of treatment and were sacrificed 96 h after TBI. For immune histochemistry gut tissues were fixed in formalin and embedded in paraffin blocks. Sections were stained with H&E, anti-Ki67 or a TUNEL assay to assess the number of regenerating crypts, mitotic and apoptotic indices. Cells isolated from Peyer's patches were subjected to immune profiling using flow cytometry., Results: Compound #5 significantly increased the number of visible Peyer's patches when compared to its control in non-irradiated and irradiated mice. Additionally, assessment of total cells per Peyer's patch isolated from these mice demonstrated an overall increase in the total number of Peyer's patch cells per mouse in Compound #5-treated mice. In non-irradiated animals the number of CD11b high in Peyer's patches increased significantly. These Compound #5-driven increases did not coincide with a decrease in apoptosis or an increase in proliferation in the germinal centers inside Peyer's patches 24 h after drug treatment. A single dose of Compound #5 significantly increased the number of CD45 + cells after 12 Gy TBI. Importantly, 96 h after 12 Gy TBI Compound #5 induced a significant rise in the number of visible Peyer's patches and the number of Peyer's patch-associated regenerating crypts., Conclusion: In summary, our study provides evidence that Compound #5 leads to an influx of immune cells into GALT, thereby supporting crypt regeneration preferentially in the proximity of Peyer's patches., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Ethnopharmacological Evidence: With fast development and high pace life in modern society, autoimmune diseases like inflammatory bowel disease had become increasingly common. Bu-Zhong-Yi-Qi-Tang (BZYQT), a famous traditional Chinese medicine prescription (TCMP), has been used for 700 years mainly in Eastern Asia countries for the treatment of gastrointestinal and respiratory disorder, and weakness after serious diseases. These diseases were proved to be closely related to human immune system, among which, mucosal immune system is the largest immune system. So it is necessary to discover the mucosal immune related bioactive components of BZYQT., Aim of the Study: To evaluate the mucosal immunomodulatory bioactivity of BZYQT and ingredients., Materials and Methods: Peyer's patches were collected from mice administrated orally with BZYQT, its related Octadecylsilane (ODS) fractions and polysaccharide part. Productions of several cytokines including IL-2, IL-4, IL-5, and IFN-γ from T lymphocytes were tested with enzyme linked immunosorbent assay (ELISA) by Peyer's patch cells ex vivo experiments. Chemical profile including low molecular part and polysaccharide part were investigated. Low molecular part of BZYQT and related ODS fractions were analyzed by ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC-Q/TOF-MS) based on LC-MS information from self-established compound library. exclusion chromatography, and chemical property has been analyzed., Result: Three-days' administration of BZYQT enhanced productions of IL-4 and IFN-γ in T lymphocytes of Peyer's patches in addition to IL-2. Some hydrophobic low molecular weight fractions (30%, 70% and 100% MeOH ODS fraction), which were fractionated from BZYQT by ODS column chromatography, showed enhancing or suppressive effects on productions of IL-2, IL-4 or IL-5 in T lymphocytes of Peyer's patches after oral administration. Besides, 161 components from hydrophobic low molecular weight fractions of BZYQT were unequivocally identified or tentatively characterized by UPLC-Q/TOF-MS according to retention time behaviors and fragments, and most of them were flavonoids and saponins from Glycyrrhizae Radix, Citri Reticulatae Pericarpium, and Cimicifugae Rhizoma. Polysaccharide part was separated and purified both by anion-exchange and size. BZYQT also contained at least one neutral and three weakly or strongly acidic polysaccharides, and analysis of their chemical properties indicated that a neutral polysaccharide was glucan, and acidic polysaccharides possessed heteroglycan and pectic arabinogalactan features. Murine administration of polysaccharide fractions of BZYQT induced different changes on functions of T lymphocytes in Peyer's patches from hydrophobic low molecular weight fractions. By experiment using intranasally-immunized mice, BZYQT negatively regulated antibody response in lung as combinatorial actions of its low molecular weight ingredients and polysaccharides., Conclusion: BZYQT contains several low and macromolecular weight ingredients, which affect to immune-function of T lymphocytes in Peyer's patches, and the formula expresses its regulative activity on lower respiratory immune system through combinatorial actions of these ingredients on immunocompetent cells in Peyer's patches., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Taurine is a sulfur-containing amino acid which has strong activities in enhancing immunity. Gut microbiota is closely interrelated with intestinal mucosal immunity, but the effects and mechanisms of taurine on intestinal microbiota and mucosal immune cells under an immunosuppressive condition remain unclear. This study was conducted to investigate the effect of taurine on gut microbiota and immune cells in Peyer's patches (PPs) of dexamethasone (Dex)-induced immunosuppressive mice. Mice (4-week-old, Male) were randomly divided into three groups: the Control group (n = 12), the Dex-induced immunosuppressive model group (n = 12) and the taurine intervention group (n = 12). The model was established by Dex injection for 7 days and the taurine intervention group was gavaged 100 mg/kg soluble taurine for 30 days. The changes of intestinal microbiota and immune cells in PPs were tested by denaturing gradient gel electrophoresis (DGGE) and flow cytometry, respectively. Results showed that the microbiota in immunosuppressive mice was obvious different compared with control group, in which, the Lachnospiraceae and Ruminococcaceae groups were significantly reduced, and their reduction were reversed after taurine intervention. Compared to the control group, the total cell number in PPs, as well as the subsets of CD3 + cells (T cells), CD19 + cells (B cells) in model groups were significantly lower, and they were dramatically improved after taurine treatment. Our results suggested that taurine has a positive effect on i ntestinal homeostasis of the immunosuppressive mice.

