Jejunal Lamina Propria Research Articles

Method of storage impacts graft immune cell populations in intestinal transplantation

Intestinal transplantation (IT) is the only treatment for intestinal failure patients who cannot tolerate parenteral nutrition. Although cold storage (CS) is the gold standard for intestinal allograft preservation, normothermic machine perfusion (NMP) has improved transplantation success in other organs. Allograft immune modulation is thought to contribute to this success. The objective of this study was to assess the impact of NMP on intestinal immune cell populations as it relates to ultimate allograft and recipient health. We hypothesized that NMP would stabilize overall immune cell populations while reducing pro-inflammatory cohorts, thus improving IT success. Porcine intestines were stored for 6H at 4°C (CS-T6, n=6) or perfused at 34°C (NMP-T6, n=8) and transplanted. Samples were collected following intestinal procurement (T0), storage (T6), 1-hour post-transplant (T1PT), and euthanasia (T48). Flow cytometric profiling and quantification of intraepithelial (IEL) and lamina propria (LP) lymphocytes and NK cells were performed at T0, T6, and T48. Immunofluorescence (IF) identified CD3+ T-cells at T1PT. One-way ANOVA analyzed cell counts with significance set at p< 0.05. Flow cytometry revealed that NMP preserved CD3+ IELs in the jejunum at T6 (63.74% vs 32.79%, p< 0.0001), and in the ileum at T6 (51.31% vs 42.77%, p< 0.0001) and at T48 (57.73% vs 34.21%, p<0.0001). Immunofluorescent cell quantification confirmed this preservation of CD3+ IEL at T1PT in the crypts of the jejunum (4.9% vs 2.1 %, p< 0.05) and ileum (6.9% vs 2.8%, p< 0.001) compared to CS. However, upon further subpopulation analyses using flow cytometry, ileal IEL T-cells were reduced throughout NMP compared to CS (T6 28.7% vs 44.0%; T48 16.65% vs 22.37%; p< 0.0001). NK cells were also decreased in ileal and jejunal LP at NMP-T6 compared to T0 (3.6% vs 5.6%, p< 0.01; 2.4% vs 4.3% p< 0.05). NMP reduces NK cells, a cell type known to be associated with rejection. Interestingly, NMP preserved the overall CD3+ T cell populations in the jejunum and ileum at T6, T1PT, and T48. The subpopulation of IELs, however, were reduced in the ileum following NMP. The role of these populations, specifically in IT, has yet to be determined. Further characterization of T-cell subpopulations and dynamics is needed. Complimentary evaluations of the microbiome and proteomic responses to IT NMP are ongoing. Understanding immune cell dynamics will improve IT outcomes for patients requiring this critical, lifesaving surgery. U.S. Department of Defense PR181265; NIH K01OD010199 SERCA, T32OD011130-15. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Dietary probiotic Lacticaseibacillus paracasei NSMJ56 modulates gut immunity and microbiota in laying hens

This study was performed to investigate supplementary effects of probiotic Lacticaseibacillus paracasei NSMJ56 strain on laying performance, egg quality, intestinal histology, antioxidant status, gut immunity and microbiota in laying hens. A total of ninety-six 21-wk-old Hy-Line Brown laying hens were randomly subjected to one of 2 dietary treatments: a control group fed a non-supplemented diet, or a probiotic group fed with a diet supplemented with 1 g of Lacticaseibacillus paracasei NSMJ56 (5 × 108 CFU/kg of diet). The trial lasted for 4 wk. Egg weight was increased (P < 0.05) in laying hens fed probiotic-fed diet compared with the control group. Dietary probiotics did not affect egg quality except for Haugh unit, which was improved (P < 0.05) in the probiotic-fed group. Neither jejunal histology nor cecal short-chain fatty acids were affected by dietary treatments. Dietary probiotics increased the activity of catalase compared with the control group. Flow cytometry analysis revealed that dietary probiotics elevated the CD4+ T cells, but not CD8+ T cells, in jejunal lamina propria. Based on the LEfSe analysis at the phylum and genus levels, Erysipelotrichales, Erysipelotrichia, Flintibater, Dielma, Hespellia, Coprobacter, Roseburia, Anaerotignum, and Coprococcus were enriched in the probiotic group compared with the control group. Taken together, our study showed that dietary probiotics could be used to improve some parameters associated with egg freshness and antioxidant capacity, and to partially alter T cell population and microbial community in laying hens.

Differences in Cholesterol Metabolism, Hepato-Intestinal Aging, and Hepatic Endocrine Milieu in Rats as Affected by the Sex and Age.

