Colonic Patch Research Articles

Colonic black spots and patches in a 50‐year‐old woman

Colonic black spots and patches in a 50‐year‐old woman

Bifidobacterium longum Subsp. infantis Promotes IgA Level of Growing Mice in a Strain-Specific and Intestinal Niche-Dependent Manner.

Throughout infancy, IgA is crucial for maintaining gut mucosal immunity. This study aims to determine whether supplementing newborn mice with eight different strains of Bifidobacterium longum subsp. infantis might regulate their IgA levels. The strains were gavaged to BALB/C female (n = 8) and male (n = 8) dams at 1-3 weeks old. Eight strains of B. longum subsp. infantis had strain-specific effects in the regulation of intestinal mucosal barriers. B6MNI, I4MI, and I10TI can increase the colonic IgA level in females and males. I8TI can increase the colonic IgA level in males. B6MNI was also able to significantly increase the colonic sIgA level in females. B6MNI, I4MI, I8TI, and I10TI regulated colonic and Peyer's patch IgA synthesis genes but had no significant effect on IgA synthesis pathway genes in the jejunum and ileum. Moreover, the variety of sIgA-coated bacteria in male mice was changed by I4MI, I5TI, I8TI, and B6MNI. These strains also can decrease the relative abundance of Escherichia coli. These results indicate that B. longum subsp. infantis can promote IgA levels but show strain specificity. Different dietary habits with different strains of Bifidobacterium may have varying effects on IgA levels when supplemented in early infancy.

Colon patch esophagoplasty for esophageal strictures refractory to multi-modal treatment revisited.

Esophageal strictures due to caustic ingestion (CI) may require repeat esophageal dilations and dilation adjuvants, including local anti-fibrinogenic injection therapy, stent placement, and radial stricture incisions. Refractory strictures require surgical intervention. Pedicled colon patch esophagoplasty (CPE) may avoid the morbidity associated with total esophageal replacement, although reports of its use are limited. Indications and outcomes for CPE in patients undergoing repeat esophageal stricture dilations following caustic ingestion are described according to our local experience and literature reports. A retrospective review of indications for surgical management of esophageal strictures to tertiary pediatric surgical services between 2015 and 2020 focused on patients undergoing CPE. English-language literature (PubMed, Google Scholar, and Scopus) describing CPE was also reviewed. Eight (12%) out of 65 patients with esophageal strictures requiring 7 or more esophageal dilations with poor response underwent surgical stricture management over a 6year period, which included stricture resection and re-anastomosis in 2 patients, total esophageal replacement with colon graft in 2 patients, gastric pull-up in 1 patient, and CPE in 3 patients. The patients undergoing CPE were aged 3-8years and had 17 to more than 25 dilations following caustic ingestion over a 2-5year period. One patient had a 4cm stricture; the other 2 had strictures 7cm in length. A transverse colon patch based on the middle and left colic vessels was utilized in all three, with the vascular pedicle placed retrogastrically via the esophageal hiatus and the patch inlay esophagoplasty concluded via right thoracotomy. Post-operative contrast studies showed near-normal anatomy, and the patients could tolerate full oral diets. During a 9-36month follow-up period, only 2 patients required dilations of a proximal anastomotic stricture at 1 and 5months postoperatively. One patient required additional proximal stricturoplasty with advancement of the original graft across the stricture via a cervical surgical approach. Colon patch esophagoplasty to restore esophageal luminal continuity and allow a normal diet should be considered for refractory esophageal strictures. CPE had excellent functional outcomes in our 3 patients and should be considered in selected cases instead of total esophageal replacement.

Outcomes of seromuscular bladder augmentation compared with standard bladder augmentation in the treatment of children with neurogenic bladder.