Polysaccharide with the enhanced immunostimulatory activities including intestinal immune system modulation was fractionated from Korean red ginseng (KRG) and its characteristics were investigated in the present experiment. When the water extracts were digested with α-amylase and amyloglucosidase and precipitated by ethanol to enhance immunostimulatory activity, enzyme digested-crude polysaccharides enhanced the macrophage and intestinal immune system via Peyer's patches compared to non-enzymatic crude polysaccharides. Starch-like polysaccharide also potently decreased in enzyme digested-crude polysaccharides. Especially, crude polysaccharide (RG-CW-EZ-CP) from the digest of cold water extracts showed significantly the most active immunostimulatory activities. By precipitation using ethanol concentrations (distilled water:ethanol = 1:4 and 1:8), two immunostimulatory polysaccharides (RG-CW-EZ-CP-4 and RG-CW-EZ-CP-8) were further fractionated from RG-CW-EZ-CP. In chemical analysis, RG-CW-EZ-CP-4 and RG-CW-EZ-CP-8 seems to be a pectic-like acidic polysaccharide and arabinose-rich polysaccharide, and heat treatment of polysaccharides (RG-CW-EZ-CP-4 and RG-CW-EZ-CP-8) did not significantly affect the intestinal immune system-modulating activity. RG-CW-EZ-CP-8 also significantly upregulated the phosphorylation of three major mitogen-activated protein kinases (MAPKs), including c-Jun N-terminal kinase, extracellular signal-regulated kinase, and p38. Thus, enzymatic digestion of KRG cold water extracts played a very important role in the isolation of the enhanced immunostimulatory polysaccharides from KRG., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Selection for prolificacy in modern pig farming has resulted in increasing litter sizes. Since rearing large litters is challenging, artificial rearing of piglets with a milk replacer is an alternative strategy. It is hypothesized that the development of the piglets' mucosa-associated lymphoid tissues (MALT) is affected by these artificial conditions. Therefore, the stereologically estimated volumes of the tonsil of the soft palate, and the lingual, nasopharyngeal and paraepiglottic tonsils, as well as the jejunal and ileal Peyer's patches were statistically compared at day 21 postpartum between six conventionally reared piglets and six piglets that were artificially reared from day 7 onwards. In addition, six 7-day-old sow-fed piglets were examined to evaluate the effect of age. All tonsils and Peyer's patches significantly increased in volume with age. The rearing strategy had no significant effect on the volumes of the tonsil of the soft palate and the lingual tonsil. The former tonsil was by far the largest with a mean volume of 967.2 ± 122.4 mm 3 and 822.3 ± 125.4 mm 3 in the conventionally and artificially reared piglets, respectively. The lingual tonsil only measured 9.4 ± 6.4 mm 3 and 6.3 ± 2.6 mm 3 in conventionally and artificially reared groups, respectively. In contrast, the rearing strategy did affect the volumes of the nasopharyngeal and paraepiglottic tonsils, which had a mean volume of 137.1 ± 32.4 mm 3 and 84.4 ± 26.9 mm 3 , and 30.7 ± 7.8 mm 3 and 20.0 ± 3.9 mm 3 in conventionally and artificially reared piglets, respectively. The rearing strategy did not affect the development of the Peyer's patches. At day 21, the jejunal Peyer's patches of the conventionally and artificially reared piglets presented a volume of 1.6 ± 0.4 cm 3 and 1.3 ± 0.2 cm 3 , respectively. The volumes of the ileal Peyer's patch amounted to 15.1 ± 3.0 cm³ in conventionally reared piglets and 12.0 ± 2.6 cm³ in artificially reared piglets at day 21. The results showed that artificial rearing hampers the morphological development of the tonsils that are exposed to inhaled antigens, but the voluminous lymphoid tissues that sample oral antigens are not influenced. Since it is unlikely that the observed differences in both tonsils are due to the milk replacer, artificial rearing could be a valuable alternative for raising large litters. In addition, the presence of developing MALT in piglets allows for investigating the value of nasal and oral vaccination in this species for human or veterinary purposes., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The effects of bisphenol A on the some plasma cytokine levels and distribution of CD8 + and CD4 + T lymphocytes in spleen, ilealPeyer's patch and bronchus-associated lymphoid tissue in rats were investigated. A total of fourty male Wistar Albino rats were divided into five groups including 8 rats in each one: control, vehicle, BPA 5, BPA 50 and BPA 500 groups. Doses of 5, 50 and 500 μg/kg BPA were dissolved in ethanol, then mixed with corn oil. The control group received no treatment. The vehicle group was given the ethanol-corn oil mixture. BPA 5, BPA 50 and BPA 500 groups were given, respectively, 5, 50, and 500 μg/kg/day orally. In blood samples, IL-4, IL-6, IL-10 and TNF-α plasma levels were determined with ELISA. Tissue samples (spleen, ileal Peyer's patches and lung) were processed by means of routine histological techniques. CD4 and CD8 were stained immunohistochemically. Data obtained from this study showed that, BPA causes the alteration on immune parameters including cytokine profile, distribution of CD8 + and CD4 + T lymhpocytes in spleen and ileal Peyer's patches. Present study indicated that BPA may affect immune systems even at lower doses.Disruption of immun system cells and cytokine levels can result in harmful outcomes triggering autoimmune diseases and immunodeficiencies., (Copyright © 2018 Elsevier GmbH. All rights reserved.)

