Porcine intestinal lymphoid tissues synthesize estradiol

Estradiol (17β-estradiol) is synthesized primarily in the gonads of both sexes and regulates the development and function of reproductive organs. Recently, we reported that intestinal lymphocyte homeostasis is regulated by estradiol synthesized de novo in the endothelial cells of the high endothelial venules (HEVs) of mesenteric lymph nodes and Peyer's patches in mice. This observation prompted us to hypothesize that HEVs of intestinal lymphoid tissues are sites of estradiol synthesis across species. In this study, we examined whether estradiol is synthesized in the intestinal lymphoid tissues of adolescent piglets. Comparisons of estradiol levels in blood and tissue showed that estradiol concentrations in mesenteric lymph nodes and Peyer's patches were significantly higher than the level in serum. Reverse transcription polymerase chain reaction showed that porcine intestinal lymphoid tissues express mRNAs for steroidogenic enzymes (StAR, 17β-Hsd, 3β-Hsd, Cyp17a1, and Cyp19a1), and immunohistochemical results in ilial tissue showed expression of aromatase (CYP19) in Peyer's patch-localized endothelial cells of HEVs. When mesenteric lymph node and Peyer's patch tissues were cultured in vitro, they produced estradiol. Taken together, the results indicate that mesenteric lymph nodes and Peyer's patches are sites of estradiol synthesis in adolescent piglets.

Oral Immunization of FMDV Vaccine Using pH-Sensitive and Mucoadhesive Thiolated Cellulose Acetate Phthalate Microparticles

Several barriers such as gastric pH, enzymatic degradation and rapid transit should be overcome to orally deliver antigens for taking up by epithelial microfold cells in Peyer's patches of small intestine. To solve the above mentioned problems, we designed pH-sensitive and mucoadhesive polymeric microparticles (MPs) prepared by double emulsion technique using cellulose acetate phthalate (CAP) to enhance immune response of foot-and-mouth disease (FMD) virus (FMDV) subunit vaccine. Thiolation of CAP improved mucoadhesive property of CAP to prolong the MPs transit time through the gastrointestinal tract. Thiolated CAP (T-CAP) also slowed down antigen release in acidic pH of stomach but released more antigens in neutral pH of small intestine due to the pH-sensitivity of the T-CAP. Oral immunization of a chimerical multi-epitope recombinant protein as the FMD subunit vaccine via T-CAP MPs effectively delivered the vaccine to Peyer's patches eliciting mucosal IgA response. It will make a step forward into a promising oral subunit vaccine development in livestock industry.

Murine γδ T Cells Render B Cells Refractory to Commitment of IgA Isotype Switching

γδ T cells are abundant in the gut mucosa and play an important role in adaptive immunity as well as innate immunity. Although γδ T cells are supposed to be associated with the enhancement of Ab production, the status of γδ T cells, particularly in the synthesis of IgA isotype, remains unclear. We compared Ig expression in T cell receptor delta chain deficient (TCRδ⁻/⁻) mice with wild-type mice. The amount of IgA in fecal pellets was substantially elevated in TCRδ⁻/⁻ mice. This was paralleled by an increase in surface IgA expression and total IgA production by Peyer's patches (PPs) and mesenteric lymph node (MLN) cells. Likewise, the TCRδ⁻/⁻ mice produced much higher levels of serum IgA isotype. Here, surface IgA expression and number of IgA secreting cells were also elevated in the culture of spleen and bone marrow (BM) B cells. Germ-line α transcript, an indicator of IgA class switch recombination, higher in PP and MLN B cells from TCRδ⁻/⁻ mice, while it was not seen in inactivated B cells. Nevertheless, the frequency of IgA+ B cells was much higher in the spleen from TCRδ⁻/⁻ mice. These results suggest that γδ T cells control the early phase of B cells, in order to prevent unnecessary IgA isotype switching. Furthermore, this regulatory role of γδ T cells had lasting effects on the long-lived IgA-producing plasma cells in the BM.

