Bacillus subtilis JATP3 improved the immunity of weaned piglets by improving intestinal flora and producing citalopram.

The purpose of this study was to evaluate the ability of Bacillus subtilis JATP3 to stimulate immune response and improve intestinal health in piglets during the critical weaning period. Twelve 28-day-old weaned piglets were randomly divided into two groups. One group was fed a basal diet, while the other group was fed a basal diet supplemented with B. subtilis JATP3 (1 × 109 CFU/mL; 10 mL) for 28 days. The results revealed a significant increase in the intestinal villus gland ratio of weaned piglets following the inclusion of B. subtilis JATP3 (P < 0.05). Inclusion of a probiotic supplement improve the intestinal flora of jejunum and ileum of weaned piglets. Metabolomics analysis demonstrated a notable rise in citalopram levels in the jejunum and ileum, along with elevated levels of isobutyric acid and isocitric acid in the ileum. The results of correlation analysis show that indicated a positive correlation between citalopram and microbial changes. Furthermore, the probiotic-treated group exhibited a significant upregulation in the relative expression of Claudin, Zonula Occludens 1 (ZO-1), and Interleukin 10 (IL-10) in the jejunum and ileum, while displaying a noteworthy reduction in the relative expression of Interleukin 1ß (IL-1ß). Overall, these findings suggest that B. subtilis JATP3 can safeguard intestinal health by modulating the structure of the intestinal microbiota and their metabolites, wherein citalopram might be a key component contributing to the therapeutic effects of B. subtilis JATP3.

Efficacy of Saccharomyces yeast postbiotics on cell turnover, immune responses, and oxidative stress in the jejunal mucosa of young pigs.

This study aimed to determine the effects of Saccharomyces yeast postbiotics on cell turnover, immune responses, and oxidative stress in the jejunal mucosa of pigs. Thirty-two newly weaned pigs at 6.05 ± 0.24 kg were assigned to two dietary treatments based on a randomized complete block design. The treatments were control group receiving a basal diet and a group supplemented with Saccharomyces yeast postbiotics (175 g/ton diet) in the basal diet. After 35 d of the study, pigs were euthanized and jejunal mucosa were collected to assess immune status, oxidative stress, barrier markers, cell proliferation, and apoptosis. Saccharomyces yeast postbiotics reduced (P < 0.05) the fecal score from d 3 to d 7 and tended to increase the gene expression of interferon-γ (IFN-γ) (P = 0.071) and mammalian/mechanistic target of rapamycin (mTOR) (P = 0.080), decrease the gene expression of B-cell lymphoma 2-associated X protein 1 (BAX1) (P < 0.05), tended to decrease the gene expression of serum and glucocorticoid-induced protein kinase 1 (SGK1) (P = 0.066), increased (P < 0.05) cell proliferation in the crypts, and tended to increase the villus height (P = 0.078) and crypt depth (P = 0.052) in the jejunum. In conclusion, the supplementation of Saccharomyces yeast postbiotics in nursery diets reduced diarrhea within the first week after weaning and provided protection to the villi in the jejunum by enhancing the immune responses of nursery pigs, promoting crypt cell proliferation, and reducing the expression of genes associated with apoptosis without affecting inflammatory and oxidative stress status in the jejunum of the nursery pigs.

AhR ligands from LGG metabolites promote piglet intestinal ILC3 activation and IL-22 secretion to inhibit PEDV infection.