Age and sex influence serum cholesterol levels, but the underlying mechanisms remain unclear. To investigate further, we measured cholesterol, precursors (surrogate synthesis markers), degradation products (oxysterols and bile acid precursors) in serum, the liver, jejunum, and ileum, as well as serum plant sterols (intestinal absorption markers) in male and female Wistar rats (4 and 24 months old). The analysis of histomorphometric and oxidative stress parameters (superoxide dismutase, catalase, glutathione-related enzyme activities, lipid peroxide, and protein carbonyl concentrations) in the liver and jejunum offered further insights into the age- and sex-related differences. The hepatic gene expression analysis included AR, ERα, and sex-specific growth hormone-regulated (Cyp2c11 and Cyp2c12) and thyroid-responsive (Dio1, Tbg, and Spot 14) genes by qPCR. We observed age-related changes in both sexes, with greater prominence in females. Aged females had significantly higher serum cholesterol (p < 0.05), jejunum cholesterol (p < 0.05), and serum plant sterols (p < 0.05). They exhibited poorer hepato-intestinal health compared with males, which was characterized by mild liver dysfunction (hydropic degeneration, increased serum ALT, p < 0.05, and decreased activity of some antioxidant defense enzymes, p < 0.05), mononuclear inflammation in the jejunal lamina propria, and age-related decreases in jejunal catalase and glutathione peroxidase activity (p < 0.05). Aged females showed increased levels of 27-hydroxycholesterol (p < 0.05) and upregulated ERα gene expression (p < 0.05) in the liver. Our study suggests that the more significant age-related increase in serum cholesterol in females is associated with poorer hepato-intestinal health and increased jejunal cholesterol absorption. The local increase in 27-hydroxycholesterol during aging might reduce the hepatoprotective effects of endogenous estrogen in the female liver.

Cell surface ATP synthase-released H+ and ATP play key roles in cocoa butter intake-mediated regulation of gut immunity through releases of cytokines in rat.

Proper food intake is important for maintaining good health in humans. Chocolate is known to exert anti-inflammatory effects; however, the mechanisms remain unclear. In this study, we aimed to investigate the effects of cocoa butter intake on gut immunity in rats and rabbits. Cocoa butter intake increased the lymph flow, cell density, and IL-1β, IL-6 and IL-10 levels in mesenteric lymph. Clodronate, a macrophage depletion compound, significantly enhanced the release of all cytokines. The immunoreactivities of macrophage markers CD68 and F4/80 in the jejunal villi were significantly decreased with clodronate. Piceatannol, a selective cell surface ATP synthase inhibitor significantly reduced the cocoa butter intake-mediated releases of IL-1β, IL-6 and IL-10. The immunoreactivities of cell surface ATP synthase were observed in rat jejunal villi. Shear stress stimulation on the myofibroblast cells isolated from rat jejunum released ATP and carbon dioxide depended with H+ release. In rabbit in vivo experiments, cocoa butter intake increased the concentrations of ATP and H+ in the portal vein. The in vitro experiments with isolated cells of rat jejunal lamina propria the pH of 3.0 and 5.0 in the medium released significantly IL-1β and IL-6. ATP selectively released IL-10. These findings suggest that cocoa butter intake regulates the gut immunity through the release and transport of IL-1β, IL-6, and IL-10 into mesenteric lymph vessels in a negative feedback system. In addition, the H+ and ATP released from cell surface ATP synthase in jejunal villi play key roles in the cocoa butter intake-mediated regulation of gut immunity.

Immunogenicity of a live bivalent non-enterotoxigenic Escherichia coli (non-ETEC) vaccine and dietary clinoptilolite efficacy against postweaning diarrheal disease of pigs due to F4+ and F18+ ETEC strains

