Number Of Intestinal Intraepithelial Lymphocytes Research Articles

Dihydromyricetin Attenuates High-Intensity Exercise-Induced Intestinal Barrier Dysfunction Associated with the Modulation of the Phenotype of Intestinal Intraepithelial Lymphocytes.

Exercise-induced gastrointestinal syndrome (GIS) has symptoms commonly induced by strenuous sports. The study aimed to determine the effect of dihydromyricetin (DHM) administration on high-intensity exercise (HIE)-induced intestinal barrier dysfunction and the underlying mechanism involved with intestinal intraepithelial lymphocytes (IELs). The HIE model was established with male C57BL/6 mice using a motorized treadmill for 2 weeks, and DHM was given once a day by oral gavage. After being sacrificed, the small intestines of the mice were removed immediately. We found that DHM administration significantly suppressed HIE-induced intestinal inflammation, improved intestinal barrier integrity, and inhibited a HIE-induced increase in the number of IELs and the frequency of CD8αα+ IELs. Meanwhile, several markers associated with the activation, gut homing and immune functions of CD8αα+ IELs were regulated by DHM. Mechanistically, luciferase reporter assay and molecular docking assay showed DHM could activate the aryl hydrocarbon receptor (AhR). These data indicate that DHM exerts a preventive effect against HIE-induced intestinal barrier dysfunction, which is associated with the modulation of the quantity and phenotype of IELs in the small intestine. The findings provide a foundation to identify novel preventive strategies based on DHM supplementation for HIE-induced GIS.

A randomized, double-blind, placebo-controlled, Phase 1/2a trial protocol to assess the safety and efficacy of TAK-101 administered by microneedles in patients with celiac disease

Introduction: Celiac disease (CD) affects 0.2 to 2.0% of the worldwide population, causing significant enteropathy and systemic symptoms. There is no effective treatment for CD, and patients must follow a strict gluten-free diet lifelong. Recent studies investigated the efficacy of the non-immunosuppressive agent TAK-101 delivered intravenously in reducing immunological response to gluten in CD patients. However, no study has evaluated transdermal delivery, which initiates different immunological pathways. Objective: In a population of CD patients, we aim to assess the safety and pharmacokinetics of TAK-1 delivered by a Hollow Microstructured Transdermal microneedle (MN) (Phase 1) and the efficacy of MN-TAK-101 compared to placebo (Phase 2). Methods: This will be a Phase 1/2a trial lasting 180 days for each phase. Phase 1 will be an open-label, 2-part multicenter study: 1A, a group of patients will be divided into escalating dose cohorts. While, in 1B, another group of patients will be divided into repeated ascending dose cohorts until the maximum tolerated dose is reached. Phase 2 will be a double-blind multicentered randomized (stratified, block) placebo-controlled trial comparing TAK-101 and placebo, using different subjects than those in Phase 1. The primary outcome is the change in Interferon-γ production from baseline after MN-TAK-101 or MN-placebo administration. Secondary outcomes will assess the changes in the ratio of villous height to crypt depth, in the number of intestinal intraepithelial lymphocytes, in CD4, CD8, and γδ cells frequency, in the Celiac symptom index-modified questionnaire and safety measurements. The sample size is between 27-49 patients for phases 1A and 1B; 76 patients in phase 2. For statistical analysis, only descriptive analysis will be done for phase 1, while for Phase 2, the choice of parametric vs. nonparametric tests will be considered according to the normality of the data. This is a first Phase 1/2a placebo control randomized trial to assess the safety and efficacy of TAK-101 applied transdermally for patients with celiac disease. Keywords: Celiac Disease; TAK-101; Microneedle; Gluten intolerance; Gluten desensitization.