Can narrow-band imaging of Peyer's patches predict the recurrence of ulcerative colitis?

No abstract available.

Can narrow-band imaging of Peyer's patches predict the recurrence of ulcerative colitis?

No abstract available.

Narrow-band imaging with magnifying endoscopy for Peyer's patches is useful in predicting the recurrence of remissive patients with ulcerative colitis

BACKGROUND/AIMS: Peyer's patches (PPs) are aggregates of lymphoid follicles that are mainly located in the distal ileum; they play a major role in mucosal immunity. We recently reported that patients with ulcerative colitis (UC) have alterations in PPs that can be detected using narrow-band imaging with magnifying endoscopy (NBI-ME). However, the usefulness of NBI-ME in UC treatment as a whole is still unknown. METHODS: We collected NBI-ME images of PPs from 67 UC patients who had undergone ileocolonoscopy. We evaluated changes in the villi using the "villi index," which is based on three categories: irregular formation, hyperemia, and altered vascular network pattern. The patients were divided into two groups on the basis of villi index: low (L)- and high (H)-types. We then determined the correlation between morphological alteration of the PPs and various clinical characteristics. In 52 patients who were in clinical remission, we also analyzed the correlation between NBI-ME findings of PPs and clinical recurrence. RESULTS: The time to clinical recurrence was significantly shorter in remissive UC patients with H-type PPs than in those with L-type PPs (P<0.01). Moreover, PP alterations were not correlated with age, sex, disease duration, clinical activity, endoscopic score, or extent of disease involvement. Multivariate analysis revealed that the existence of H-type PPs was an independent risk factor for clinical recurrence (hazard ratio, 3.3; P<0.01). CONCLUSIONS: UC patients with morphological alterations in PPs were at high risk of clinical relapse. Therefore, to predict the clinical course of UC, it may be useful to evaluate NBI-ME images of PPs.

Narrow-band imaging with magnifying endoscopy for Peyer's patches is useful in predicting the recurrence of remissive patients with ulcerative colitis

BACKGROUND/AIMS: Peyer's patches (PPs) are aggregates of lymphoid follicles that are mainly located in the distal ileum; they play a major role in mucosal immunity. We recently reported that patients with ulcerative colitis (UC) have alterations in PPs that can be detected using narrow-band imaging with magnifying endoscopy (NBI-ME). However, the usefulness of NBI-ME in UC treatment as a whole is still unknown. METHODS: We collected NBI-ME images of PPs from 67 UC patients who had undergone ileocolonoscopy. We evaluated changes in the villi using the "villi index," which is based on three categories: irregular formation, hyperemia, and altered vascular network pattern. The patients were divided into two groups on the basis of villi index: low (L)- and high (H)-types. We then determined the correlation between morphological alteration of the PPs and various clinical characteristics. In 52 patients who were in clinical remission, we also analyzed the correlation between NBI-ME findings of PPs and clinical recurrence. RESULTS: The time to clinical recurrence was significantly shorter in remissive UC patients with H-type PPs than in those with L-type PPs (P<0.01). Moreover, PP alterations were not correlated with age, sex, disease duration, clinical activity, endoscopic score, or extent of disease involvement. Multivariate analysis revealed that the existence of H-type PPs was an independent risk factor for clinical recurrence (hazard ratio, 3.3; P<0.01). CONCLUSIONS: UC patients with morphological alterations in PPs were at high risk of clinical relapse. Therefore, to predict the clinical course of UC, it may be useful to evaluate NBI-ME images of PPs.