No safe and effective vaccine exists against porcine enterotoxigenic Escherichia coli (ETEC) strains, which are the etiological agents of post-weaning diarrhoea (PWD), economically one of the most significant diseases of swine, which encountered for major productive losses in swine industry worldwide. The current study was designed to evaluate: (1) efficacy of an oral bivalent F4ac+/F18ac+ non-ETEC live vaccine candidate (VACCINE) in stimulating systemic and intestinal cellular immunity in 4-week-old weaned pigs, (2) the onset and duration of protective immunity of weaned pigs against naturally occurring PWD during the period of 6 weeks following weaning, and (3) the dietary supplement potential of zeolite clinoptilolite (CPL), an antimicrobial mineral and/or immunomodulator/ vaccine adjuvant (VACCINE + CPL). The pigs immunized either with the VACCINE or its combination with dietary CPL had significantly increased body weight gain from Day 7 to Day 42 (P&lt;0.05) of the experiment, as compared to the control pigs (CONTROLS). Conversely, the pigs that were only supplemented with CPL had mostly significantly lower (P&lt;0.05) body weight. The pigs that received VACCINE + CPL were neither diarrheic nor were there any mortalities during the entire period of the experiment. On Day 42 the total bacterial load in the jejunum was much lower in the pigs from all three principal groups than in the CONTROLS (30 x 108 vs. 18 x 107 vs. 14 x 107 vs. 13 x 107 CFU/mL, respectively). Regarding CD4+ and CD8+ T cells, specific immunization with either VACCINE or with VACCINE + CPL stimulated a significantly higher proportion of these cells (P&lt;0.05) from Day 7 to Day 42 of the experiment. Quite similar findings were obtained for CD21+ B cells, as their proportion was significantly elevated in the pigs treated with either VACCINE or VACCINE + CPL (P&lt;0.05 and P&lt;0.05, respectively). The pigs from the VACCINE + CPL group had a significantly higher proportion of CD45+ lymphoid cells than the pigs from the CONTROL group (P&lt;0.05). Quite sparsely distributed CD45RA+ naïve T lymphocytes were observed in the jejunal lamina propria of the intestinal villi, within the Lieberkühn crypts (LC) and in the submucosa of the CONTROLS and CPL supplemented pigs. The treatment with the VACCINE induced moderate recruitment of CD45 RA+ cells within both the IFA and FA of the jejunal PP of the pigs 6 weeks following the vaccination. In the CONTROLS, CD45 RC+ memory T cells were not abundant and were mostly dispersed in the middle of the villous lamina propria, but only rarely adjacent to the basal membrane of the intestinal enterocytes. These cells were more frequent within the lamina propria of the villi in the CPL group of pigs than in the CONTROLS. Even more numerous CD45 RC+ memory T cells were observed in the villous lamina propria of the jejunum of the pigs from the VACCINE group. These cells were predominantly found in the villous lamina propria and in the IFA, but were less frequent in the FA of the jejunal PP of the pigs that received the VACCINE and CPL. Due to the nature of the disease, challenges in PWD vaccine development will continue to exist. Although our research approach was at least partially successful, developing a safe and immunogenically effective live oral vaccine against PWD that will provide solid protection and sustained cellular and humoral immune responses remains a significant challenge.

Gross, Histomorphological and Scanning Electronic Microscopic Studies on Gut Associated Lymphoid Tissue of Intestine of Pati Duck (Anas platyrhynchos domesticus) of Assam

Background: The study on Gut Associated Lymphoid Tissue (GALT) of Pati duck of Assam is of great value in regard to normal academic and bio-medical research aspects. The aim of the study was to evaluate the gross, histomorphological and scanning electronic microscopic examination of gut-associated lymphoid tissue of the intestine of Pati duck at different age group. Methods: For this study, forty five Pati ducks were divided into five groups depending on its age viz., 1st week, 4th week, 16th week, 24th week and 42nd weeks old. The pieces of gut having lymphoid tissue or Peyer’s patches were collected immediately after slaughter. These samples were fixed in 10% neutral buffered formalin solution and were processed as per the standard technique of procedure (Luna, 1968). The paraffin blocks were sectioned in Shandon Finesse microtome at 5 µm thickness and the sections were stained with Mayer’s Haematoxylin and Eosin staining technique for Cellular details, Van Gieson’s method for collagen fibres, Gomori’s method for reticular fibres, Hart’s method for elastic fibres and Bielchowsky’s method for axis cylinder and dendrites as per the method of Luna (1968). Result: Gut-associated lymphoid tissue was found in the duodenum, jejunum, ileum, caecum and the terminal part of the rectum in all the age group of Pati duck. The lymphoid compartment of the gut-associated lymphoid tissue in duck included a follicular structure, dome, follicle associated epithelia and interfollicular area. Lamina propria of jejunum was heavily infiltrated with diffuse lymphatic tissue in the 16th, 24th and 42nd week of age of Pati duck. The scattered and diffuse lymphatic infiltration occurred in all age groups. The lamina propria of the colorectum revealed an extensive network of reticular fibre with diffused lymphatic tissue in all the age group of duck. In Scanning Electron Microscope, the lumen of the jejunum was covered by finger-like villi with numerous opening of goblet cells. The lymphoid follicle of Lamina propria contains numerous lymphocytes along with connective tissue fibres.

Influences of Maternal Conjugated Linoleic Acid and Essential Fatty Acid Supply During Late Pregnancy and Early Lactation on T and B Cell Subsets in Mesenteric Lymph Nodes and the Small Intestine of Neonatal Calves.