Evaluation of immune efficacy of Omp2 protein against Lawsonia intracellularis in mice

Porcine proliferative enteropathy (PPE) is caused by the obligate intracellular bacterium Lawsonia intracellularis. Infection results in an enteric disease characterised by decreased growth performance of pigs, and presents a major economic burden for swine industries worldwide. Since vaccination is an effective technique for controlling PPE, novel effective vaccine platforms are need to be developed. In this study, five proteins of L. intracellularis were screened through animal experiments and the highly immunoprotective Omp2 protein was identified. Then, the immune efficacy of Omp2 was further evaluated based on humoral and cell mediated immune (CMI) responses, faecal bacterial shedding, histopathological lesions, immune barrier function of intestinal mucosa as well as digestive and absorptive capacity following challenge of mice with L. intracellularis. Mice immunised with Omp2 had reduced faecal shedding, fewer histopathological lesions and reduced bacteria colonisation of the ileum. Additionally, Omp2 immunised mice showed stronger serum IgG and IFN-γ levels, up-regulated Occludin and zonula occludens-1 (ZO-1) mRNA levels, as well as increased numbers of intestinal intraepithelial lymphocytes (IELs) and levels of sIgA. On the contrary, the activities of LPS, α-AMS and AKP were significantly increased.Our investigation indicated that immunization with Omp2 reduced the severity of clinical signs and provided efficacious immunoprotection for target animals against L. intracellularis infection in mouse model.

More fuel to the fire: some patients with non-celiac self-reported wheat sensitivity exhibit adaptive immunological responses in duodenal mucosa

BackgroundIn contrast to the well-characterized Celiac Disease (CD), the clinical scenarios encompassed by the non-celiac self-reported wheat sensitivity (NCSRWS) might be related to different antigens that trigger distinct immune-inflammatory reactions. Although an increased number of intestinal intraepithelial lymphocytes is observed at the inception of both diseases, the subsequent immunopathogenic pathways seem to be different. We aimed to describe the cytokine profile observed in the duodenal mucosa of patients with NCSRWS.MethodsIn a blind, cross-sectional study, we included duodenal biopsies from 15 consecutive untreated patients with active CD, 9 individuals with NCSRWS and 10 subjects with dyspepsia without CD and food intolerances. Immunohistochemistry and flow-cytometry were used to determine the presence of pro-inflammatory cytokine expressing monocytes and monocyte-derived dendritic cells involved in innate immune activation, cytokine-driven polarization and maintenance of Th1 and Th17/Th 22, and anti-inflammatory/profibrogenic cytokines.ResultsThe percentage of cells expressing all tested cytokines in the lamina propria and the epithelium was higher in CD patients than in the control group. Cytokines that induce and maintain Th1 and Th17 polarization were higher in CD than in NCSRWS and controls, also were higher in NCSRWS compared to controls. Similar differences were detected in the expression of IL-4 and TGF-1, while IL-10-expressing cells were lower in NCSRWS patients than in controls and CD subjects.ConclusionsNCSRWS patients exhibit components of both, innate and adaptive immune mechanisms but to a lesser extent compared to CD.

Intestinal epithelial cell-derived IL-15 determines local maintenance and maturation of intra-epithelial lymphocytes in the intestine.

Interleukin-15 (IL-15) is a cytokine critical for maintenance of intestinal intra-epithelial lymphocytes (IELs), especially CD8αα + IELs (CD8αα IELs). In the intestine, IL-15 is produced by intestinal epithelial cells (IECs), blood vascular endothelial cells (BECs) and hematopoietic cells. However, the precise role of intestinal IL-15 on IELs is still unknown. To address the question, we generated two kinds of IL-15 conditional knockout (IL-15cKO) mice: villin-Cre (Vil-Cre) and Tie2-Cre IL-15cKO mice. IEC-derived IL-15 was specifically deleted in Vil-Cre IL-15cKO mice, whereas IL-15 produced by BECs and hematopoietic cells was deleted in Tie2-Cre IL-15cKO mice. The cell number and frequency of CD8αα IELs and NK IELs were significantly reduced in Vil-Cre IL-15cKO mice. By contrast, CD8αα IELs were unchanged in Tie2-Cre IL-15cKO mice, indicating that IL-15 produced by BECs and hematopoietic cells is dispensable for CD8αα IELs. Expression of an anti-apoptotic factor, Bcl-2, was decreased, whereas Fas expression was increased in CD8αα IELs of Vil-Cre IL-15cKO mice. Forced expression of Bcl-2 by a Bcl-2 transgene partially restored CD8αα IELs in Vil-Cre IL-15cKO mice, suggesting that some IL-15 signal other than Bcl-2 is required for maintenance of CD8αα IELs. Furthermore, granzyme B production was reduced, whereas PD-1 expression was increased in CD8αα IELs of Vil-Cre IL-15cKO mice. These results collectively suggested that IEC-derived IL-15 is essential for homeostasis of IELs by promoting their survival and functional maturation.