In maintaining organismal homeostasis, gut immunity plays a crucial role. The coordination between the microbiota and the immune system through bidirectional interactions regulates the impact of microorganisms on the host. Our research focused on understanding the relationships between substantial changes in jejunal intestinal flora and metabolites and intestinal immunity during porcine epidemic diarrhea virus (PEDV) infection in piglets. We discovered that Lactobacillus rhamnosus GG (LGG) could effectively prevent PEDV infection in piglets. Further investigation revealed that LGG metabolites interact with type 3 innate lymphoid cells (ILC3s) in the jejunum of piglets through the aryl hydrocarbon receptor (AhR). This interaction promotes the activation of ILC3s and the production of interleukin-22 (IL-22). Subsequently, IL-22 facilitates the proliferation of IPEC-J2 cells and activates the STAT3 signaling pathway, thereby preventing PEDV infection. Moreover, the AhR receptor influences various cell types within organoids, including intestinal stem cells (ISCs), Paneth cells, and enterocytes, to promote their growth and development, suggesting that AhR has a broad impact on intestinal health. In conclusion, our study demonstrated the ability of LGG to modulate intestinal immunity and effectively prevent PEDV infection in piglets. These findings highlight the potential application of LGG as a preventive measure against viral infections in livestock.IMPORTANCEWe observed high expression of the AhR receptor on pig and human ILC3s, although its expression was negligible in mouse ILC3s. ILC3s are closely related to the gut microbiota, particularly the secretion of IL-22 stimulated by microbial signals, which plays a crucial regulatory role in intestinal immunity. In our study, we found that metabolites produced by beneficial gut bacteria interact with ILC3s through AhR, thereby maintaining intestinal immune homeostasis in pigs. Moreover, LGG feeding can enhance the activation of ILC3s and promote IL-22 secretion in the intestines of piglets, ultimately preventing PEDV infection.

Infant and adult human intestinal enteroids are morphologically and functionally distinct.

Human intestinal enteroids (HIEs) are gaining recognition as physiologically relevant models of the intestinal epithelium. While HIEs from adults are used extensively in biomedical research, few studies have used HIEs from infants. Considering the dramatic developmental changes that occur during infancy, it is important to establish models that represent infant intestinal characteristics and physiological responses. We established jejunal HIEs from infant surgical samples and performed comparisons to jejunal HIEs from adults using RNA sequencing (RNA-Seq) and morphologic analyses. We then validated differences in key pathways through functional studies and determined whether these cultures recapitulate known features of the infant intestinal epithelium. RNA-Seq analysis showed significant differences in the transcriptome of infant and adult HIEs, including differences in genes and pathways associated with cell differentiation and proliferation, tissue development, lipid metabolism, innate immunity, and biological adhesion. Validating these results, we observed a higher abundance of cells expressing specific enterocyte, goblet cell, and enteroendocrine cell markers in differentiated infant HIE monolayers, and greater numbers of proliferative cells in undifferentiated 3D cultures. Compared to adult HIEs, infant HIEs portray characteristics of an immature gastrointestinal epithelium including significantly shorter cell height, lower epithelial barrier integrity, and lower innate immune responses to infection with an oral poliovirus vaccine. HIEs established from infant intestinal tissues reflect characteristics of the infant gut and are distinct from adult cultures. Our data support the use of infant HIEs as an ex vivo model to advance studies of infant-specific diseases and drug discovery for this population. IMPORTANCE: Tissue or biopsy stem cell-derived human intestinal enteroids are increasingly recognized as physiologically relevant models of the human gastrointestinal epithelium. While enteroids from adults and fetal tissues have been extensively used for studying many infectious and non-infectious diseases, there are few reports on enteroids from infants. We show that infant enteroids exhibit both transcriptomic and morphological differences compared to adult cultures. They also differ in functional responses to barrier disruption and innate immune responses to infection, suggesting that infant and adult enteroids are distinct model systems. Considering the dramatic changes in body composition and physiology that begin during infancy, tools that appropriately reflect intestinal development and diseases are critical. Infant enteroids exhibit key features of the infant gastrointestinal epithelium. This study is significant in establishing infant enteroids as age-appropriate models for infant intestinal physiology, infant-specific diseases, and responses to pathogens.

Lactobacillus rhamnosus GG alleviates radiation-induced intestinal injury by modulating intestinal immunity and remodeling gut microbiota.