Effects of extracellular heat shock protein 70 on intestinal immune function of rats with severe scald injury / 中华烧伤杂志

<p><b>OBJECTIVE</b>To explore the change in the expression of extracellular heat shock protein 70 (eHSP70) and interleukin 2 (IL-2) and their correlation in intestine of rats with severe scald injury, and to observe the effects of eHSP70 on CD3(+) T lymphocytes in Peyer's patch of intestine in rats with severe scald injury in vitro.</p><p><b>METHODS</b>(1) Sixty male SD rats were divided into normal control group (NC, n=10, only anesthetized) and scald group (S, n=50) according to the random number table. Rats in scald group were inflicted with 30% total body surface area full-thickness scald on the back. Ten rats from group NC immediately after anesthetization and 10 rats from group S at post injury hour (PIH) 3, 6, 12, 24, 48 were sacrificed to harvest their small intestines. The expressions of eHSP70 and IL-2 were determined with enzyme-linked immunosorbent assay (ELISA), and their correlation was analyzed. (2) Another 2 male SD rats were inflicted with the same injury as above. At PIH 12, CD3(+) T lymphocytes in Peyer's patch of small intestine were isolated and cultured with RPMI 1640 nutrient solution containing 10% fetal bovine serum. Cells were divided into blank control group (BC) and 5, 10, 20 μg/mL eHSP70 groups according to the random number table, with 6 wells in each group. Cells in group BC didn't receive any other treatment, while cells in the latter three groups were treated with corresponding mass concentration of recombinant rat eHSP70. After being cultured for 48 hours, the proportions of Th1 and Th2 in CD3(+) T lymphocytes, and the apoptosis rate of CD3(+) T lymphocytes were detected with flow cytometer, while the expressions of IL-2 and IL-10 in culture supernatant of cells were determined with ELISA. The cell experiments were repeated for 10 times. Data were processed with one-way analysis of variance, Kruskal-Wallis rank sum test, SNK-q test, and Pearson correlation analysis.</p><p><b>RESULTS</b>(1) Compared with those in group NC [(1 278±135) and (48.6±4.9) ng/mg], the levels of eHSP70 [(728±93), (412±31), (314±21), (528±40), (1 028±97) ng/mg] and IL-2 [(38.6±2.3), (32.3±1.0), (25.3±3.6), (33.9±4.1), (44.3±2.6) ng/mg] in intestine of rats in group S obviously decreased at PIH 3, 6, 12, 24, 48 (with q values from 3.48 to 5.32, P values below 0.05), reaching the nadir both at PIH 12, with a significantly positive correlation between the level of IL-2 and the level of eHSP70 (r=0.920, P<0.01). (2) Compared with those in group BC [(8.6±1.1)% and (3.75±0.45)%], the proportion of Th1 obviously increased [(11.3±2.1)%, (15.7±1.8)%, (10.8±1.5)%, with q values from 2.97 to 4.57, P values below 0.05], while the proportion of Th2 obviously decreased [(2.39±0.38)%, (1.05±0.23)%, (2.67±0.26)%, with q values from 2.48 to 4.32, P values below 0.05] in CD3(+) T lymphocytes of rats in 5, 10, 20 μg/mL eHSP70 groups. Compared with those in group BC [(34.3±2.2)% and (254±16) pg/mL], the apoptosis rate of CD3(+) T lymphocytes obviously decreased [(26.1±2.6)%, (20.7±1.5)%, (31.5±2.4)%, with q values from 3.47 to 4.95, P values below 0.05], while the level of IL-2 obviously increased [(417±22), (587±19), (307±27) pg/mL, with q values from 3.02 to 4.98, P values below 0.05] in culture supernatant of CD3(+) T lymphocytes of rats in 5, 10, 20 μg/mL eHSP70 groups. There was no significant difference in the level of IL-10 in culture supernatant of CD3(+) T lymphocytes of rats among the four groups (F=2.12, P>0.05).</p><p><b>CONCLUSIONS</b>The expressions of eHSP70 and IL-2 in intestine of rats are decreased after severe scald, with a obviously positive correlation between them. eHSP70 can promote the differentiation of CD3(+) T lymphocytes in Th1 orientation, decrease the apoptosis rate of the cells, and promote the release of IL-2 of cells in Peyer's patch of intestine in rats with severe scald injury in vitro.</p>