Protective effects of γ-irradiated Astragalus polysaccharides on intestinal development and mucosal immune function of immunosuppressed broilers

This study was aimed to assess the protective effects of γ-irradiated Astragalus polysaccharides (IAPS) on the development of small intestine and intestinal mucosal immunity of immunosuppressed broilers induced by cyclophosphamide (CPM). A total of 384 one-day-old broiler chicks with similar initial weight were randomly assigned into 6 groups: non-treated group (control), and CPM-treated groups fed either a basal diet or the diets containing 900 mg/kg APS, or 900, 600, 300 mg/kg IAPS, respectively. On days 16, 18, and 20, all broilers except for control group were intramuscularly injected with 0.5 mL CPM (40 mg/kg of BW). Broilers in the control group were intramuscularly injected with 0.5 mL sterilized saline (0.75%, wt/vol). This trial was lasted for 21 d. The results revealed that both APS and IAPS treatment elevated the duodenal IgA-producing cells number and the jejunal mRNA expression of interleukin-2 (IL-2), interleukin-10 (IL-10), and interferon γ of CPM-injected broilers (P < 0.05). The decreased jejunal villus height (VH), the ratio of VH to crypt depth (V/C), as well as the intestinal intraepithelial lymphocytes (IELs) and goblet cells number in CPM-injected broilers were elevated by dietary supplementation with 900 mg/kg APS or 900, 600 mg/kg IAPS (P < 0.05). The CPM-induced decrease in jejunum index, the duodenal VH and the jejunal IgA-producing cells number were only improved in the 900 mg/kg IAPS group (P < 0.05). Furthermore, the number of IELs and IgA-producing cells in duodenum, VH, V/C, the number of goblet cells, and mRNA expression of IL-2 and IL-10 in jejunum were higher in the 900 mg/kg IAPS group than those in the 900 mg/kg APS group (P < 0.05). In summary, IAPS possessed stronger immunomodulatory effect than APS at the same supplementation level. Therefore, gamma irradiation can be used as an alternative treatment to enhance the immunomodulatory activity of APS.

Cell Density Counts of the Intestinal Intraepithelial Lymphocytes in the Celiac Patients.

Increased number of intestinal intraepithelial lymphocytes (IELs) is a key histological finding in the diagnosis of celiac disease (CD); however, the number of IELs in celiac patients and healthy subjects may vary from one region to another. Additionally, there are some seronegative celiac patients with a borderline histology. To determine the number of the CD3+ and CD8+ IELs T-cells in the celiac patients and healthy subjects (controls) in Isfahan. The duodenal biopsies were obtained from the celiac patients (n=15) and the controls (n=19). The total number of IELs/100 epithelial cells (ECs) were counted using the hematoxylin-eosin (H&E) staining method, and that of CD3+ and CD8+ IELs/100 ECs were counted using the immunohistochemistry (IHC) staining method. This study defined the upper normal limit for each variable as mean + 2SD. Accordingly, the upper normal limits of the total IELs, CD3+ IELs, and CD8+ IELs/100 ECs were calculated as 37 (95% confidence intervals, CI: 33-41), 22 (95% CI: 19-25) and 12 (95% CI: 10-14), respectively. In 3 clinically CD diagnoses, the total IELs counts/100 ECs were below the upper normal limit, and the histopathological and serologic assays were negative. Nevertheless, the CD8+ IELs T-cells counts/100 ECs showed borderline values. Interestingly, these patients responded to a gluten-free diet (GFD). The study findings suggest that in the clinically diagnosed celiac disease, IELs count/100 ECs below the upper normal limit as well as negative histopathological and serologic assays and the cell density counts of the CD8+ IELs T-cells/100 ECs could be a useful parameter in CD diagnosis and make a decision to put them on a GFD.