BACKGROUNDIntestinal seromuscular bladder augmentation (SMBA) surgery has produced no mucosal-related complications, but its outcomes need to be studied.AIMTo evaluate the safety and effectiveness of SMBA in the treatment of children with neurogenic bladder.METHODSA retrospective analysis of the clinical data of children with SMBA was performed from March 2008 to February 2018, and the data were compared with those of children receiving standard cystoplasty (SC).RESULTSIn a cohort of 67 children who underwent bladder augmentation, the 46 children in the SC group had an average age of 10.6 years and a follow-up time of 36 mo, and the 21 children in the SMBA group had an average age of 7.6 years and a follow-up time of 29.7 mo. The preoperative and postoperative bladder volumes in the SMBA group were 151.7 mL and 200.4 mL, respectively, and those in the SC group were 173.9 mL and 387.0 mL, respectively. No significant difference in preoperative urinary dynamic parameters was found between the two groups, but the difference after operation was statistically significant. The main complications after SMBA were residual ureteral reflux and failed bladder augmentation, with incidences of 33.3% and 28.6%, respectively. In all 6 patients with failed augmentation in the SMBA group, ileum seromuscular patches were used for augmentation, and SC was chosen for reaugmentation. During reoperation, patch contracture and fibrosis were observed.CONCLUSIONThe improvement of urinary dynamic parameters in the SMBA group was significantly lower than that in the SC group. Children with SMBA had a higher probability of patch contracture and reaugmentation, which might be related to impaired blood supply and urine stimulation, and the sigmoid colon patch should be the priority.

Cecal Patches Generate Abundant IgG2b-Bearing B Cells That Are Reactive to Commensal Microbiota.

Gut-associated lymphoid tissue (GALT), such as Peyer's patches (PPs), are key inductive sites that generate IgA+ B cells, mainly through germinal center (GC) responses. The generation of IgA+ B cells is promoted by the presence of gut microbiota and dietary antigens. However, the function of GALT in the large intestine, such as cecal patches (CePs) and colonic patches (CoPs), and their regulatory mechanisms remain largely unknown. In this study, we demonstrate that the CePs possess more IgG2b+ B cells and have fewer IgA+ B cells than those in PPs from BALB/c mice with normal gut microbiota. Gene expression analysis of postswitched transcripts supported the differential expression of dominant antibody isotypes in B cells in GALT. Germ-free (GF) mice showed diminished GC B cells and had few IgA+ or IgG2b+ switched B cells in both the small and large intestinal GALT. In contrast, myeloid differentiation factor 88- (MyD88-) deficient mice exhibited decreased GC B cells and presented with reduced numbers of IgG2b+ B cells in CePs but not in PPs. Using ex vivo cell culture, we showed that CePs have a greater capacity to produce total and microbiota-reactive IgG2b, in addition to microbiota-reactive IgA, than the PPs. In line with the frequency of GC B cells and IgG2b+ B cells in CePs, there was a decrease in the levels of microbiota-reactive IgG2b and IgA in the serum of GF and MyD88-deficient mice. These data suggest that CePs have a different antibody production profile compared to PPs. Furthermore, the innate immune signals derived from gut microbiota are crucial for generating the IgG2b antibodies in CePs.

Berberine augments hypertrophy of colonic patches in mice with intraperitoneal bacterial infection

Colonic patches, the counterparts of Peyer’s patches in the small intestine, are dynamically regulated lymphoid tissues in the colon that have an important role in defensing against microbial infections. Berberine is an isoquinoline alkaloid extracted from medicinal herbs including Rhizoma coptidis and has long been used for the treatment of infectious gastroenteritis, but its impact on the colonic lymphoid tissues (such as colonic patches) is unknown. In this study, we aimed to investigate whether berberine had any influences on the colonic patches in mice with bacterial infection. The results showed that oral berberine administration in bacterial infected mice substantially enhanced the hypertrophy of colonic patches, which usually possessed the features of two large B-cell follicles with a separate T-cell area. Moreover, the colonic patches displayed follicular dendritic cell networks within the B-cell follicles, indicative of mature colonic patches containing germinal centers. Concomitant with enlarged colonic patches, the cultured colon of infected mice treated with berberine secreted significantly higher levels of interleukin-1β (IL-1β), IL-6, TNF-α, and CCL-2, while NLRP3 inhibitor MMC950 or knockout of NLRP3 gene abrogated berberine-induced hypertrophy of colonic patches, suggesting the involvement of the NLRP3 signaling pathway in this process. Functionally, oral administration of berberine ameliorated liver inflammation and improved formed feces in the colon. Altogether, these results indicated that berberine was able to augment the hypertrophy of colonic patches in mice with bacterial infection probably through enhancing local inflammatory responses in the colon.