The lipid sensor oleoylethanolamide (OEA), an endogenous high-affinity agonist of peroxisome proliferator-activated receptor-α (PPAR-α) secreted in the proximal intestine, is endowed with several distinctive homeostatic properties, such as control of appetite, anti-inflammatory activity, stimulation of lipolysis and fatty acid oxidation. When administered exogenously, OEA has beneficial effects in several cognitive paradigms; therefore, in all respects, OEA can be considered a hormone of the gut-brain axis. Here we report an unexplored modulatory effect of OEA on the intestinal microbiota and on immune response. Our study shows for the first time that sub-chronic OEA administration to mice fed a normal chow pellet diet, changes the faecal microbiota profile, shifting the Firmicutes:Bacteroidetes ratio in favour of Bacteroidetes (in particular Bacteroides genus) and decreasing Firmicutes (Lactobacillus), and reduces intestinal cytokines expression by immune cells isolated from Peyer's patches. Our results suggest that sub-chronic OEA treatment modulates gut microbiota composition towards a "lean-like phenotype", and polarises gut-specific immune responses mimicking the effect of a diet low in fat and high in polysaccharides content.

The role of the spleen in the induction of an immune response to orally administered antigens is still under discussion. Although it is well known that after oral antigen administration specific germinal centres are not only formed in the Peyers patches (PP) and the mesenteric lymph nodes (mLN) but also in the spleen, there is still a lack of functional data showing a direct involvement of splenic B cells in an IgA immune response in the gut. In addition, after removal of mLN a high level of IgA+ B cells was observed in the gut. Therefore, in this study we analysed the role of the spleen in the induction of IgA+ B cells in the gut after mice were orally challenged with antigens. Here we have shown that antigen specific splenic IgM+ B cells after in vitro antigen stimulation as well as oral immunisation of donor mice were able to migrate into the gut of recipient mice, where they predominantly switch to IgA+ plasma cells. Furthermore, stimulation of recipient mice by orally administered antigens enhanced the migration of the splenic B cells into the gut as well as their switch to IgA+ plasma cells. Removal of the mLN led to a higher activation level of the splenic B cells. Altogether, our results imply that splenic IgM+ B cells migrate in the intestinal lamina propria, where they differentiate into IgA+ plasma cells and subsequently proliferate. In conclusion, we demonstrated that the spleen plays a major role in the gut immune response serving as a reservoir of immune cells that migrate to the site of antigen entrance., Competing Interests: The authors have declared that no competing interests exist.

Background: The traditional view considers that Chenpi (dried citrus peel) stored over the long-term has better health efficacies compared to fresh Chenpi, although the detailed mechanism responsible for this remains obscure., Results: The three water-soluble pectic polysaccharides (CPP1, CPP5 and CPP10) were obtained from 1-, 5- and 10-year Chenpi, respectively, and their physicochemical characteristics and intestinal immunomodulating activities were investigated and compared. The results obtained showed that CPP5 and CPP10 demonstrated a lower dynamic viscosity and degree of methylesterification, as well as a higher molecular heterogeneity, compared to CPP1. Monosaccharide composition analysis indicated that CPP1 was composed of arabinose, galacturonic acid and galactose, and a small amount of rhamnose; however, CPP5 and CPP10 consisted of arabinose, galacturonic acid, galactose, glucose and xylose, and a small amount of rhamnose. With the extension of storage period of Chenpi, the content of soluble conjugate phenolic acids increased in the pectic polysaccharide. Furthermore, it was confirmed that the pectic polysaccharides extracted from the 5-year and 10-year Chenpi could significantly enhance the proliferation of bone marrow cells via activating the Peyer's patch cells in vitro., Conclusion: The present study demonstrates the differences in the pectic polysaccharides from Chenpi with different storage periods and also confirms that the pectic polysaccharides extracted from Chenpi stored over the long-term had more significant intestinal activities compared to that obtained from the fresh Chenpi. This phenomenon might partly explain why the Chenpi stored over the long-term has better healthcare effects. © 2018 Society of Chemical Industry., (© 2018 Society of Chemical Industry.)