Asparagine preserves intestinal barrier function from LPS-induced injury and regulates CRF/CRFR signaling pathway.

Stress causes intestinal inflammation and barrier dysfunction. Corticotrophin-releasing factor (CRF)/CRF receptor (CRFR) signaling pathway has been shown to be important for stress-induced intestinal mucosal alteration. L-Asparagine (ASN) is a powerful stimulator of ornithine decarboxylase and cell proliferation in a variety of cell types, including colonic cells. In the present study, we investigated whether dietary ASN supplementation could alleviate the damage of intestinal barrier function caused by LPS through modulation of CRF/CRFR signaling pathway. Twenty-four weaned pigs were randomly divided into one of four treatments: (1) non-challenged control; (2) Escherichia coli LPS challenged control; (3) LPS + 0.5% ASN; (4) LPS + 1.0% ASN. LPS stress induced villous atrophy, intestinal morphology disruption and decreased claudin-1 expression. ASN supplementation increased intestinal claudin-1 protein expression and alleviated villous atrophy and intestinal morphology impairment caused by LPS stress. In addition, ASN supplementation increased the number of intestinal intraepithelial lymphocytes and reversed the elevations of intestinal mast cell number and neutrophil number induced by LPS stress. Moreover, ASN decreased the mRNA expression of intestinal CRF, glucocorticoid receptors and tryptase. These results indicate that ASN attenuates intestinal barrier dysfunction induced by LPS stress, and regulates CRF/CRFR1 signaling pathway and mast cell activation.

Enhanced immune response to foot-and-mouth disease vaccine by oral administration of ginseng stem-leaf saponins

Vaccination is an important approach to the control of foot-and-mouth disease (FMD). This study evaluated the effect of oral administration of ginseng stem–leaf saponins (GSLS) on the immune response to FMD vaccine and the gut mucosal immunity in mice. In experiment 1, mice were orally administered GSLS or not treated as a control. The animals were then immunized twice with FMD vaccine. Blood was sampled weekly within five weeks after the boost immunization for measurement of serum IgG and the isotypes. In experiment 2, mice were orally administrated GSLS or not treated as a control. After that, splenocytes were prepared from sacrificed mice for lymphocyte proliferation assay and intestinal tissues were sampled for immunohistochemistry and histological examination. The results showed that oral administration of GSLS significantly enhanced serum IgG and the isotype responses to FMD vaccine as well as the number of intestinal intraepithelial lymphocytes (IELs) and immunoglobulin A (IgA)+ cells. Therefore, GSLS may be a potent oral adjuvant and deserve further study to improve vaccination in susceptible animals.

Effect of alemtuzumab on intestinal intraepithelial lymphocytes and intestinal barrier function in cynomolgus model.