Conjugated linoleic acid (CLA) isomers are known for their health-promoting effects in mammals and metabolic functions in dairy cows and are synthesized in the forestomach depending on essential fatty acid (EFA) intake. The current preliminary study investigated effects of a maternal fatty acid supplementation (MFAS) during late pregnancy and early lactation with coconut oil (CON, control), CLA (Lutalin®), or CLA + EFA (Lutalin® linseed oil; safflower oil) on plasma fatty acid composition and T and B cell subsets in mesenteric lymph nodes (MLN) and the small intestine of 5-day-old calves. MFAS of CLA + EFA increased α-linolenic, eicosapentaenoic, docosapentaenoic, and n-3 fatty acid proportions in calf plasma fat on days 1 and 5 after birth (P < 0.05). On day 5, CLA and CLA + EFA calves showed higher plasma fat trans-10, cis-12 CLA proportions, and CLA calves had higher plasma cis-9, trans-11 CLA proportions compared with CON calves (P < 0.1). MFAS of CLA tended to increase CD4+ T cell subsets in MLN and increased CD21+ B cell subsets in ileal lamina propria compared with CON but decreased CD2+ T cell subsets in jejunal lamina propria (P < 0.05). CLA + EFA decreased CD4+ T cell subsets in MLN compared with CLA (P < 0.05). MFAS of CLA seemed to affect the intestinal adaptive immune system of calves, but additional EFA supplementations reversed CLA effects. Possible direct CLA and EFA effects or whether changes in milk composition affected this immune modulation must be clarified in further studies.

Fine Grinding or Expanding as Pre-treatment for Pelleting in Processing Diets Varying in Dietary Rapeseed Expeller Proportions: Investigations on Performance, Visceral Organs, and Immunological Traits of Broilers.

Pelleted feed is associated with improved broiler performance but also with a higher incidence of proventricular dilatation and ascites. The present study aimed to investigate influences of expanded and pelleted (ExP) or finely ground and pelleted feeds (FgP) containing either 6% rapeseed expeller (RSE) or 12% RSE on these adverse effects by studying performance, visceral organ, and immunological traits in 36 broilers. ExP reduced daily feed intake compared to FgP when feeding a 6% RSE diet (P < 0.05) but did not affect the daily feed intake when feeding a 12% RSE diet, which was also reflected in the body weight gain. There were no significant differences in the size of proventriculus and gizzard between feeding groups but significant diet-by-technical feed treatment interactions in case of proventricular and gizzard weights and the proventricular length (P < 0.05). Proventriculi and gizzards were heavier in birds fed 6%ExP than proventriculi or gizzards of animals from all other groups except for birds of the group 12%FgP. A total of three animals (1 from 6%ExP, 1 from 6%FgP, and 1 from 12%ExP) developed ascites during the study. Pooled LsMeans of peripheral blood leucocyte proportions of CD3+/CD4−/CD8− cells were increased in birds fed FgP compared to birds fed ExP (P = 0.048). Pooled LsMeans of CD3+/CD4+/CD8+ T cell subsets in jejunal lamina propria were higher in birds fed 12% RSE compared to birds fed 6% RSE (P = 0.024). Concluding, technical feed treatment or diet did not inhibit adverse effects of pelleting on gizzard and proventricular development. Morphometric alterations of proventriculus and gizzard might modify the local immune system of the distal digestive tract and promote the development of ascites; however, further studies are required to confirm this hypothesis since in the present study only three birds developed ascites.

Chlamydia suis is associated with intestinal NF-κB activation in experimentally infected gnotobiotic piglets.

ABSTRACT Chlamydia suis intestinal infection of single-animal experimental groups of gnotobiotic newborn piglets was previously reported to cause severe, temporary small intestinal epithelium damage. We investigated archived intestinal samples for pro-inflammatory nuclear factor kappa B (NF-κB) activation, Interleukin (IL)-6 and IL-8 production and immune cell influx. Samples were collected 2, 4 and 7 days post-inoculation with C. suis strain S45/6 or mock inoculum (control). Increased nuclear localization of epithelial NF-κB, representative of activation, in the jejunum and ileum of C. suis-infected animals, compared to uninfected controls, began by 2 days post-infection (dpi) and persisted through 7 dpi. Infected animals showed increased production of IL-8, peaking at 2 dpi, compared to controls. Infection-mediated CD45-positive immune cell influx into the jejunal lamina propria peaked at 7 dpi, when epithelial damage was largely resolved. Activation of NF-κB appears to be a key early event in the innate response of the unprimed porcine immune system challenged with C. suis. This results in an acute phase, coinciding with the most severe clinical symptoms, diarrhea and weight loss. Immune cells recruited shortly after infection remain present in the lamina propria during the recovery phase, which is characterized by reduced chlamydial shedding and restored intestinal epithelium integrity.

Histological study of intestinal goblet cells, IgA, and CD3+ lymphocyte distribution in Huang-huai white goat.