Oxaliplatin is a platinum-based chemotherapeutic used for cancer treatment. Its use associates with peripheral neuropathies and chronic gastrointestinal side-effects. Oxaliplatin induces immunogenic cell death by provoking the presentation of damage associated molecular patterns. The damage associated molecular patterns high-mobility group box 1 (HMGB1) protein exerts pro-inflammatory cytokine-like activity and binds to toll-like receptors (namely TLR4). Gastrointestinal microbiota may influence chemotherapeutic efficacy and contribute to local and systemic inflammation. We studied effects of oxaliplatin treatment on 1) TLR4 and high-mobility group box 1 expression within the colon; 2) gastrointestinal microbiota composition; 3) inflammation within the colon; 4) changes in Peyer's patches and mesenteric lymph nodes immune populations in mice. TLR4+ cells displayed pseudopodia-like extensions characteristic of antigen sampling co-localised with high-mobility group box 1 -overexpressing cells in the colonic lamina propria from oxaliplatin-treated animals. Oxaliplatin treatment caused significant reduction in Parabacteroides and Prevotella1, but increase in Prevotella2 and Odoribacter bacteria at the genus level. Downregulation of pro-inflammatory cytokines and chemokines in colon samples, a reduction in macrophages and dendritic cells in mesenteric lymph nodes were found after oxaliplatin treatment. In conclusion, oxaliplatin treatment caused morphological changes in TLR4+ cells, increase in gram-negative microbiota and enhanced HMGB1 expression associated with immunosuppression in the colon., Competing Interests: The authors have declared that no competing interests exist.

Particulate adjuvants have shown increasing promise as effective, safe, and durable agents for the stimulation of immunity, or alternatively, the suppression of autoimmunity. Here we examined the potential of the adjuvant carbonyl iron (CI) for the modulation of organ-specific autoimmune disease-type 1 diabetes (T1D). T1D was induced by multiple low doses of streptozotocin (MLDS) that initiates beta cell death and triggers immune cell infiltration into the pancreatic islets. The results of this study indicate that the single in vivo application of CI to MLDS-treated DA rats, CBA/H mice, or C57BL/6 mice successfully counteracted the development of insulitis and hyperglycemia. The protective action was obtained either when CI was applied 7 days before, simultaneously with the first dose of streptozotocin, or 1 day after MLDS treatment. Ex vivo cell analysis of C57BL/6 mice showed that CI treatment reduced the proportion of proinflammatory F4/80 + CD40 + M1 macrophages and activated T lymphocytes in the spleen. Moreover, the treatment down-regulated the number of inflammatory CD4 + IFN-γ + cells in pancreatic lymph nodes, Peyer's patches, and pancreas-infiltrating mononuclear cells, while simultaneously potentiating proportion of CD4 + IL17 + cells. The regulatory arm of the immune system represented by CD3 + NK1.1 + (NKT) and CD4 + CD25 + FoxP3 + regulatory T cells was potentiated after CI treatment. In vitro analysis showed that CI down-regulated CD40 and CD80 expression on dendritic cells thus probably interfering with their antigen-presenting ability. In conclusion, particulate adjuvant CI seems to suppress the activation of the innate immune response, which further affects the adaptive immune response directed toward pancreatic beta cells., (© 2017 Wiley Periodicals, Inc.)

Ethnopharmacological Relevance: Immunoglobulin A (IgA) secretion and alpha-defensins play a role in the innate immune system to protect against infection. Ganoderma lucidum (W.Curt.: Fr.) P. Karst. (Reishi) is a well-known mushroom in traditional Chinese medicine. This study aimed to determine the effects of Reishi on IgA secretion from Peyer's patch (PP) cells and alpha-defensin-5 (RD-5) and RD-6 expression in the rat small intestine., Materials and Methods: The rats received an oral injection of 0.5-5mg/kg of Reishi powder (1mL/kg) by sonde. All animals were euthanized 24h after Reishi administration. We examined RD-5, RD-6, and Toll-like receptor (TLR) 4 mRNA levels in the jejunum, ileum, and in Peyer's patches (PP) through quantitative real-time PCR analysis. IgA secretion from PP was measured through enzyme-linked immunosorbent assay of the supernatant after primary culture., Results: Reishi increased IgA secretion in the presence of lipopolysaccharide (LPS) and increased TLR4 mRNA levels, but had no effect on the viability of PP cells. Moreover, Reishi increased RD-5, RD-6, and TLR4 mRNA levels significantly in the ileum in a concentration-dependent manner., Conclusions: Reishi can induce IgA secretion and increase the mRNA levels of RD-5 and RD-6 in the rat small intestine, through a TLR4-dependent pathway. The present results indicate that Reishi might reduce the risk of intestinal infection., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Agomelatine (AGM) is a new antidepressant drug with a novel mechanism of action and fewer side effects compared with older antidepressants. AGM is a melatonin receptor (MT1 and MT2) agonist and 5-hydroxytryptamine receptor (5-HT 2C ) antagonist. In the present study, the enhancement of the oral bioavailability of AGM was formulated and loaded into nanostructured lipid carriers (NLCs), using ultrasonication method. In vitro and ex vivo drug release was performed using a dialysis bag and rat duodenum, respectively. Our pharmacodynamic study showed that AGM-NLCs are more efficacious than a pure drug and marketed product, and confocal microscopy revealed lymphatic uptake of AGM-NLCs. The present study concluded that the NLCs enhanced the oral bioavailability of AGM (6.5-fold) by avoiding its first-pass metabolism by way of lymphatic uptake., Competing Interests: Disclosure The authors report no conflicts of interest in this work.