Background:Alemtuzumab has been used in organ transplantation and a variety of hematologic malignancies (especially for the treatment of B-cell chronic lymphocytic leukemia). However, serious infectious complications frequently occur after treatment. The reason for increased infections postalemtuzumab treatment is unknown at this stage. We explore the effect of alemtuzumab on intestinal intraepithelial lymphocytes (IELs) and intestinal barrier function in cynomolgus model to explain the reason of infection following alemtuzumab treatment.Methods:Twelve male cynomolguses were randomly assigned to either a treatment or control group. The treatment group received alemtuzumab (3 mg/kg, intravenous injection) while the control group received the same volume of physiological saline. Intestinal IELs were isolated from the control group and the treatment group (on day 9, 35, and 70 after treatment) for counting and flow cytometric analysis. Moreover, intestinal permeability was monitored by enzymatic spectrophotometric technique and enzyme-linked immunosorbent assay.Results:The numbers of IELs were decreased significantly on day 9 after treatment compared with the control group (0.35 ± 0.07 × 108 and 1.35 ± 0.09 × 108, respectively; P < 0.05) and were not fully restored until day 70 after treatment. There were significant differences among four groups considering IELs subtypes. In addition, the proportion of apoptotic IELs after alemtuzumab treatment was significantly higher than in the control group (22.01 ± 3.67 and 6.01 ± 1.42, respectively; P < 0.05). Moreover, the concentration of D-lactate and endotoxin was also increased significantly on day 9 after treatment.Conclusions:Alemtuzumab treatment depletes lymphocytes in the peripheral blood and intestine of cynomolgus model. The induction of apoptosis is an important mechanism of lymphocyte depletion after alemtuzumab treatment. Notably, intestinal barrier function may be disrupted after alemtuzumab treatment.

Recognition of gut microbiota by NOD2 is essential for the homeostasis of intestinal intraepithelial lymphocytes

NOD2 functions as an intracellular sensor for microbial pathogen and plays an important role in epithelial defense. The loss-of-function mutation of NOD2 is strongly associated with human Crohn's disease (CD). However, the mechanisms of how NOD2 maintains the intestinal homeostasis and regulates the susceptibility of CD are still unclear. Here we found that the numbers of intestinal intraepithelial lymphocytes (IELs) were reduced significantly in Nod2(-/-) mice and the residual IELs displayed reduced proliferation and increased apoptosis. Further study showed that NOD2 signaling maintained IELs via recognition of gut microbiota and IL-15 production. Notably, recovery of IELs by adoptive transfer could reduce the susceptibility of Nod2(-/-) mice to the 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis. Our results demonstrate that recognition of gut microbiota by NOD2 is important to maintain the homeostasis of IELs and provide a clue that may link NOD2 variation to the impaired innate immunity and higher susceptibility in CD.

Recognition of gut microbiota by NOD2 is essential for the homeostasis of intestinal intraepithelial lymphocytes

NOD2 functions as an intracellular sensor for microbial pathogen and plays an important role in epithelial defense. The loss-of-function mutation of NOD2 is strongly associated with human Crohn's disease (CD). However, the mechanisms of how NOD2 maintains the intestinal homeostasis and regulates the susceptibility of CD are still unclear. Here we found that the numbers of intestinal intraepithelial lymphocytes (IELs) were reduced significantly in Nod2(-/-) mice and the residual IELs displayed reduced proliferation and increased apoptosis. Further study showed that NOD2 signaling maintained IELs via recognition of gut microbiota and IL-15 production. Notably, recovery of IELs by adoptive transfer could reduce the susceptibility of Nod2(-/-) mice to the 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis. Our results demonstrate that recognition of gut microbiota by NOD2 is important to maintain the homeostasis of IELs and provide a clue that may link NOD2 variation to the impaired innate immunity and higher susceptibility in CD.