Ten healthy adult Huang-huai white goats were selected and sacrificed by jugular vein bleeding after anaesthesia to observe the distribution characteristics of the histological structure of the intestinal mucosa, goblet cells, IgA, and CD3+ lymphocytes. Three sections of the duodenum, the jejunum, and the ileum were immediately collected and fixed with 4% paraformaldehyde for 72 h to prepare tissue sections. After haematoxylin and eosin, periodic acid Schiff, and immunohistochemical staining was performed, the distribution characteristics of goblet cells, IgA-positive cells, and CD3+ lymphocytes were observed. Results showed high columnar epithelial cells in the duodenum and jejunum of Huang-huai white goat and low columnar epithelial cells in the ileum mucosa. Mucopolysaccharides secreted by intestinal goblet cells were mainly neutral, and the number of ileum goblet cells was significantly higher than that of the duodenum and the jejunum (p < 0.05). IgA-positive cells were distributed in the lamina propria of the duodenum, and the number of cells was significantly higher than that in the jejunum and the ileum (p < 0.01). The significant difference was found between the jejunum and the ileum (p < 0.01). The CD3+ cells in the intestinal mucosa were distributed in the lamina propria mucosae, and some of the positive cells in the jejunum were distributed between epithelial cells. CD3+ cells had the largest number in the jejunal lamina propria but had the lowest number in the ileum. The jejunum was significantly higher than the duodenum (p < 0.05), and the ileum was much less than the jejunum (p < 0.01).

Immunolocalization of Na+/K+-ATPase and proliferative activity of enterocytes after administration of glucan in chickens fed T-2 toxin

The protective effect of polysaccharide glucan in chickens fed low doses of T-2 toxin was assessed. The binder effect of β-D-glucan on jejunal mucosa in relation to the expression of Na+/K+-ATPase, proliferative activity of enterocytes and number of goblet cells was investigated. A total of 40 one-day-old chickens were allocated to four groups: control (C), β-D-glucan (G), T-2 toxin (T) and combined β-D-glucan+T-2 toxin (GT). The chickens were individually administrated per os 1.0 mg/bird/day of β-D-glucan derived from Candida albicans on days 11, 12, and 21 of the experiment (totally 3 mg per bird). T-2 toxin at a concentration of 1.45 μg·kg-1 was added to the feed from day 14 to day 28 of the experiment. The α subunit-specific anti-Na+/K+-ATPase antibody was used to identify the protein by immunofluorescence in the cell membrane of jejunal enterocytes. Higher expression of Na+/K+-ATPase was found in the jejunal epithelial cells and lamina propria in the chickens fed T-2 toxin and administered glucan (P &lt; 0.05) compared to control. The number of proliferated enterocytes was higher in group T compared to group G and control (P &lt; 0.001), as well group GT (P &lt; 0.01). Goblet cell density did not present significant differences between groups of chickens, but group G showed the highest values. These data suggest that administration of pure T-2 toxin at low doses affects primarily the protein synthesis of actively dividing cells. Higher distribution of Na+/K+-ATPase in enterocytes of chickens in GT group suggests positive influence of glucan and mycotoxin on the ion pump. A binding effect of this immunomodulator on the digestive tract mucosa in the applied setup was not observed.

Increased CD4+CD45RA-FoxP3low cells alter the balance between Treg and Th17 cells in colitis mice.

AIMTo investigate the role of regulatory T cell (Treg) subsets in the balance between Treg and T helper 17 (Th17) cells in various tissues from mice with dextran sulfate sodium-induced colitis.METHODSTreg cells, Treg cell subsets, Th17 cells, and CD4+CD25+FoxP3+IL-17+ cells from the lamina propria of colon (LPC) and other ulcerative colitis (UC) mouse tissues were evaluated by flow cytometry. Forkhead box protein 3 (FoxP3), interleukin 17A (IL-17A), and RORC mRNA levels were assessed by real-time PCR, while interleukin-10 (IL-10) and IL-17A levels were detected with a Cytometric Beads Array.RESULTSIn peripheral blood monocytes (PBMC), mesenteric lymph node (MLN), lamina propria of jejunum (LPJ) and LPC from UC mice, Treg cell numbers were increased (P < 0.05), and FoxP3 and IL-10 mRNA levels were decreased. Th17 cell numbers were also increased in PBMC and LPC, as were IL-17A levels in PBMC, LPJ, and serum. The number of FrI subset cells (CD4+CD45RA+FoxP3low) was increased in the spleen, MLN, LPJ, and LPC. FrII subset cells (CD4+CD45RA-FoxP3high) were decreased among PBMC, MLN, LPJ, and LPC, but the number of FrIII cells (CD4+CD45RA-FoxP3low) and CD4+CD25+FoxP3+IL-17A+ cells was increased. FoxP3 mRNA levels in CD4+CD45RA-FoxP3low cells decreased in PBMC, MLN, LPJ, and LPC in UC mice, while IL-17A and RORC mRNA increased. In UC mice the distribution of Treg, Th17 cells, CD4+CD45RA-FoxP3high, and CD4+CD45RA-FoxP3low cells was higher in LPC relative to other tissues.CONCLUSIONIncreased numbers of CD4+CD45RA-FoxP3low cells may cause an imbalance between Treg and Th17 cells that is mainly localized to the LPC rather than secondary lymphoid tissues.

Intestinal absorption of fucoidan extracted from the brown seaweed, Cladosiphon okamuranus.