What is the Best Choice for Esophageal Replacement in Children?

Esophageal replacement surgery is performed in children with either congenital long gap esophageal atresia or acquired esophageal damages such as caustic injury of the esophagus. although the left colon because of less variation in blood supply and suitable diameter in comparison with right colon is the better choice. A secured pedicled colon is mandatory for reducing the sever complications, such as leak and necrosis. Ileocolic conduit is an alternative method of colon interposition which has anti reflux effect and therefore with less complications related to gastroesophageal reflux. When we have a short segment esophageal stricture due to corrosive esophagitis or other causes of esophageal strictures which is refractory to repeated dilatations, it is advisable to perform colon patch esophagoplasty. Gastric transposition can produce a good way for gastrointestinal continuity with a perfect weight gain and oral feeding, therefor it can be a safe choice for esophageal replacement in children. Partial gastric pull-up is an alternative operation for esophageal replacement in children and infants with long gap esophageal atresia. Gastric conduit replacement is another alternative technique for esophageal replacement, in which a gastric tube is created in the abdomen and it is pulled to via thoracic cavity to the neck and is committed by cervical anastomosis. Antral patch esophagoplasty is used for benign and limited esophageal stricture due to gastroesophageal reflux. Usefulness of pedicled jejunum was under optimal results because of technical problems and high rate of necrosis and mortality for decades. Sternocleidomastoid myocutaneous esophagoplasty is a scarce method which is reported by some surgeons for limited cervical esophageal stricture repair. Free microvascular transfer of the reverse ileo-colon flap with ileocaecal valve valvuloplasty is used for reconstruction of a pharyngoesophageal defect, and Patch esophagoplasty by using of degradable bioscaffolds of extracellular matrix have shown good results in preclinical and clinical outcomes to prevent stenosis after endoscopic mucosectomy. We will explain the advantages and disadvantages of these different surgical methods in this review article.

Urethro vaginal injuries associated with pelvic fracture – A spectrum of clinical presentation and management

Blunt trauma to the paediatric pelvis is associated with urethral rupture, sometimes even without a bony fracture. While such rupture of the male urethra has received considerable mention, female urethral injury is both less common and has received less attention. We describe 4 cases of urethro vaginal injury associated with pelvic fracture, its varied presentations and the modalities employed in its management. A retrospective study was done to identify 4 patients who presented to our institution between 2007 and 2018. All 4 girls suffered a loss of a urethral segment ranging from the distal urethra (n=2) to complete urethral loss (n=2) and rupture of the bladder neck in one. All 4 girls also had associated vaginal injury resulting in varied clinical presentation including total urinary incontinence, urocolpos, vaginal voiding via an acquired hypospadias and urinary retention with late onset haematocolpos. All were managed initially with SPC and three of them underwent urethral substitution with Monti ileal tube in two and vestibular mucosal flap in one. The hypospadiac neo-meatus was continent and was left alone. The ruptured vagina was repaired by rectus muscle interposition, direct suturing, posterior vaginal U flap or colonic patch. An appendicular Mitrofanoff was added for safety in 2 girls. Follow up was done till June 2019 (range 1-12 years). All patients voided satisfactorily and were fully continent. Normal menstrual function was present in the 3 post pubertal children. A traumatic force capable of causing urethral injury may often result in associated vaginal injury and should not be overlooked. Thus urinary retention is not the only presentation of urethral injury in girls. Fistulation to the vagina may result in continent or incontinent vaginal voiding if the vagina has not been transected and urocolpos/haematocolpos in those with vaginal transection. Various modalities maybe employed to maintain continuity of the urethra and vagina including use of bowel and local flaps.