Statins directly suppress cytokine production in murine intraepithelial lymphocytes

Statins, inhibitors of the enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, are known not only as cholesterol-lowering agents but also as anti-inflammatory mediators. However, their regulatory effect on intestinal mucosal immunity remains unclear. The present study examined the possible direct effects of statin on intestinal intraepithelial lymphocytes (IELs), the front line cells of the intestinal mucosal immune system. Murine IELs were isolated from the small intestines of C57BL/6 mice. IELs activated with anti-CD3/CD28 monoclonal antibodies produced interferon (IFN)-γ, tumor necrosis factor (TNF)-α, interleukin (IL)-2, and IL-4 in significant numbers; however, they did not produce IL-5. Both simvastatin and lovastatin suppressed IEL production of IFN-γ, TNF-α, IL-2, and IL-4 in a dose-dependent manner, whereas 48-h treatment with high concentrations (5×10−5M) of simvastatin and lovastatin did not affect the number of IELs. The suppressive effect of the simvastatin was significantly restored by the addition of mevalonate, farnesyl pyrophosphate ammonium salt, and geranylgeranyl pyrophosphate ammonium salt, which are downstream metabolites of HMG-CoA. These findings suggest that statins have direct suppressive effects on the production of T helper 1-cytokines and IL-4 in IELs; these effects are associated with inhibition of the mevalonate pathway to some extent.

Effects of monochromatic light on mucosal mechanical and immunological barriers in the small intestine of broilers

Our previous studies demonstrated that green and blue monochromatic lights were effective to stimulate immune response of the spleen in broilers. This study was designed to investigate the effects of monochromatic light on both gut mucosal mechanical and immunological barriers. A total of 120 Arbor Acre male broilers on post-hatching day (P) 0 were exposed to red light, green light (GL), blue light (BL), and white light (WL) for 49 d, respectively. As compared with broilers exposed to WL, the broilers exposed to GL showed that the villus height of small intestine was increased by 19.5% (P = 0.0205) and 38.8% (P = 0.0149), the crypt depth of small intestine was decreased by 15.1% (P = 0.0049) and 10.1% (P = 0.0005), and the ratios of villus height to crypt depth were increased by 39.3% (P < 0.0001) and 52.5% (P < 0.0001) at P7 and P21, respectively. Until P49, an increased villus height (33.6%, P = 0.0076), a decreased crypt depth (15.4%, P = 0.0201), and an increased villus height-to-crypt depth ratio (58.5%, P < 0.0001) were observed in the BL group as compared with the WL group. On the other hand, the numbers of intestinal intraepithelial lymphocytes (27.9%, P < 0.0001 and 37.0%, P < 0.0001), goblet cells (GC, 22.1%, P < 0.0001 and 18.1%, P < 0.0001), and IgA(+) cells (14.8%, P = 0.0543 and 47.9%, P = 0.0377) in the small intestine were significantly increased in the GL group as compared with the WL group at P7 and P21, respectively. The numbers of intestinal intraepithelial lymphocytes (36.2%, P < 0.0001), GC (26.5%, P < 0.0001), and IgA(+) cells (68.0%, P = 0.0177) in the BL group were also higher than those in the WL group at P49. These results suggest that both mucosal mechanical and immunological barriers of the small intestine may be improved by rearing broilers under GL at an early age and under BL at an older age.

Effect of Anti-Mouse CD52 Monoclonal Antibody on Mouse Intestinal Intraepithelial Lymphocytes

CD52 monoclonal antibody (mAb) has been used therapeutically in lymphocytic leukemia, autoimmune disease, and organ transplantation. But the effect of CD52 mAb on intestinal intraepithelial lymphocytes (IELs) was unknown. The aim of this study was to assess the influence of anti-mouse CD52 mAb on IELs. Twenty male C57BL/6 mice were randomly assigned to a treatment or a control group. The treatment group received anti-mouse CD52 mAb (20 mug, subcutaneously), whereas the control group received the same volume of phosphate-buffered solution. On the seventh day after treatment, mice were killed, and ileum and colon were obtained for histopathology and immunohistochemistry examination, IELs were isolated for flow cytometric analysis and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide analysis. Furthermore, the intestinal permeability was measured by lactulose-mannitol test. The number and viability of IELs were decreased significantly in treatment compared with the control group. There were significant differences between the two groups considering IELs phenotypes. In addition, the proportion of apoptotic IELs in CD52 mAb treatment group was significantly higher than the control group (19.59%+/-3.13% and 2.02%+/-0.33%, respectively; P<0.05). Furthermore, lactulose-mannitol test showed a marked increase intestinal permeability after CD52 treatment (90.38%+/-5.96% and 46.02%+/-6.40%, respectively; P<0.05). Anti-mouse CD52 mAb could induce more IELs to apoptosis and result in reducing the number of IELs, which may disrupt intestinal barrier function.