The aim of this study was to examine the absorption of fucoidan through the intestinal tract. Fucoidan (0.1, 0.5, 1.0, 1.5 and 2.0 mg/mL) was added to Transwell inserts containing Caco-2 cells. The transport of fucoidan across Caco-2 cells increased in a dose-dependent manner up to 1.0 mg/mL. It reached a maximum after 1 h and then rapidly decreased. In another experiment, rats were fed standard chow containing 2% fucoidan for one or two weeks. Immunohistochemical staining revealed that fucoidan accumulated in jejunal epithelial cells, mononuclear cells in the jejunal lamina propria and sinusoidal non-parenchymal cells in the liver. Since we previously speculated that nitrosamine may enhance the intestinal absorption of fucoidan, its absorption was estimated in rats administered N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) in their drinking water. Rats were fed 0.2% fucoidan chow (BBN + 0.2% fucoidan rats), 2% fucoidan chow (BBN + 2% fucoidan rats) and standard chow for eight weeks. The uptake of fucoidan through the intestinal tract seemed to be low, but was measurable by our ELISA method. Fucoidan-positive cells were abundant in the small intestinal mucosa of BBN + 2% fucoidan rats. Most fucoidan-positive cells also stained positive for ED1, suggesting that fucoidan was incorporated into intestinal macrophages. The uptake of fucoidan by Kupffer cells was observed in the livers of BBN + 2% fucoidan rats. In conclusion, the absorption of fucoidan through the small intestine was demonstrated both in vivo and in vitro.

Soybean glycinin- and β-conglycinin-induced intestinal immune responses in a murine model of allergy

Glycinin and β-conglycinin are major soybean allergens involved in food hypersensitivity. The study was aimed to investigate the soybean protein-induced intestinal immune responses and its possible mechanism. Balb/c mice were sensitised intragastrically with glycinin and β-conglycinin without an adjuvant for five weeks. Results showed that the sensitised mice displayed diarrhoea symptoms and jejunal morphological changes, including decreased villous height and thickened crypt depth. Both the histamine and immunoglobulin A levels in jejunum were increased in soybean allergen-sensitised mice. Moreover, the number of IgA+B cells and CD4+T cells in the jejunal lamina propria of sensitised mice were significantly increased. The expression levels of interleukin-4 and interferon-γ were increased, whereas the levels of IL-10 and transforming growth factor-β (TGF-β) were decreased in the jejunum mucosa. In conclusion, glycinin and β-conglycinin induce a mixed Th1/Th2 immune response. The suppression of IL-10 and TGF-β may play important roles in the development of intestinal allergic reactions.

Heat stress impairs performance parameters, induces intestinal injury, and decreases macrophage activity in broiler chickens

Studies on environmental consequences of stress on animal production have grown substantially in the last few years for economic and animal welfare reasons. Physiological, hormonal, and immunological deficits as well as increases in animals' susceptibility to diseases have been reported after different stressors in broiler chickens. The aim of the current experiment is to describe the effects of 2 different heat stressors (31 +/- 1 and 36 +/- 1 degrees C/10 h per d) applied to broiler chickens from d 35 to 42 of life on the corticosterone serum levels, performance parameters, intestinal histology, and peritoneal macrophage activity, correlating and discussing the obtained data under a neuroimmune perspective. In our study, we demonstrated that heat stress (31 +/- 1 and 36 +/- 1 degrees C) increased the corticosterone serum levels and decreased BW gain and food intake. Only chickens submitted to 36 +/- 1 degrees C, however, presented a decrease in feed conversion and increased mortality. We also showed a decrease of bursa of Fabricius (31 +/- 1 and 36 +/- 1 degrees C), thymus (36 +/- 1 degrees C), and spleen (36 +/- 1 degrees C) relative weights and of macrophage basal (31 +/- 1 and 36 +/- 1 degrees C) and Staphylococcus aureus-induced oxidative burst (31 +/- 1 degrees C). Finally, mild multifocal acute enteritis characterized by an increased presence of lymphocytes and plasmocytes within the jejunum's lamina propria was also observed. The stress-induced hypothalamic-pituitary-adrenal axis activation was taken as responsible for the negative effects observed on the chickens' performance and immune function and also the changes of the intestinal mucosa. The present obtained data corroborate with others in the field of neuroimmunomodulation and open new avenues for the improvement of broiler chicken welfare and production performance.