Radiation injury to the intestine is one of the most common complications in patients undergoing abdominal or pelvic cavity radiotherapy. In this study, we investigated the potential protective effect of Lactobacillus rhamnosus GG (LGG) on radiation-induced intestinal injury and its underlying mechanisms. Mice were assigned to a control group, a 10 Gy total abdominal irradiation (TAI) group, or a group pretreated with 108 CFU LGG for three days before TAI. Small intestine and gut microbiota were analyzed 3.5 days post-exposure. LGG intervention improved intestinal structure, reduced jejunal DNA damage, and inhibited the inflammatory cGAS/STING pathway. Furthermore, LGG reduced M1 proinflammatory macrophage and CD8+ T cell infiltration, restoring the balance between Th17 and Treg cells in the inflamed jejunum. LGG also partially restored the gut microbiota. These findings suggest the possible therapeutic radioprotective effect of probiotics LGG in alleviating radiation-induced intestinal injury by maintaining immune homeostasis and reshaping gut microbiota.

Supplementation with organic yeast-derived selenium provides immune protection against experimental necrotic enteritis in broiler chickens.

Necrotic enteritis (NE) is a potentially fatal poultry disease that causes enormous economic losses in the poultry industry worldwide. The study aimed to evaluate the effects of dietary organic yeast-derived selenium (Se) on immune protection against experimental necrotic enteritis (NE) in commercial broilers. Chickens were fed basal diets supplemented with different Se levels (0.25, 0.50, and 1.00 Se mg/kg). To induce NE, Clostridium perfringens (C. perfringens) was orally administered at 14 days of age post hatch. The results showed that birds fed 0.25 Se mg/kg exhibited significantly increased body weight gain compared with the non-supplemented/infected birds. There were no significant differences in gut lesions between the Se-supplemented groups and the non-supplemented group. The antibody levels against α-toxin and NetB toxin increased with the increase between 0.25 Se mg/kg and 0.50 Se mg/kg. In the jejunal scrapings and spleen, the Se-supplementation groups up-regulated the transcripts for pro-inflammatory cytokines IL-1ß, IL-6, IL-8, iNOS, and LITAF and avian ß-defensin 6, 8, and 13 (AvBD6, 8 and 13). In conclusion, supplementation with organic yeast-derived Se alleviates the negative consequences and provides beneficial protection against experimental NE.

The macrophage polarization in allergic responses induced by tropomyosin of Macrobrachium nipponense in cell and murine models.

Macrophages are one of the important immune cells, which play important roles in innate and adaptive immune. However, the roles of macrophages in food allergy are not thoroughly understood. To investigate the roles of macrophages during food allergy, we focused on the relationship between macrophage polarization and allergic responses induced by tropomyosin (TM) in the present study. Arg 1 and CD206 expressions in the TM group were significantly higher than those of the PBS group, while iNOS and TNF-α expressions were no obvious difference, moreover, the morphology of macrophages stimulated by TM was similar to that of M2 macrophages. These results indicated macrophages were mainly polarized toward M2 phenotypes in vitro. The antibodies, mMCP-1, histamine and cytokines, revealed that macrophages could participate in food allergy, and macrophage polarization was associated with changes in allergic-related factors. The cytokine levels of M2 phenotypes were significantly higher than those of M1 phenotypes in peripheral blood. The mRNA expressions and protein levels of Arg1 and iNOS in the jejunum and peritoneal cells indicated that M2 phenotypes were the major macrophage in these tissues compared with M1 phenotypes. Hence, macrophage polarization plays an important role in food allergy.

Characterization of the potential allergenicity of enzymatically hydrolyzed casein in Balb/c mouse model.