Objectives: The aim of this study was to investigate the effects of parenteral glutamine (GLN) supplementation combined with enteral nutrition (EN) on heat shock protein (Hsp) 90 expression and Peyer's patch (PP) apoptosis in severely burned rats., Methods: Male Sprague-Dawley (SD) rats were randomly assigned to four groups: Sham burn + EN + GLN-free amino acid (AA; n = 10), sham burn + EN + GLN (n = 10), burn + EN + AA (n = 10), and burn + EN + GLN (n = 10). Two hours after a 30% total body surface area (TBSA), full-thickness scald burn injury on the back, burned rats in two of the experimental groups (burn + EN + AA and burn + EN + GLN groups) were fed with a conventional EN solution by oral gavage for 7 d. Simultaneously, rats in the burn + EN + GLN group were given 0.35 g GLN/kg body weight/d once via a tail vein injection for 7 d and rats in the burn + EN + AA group were administered isocaloric/isonitrogenous GLN-free amino acid solution (Tyrosine) for comparison. Rats in two sham burn control groups (sham burn + EN + AA and sham burn + EN + GLN groups) were treated in the same manner except for the burn injury. All rats in the four groups were given 175 kcal/kg body wt/d. There was isonitrogenous, isovolumic, and isocaloric intake among the four groups. At the end of the seventh day after completion of the nutritional program, all rats were anesthetized and samples were collected for further analysis. PP apoptosis was measured by terminal deoxyuridine nick-end labeling (TUNEL). The expression of Hsp90 in PPs was analyzed by western blotting. Caspase-3 activity of PPs was also assessed. Levels of proinflammatory cytokines of gut tissues were evaluated by enzyme-linked immunosorbent assay (ELISA). The intestinal immunoglobulin A (IgA) content was also determined by ELISA., Results: The results revealed that intestinal IgA content in rats of the burn + EN + GLN group were significantly increased compared with those in the burn + EN + AA group (P < 0.05). The expression of Hsp90 of PPs in rats in the burn + EN + GLN group was significantly upregulated compared with those in the burn + EN + AA group (P < 0.05). On the other hand, levels of proinflammatory cytokines of gut tissues, caspase-3 activity, and the number of TUNEL-stained cells of PPs in rats of the burn + EN + GLN group were markedly decreased compared with those of the burn + EN + AA group (P < 0.05)., Conclusions: The results of this study show that parenteral glutamine supplementation combined with EN may upregulate the expression of Hsp90, reduce caspase-3 activity, lessen the release of proinflammatory cytokines, attenuate PP apoptosis, and improve intestinal IgA response in burned rats. Clinically, therapeutic efforts to improve intestinal immunity may contribute to a favorable outcome in severely burned patients., (Copyright © 2017 Elsevier Inc. All rights reserved.)

The aims of this study were to determine the effects of gamma-aminobutyric acid (GABA) on immunoglobulin A (IgA) secretion from Peyer's patch (PP) cells; to assess rat alpha-defensin-5 (RD-5) expression in the rat small intestine; and to determine the effect of GABA on intestinal ischemia reperfusion (I/R) injury-induced intestinal innate immunity. We found that GABA caused an increase in IgA secretion in the presence and absence of lipopolysaccharide (LPS). Moreover, GABA also significantly increased the mRNA levels of RD-5 and superoxide dismutase (Sod) 1, 3. Intestinal I/R was induced by a 30-min occlusion of the superior mesenteric artery followed by a reperfusion for 60-min. This led to a significant decrease in IgA secretion, and mRNA levels of RD-5 and Sod 1-3 in the ileum. On the other hand, administration of GABA before I/R induction had a significant protective effect against oxidative injury and attenuated the effects on intestinal immunity.

Three polysaccharide complexes (PSCs) were isolated from the aerial parts of common purslane (Portulaca oleracea L.), and the flowers of common lavender (Lavandula angustifolia Mill.) and silver linden (Tilia tomentosa Moench) by boiling water extraction and ethanol precipitation. The chemical composition and immunomodulating effects of isolated PSCs were characterized. The chemical characterization revealed that the three samples contain mainly pectic polysaccharides. They exhibited ex vivo intestinal immunomodulating activity through the murine Peyer's patch-mediated bone marrow cell proliferation test at 100μg/ml concentration. At the same time, they stimulated ex vivo human blood T-cell populations (CD4 + /CD25 + and CD8 + /CD25 + ), phagocytic leukocytes (CD14 + and CD64 + cells) and induced IL-6 production from human white blood cells and Peyer's patch cells. The herbal PSCs stimulated ex vivo ROS production from whole blood phagocytes and showed unspecific in vitro anti-proliferative activity against normal and A549, HeLa and LS180 tumor cells. This is the first report on immunomodulating studies of linden flower pectins and chemical and biological activity characterization of lavender polysaccharides. Our study demonstrates that similarly to purslane, lavender and silver linden herbal materials contain immunomodulating polysaccharides that could be useful for support of compromised immune system., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Ethyl pyruvate is a redox analogue of dimethyl fumarate (Tecfidera), a drug for multiple sclerosis treatment. We have recently shown that ethyl pyruvate ameliorates experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. It affects encephalitogenic T cells and macrophages in vitro, as well as in lymph nodes draining the site of encephalitogenic immunization and within the central nervous system (CNS). Here, in vivo effects of ethyl pyruvate on EAE are thoroughly investigated in the CNS and within the gut associated lymphoid tissue. Ethyl pyruvate reduced infiltrates within the CNS and number of activated macrophages/microglia (ED1 + /Iba1 + ) and proliferating astrocytes (GFAP + ). Furthermore, it reduced expression of HMGB1 in activated macrophages/microglia. It also reduced number of activated T cells and antigen-presenting cells and expression of Th1/Th17-related molecules in mesenteric lymph nodes and Peyer's patches. These results contribute to our understanding of anti-encephalitogenic effects of ethyl pyruvate as they provide evidence of its effects within the CNS and imply that these effects are related to reduction of inflammatory immune response in gut associated lymphoid tissue., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