Secondary bile acids effects in colon pathology. Experimental mice study

ABSTRACTPURPOSE:To assess whether deoxycholic acid (DOC) and lithocholic acid (LCA) administered in a period of six months in a concentration of 0.25% may have a carcinogenic role in mice colon.METHODS:The study used C57BL6 female mice divided into four groups. The control group received a balanced diet and the others received diets supplemented with 0.25% DOC, 0.25% LCA and 0.125% DOC+0.125% LCA, respectively. After euthanasia, the lesions found in the resected gastrointestinal tracts were stained with hematoxylin-eosin and examined microscopically.RESULTS:No gastrointestinal tract changes were observed in the control group, while hyperplastic Peyer's patches in the small intestine, flat adenomas with mild dysplasia and chronic colitis at the level of the colon were found in all three test groups. The colonic lesions prevailed in the proximal colon. The highest number of flat adenoma lesions (8), hyperplasia of Peyer's patches (25) and chronic colitis (2) were found in mice fed with diet and LCA.CONCLUSION: Precancerous or cancerous pathological lesions could not be identified. Instead, adenomatous colonic injuries occurred in a shorter period of time (six months), compared to the reported data.

Effects of astragalus polysaccharide on intestinal immune function of rats with severe scald injury / 中华烧伤杂志

<p><b>OBJECTIVE</b>To observe the effects of astragalus polysaccharide (AP) on the intestinal mucosal morphology, level of secretory IgA (s-IgA) in intestinal mucus, and distribution of T lymphocyte subsets in Peyer's patch in rats with severe scald injury.</p><p><b>METHODS</b>One hundred and thirty SD rats were divided into sham injury group (SI, sham injured, n = 10), scald group (S, n = 30), low dosage group (LD, n = 30), moderate dosage group (MD, n = 30), and high dosage group (HD, n = 30) according to the random number table. Rats in the latter 4 groups were inflicted with 30% TBSA full-thickness scald on the back. From post injury hour 2, rats in groups LD, MD, and HD were intraperitoneally injected with 0.5 mL AP solution with the dosage of 100, 200, and 300 mg/kg each day respectively, and rats in group S were injected with 0.5 mL normal saline instead. Ten rats from group SI immediately after injury and 10 rats from each of the latter 4 groups on post injury day (PID) 3, 7, 14 were sacrificed, and their intestines were harvested. The morphology of ileal mucosa was examined after HE staining; the level of s-IgA in ileal mucus was determined with double-antibody sandwich ELISA method; the proportions of CD3⁺, CD4⁺, CD8⁺ T lymphocytes in Peyer's patches of intestine were determined with flow cytometer, and the proportion of CD4⁺ to CD8⁺ was calculated. Data were processed with one-way analysis of variance, analysis of variance of factorial design, and SNK test.</p><p><b>RESULTS</b>(1) Villi in normal form and intact villus epithelial cells were observed in rats of group SI immediately after injury, while edema of villi and necrosis and desquamation of an enormous amount of villi were observed in groups with scalded rats on PID 3, with significant infiltration of inflammatory cells. On PID 7, no obvious improvement in intestinal mucosal lesion was observed in groups with scalded rats. On PID 14, the pathology in intestinal mucosa of rats remained nearly the same in group S, and it was alleviated obviously in groups LD and MD, and the morphology