Chito-oligosaccharide reduces diarrhea incidence and attenuates the immune response of weaned pigs challenged with Escherichia coli K881

Seventy-two barrows (Landrace × Large White, initial BW of 4.9 ± 0.3 kg and 17 ± 3 d old) were used to determine if dietary chito-oligosaccharides can replace antibiotics as a means to reduce signs associated with infection in weaned pigs challenged with Escherichia coli. Pigs were assigned to 1 of 4 treatments in a randomized complete block design using 6 pens per treatment with 3 pigs per pen. The treatments consisted of pigs fed the unsupplemented corn-soybean meal diet challenged or unchallenged with E. coli K88 and pigs fed the same diet supplemented with 160 mg of chito-oligosaccharides or 100 mg of cyadox/kg and challenged with E. coli K88. On d 7, 1 group of pigs fed the unsupplemented diet, as well as all pigs fed diets containing chito-oligosaccharides or cyadox, were orally dosed with 30 mL of an alkaline broth containing E. coli K88. Another group of pigs fed the unsupplemented diet was orally dosed with 30 mL of sterilized alkaline broth. Fecal consistency was visually assessed each morning from d 7 to 14. Blood samples were collected at 0, 24, 48, and 168 h postinfection. On d 14 postchallenge, all pigs were killed to evaluate intestinal morphology and determine E. coli concentrations in the intestine. During the postchallenge period (wk 2), unsupplemented pigs challenged with E. coli had decreased (P < 0.05) BW gain, feed intake, fecal consistency, villus height, villus height:crypt depth ratio, and plasma IGF-1, and increased (P < 0.05) diarrhea incidence, E. coli counts in the intestine, plasma interleukin-1β, plasma IL-10, and IGA-positive cells in the jejunal and ileal lamina propria, compared with unchallenged pigs. Supplementation with cyadox largely mitigated these effects. Although chito-oligosaccharide reduced the incidence of diarrhea, the growth performance of E. coli-challenged pigs supplemented with chito-oligosaccharide was not better than that of unsupplemented pigs challenged with E. coli. Therefore, chito-oligosaccharide, at the amount used in this experiment, does not seem to be an effective substitute for antibiotics as a growth promoter for newly weaned pigs challenged with E. coli.

Experimentally induced epizootic rabbit enteropathy: clinical, histopathologicaI, ultrastructural, bacteriological and haematological findings

Epizootic rabbit enteropathy is an emerging disease that has appeared in French intensive enclosed rabbit farms since the beginning of 1997. Common clinical signs are mild watery diarrhoea with considerable distension of the abdomen. At necropsy, a significant dilation of the stomach and small intestine without gross evidence of acute or chronic enteric lesions (inflammation or congestion) was observed. The purpose of this study was to describe the anatomopathologic changes concerning the small intestine and those concerning the blood profile, in experimentally infected rabbits. In a first part of the experiment, thirty animals were inoculated with a reference inoculum and five were kept as controls for clinical signs examination and histopathological study. In a second part, 17 out of the inoculated rabbits and the 5 controls animals were randomly assigned to blood testing. Microscopic lesions were studied in sections from the different parts of the small intestine (duodenum, jejunum and ileum) by light microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The histological findings revealed only limited inflammation in inoculated animals. Major villous changes were atrophy, fusion, destruction and loss of epithelial cells. In inoculated rabbits, the congestion and dilation of blood vessels of jejunal lamina propria were significantly higher than in control animals (P&lt;0.005). There was significantly more (P&lt;0.05) apoptosis of cells of the jejunal epithelium in inoculated rabbits than in control animals. Infiltration of polymorphonuclear neutrophiles was observed into the jejunal or ileal tunica muscularis. SEM performed on the intestinal tract of 15 inoculated rabbits revealed blankets and globular particles of mucus associated with numerous bacteria on jejunum and ileum villi. This was not observed in the intestinal tract of control rabbits. Bacteria were found adhering to the epithelial surface and inside intestinal epithelial cells in a few animals by TEM and by light microscopy after Warthin-Starry staining. None of the bacteria isolated from the intestinal mixed contents and cultivated on usual media, are commonly known as rabbit?s pathogens. Regarding the haematological profile, neutrophil counts significantly increased (P&lt;0.05) and lymphocyte counts significantly decreased (P&lt;0.01), in inoculated rabbits compared to those of the control group.

Dietary zinc oxide affects the expression of genes associated with inflammation: Transcriptome analysis in piglets challenged with ETEC K88

The post-weaning growth check in commercial pig production systems is often associated with gastrointestinal infection, in particular that caused by enterotoxigenic Escherichia coli (ETEC) K88. Pharmacological doses of zinc oxide (ZnO) in the post-weaning diet reduce the incidence of diarrhoea and improve piglet performance. In the present study, piglets reared indoors or outdoors and weaned onto diets with or without pharmacological levels of ZnO were orally challenged with ETEC K88. Quantitative real-time PCR was performed on RNA extracted from jejunal lamina propria and Peyer's patch samples, to compare expression of a variety of candidate genes between treatments. Candidate genes were selected from an initial microarray study using pooled RNA to identify differentially expressed genes. Dietary treatment with ZnO was associated with significant differences in the transcript abundance of several genes. Zinc supplementation was associated with a marked decrease in expression of immune response genes concerned with inflammation, and possibly related to the stage of infection. Interestingly, evidence was also obtained that a reduced level of MUC4 (a proposed ETEC K88 receptor) was associated with zinc supplementation suggesting a mechanism that might influence ETEC infection. These findings indicate that zinc oxide supplementation may reduce the level of inflammation caused by ETEC challenge.