Bovine casein is a major allergen present in cow milk to induce anaphylaxis. In this study, the potential allergenicity of enzymatically hydrolyzed casein (HC) was evaluated based on in vitro and in vivo. The results showed that Alcalase and Protamex treatment (AT, PT) reduced the potential allergenicity of CN, with the greatest reductions of 68.25% and 50.75%, respectively. In addition, in vivo results showed that HC effectively alleviated allergic response symptoms of Balb/c mice; a significant tendency toward decreased serum IgG1 and mast cell tryptase levels was observed, accompanied by a decrease of Th2-associated IL-4, IL-5, and IL-13 and an increase of IFN-γ levels in spleen. Moreover, the inflammation of the lung, jejunum, and ileum was remarkably ameliorated. The findings indicated that HC induced a shift toward Th1 response and maintained the Th1/Th2 immune balance. Importantly, our results provide the basis for the production of hypoallergenic dairy products.

SARS-CoV-2 Spike protein triggers gut impairment since mucosal barrier to innermost layers: From basic science to clinical relevance.

Studies have reported the occurrence of gastrointestinal (GI) symptoms, primarily diarrhea, in COVID-19. However, the pathobiology regarding COVID-19 in the GI tract remains limited. This work aimed to evaluate SARS-CoV-2 Spike protein interaction with gut lumen in different experimental approaches. Here, we present a novel experimental model with the inoculation of viral protein in the murine jejunal lumen, in vitro approach with human enterocytes, and molecular docking analysis. Spike protein led to increased intestinal fluid accompanied by Cl- secretion, followed by intestinal edema, leukocyte infiltration, reduced glutathione levels, and increased cytokine levels [interleukin (IL)-6, tumor necrosis factor-α, IL-1ß, IL-10], indicating inflammation. Additionally, the viral epitope caused disruption in the mucosal histoarchitecture with impairment in Paneth and goblet cells, including decreased lysozyme and mucin, respectively. Upregulation of toll-like receptor 2 and toll-like receptor 4 gene expression suggested potential activation of local innate immunity. Moreover, this experimental model exhibited reduced contractile responses in jejunal smooth muscle. In barrier function, there was a decrease in transepithelial electrical resistance and alterations in the expression of tight junction proteins in the murine jejunal epithelium. Additionally, paracellular intestinal permeability increased in human enterocytes. Finally, in silico data revealed that the Spike protein interacts with cystic fibrosis transmembrane conductance regulator (CFTR) and calcium-activated chloride conductance (CaCC), inferring its role in the secretory effect. Taken together, all the events observed point to gut impairment, affecting the mucosal barrier to the innermost layers, establishing a successful experimental model for studying COVID-19 in the GI context.

γδ Intraepithelial Lymphocytes Facilitate Pathological Epithelial Cell Shedding Via CD103-Mediated Granzyme Release.

BACKGROUND & AIMS: Excessive shedding of apoptotic enterocytes into the intestinal lumen is observed in inflammatory bowel disease and is correlated with disease relapse. Based on their cytolytic capacity and surveillance behavior, we investigated whether intraepithelial lymphocytes expressing the γδ T cell receptor (γδ IELs) are actively involved in the shedding of enterocytes into the lumen. METHODS: Intravital microscopy was performed on GFP γδ T cell reporter mice treated with intraperitoneal lipopolysaccharide (10 mg/kg) for 90 minutes to induce tumor necrosis factor-mediated apoptosis. Cell shedding in various knockout or transgenic mice in the presence or absence of blocking antibody was quantified by immunostaining for ZO-1 funnels and cleaved caspase-3 (CC3). Granzyme A and granzyme B release from ex vivo-stimulated γδ IELs was quantified by enzyme-linked immunosorbent assay. Immunostaining for γδ T cell receptor and CC3 was performed on duodenal and ileal biopsies from controls and patients with Crohn's disease. RESULTS: Intravital microscopy of lipopolysaccharide-treated mice revealed that γδ IELs make extended contact with shedding enterocytes. These prolonged interactions require CD103 engagement by E-cadherin, and CD103 knockout or blockade significantly reduced lipopolysaccharide-induced shedding. Furthermore, we found that granzymes A and B, but not perforin, are required for cell shedding. These extracellular granzymes are released by γδ IELs both constitutively and after CD103/E-cadherin ligation. Moreover, we found that the frequency of γδ IEL localization to CC3-positive enterocytes is increased in Crohn's disease biopsies compared with healthy controls. CONCLUSIONS: Our results uncover a previously unrecognized role for γδ IELs in facilitating tumor necrosis factor-mediated shedding of apoptotic enterocytes via CD103-mediated extracellular granzyme release.