of intestinal mucosa of rats in group HD was recovered to that of group SI. (2) On PID 3, 7, and 14, the level of s-IgA in intestinal mucus significantly decreased in groups S, LD, MD, and HD [(43 ± 5), (45 ± 5), (46 ± 5) µg/mL; (47 ± 5), (48 ± 5), (49 ± 6) µg/mL; (50 ± 6), (51 ± 5), (52 ± 5) µg/mL; (53 ± 6), (54 ± 5), (55 ± 5) µg/mL] as compared with that of rats in group SI immediately after injury [(69 ± 4) µg/mL, with P values below 0.05]. The level of s-IgA in intestinal mucus of rats in group MD was significantly higher than that in group S at each time point (with P values below 0.05), and that of group HD was significantly higher than that in groups S and LD at each time point (with P values below 0.05). (3) Compared with those of rats in group SI immediately after injury, the proportions of CD3⁺ T lymphocytes and CD4⁺ T lymphocytes significantly decreased in groups with scalded rats at each time point (with P values below 0.05), except for those in group HD on PID 14. The proportion of CD4⁺ T lymphocytes of rats in group LD was significantly higher than that in group S on PID 3 (P < 0.05). The proportions of CD3⁺ T lymphocytes and CD4⁺ T lymphocytes were significantly higher in groups MD and HD than in groups S and LD (except for the proportion of CD4⁺ T lymphocytes in group MD on PID 3 and 14) at each time point (with P values below 0.05). The proportion of CD3⁺ T lymphocytes on PID 7 and 14 and that of CD4⁺ T lymphocytes on PID 3 were significantly higher in group HD than in group MD (with P values below 0.05). Compared with that of rats in group SI immediately after injury, the proportion of CD8⁺ T lymphocytes significantly increased in the other 4 groups at each time point (with P values below 0.05). The proportion of CD8⁺ T lymphocytes was significantly lower in rats of group LD on PID 7 and 14 and groups MD and HD at each time point than in group S (with P values below 0.05). The proportion of CD8⁺ T lymphocytes was significantly lower in rats of group MD on PID 7 and 14 and group HD at each time point than in group LD (with P values below 0.05). The proportion of CD8⁺ T lymphocytes was significantly lower in rats of group HD on PID 7 and 14 than in group MD (with P values below 0.05). On PID 3, 7, and 14, the proportion of CD4⁺ to CD8⁺ was significantly lower in groups S, LD, MD, and HD (0.65 ± 0.11, 0.68 ± 0.13, 0.73 ± 0.22; 0.76 ± 0.15, 0.78 ± 0.14, 0.90 ± 0.10; 0.85 ± 0.21, 0.89 ± 0.18, 1.08 ± 0.19; 0.99 ± 0.20, 1.05 ± 0.21, 1.25 ± 0.23) as compared with that of rats in group SI immediately after injury (1.74 ± 0.20, with P values below 0.05). The proportion of CD4⁺ to CD8⁺ was significantly higher in rats of group HD than in group MD on PID 7 (P < 0.05), and the proportion was significantly higher in these two groups than in group S at each time point (with P values below 0.05). The proportion of CD4⁺ to CD8⁺ was significantly higher in rats of group MD on PID 14 and group HD at each time point than in group LD (with P values below 0.05). Compared within each group, the proportions of CD3⁺, CD4⁺, CD8⁺ T lymphocytes and the proportion of CD4⁺ to CD8⁺ of rats in groups LD, MD, and HD showed a trend of gradual elevation along with passage of time.</p><p><b>CONCLUSIONS</b>AP can improve the injury to intestinal mucosa and modulate the balance of T lymphocyte subsets in Peyer's patch in a time- and dose-dependent manner, and it can promote s-IgA secretion of intestinal mucosa in a dose-dependent manner.</p>