The oral uptake of intact nanocarriers through Peyer's patches is an important uptake pathway. We report Rifampicin Lipid-Polymer hybrid nanoparticles (RIF-LIPOMER) using glyceryl monostearate as lipid and the mucoadhesive polymer, Gantrez, with the objective of balancing hydrophobicity and mucoadhesion for enhanced Peyer's patch uptake. RIF-LIPOMER was optimized for size, hydrophobicity, and mucoadhesion using Box-Behnken. Designed RIF-LIPOMER (RIF-LIPO-120) exhibited average particle size in the range 300-400nm with drug loading >12%. DSC and XRD confirmed complete amorphization. Contact angle and mucoadhesion force revealed that RIF-LIPO-120 exhibited greater hydrophobicity and lower mucoadhesion compared to Gantrez nanoparticles (RIF-GzNP). Comparative uptake of fluorescent labelled RIF-LIPO-120 and RIF-GzNP, through Peyer's patch following intraduodenal administration in rats, revealed the high accumulation of RIF-GzNP at the villi border, and high Peyer's patch uptake of RIF-LIPO-120. Furthermore, lower accumulation of RIF-LIPO-120 in the liver, compared to RIF-GzNP, suggested bypass of the portal circulation and lymphatic uptake through Peyer's patches. Significantly higher lung: plasma concentration ratio exhibited by RIF-LIPO-120 compared to RIF-GzNP confirmed the same (p<0.05). Our study demonstrated that optimization of hydrophobicity and mucoadhesion of nanoparticles could favor Peyer's patch uptake, which in turn could enable enhanced drug accumulation in the lungs with advantage in the therapy of pulmonary afflictions., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: Salmonella enterica infections often exhibit a form of immune evasion. We previously observed that probiotic bacteria could prevent inhibition of lymphoproliferation and apoptosis responses of T cells associated with S. enterica infections in orally challenged mice., Results: In this study, changes in expression of genes related to lymphocyte activation in mucosa-associated lymphoid tissues (MALT) of mice orally infected with S. enterica with and without treatment with probiotic bacteria were evaluated. Probiotic bacteria increased expression of mRNA for clusters of differentiation antigen 2 (Cd2), protein tyrosine phosphatase receptor type C (Ptprc), and Toll-like receptor 6 (Tlr6) genes related to T and B cell activation in mouse intestinal tissue. The probiotic bacteria were also associated with reduced mRNA expression of a group of genes (RelB, Myd88, Iκκa, Jun, Irak2) related to nuclear factor of kappa light chains enhancer in B cells (NF-κB) signal transduction pathway-regulated cytokine responses. Probiotic bacteria were also associated with reduced mRNA expression of apoptotic genes (Casp2, Casp12, Dad1, Akt1, Bad) that suggest high avidity lymphocyte sparing. Reduced CD2 immunostaining in mesenteric lymph nodes (MLN) was suggestive of reduced lymphocyte activation in probiotic-treated mice. Reduced immunostaining of TLR6 in MALT of probiotic-treated, S. enterica-infected mice suggests that diminished innate immune sensitivity to S. enterica antigens is associated with preventing lymphocyte deletion., Conclusions: The results of this study are consistent with prevention of S. enterica-induced deletion of lymphocytes by the influence of probiotic bacteria in mucosal lymphoid tissues of mice.

Fusarenon X, a member of the type B trichothecene mycotoxin group, has been frequently observed, along with deoxynivalenol (DON) and nivalenol (NIV) as a contaminant in cereals. Our previous study demonstrated that a 14-day FX exposure caused apoptosis in the lymphoid tissues of mice, especially at 0.5 mg/kg bodyweight. However, the relationship between low concentrations of FX and apoptotic molecular machinery remains unclear. In the present study, we investigated the genetic regulatory mechanisms in the thymus and Peyer's patches of mice after 14 days oral administration of FX at 0.5 mg/kg bodyweight. FX caused the up-regulation of Bax, Bid, Trp53, and Caspase-9 mRNA but the relative expression of Fas, TNF, and Caspase-8 remained unchanged. Furthermore, we also determined the toxicity of FX in Jurkat T-cells. FX exhibited a concentration- and time-dependent inhibition of cell viability. Thus, incubation time and FX concentration influence the percentage of apoptotic cells. These data suggested that treatment with low dosage of FX can induce apoptosis in lymphocytes through an effect on Bax, Bid, Trp53, and Caspase-9 and therefore the mitochondrial apoptotic pathway., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