Selenium exerts protective effects against heat stress-induced barrier disruption and inflammation response in jejunum of growing pigs.

BACKGROUND: Heat stress (HS) has a negative impact on the intestinal barrier and immune function of pigs. Selenium (Se) may improve intestinal health through affecting selenoproteins. Thus we investigate the protective effect of new organic Se (2-hydroxy-4-methylselenobutanoic acid, HMSeBA) on jejunal damage in growing pigs upon HS and integrate potential roles of corresponding selenoproteins. RESULTS: HS decreased the villus height and increased (P < 0.05) the protein abundance of HSP70, and downregulated (P < 0.05) protein levels of tight junction-related proteins (CLDN-1 and OCLD). HS-induced jejunal damage was associated with the upregulation of four inflammation-related genes and ten selenoprotein-encoding genes, downregulation (P < 0.05) of four selenoprotein-encoding genes and decreased (P < 0.05) the protein abundance of GPX4 and SELENOS. Compared with the HS group, HMSeBA supplementation not only elevated the villus height and the ratio of V/C (P < 0:05), but also reduced (P < 0.05) the protein abundance of HSP70 and MDA content, and increased (P < 0.05) the protein abundance of OCLD. HMSeBA supplementation downregulated the expression of seven inflammation-related genes, changed the expression of 12 selenoprotein-encoding genes in jejunum mucosa affected by HS, and increased the protein abundance of GPX4, TXNRD1 and SELENOS. CONCLUSION: Organic Se supplementation beyond nutritional requirement alleviates the negative effect of HS on the jejunum of growing pigs, and its protective effect is related to the response of corresponding selenoproteins. © 2021 Society of Chemical Industry.

Clostridium butyricum Alleviates Enterotoxigenic Escherichia coli K88-Induced Oxidative Damage Through Regulating the p62-Keap1-Nrf2 Signaling Pathway and Remodeling the Cecal Microbial Community.

Clostridium butyricum (CB) can enhance antioxidant capacity and alleviate oxidative damage, but the molecular mechanism by which this occurs remains unclear. This study used enterotoxigenic Escherichia coli (ETEC) K88 as a pathogenic model, and the p62-Keap1-Nrf2 signaling pathway and intestinal microbiota as the starting point to explore the mechanism through which CB alleviates oxidative damage. After pretreatment with CB for 15 d, mice were challenged with ETEC K88 for 24 h. The results suggest that CB pretreatment can dramatically reduce crypt depth (CD) and significantly increase villus height (VH) and VH/CD in the jejunum of ETEC K88-infected mice and relieve morphological lesions of the liver and jejunum. Additionally, compared with ETEC-infected group, pretreatment with 4.4×106 CFU/mL CB can significantly reduce malondialdehyde (MDA) level and dramatically increase superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) levels in the serum. This pretreatment can also greatly increase the mRNA expression levels of tight junction proteins and genes related to the p62-Keap1-Nrf2 signaling pathway in the liver and jejunum in ETEC K88-infected mice. Meanwhile, 16S rDNA amplicon sequencing revealed that Clostridium disporicum was significantly enriched after ETEC K88 challenge relative to the control group, while Lactobacillus was significantly enriched after 4.4×106 CFU/mL CB treatment. Furthermore, 4.4×106 CFU/mL CB pretreatment increased the short-chain fatty acid (SCFA) contents in the cecum of ETEC K88-infected mice. Moreover, we found that Lachnoclostridium, Roseburia, Lactobacillus, Terrisporobacter, Akkermansia, and Bacteroides are closely related to SCFA contents and oxidative indicators. Taken together, 4.4×106 CFU/mL CB pretreatment can alleviate ETEC K88-induced oxidative damage through activating the p62-Keap1-Nrf2 signaling pathway and remodeling the cecal microbiota community in mice.