Lack of the pH-sensing Receptor TDAG8 [GPR65] in Macrophages Plays a Detrimental Role in Murine Models of Inflammatory Bowel Disease.

Tissue inflammation in inflammatory bowel diseases [IBD] is associated with local acidification. Genetic variants in the pH-sensing G protein-coupled receptor 65, also known as T cell death-associated gene 8 [TDAG8], have been implicated in IBD and other autoimmune diseases. Since the role of TDAG8 in intestinal inflammation remains unclear, we investigated the function of TDAG8 using murine colitis models. The effects of TDAG8 deficiency were assessed in dextran sodium sulphate [DSS], IL-10-/-, and T cell transfer colitis murine models. RNA sequencing of acidosis-activated TDAG8-/- and wild-type [WT] peritoneal macrophages [MΦs] was performed. mRNA expression of IFN-γ, TNF, IL-6, and iNOS in TDAG8-/- mice increased significantly in colonic lymphoid patches and in colonic tissue in acute and chronic DSS colitis, respectively. In transfer colitis, there was a trend towards increased IFN-γ, iNOS, and IL-6 expression in mice receiving TDAG8-/- T cells. However, absence of TDAG8 did not lead to changes in clinical scores in the models tested. Increased numbers of infiltrating MΦs and neutrophils, but not CD3+ T cells, were observed in DSS-treated TDAG8-/- mice. No differences in infiltrating CD3+ T cells were observed between mice receiving TDAG8-/- or WT naïve T cells in transfer colitis. RNA sequencing showed that acidosis activation of TDAG8 in MΦs modulated the expression of immune response genes. TDAG8 deficiency triggers colonic MΦ and neutrophil infiltration, and expression of pro-inflammatory mediators in DSS colitis models. In transfer colitis, mice receiving TDAG8-/- T cells presented a significantly higher spleen weight and a tendency towards increased expression of pro-inflammatory markers of monocyte/MΦ activity.

Assessment of Patients with Hirschsprung Disease and the Use of Laparoscopy.

Objectives:This study aims to evaluate patients who were diagnosed and treated due to Hirschsprung disease (HD) in our clinic.Methods:We retrospectively evaluated the demographic and clinical findings of the patients with HD, who were operated in our clinic between January 2010 and December 2015.Results:During study period, 28 patients (19 male 9 female) were found to be operated due to HD in our clinic. Mean age was 16.8 months (1-168). “Transanal Endorectal Pull–through (TERPT)” was performed to 20 of them, Duhamell procedure to five and Soave procedure to three of them. TERPT was applied as laparoscopy assisted in four of them and biopsies were taken laparoscopically preoperatively from one of the patients from each group. Soave procedure was performed in three patients; one had anal stenosis and history of recurrent enterocolitis after TERPT procedure and pathologic analysis revealed neuronal intestinal dysplasia and the other one had total colonic HD and performed Soave procedure with colonic patch. Seven (25%) patients had enterocolitis. Frequencies of enterocolitis were three in two patients, two in two patients and one in three patients. Broad spectrum anibiotics and rectal washouts were supplied to these patients. Five of the seven patients with enterocolitis were operated with TERPT; two patients were operated with Duhamell procedure. Only one of them had total colonic HD. Three patients had total colonic HD diagnosis. Two of them were operated with Duhamell-Martin procedure and one was with Soave procedure with colonic patch according to Kimura technique. Anal stenosis developed in two patients after TERPT and treated with dilatations. Soiling rate was 3% (1/28) and this single patient was treated with laxatives and toilet training. Mean duration of hospitalization was 8.75 (2-14) days. Mean length of the removed intestinal segment was 23.6 (5-38) cm. Mean follow-up was for 35.5 (2-56) months. Neither of the patients was followed in the intensive care unit postoperatively nor died.Conclusion:TERPT procedure win priority in HD, but other procedures keep importance. Recently, laparoscopy-assisted TERPT is preferred in our clinic in HD therapy due to easy biopsy, full exposure to the transitional zone, the advantage of meso preparation of colon and prevention of strained anastomosis.