We studied the structure of fucoidans extracted from two brown seaweed species, Sargassum crassifolium and Padina australis, and their intestinal immunomodulating activity via Peyer's patch cells of C3H/HeJ mice. ESI-MS analysis indicated that the dominant structure of both fucoidans has a backbone of α-(1→4)-linked and α-(1→3)-linked l-fucose residues and sulfate groups are attached at the C-2 and C-4 positions; branches of fucoidan from S. crassifolium are galactose residues with (1→4)- linkage and branching points are at C-4 of fucose, while fucoidan from P. australis, branches are sulfated galactose-fucose disaccharides and sulfated galactose monosaccharides attached to the main chain through (1→3)- or (1→4)- linkages. According to small angle X-ray scattering (SAXS) measurements, the two fucoidans have a branched structure. We simulated them with molecular models based on our proposed primary structure. These fucoidan samples have the ability to stimulate intestinal immunological activity via Peyer's patch cells., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Objective To investigate the effect of Shengqifuzheng Injection (SQFZ) on the number recovery of B cells in gut-associated lymphoid tissues (GALTs) of mice receiving cyclophosphamide-based chemotherapy. Methods BALB/c mice were randomly divided into control group, cyclophosphamide (Cy) group and SQFZ group. Mice in Cy group and SQFZ group were injected intraperitoneally with Cy (100 mg/kg), while the control mice were injected with an equal volume of normal saline. Twenty-four hours later, mice in SQFZ group were administrated intragastricly with 1 mL SQFZ once daily for 10 consecutive days, and mice in the other groups were given the same volume of normal saline. Body mass of all the mice was measured every day. Mice were killed on day 10, and the indexes of spleen and thymus were measured. Cell cycles of bone marrow cells and the percentage of B cells in lymphocytes in mesenteric lymph node (MLN) and Peyer's patch (PP) were detected by flow cytometry. In vitro, after being treated with SQFZ, activity of lymphocytes was evaluzed by MTT assay; expression of CD86 on B cell surface was analyzed by flow cytometry; and B cell proliferation was tested by carboxyfluorescein succinimidyl ester (CFSE)-based lymphocyte proliferation assay. Results SQFZ alleviated the loss of body mass caused by Cy and promoted the recovery of thymus indexes, spleen indexes and B cell number in MLN and PP. But it did not alleviate the bone marrow suppression of mice in this condition. In vitro, SQFZ enhanced lymphocyte activity, and improved the activation and proliferation of B cells. Conclusion SQFZ could accelerate the recovery of B cells in GALTs of mice receiving chemotherapy and it might act by promoting B cell proliferation.

A homogeneous polysaccharide fraction (DOP-W3-b) with a high intestinal immunomodulating activity was obtained from the stems of Dendrobium officinale through a bioactivity-guided sequential isolation procedure based on the screening of Peyer's patch-mediated immunomodulating activity. Oral administration experiments of mice showed that DOP-W3-b could effectively regulate intestinal mucosal immune activity by changing intestinal mucosal structures, promoting the secretions of cytokines from Peyer's patches (PPs) and mesenteric lymph nodes (MLNs), and increasing the production of secretory immunoglobulin A (sIgA) in the lamina propria. Structure analysis indicated that DOP-W3-b was composed of mannose and glucose in a molar ratio of 4.5 with a relatively low molecular weight of 1.543 × 10(4) Da, and its repeat unit contained a backbone consisting of β-(1→4)-d-Manp, β-(1→4)-d-Glcp and β-(1→3,6)-d-Manp residues, a branch consisting of β-(1→4)-d-Manp, β-(1→4)-d-Glcp and terminal β-d-Glcp, and O-acetyl groups attached to O-2 of β-(1→4)-d-Manp. These results suggested that DOP-W3-b was a new polysaccharide with an essential potential for modulating body's immune functions.

Objective: To explore the underlying mechanism of "Gubentongluo Formula" in treatment of IgA nephropathy (IgAN)., Methods: After the IgAN model was successfully induced at week 12, the Kunming mice were randomly divided into three groups: normal control group (n = 15), IgAN group (n = 15) and Traditional Chinese Medicine (TCM) group. The mice in normal control and IgAN group were intragastriclly administrated with normal saline for 8 weeks; meanwhile, the mice in TCM group were intragastriclly administrated with "Gubentongluo Formula" 1.35 mL/ (g · d). The levels of 24 h urine protein were determined at Week 0, 12 and 20. At week 20, the changes of renal pathology were detected; the mRNA expressions of transforming growth factor-β (TGF-β) and small mothers against decapentaplegic (Smad) 3 in Peyer's patches (PPs) were detected by fuorescent quantitative reverse transcription-polymerase chain reaction; the protein expressions of TGF-β and Smad 3 in PPs were detected by immunohistochemistry technique; the levels of (IgA + B)/B lymphocytes in PPs were determined by flow cytometry., Results: Compared with those results of normal control group, the levels of 24 h urine protein, IgA deposition in glomerular mesangial area, and expressions of protein and mRNA of TGF-β and Smad3 in IgAN group were significantly increased (P < 0.01). Besides, the levels of (IgA+B)/B lymphocytes were significantly elevated in IgAN group (P < 0.01). All these indicators were improved in TCM group. Compared with IgAN group, the differences were statistically significant (P < 0.01). Compared with those results of control group, the levels of (IgA + B)/B lymphocytes showed no significant difference in TCM group (P > 0.05), but other indicators showed significant differences (P < 0.01)., Conclusion: "Gubentongluo Formula" could effectively improve proteinuria and suppress IgA deposition in glomerular mesangial area in IgAN mice, due to affect IgA class switch recombination of B lymphocytes in PPs through regulating TGF-β/Smad3 pathway.