Expression of the ATP-gated P2X7 Receptor on M Cells and Its Modulating Role in the Mucosal Immune Environment

Interactions between microbes and epithelial cells in the gastrointestinal tract are closely associated with regulation of intestinal mucosal immune responses. Recent studies have highlighted the modulation of mucosal immunity by microbe-derived molecules such as ATP and short-chain fatty acids. In this study, we undertook to characterize the expression of the ATP-gated P2X7 receptor (P2X7R) on M cells and its role in gastrointestinal mucosal immune regulation because it was poorly characterized in Peyer's patches, although purinergic signaling via P2X7R and luminal ATP have been considered to play an important role in the gastrointestinal tract. Here, we present the first report on the expression of P2X7R on M cells and characterize the role of P2X7R in immune enhancement by ATP or LL-37.

Gut-residing Microbes Alter the Host Susceptibility to Autoantibody-mediated Arthritis

K/BxN serum can transfer arthritis to normal mice owing to the abundant autoantibodies it contains, which trigger innate inflammatory cascades in joints. Little is known about whether gut-residing microbes affect host susceptibility to autoantibody-mediated arthritis. To address this, we fed C57BL/6 mice with water containing a mixture of antibiotics (ampicillin, vancomycin, neomycin, and metronidazol) for 2 weeks and then injected them with K/BxN serum. Antibiotic treatment significantly reduced the amount of bacterial genomic DNA isolated from fecal samples, in particular a gene encoding 16S ribosomal RNA derived from segmented filamentous bacteria. Arthritic signs, as indicated by the arthritic index and ankle thickness, were significantly attenuated in antibiotic-treated mice compared with untreated controls. Peyer's patches and mesenteric lymph nodes from antibiotic-treated mice contained fewer IL-17-expressing cells than those from untreated mice. Antibiotic treatment reduced serum C3 deposition in vitro via the alternative complement pathway. IL-17-/- congenic C57BL/6 mice were less susceptible to K/BxN serum-transferred arthritis than their wild-type littermates, but were still responsive to treatment with antibiotics. These results suggest that gut-residing microbes, including segmented filamentous bacteria, induce IL-17 production in GALT and complement activation via the alternative complement pathway, which cause the host to be more susceptible to autoantibody-mediated arthritis.

Antigen targeting to M cells for enhancing the efficacy of mucosal vaccines

Vaccination is one of the most successful applications of immunology and for a long time has depended on parenteral administration protocols. However, recent studies have pointed to the promise of mucosal vaccination because of its ease, economy and efficiency in inducing an immune response not only systemically, but also in the mucosal compartment where many pathogenic infections are initiated. However, successful mucosal vaccination requires the help of an adjuvant for the efficient delivery of vaccine material into the mucosa and the breaking of the tolerogenic environment, especially in oral mucosal immunization. Given that M cells are the main gateway to take up luminal antigens and initiate antigen-specific immune responses, understanding the role and characteristics of M cells is crucial for the development of successful mucosal vaccines. Especially, particular interest has been focused on the regulation of the tolerogenic mucosal microenvironment and the introduction of the luminal antigen into the lymphoid organ by exploiting the molecules of M cells. Here, we review the characteristics of M cells and the immune regulatory factors in mucosa that can be exploited for mucosal vaccine delivery and mucosal immune regulation.

Histologia do intestino do avestruz (Struthio camelus, Linnaeus 1758) / Histology of ostrich intestine (Struthio camelus, Linnaeus 1758)

A despeito de o avestruz (Struthio camelus) compartilhar muitas adaptações evolucionárias presentes em outras aves, estes animais apresentam algumas características anatômicas peculiares, como é o caso do seu tubo digestivo em que o cólon é maior que o ceco. Há algum tempo, essa ave tem sido explorada econômicamente e principalmente como fonte alternativa de proteína animal na alimentação humana. O presente trabalho analisou os aspectos histológicos do intestino de avestruzes produzidos em boas condições de manejo ambiental e nutricional. Foram utilizados 13 avestru-zes, com 18 a 30 meses de idade, provenientes da empresa Brasil Ostrich, e encaminhados para o abate no Abatedouro Escola da Universidade de São Paulo, Campus Administrativo de Pirassununga. Os animais foram abatidos com pistola pneumática e, após a sangria e evisceração, foram colhidas amostras de diferentes segmentos do intestino: duodeno, jejuno, íleo e ceco duplo. Os materiais foram processados, corados pela técnica de hematoxilina-eosina (H-E) e exami-nados em microscopia de campo claro. Os resultados obtidos revelaram que as vilosidades estão presentes no duodeno, porém, não existem no ceco. Dos quatro segmentos intestinais examinados, o ceco foi o que apresentou maior número de células caliciformes. Os nódulos linfáticos e os linfócitos foram observados em todos os segmentos examinados. No ceco, os nódulos linfáticos se agregam para constituir a placa de Peyer. O plano histológico dos segmentos intestinais examinados seguiu o padrão observado nos mamíferos domésticos e em outras aves. O conhecimento da histologia dos intestinos desses animais pode oferecer subsídios para a avaliação comparativa de procedimentos de manejo ambiental e nutricional que possam aumentar os níveis de produção e produtividade dessa atividade pecuária.