CD32+CD4+ T Cells Sharing B Cell Properties Increase With Simian Immunodeficiency Virus Replication in Lymphoid Tissues.

CD4 T cell responses constitute an important component of adaptive immunity and are critical regulators of anti-microbial protection. CD4+ T cells expressing CD32a have been identified as a target for HIV. CD32a is an Fcγ receptor known to be expressed on myeloid cells, granulocytes, B cells and NK cells. Little is known about the biology of CD32+CD4+ T cells. Our goal was to understand the dynamics of CD32+CD4+ T cells in tissues. We analyzed these cells in the blood, lymph nodes, spleen, ileum, jejunum and liver of two nonhuman primate models frequently used in biomedical research: African green monkeys (AGM) and macaques. We studied them in healthy animals and during viral (SIV) infection. We performed phenotypic and transcriptomic analysis at different stages of infection. In addition, we compared CD32+CD4+ T cells in tissues with well-controlled (spleen) and not efficiently controlled (jejunum) SIV replication in AGM. The CD32+CD4+ T cells more frequently expressed markers associated with T cell activation and HIV infection (CCR5, PD-1, CXCR5, CXCR3) and had higher levels of actively transcribed SIV RNA than CD32-CD4+T cells. Furthermore, CD32+CD4+ T cells from lymphoid tissues strongly expressed B-cell-related transcriptomic signatures, and displayed B cell markers at the cell surface, including immunoglobulins CD32+CD4+ T cells were rare in healthy animals and blood but increased strongly in tissues with ongoing viral replication. CD32+CD4+ T cell levels in tissues correlated with viremia. Our results suggest that the tissue environment induced by SIV replication drives the accumulation of these unusual cells with enhanced susceptibility to viral infection.

Effective Model of Food Allergy in Mice Sensitized with Ovalbumin and Freud's Adjuvant.

To better explore the pathophysiology of FA and its therapy, we aimed to establish a simple and practicable FA model with Freund's adjuvant and introduce an easy and reliable laboratory evaluation method for assessment of inflammation in intestinal segments at different anatomical locations. BALB/c mice were sensitized with ovalbumin combined with Freund's adjuvant. Complete Freund's adjuvant was chosen for the first sensitization and two weeks later incomplete Freund's adjuvant was used for a second sensitization. Two weeks later, the sensitized mice were challenged with 50 mg ovalbumin every other day. After the 6 challenge, all mice were assessed for systemic anaphylaxis, and then sacrificed for sample collection. All sensitized mice showed anaphylactic symptoms and markedly increased levels of serum ovalbumin-specific IgE and IgG1. The activity of mast cell protease-1 (mMCPT-1) was significantly increased in the serum and interstitial fluid of the duodenum, jejunum, ileum, and colon. A successful FA model was established, of which inflammation occurred in the duodenum, jejunum, ileum, and colon. This model provides a reliable and simple tool for analysis of the mechanism of FA and methods of immunotherapy. Moreover, combined detection of ovalbumin-specific antibody and local mMCPT-1 levels could potentially be used as the major indicator for assessment of food allergy.

Jejunal mucosa proteomics unravel metabolic adaptive processes to mild chronic heat stress in dairy cows.