We examined the pathogenesis of glomerular damage in Th2 type-dependent GATA-3 transgenic (GATA-3 Tg) mice with IgA nephropathy (IgAN). GATA-3 Tg mice were immunized orally using OVA plus cholera toxin B (CTB), and measurement of the serum IgA antibody level and histopathological examination were performed. Marked increases in the serum levels of OVA-specific IgA antibody, IgA and IgG, C3 deposits analogous to those seen in IgAN, and expansion of the matrix in association with mesangial cell proliferation were observed. Furthermore, glomerular IgA deposits were co-localized with mannan-binding lectin (MBL) deposits, which might actually have been abnormal IgA deposits. In GATA-3/TCR-Tg mice that had been orally sensitized with CTB plus OVA and were re-stimulated with OVA in vitro, cultured Peyer's patch cells showed the enhanced production of IL-5 and supernatants from cultures of spleen cells showed a reduction of TGF-β production with a simultaneous increase in IL-2 production and the recovery of IFN-γ formation. The amount of TGF-β produced by the spleen cells was found to be correlated with the amount of IFN-γ and IL-IL-2 produced by the cells. Also, the percentage of regulatory T cells (Treg) in the spleens of mice sensitized with OVA plus CTB was lower than that in mice orally sensitized with OVA alone. These results suggest that the increased production of IL-5 from Peyer's patch cells (PPc) and the restored Th1-type immune response might cause the production of abnormal IgA and might induce the deposition of IgA in glomeruli., (Copyright © 2015 The Authors. Published by Elsevier GmbH.. All rights reserved.)

Background: Breastfeeding is associated with a variety of positive health outcomes in children and is recommended exclusively for the first 6 months of life; however, 50-70 % of infants in the US are formula-fed. To test the hypothesis that immune system development and function in neonates and infants are significantly influenced by diet, 2-day old piglets were fed soy or milk formula (n = 6/group/gender) until day 21 and compared to a sow-fed group (n = 6/gender)., Methods: Histomorphometric analyses of ileum, jejunum and Peyer's patches were carried out, to determine the inflammation status, mRNA and protein expression of pro-inflammatory, anti-inflammatory and growth-related chemokines and cytokines., Results: In formula-fed animals, increases in ileum and jejunum villus height and crypt depth were observed in comparison to sow-fed animals (jejunum, p < 0.01 villus height, p < 0.04 crypt depth; ileum p < 0.001 villus height, p < 0.002 crypt depth). In formula-fed the lymphoid follicle size (p < 0.01) and germinal centers (p < 0.01) with in the Peyer's patch were significantly decreased in comparison to sow-fed, indicating less immune education. In ileum, formula diet induced significant up-regulation of AMCFII, IL-8, IL-15, VEGFA, LIF, FASL, CXCL11, CCL4, CCL25 and down-regulation of IL-6, IL-9, IL-10, IL-27, IFNA4, CSF3, LOC100152038, and LOC100736831 at the transcript level. We have confirmed some of the mRNA data by measuring protein, and significant down-regulation of anti-inflammatory molecule IL-10 in comparison to sow-fed piglets was observed. To further determine the membrane protein expression in the ileum, VE-cadherin, occludin, and claudin-3, Western blot analyses were conducted. Sow fed piglets showed significantly more VE-Cadherin, which associated with levels of calcium, and putrescine measured. It is possible that differences in GI tract and immune development are related to shifts in the microbiome; notably, there were 5-fold higher amounts of Lactobacillaceae spp and 3 fold higher Clostridia spp in the sow fed group in comparison to milk formula-fed piglets, whereas in milk formula-fed pigs Enterobacteriaceae spp was 5-fold higher., Conclusion: In conclusion, formula diet alters GI morphology, microbial abundance, intestinal barrier protein VE-cadherin and anti-inflammatory molecule IL-10 expression. Further characterization of formula effects could lead to modification of infant formula to improve immune function, reduce inflammation and prevent conditions such as allergies and infections.

Aim: To explore probable mechanism underlying the therapeutic effect of Astragalus polysaccharide (APS) against experimental colitis., Methods: Thirty-two Sprague-Dawley rats were randomly divided into four groups. Colitis was induced with 2, 4, 6-trinitrobenzene sulfonic acid (TNBS). The rats with colitis were treated with 400 mg/kg of APS for 7 d. The therapeutic effect was evaluated by colonic weight, weight index of the colon, colonic length, and macroscopic and histological scores. The levels of regulatory T (Treg) cells in Peyer's patches were measured by flow cytometry, and cytokines in colonic tissue homogenates were analyzed using enzyme-linked immunosorbent assay. The expression of related orphan receptor-γt (ROR-γt), IL-23 and STAT-5a was measured by Western blot., Results: After 7-d treatment with APS, the weight index of the colon, colonic weight, macroscopical and histological scores were decreased, while the colonic length was increased compared with the model group. The expression of interleukin (IL)-2, IL-6, IL-17, IL-23 and ROR-γt in the colonic tissues was down-regulated, but Treg cells in Peyer's patches, TGF-β and STAT5a in the colonic tissues were up-regulated., Conclusion: APS effectively ameliorates TNBS-induced experimental colitis in rats, probably through restoring the number of Treg cells, and inhibiting IL-17 levels in Peyer's patches.