Regardless of the ostrich (Struthio camelus) share many adaptations to other evolutionary present birds, these animals show some peculiar anatomical features such as their digestive tract than the colon is greater than the cecum. For some time this bird has been economically exploited and especially as an alternative source of animal protein for human consumption. This study examined the histological bowel ostrich produced in good environmental management and nutrition. Thirteen ostriches were used, with 18 to 30 months old, from Brazil Ostrich company, and sent for slaughter in Slaughterhouse School, University of São Paulo Campus Administrative Pirassununga. The animals were killed with pneumatic gun and after bleeding and evisceration were collected, samples of different intestinal segments: duodenum, jejunum, ileum and cecum double. The materials were processed, stained with hematoxylin - eosin (HE) and examined under brightfield microscopy. The results showed that the villi are present in the duodenum but not exist in the cecum. Of the four intestinal segments examined the cecum showed the highest number of goblet cells. Lymph nodes and lymphocytes were observed in all segments examined. In the cecum lymph nodes are added to form the Peyer’s patch. The plan of histological intestinal segments examined followed the pattern observed in other domestic mammals and birds. The knowledge of the histology of the intestines of these animals can provide insight for comparative assessment procedures for environmental management and nutrition that may increase the levels of production and productivity of this livestock activity.

Ultrastructural study on microfold cells and microvillus cells in the follicle-associated epithelium over Peyer's Patches in albino rat

Microfold cells [M cells] act as gateways to the mucosal immune system. The aim of the study was to perform a detailed ultrastructural study on M cells and microvillus enterocytes in the follicle-associated epithelium that covers the dome region of the ileal Peyer's patches in the albino rat to understand the relationship between the two types of cells, the origin of M cells, and their possible mechanism in sampling of the luminal antigens. The follicle-associated epithelium over the Peyer's patches in 10 adult albino rats was studied carefully under transmission electron microscope with a special attention to M cells and microvillus enterocytes. M cells were characterized by pale cytoplasm and either paucity or lack of apical microvilli beside intracytoplasmic pockets harboring migrating lymphocytes. In the microvilli-lacking areas, however, bundles of microvillus filaments occasionally remained in the apical cytoplasm and small vesicles and tubules were found at the apical poles of M cells. Microvillus cells had apical brush borders composed of long, regular, and densely packed microvilli; however, a wide range of diversity of the apical surface morphology was noted. Sometimes, transitional epithelial cells from microvillus to M cells were observed as columnar cells, which had microvilli of moderate height in their apical border with appearance of bare areas, in addition to other cells, which had a microfolded profile that bore few stout and short microvilli. Pale cytoplasmic extensions of dendritic morphology were seen extending among the epithelial cells covering the Peyer's patches. The M cells were differentiated from the intestinal enterocytes by distinctive ultrastructural features. The observed transitional epithelial cells might indicate that the M cells probably originated from the microvillus enterocytes. The M cells transport the antigens from the intestinal lumen to the lymphocytes in the intraepithelial pockets for induction of mucosal-associated immune response

C6, a new monoclonal antibody, reacts with the follicle-associated epithelium of calf ileal Peyer's patches

The follicle-associated epithelium (FAE) of Peyer's patches (PPs) contains M cells that are important for reducing mucosal immune responses by transporting antigens into the underlying lymphoid tissue. We generated a monoclonal antibody (C6) that reacted with the FAE of calf ileal PPs, and analyzed the characteristics of C6 using immunohistochemistry and Western blotting. FAE of the ileal PP was stained with C6 during both late fetal developmental and postnatal stages. Neither the villous epithelial cell nor intestinal crypt basal cells were stained at any developmental stage. During the prenatal stages, FAE of the jejunal PP was C6-negative. However, a few C6-positive cells were distributed diffusely in some FAE of the jejunal PPs during the postnatal stages. The protein molecular weight of the antigen recognized by C6 was approximately 45 kDa. These data show that C6 is useful for identifying the FAE in ileal PPs and further suggest that differentiation of the FAE in these areas is independent of external antigens.