Climate change affects the duration and intensity of heat waves during summer months and jeopardizes animal health and welfare. High ambient temperatures cause heat stress in dairy cows resulting in a reduction of milk yield, feed intake, and alterations in gut barrier function. The objectives of this study were to investigate the mucosal amino acid, glucose and lactate metabolism, as well as the proteomic response of the small intestine in heat stressed (HS) Holstein dairy cows. Cows of the HS group (n = 5) were exposed for 4 days to 28 °C (THI = 76) in a climate chamber. Percentage decrease in daily ad libitum intake of HS cows was calculated to provide isocaloric energy intake to pair-fed control cows kept at 15 °C (THI = 60) for 4 days. The metabolite, mRNA and proteomic analyses revealed that HS induced incorrect protein folding, cellular destabilization, increased proteolytic degradation and protein kinase inhibitor activity, reduced glycolysis, and activation of NF-κB signaling, uronate cycling, pentose phosphate pathway, fatty acid and amino acid catabolism, mitochondrial respiration, ATPase activity and the antioxidative defence system. Our results highlight adaptive metabolic and immune mechanisms attempting to maintain the biological function in the small intestine of heat-stressed dairy cows.

Intestinal cDC1 drive cross-tolerance to epithelial-derived antigen via induction of FoxP3+CD8+ Tregs.

Although CD8+ T cell tolerance to tissue-specific antigen (TSA) is essential for host homeostasis, the mechanisms underlying peripheral cross-tolerance and whether they may differ between tissue sites remain to be fully elucidated. Here, we demonstrate that peripheral cross-tolerance to intestinal epithelial cell (IEC)-derived antigen involves the generation and suppressive function of FoxP3+CD8+ T cells. FoxP3+CD8+ Treg generation was dependent on intestinal cDC1, whose absence led to a break of tolerance and epithelial destruction. Mechanistically, intestinal cDC1-derived PD-L1, TGFß, and retinoic acid contributed to the generation of gut-tropic CCR9+CD103+FoxP3+CD8+ Tregs Last, CD103-deficient CD8+ T cells lacked tolerogenic activity in vivo, indicating a role for CD103 in FoxP3+CD8+ Treg function. Our results describe a role for FoxP3+CD8+ Tregs in cross-tolerance in the intestine for which development requires intestinal cDC1.

Kinetics of the Cellular and Transcriptomic Response to Eimeria maxima in Relatively Resistant and Susceptible Chicken Lines.

Eimeria maxima is a common cause of coccidiosis in chickens, a disease that has a huge economic impact on poultry production. Knowledge of immunity to E. maxima and the specific mechanisms that contribute to differing levels of resistance observed between chicken breeds and between congenic lines derived from a single breed of chickens is required. This study aimed to define differences in the kinetics of the immune response of two inbred lines of White Leghorn chickens that exhibit differential resistance (line C.B12) or susceptibility (line 15I) to infection by E. maxima. Line C.B12 and 15I chickens were infected with E. maxima and transcriptome analysis of jejunal tissue was performed at 2, 4, 6 and 8 days post-infection (dpi). RNA-Seq analysis revealed differences in the rapidity and magnitude of cytokine transcription responses post-infection between the two lines. In particular, IFN-γ and IL-10 transcript expression increased in the jejunum earlier in line C.B12 (at 4 dpi) compared to line 15I (at 6 dpi). Line C.B12 chickens exhibited increases of IFNG and IL10 mRNA in the jejunum at 4 dpi, whereas in line 15I transcription was delayed but increased to a greater extent. RT-qPCR and ELISAs confirmed the results of the transcriptomic study. Higher serum IL-10 correlated strongly with higher E. maxima replication in line 15I compared to line C.B12 chickens. Overall, the findings suggest early induction of the IFN-γ and IL-10 responses, as well as immune-related genes including IL21 at 4 dpi identified by RNA-Seq, may be key to resistance to E. maxima.

Selenomethionine ameliorates LPS-induced intestinal immune dysfunction in chicken jejunum.