Impaired intestinal mucosal immunity in specific-pathogen-free chickens after infection with very virulent infectious bursal disease virus

Diarrhea is one of the most important clinical side effects that occurs in chickens after infection with bursal disease virus. However, the kinetics of the intestinal mucosal immune parameters in infectious bursal disease virus (IBDV)-infected birds remains unclear. Forty-five specific-pathogen-free chickens were randomly divided into 2 groups [30 chickens in the very virulent IBDV (vvIBDV)-infected group and 15 chickens in the control group] to determine the effect of vvIBDV infection on intestinal mucosal immunity. All chickens were raised in negative-pressure isolators and fed the same diet. Results indicate that severe histologic lesions were observed in the intestinal tract in the vvIBDV-infected group, and the villus heights of the duodenum, jejunum, and ileum were decreased after vvIBDV infection (P < 0.01 or P < 0.05). The number of intestinal intraepithelial lymphocytes, mast cells, and goblet cells decreased significantly in the vvIBDV-infected group compared with the control (P < 0.01 or P < 0.05) on d 1, 2, and 3 postchallenge with vvIBDV. Very virulent IBDV infection reduced the expression of each fragment of intestinal secretory IgA at all 3 time points. Intestinal alkaline phosphatase decreased dramatically on d 2 and 3 postchallenge with vvIBDV. Taken together, these results indicate that vvIBDV infection contributes to considerable damage to the normal structure of the intestine and intestinal mucosal immune parameters of specific-pathogen-free chickens. Our research helps to increase an understanding of the pathogenesis of diarrhea induced by vvIBDV infection. These findings provide new insights into the pathogenesis and pathophysiology of vvIBDV infection.

Effects of Rabbit Sacculus Rotundus Antimicrobial Peptides on the Intestinal Mucosal Immunity in Chickens

Ninety chickens were randomly divided into 2 groups (45 chickens in each group) to determine the effect of oral administration of rabbit sacculus rotundus antimicrobial peptides (RSRP) on the intestinal mucosal immune responses in chicken. On d 7, 14, 21, and 28, the animals received 0.1 mg of RSRP dissolved in 0.5 mL of physiological saline. The control groups received the same dose of physiological salt solution on the same day. The results showed that RSRP increased the villus height of the duodenum (P < 0.01) and jejunum (P < 0.05) at the ages of 28, 42, and 56 d. The numbers of intestinal intraepithelial lymphocytes in different parts of intestine of the RSRP group were increased significantly more than that of the control (P < 0.01 or P < 0.05) at the ages of 28, 42, and 56 d. The RSRP increased the area of IgA-secreting cells of each fragment of intestine at all 3 time points. These results indicated that the presence of RSRP affected and considerably modified the structure of the intestine and mucosal immune parameters in healthy chickens when compared with controls.