C6, a new monoclonal antibody, reacts with the follicle-associated epithelium of calf ileal Peyer's patches

The follicle-associated epithelium (FAE) of Peyer's patches (PPs) contains M cells that are important for reducing mucosal immune responses by transporting antigens into the underlying lymphoid tissue. We generated a monoclonal antibody (C6) that reacted with the FAE of calf ileal PPs, and analyzed the characteristics of C6 using immunohistochemistry and Western blotting. FAE of the ileal PP was stained with C6 during both late fetal developmental and postnatal stages. Neither the villous epithelial cell nor intestinal crypt basal cells were stained at any developmental stage. During the prenatal stages, FAE of the jejunal PP was C6-negative. However, a few C6-positive cells were distributed diffusely in some FAE of the jejunal PPs during the postnatal stages. The protein molecular weight of the antigen recognized by C6 was approximately 45 kDa. These data show that C6 is useful for identifying the FAE in ileal PPs and further suggest that differentiation of the FAE in these areas is independent of external antigens.

Gastric Helicobacter spp. infection in captive neotropical Brazilian feline

Ten captive neotropical Brazilian feline were submitted to gastroscopic examination and samples of gastric mucosa from fundus, corpus and pyloric antrum were evaluated for the presence of Helicobacter species. Warthin-Starry (WS) staining and PCR assay with species-specific primers and enzymatic cleavage were applied for bacterial detection and identification. Histological lesions were evaluated by haematoxylin and eosin staining. All animals showed normal gross aspect of gastric mucosa. Helicobacter heilmannii was confirmed in 100 percent of the samples by WS and PCR assay. Mild lymphocytic infiltrate in the lamina propria was observed in eight animals, mainly in the fundus region. Small lymphoid follicles were seen in three animals. No significant association between Helicobacter infection and histological findings was verified. These observations suggest that gastric Helicobacter spp. could be a commensal or a eventual pathogen to captive neotropical feline, and that procedures, way life, and stress level on the shelter apparently had no negative repercussion over the integrity of the stomach.

M cell in vitro model and its application in oral delivery of macromolecular drugs / 药学学报

The oral administration of bioactive macromolecular drugs such as proteins, peptides and nucleic acids represents unprecedented challenges from the drug delivery point of view. One key consideration is how to overcome the gastrointestinal tract absorption barrier. Recent studies suggest that microfold cell (M cell), a kind of specialized antigen-sampling epithelial cell which is characterized by a high endocytic rate and low degradation ability, may play an important role in macromolecule oral absorption. The development of an in vitro M cell coculture system and its modified models greatly advanced the study of M cells and the development of oral delivery system for macromolecular drugs. The special structure, function and formation characteristics, and biomarkers of M cell are summarized in this review. The applications of in vitro M cell models in developing oral delivery system ofbioactive macromolecular drugs are discussed.

Ill-defined Granulomas Demonstrated in Ulcers of the Terminal Ileum and Transverse Colon in a Patient with Typhoid Fever / 대한소화기내시경학회지

Typhoid fever, the most serious human salmonellosis, is a systemic infectious disease caused by Salmonella enterica serovar Typhi and is characterized by prolonged fever, bacteremia, and multiplication of the organism within mononuclear phagocytic cells of the liver, spleen, lymph nodes, and Peyer's patches. The characteristic lesion of typhoid fever is an ulceration of the small intestinal lymphoid tissue, particularly the Peyer's patches. The usual histological findings of typhoid ulcer are necrosis and histiocytic proliferation that phagocytizes erythrocytes and degenerated lymphocytes. A granuloma is an unusual histopathological presentation of a typhoid lesion. Even if granulomas have been reported in the bone marrow, liver, and spleen in cases of typhoid fever, granulomas in primary ulcers of the ileum and transverse colon have been reported very rarely. We experienced a case of typhoid fever in which ill-defined granulomas were seen in ulcers of the terminal ileum and transverse colon.