Selenomethionine (SeMet) is a widely used food supplement. However, the research on the effect of SeMet on intestinal immune function is not enough. Therefore, in this experiment, SeMet was added to the diet of chickens, and lipopolysaccharide (LPS) was used as harmful stimulation to study the effect of SeMet on intestinal immune function in chickens. We chose chicken jejunum as the research object. The results showed that LPS treatment decreased the expressions of selenoproteins and induced inflammatory reaction, cytokine disorder, decreases of immunoglobulin levels, heat shock protein expression disorder, and decreases of defensin expression levels in jejunum. However, dietary SeMet can effectively alleviate the above injury caused by LPS. Our results showed that SeMet could improve the intestinal immunity in chickens, and feeding SeMet could alleviate the intestinal immune dysfunction caused by LPS. The application range of SeMet in feed can be roughly given through our experiment; i.e. 0.35-0.5 mg/kg SeMet was effective. We speculated that dietary SeMet could effectively alleviate the intestinal immune dysfunction caused by harmful stimulation and help to resist the further damage caused by harmful stimulation.

Molecular mechanism of Escherichia coli H10407 induced diarrhoea and its control through immunomodulatory action of bioactives from Simarouba amara (Aubl.).

Enterotoxigenic Escherichia coli (ETEC) infection is a major cause of death in children under the age of five in developing countries. ETEC (O78:H11:CFA/I:LT+:ST+) mechanism has been studied in detail with either heat labile (LT) or heat stable (ST) toxins using in vitro and in vivo models. However, there is no adequate information on ETEC pathogenesis producing both the toxins (LT, ST) in BALB/c mice model. In this study, female mice have been employed to understand ETEC H10407 infection induced changes in physiology, biochemical and immunological patterns up to seven days post-infection and the antidiarrhoeal effect of Simarouba amara (Aubl.) bark aqueous extract (SAAE) has also been looked into. The results indicate that BALB/c is sensitive to ETEC infection resulting in altered jejunum and ileum histomorphology. Withal, ETEC influenced cAMP, PGE2, and NO production resulting in fluid accumulation with varied Na+, K+, Cl-, and Ca2+ levels. Meanwhile, ETEC subverted expression of IL-1ß, intestine alkaline phosphatase (IAP), and myeloperoxidase (MPO) in jejunum and ileum. Our data also indicate the severity of pathogenesis reduction which might be due to attainment of equilibrium after reaching optimum rate of infection. Nevertheless, degree of pathogenesis was highly significant (p < 0.01) in all the studied parameters. Besides that, SAAE was successful in reducing the infectious diarrhoea by inhibiting ETEC H10407 in intestine (jejunum and ileum), and shedding in feces. SAAE decreased cAMP, PGE2, and fluid accumulation effectively and boosted the functional activity of immune system in jejunum and ileum IAP, MPO, IL-1ß, and nitric oxide.

Steroid Receptor Coactivator-3 Is Required for Inhibition of the Intestinal Muscularis Inflammatory Response of Postoperative Ileus in Mice.

Inflammation theory has suggested that the pathogenesis of postoperative ileus (POI) involves the steroid receptor coactivator-3 (SRC-3). Therefore, we investigated the role of SRC-3 in the muscles of the small intestine using a mouse POI model. Here, we reported that intestinal manipulation (IM) significantly reduced the extent of phenol red migration in the entire gastrointestinal tract, and the calculated geometric center (GC) value in wild-type (WT) mice at 24 h after surgery was higher than that in the knockout (KO) mice and in the sham-operated control group. The expression of SRC-3 was upregulated in the mouse intestinal muscularis at 24 h after surgical manipulation, and the mRNA and protein levels of inflammatory cytokines were upregulated compared with those in the control group. At 24 h after IM, the number of neutrophils in the experimental group was significantly higher than that in the control group; in the IM group, the number of neutrophils in the SRC-3-/- mice was markedly higher than that in the WT mice. At 24 h after IM, the myeloperoxidase (MPO) activity in the experimental group was significantly higher than that in the control group. In the IM group, the MPO activity of the SRC-3-/- mice was markedly higher than that of the WT mice. In summary, proinflammatory cytokines, the number of neutrophils, and the MPO activity were significantly increased in the muscularis of the jejunum and ileum of KO mice after IM compared with those of the WT mice, indicating that SRC-3 might play a protective role in POI.