Effects of dietary egg yolk antibody powder on growth performance, intestinal Escherichia coli colonization, and immunocompetence of challenged broiler chicks

The present study aimed to investigate the effects of dietary supplementation of different levels of specific IgY (sIgY) and nonspecific IgY (nsIgY) egg yolk antibody powder on growth performance, immune functions, and intestinal morphology of Escherichia coli O78:K80-challenged broiler chicks. Lyophilized antibody isolated by the water-dilution method was obtained from the eggs of laying hens hyperimmunized with E. coli O78:K80. A total of 392 broiler chicks were randomly assigned to 7 dietary treatments with 4 replicates of 14 chicks (7 males and 7 females) each. Before offering the experimental diets, 7-d-old broiler chicks (except the negative control) were challenged orally with 0.5 mL (10(9) cfu/mL) of E. coli O78:K80 suspension. The challenge was continued for an additional 7 d from d 14 to 21 with 1.0 mL of a late log phase culture (10(9) cfu/mL) until the level of E. coli in feces reached 10(5) cfu/g. The 6 challenged groups received a basal diet supplemented with 0 (as positive control), 0.1, 0.2, or 0.4% (wt/wt) sIgY from eggs of immunized hens or levels of 0.2 or 0.4% (wt/wt) nsIgY from eggs laid by the nonimmunized hens. The negative control group was fed with the same unsupplemented diet. Oral infection caused an increase in ileal E. coli enumeration, total blood leukocytes, heterophil:lymphocyte ratio, the concentration of serum and intestinal secretory IgA, and the numbers of jejunal goblet cells and lamina propria lymphatic follicles. After 3 wk of feeding, the levels of 0.2 and 0.4% sIgY and 0.4% nsIgY had the most suppressive effects (P < 0.01) on the ileal E. coli enumeration and secretory IgA concentration. However, serum IgA concentration was slightly decreased only at the presence of 0.4% sIgY and nsIgY. Dietary supplementation with at least 0.2% sIgY decreased (P < 0.05) the circulating heterophil:lymphocyte ratio. Inclusion of both sIgY and nsIgY increased the villus height:crypt depth ratio and decreased the jejunal goblet cells and lamina propria lymphatic follicle numbers, with the most pronounced effects assigned to sIgY-supplemented groups. The best feed conversion ratio was obtained when the dietary inclusion of at least 0.2% sIgY continued for 3 wk. The present results indicate that dietary administration of at least 0.2% sIgY for 3 wk improved the intestinal health indices and immunological responses of broiler chicks orally challenged by E. coli O78:K80.

Milk supplemented with immune colostrum: Protection against rotavirus diarrhea and modulatory effect on the systemic and mucosal antibody responses in calves experimentally challenged with bovine rotavirus

Group A bovine rotavirus (BRV) is the major cause of neonatal calf diarrhea worldwide. As a preventive strategy, we evaluated the protection and immunomodulation in two groups of BRV-inoculated calves. All calves received control colostrum (CC; VN = 65,536; IgG 1 = 16,384) prior to gut closure followed by the milk supplemented with immune colostrum (VN = 1,048,576; IgG 1 = 262,144), twice a day, for 14 days. Calves received milk supplemented with 0.8% immune colostrum [(Gp 1) VN = 16,384; IgG 1 = 4096] or milk supplemented with 0.4% immune colostrum [(Gp 2) VN = 1024; IgG 1 = 1024]. Calves receiving CC or colostrum deprived calves (CD) fed antibody (Ab) free milk served as controls (Gp 3 and 4). Calves were inoculated with virulent BRV IND at 2 days of age. Group 1 calves (milk IgG 1 4096) showed 80% protection against BRV diarrhea and significantly reduced virus shedding. At 21 post-inoculation days (PID), the antibody secreting cell (ASC) responses of Gp 1 calves were limited mainly to duodenal and jejunal lamina propria (LP) with limited or no responses in systemic sites (spleen and PBL) and mesenteric lymph nodes. The profile of serum and fecal Ab responses as well as the ASC responses was also modulated by the presence of passive IgG 1 Abs and probably other colostrum components, toward higher titers of IgA Ab in serum and feces and a greater number of IgA ASC in the proximal intestine, reflecting positive modulation by colostrum toward this isotype associated with optimal protection of the intestinal mucosa. After challenge, at PID 21, all calves in Gp 1 and 2 were fully protected against diarrhea and only 1 of 5 calves in Gp 1 shed virus asymptomatically, indicating that the passive Ab treatment for 14 days was effective in protecting most of the animals after a first and a second virus exposure. The final outcome was a positive modulation of the mucosal immune responses and a high protection rate against diarrhea and virus shedding during the period of peak susceptibility to BRV infection.