Intestinal intraepithelial lymphocytes in cirrhosis: experiment with rats

To investigate the phenotypes of T lymphocytes in the intestinal epithelium in cirrhosis. Forty Wistar rats were randomly divided into 2 groups: cirrhosis group (n = 25) undergoing subcutaneous injection of 40% carbon tetrachloride twice a week for 10-12 weeks to establish cirrhosis models, and control group (n = 15). Twelve weeks later the rats were killed with their levers taken out. The T lymphocytes in the intestinal epithelium were isolated and labeled with mouse anti-rat CD3, CD4 and CD8 monoclonal antibody, Flow cytometry was performed. The number of intestinal intraepithelial lymphocytes of the cirrhosis group was (3.4 +/- 1.1) x 10(5)/cm, significantly higher than that of the control group [(2.3 +/- 0.5) x 10(5)/cm, P < 0.05]. The proportion of CD3(+) cells of the cirrhosis group were (76 +/- 8)%, not significantly different from that of the control group [(80 +/- 6)%, P > 0.05]. There were no significant different between two group (P > 0.05). The proportion of CD4(+)CD8(+) subpopulation of the cirrhosis group was (6.9 +/- 3.3)%, significantly higher than that of the control group [(3.7 +/- 1.8)%, P < 0.05]. The proportion of CD4(+)CD8(-) subpopulation of the cirrhosis group was (6.9 +/- 3.0)%, significantly higher than that of the control group [(4.4 +/- 1.4)%, P < 0.05]. There were alterations of the immune barrier function in cirrhosis. The increase of the proportion of CD4(+)CD8(+) subpopulation may be associated with the increases of the number of intestinal bacteria.

Effects of Long-Term Cyclosporine A on Rat Intestinal Intraepithelial Lymphocytes

The aim of this study was to assess the influence of long-term administration of cyclosporine (CsA) on rat intestinal intraepithelial lymphocytes (IEL). Ten male Lewis rats were randomly assigned to either a treatment or a control group. For 12 weeks the treatment group received CsA (5 mg/kg per day) while the control group received the same volume of vehicle. Peripheral blood lymphocytes were counted and IEL were isolated for flow cytometric analysis. Peripheral blood lymphocytes numbers were significantly decreased in the CsA compared with the control group (4.80 ± 1.02 × 10 6/mL and 3.34 ± 0.70 × 10 6/mL, respectively, P = .029). IEL numbers were increased significantly in CsA compared with the control group. (23.2 ± 8.0 × 10 6 and 7.8 ± 1.8 × 10 6, respectively, P = .012). There were no significant differences between the two groups considering IEL phenotypes. In conclusion, CsA did not influence the subpopulation but significantly increased the number of IEL.

Intestinal Intraepithelial Lymphocytes Sustain the Epithelial Barrier Function againstEimeria vermiformisInfection

Eimeria spp. are intracellular protozoa that infect intestinal epithelia of most vertebrates, causing coccidiosis. Intestinal intraepithelial lymphocytes (IEL) that reside at the basolateral site of epithelial cells (EC) have immunoregulatory and immunoprotective roles against Eimeria spp. infection. However, it remains unknown how IEL are involved in the regulation of epithelial barrier during Eimeria sp. infection. Here, we demonstrated two distinct roles of IEL against infection with Eimeria vermiformis, a murine pathogen: production of cytokines to induce protective immunity and expression of junctional molecules to preserve epithelial barrier. The number of IEL markedly increased when oocyst production reached a peak. During infection, IEL increased production of gamma interferon (IFN-gamma) and tumor necrosis factor alpha (TNF-alpha) and decreased transforming growth factor beta (TGF-beta) production. Addition of IFN-gamma and TNF-alpha or supernatants obtained from cultured IEL from E. vermiformis-infected mice reduced transepithelial electrical resistance (TER) in a confluent CMT93 cell monolayer, a murine intestine-derived epithelial line, but antibodies against these cytokines suppressed the decline of TER. Moreover, TGF-beta attenuated the damage of epithelial monolayer and changes in TER caused by IFN-gamma and TNF-alpha. The expression of junctional molecules by EC was decreased when IEL produced a high level of IFN-gamma and TNF-alpha and a low level of TGF-beta in E. vermiformis-infected mice. Interestingly, IEL constantly expressed junctional molecules and a coculture of EC with IEL increased TER. These results suggest that IEL play important multifunctional roles not only in protection of the epithelium against E. vermiformis-induced change by cytokine production but also in direct interaction with the epithelial barrier when intra-EC junctions are down-regulated.