Гиперваскуляризация эзофагоколотрансплантата: обзор литературы и собственный опыт

Пластика пищевода сегментом толстой кишки при его послеожоговой стриктуре является сложной операцией. Основная проблема – жизнеспособность шейной части толстокишечного графта. Изучение сосудистой анатомии ободочной кишки позволяет выбрать ее наиболее эффективно кровоснабжаемую часть в качестве эзофагоколотрансплантата. Для гиперваскуляризации графта при его недостаточном кровоснабжении предложено формирование прямых сосудистых анастомозов его шейной части с сосудами шеи или внутренними грудными сосудами. Разработана технология лигирования его сосудов, при этом интенсивно развивается коллатеральный кровоток. Приведен обзор источников литературы по мезентерикографии перед эзофагоколопластикой и гиперваскуляризации графта из ободочной кишки. Приведен собственный опыт авторов.

Vagal innervation is required for the formation of tertiary lymphoid tissue in colitis.

Tertiary lymphoid tissue (TLT) is lymphoid tissue that forms in adult life as a result of chronic inflammation in a tissue or organ. TLT has been shown to form in a variety of chronic inflammatory diseases, though it is not clear if and how TLT develops in the inflamed colon during inflammatory bowel disease. Here, we show that TLT develops as newly formed lymphoid tissue in the colon following dextran sulphate sodium induced colitis in C57BL/6 mice, where it can be distinguished from the preexisting colonic patches and solitary intestinal lymphoid tissue. TLT in the inflamed colon develops following the expression of lymphoid tissue-inducing chemokines and adhesion molecules, such as CXCL13 and VCAM-1, respectively, which are produced by stromal organizer cells. Surprisingly, this process of TLT formation was independent of the lymphotoxin signaling pathway, but rather under neuronal control, as we demonstrate that selective surgical ablation of vagus nerve innervation inhibits CXCL13 expression and abrogates TLT formation without affecting colitis. Sympathetic neuron denervation does not affect TLT formation. Hence, we reveal that inflammation in the colon induces the formation of TLT, which is controlled by innervation through the vagus nerve.

Perils of Total Colonic Aganglionosis Presenting in Neonatal Age

Background: The purpose of this study is to review the cases of total colonic aganglionosis seen in the span of ten years at a pediatric surgery unit of a tertiary care public hospital in New Delhi.Methods: Medical records of eleven patients with total colonic aganglionosis were retrieved.Results: Ten out of the twelve patients were males; seven were of the Muslim community. Average recorded birth weight was 2.2 kg. Ten patients presented with features of intestinal obstruction, while two presented with perforation peritonitis. Among the cases of obstruction, Hirschsprung's disease was suspected in eight cases (one was associated with Shah-Waardenburg syndrome), one case each was preoperatively diagnosed as ileal atresia and meconium ileus. Abdominal X-rays at presentation of all the neonates except in one with Shah-Waardenburg syndrome showed multiple air fluid levels. Contrast enema was done in five patients. It showed micro-colon in two patients, and typical question mark sign, dilated small bowel with transition zone in hepatic flexure and normal caliber colon in one each. All the patients underwent exploratory laparotomy. Intra-operatively, the transition zone was seen at distal ileum in ten cases and at hepatic flexure and transverse colon in one each. Biopsies of all the twelve patients eventually showed absence of ganglion cells in entire colon. Ileostomy was done in nine cases, colostomy in two and primary Kimura's procedure in one (this patient was discharged and lost to follow up). Left colonic patch with Swenson’s pull through with ileostomy was done for one patient on colostomy. His stoma was closed; he was eventually discharged and lost to follow up. In the other patient with colostomy, the stoma was closed and an ileostomy was created. Of all the patients on ileostomy, three expired in the immediate postoperative period. Four were lost to follow up. Two underwent Kimura's procedure; and expired few months later. One patient on ileostomy is awaiting further treatment.Conclusion: Management of total colonic aganglionosis is still in its infancy in the developing world. There is a lot of scope for improvement in the management. There is a need to have a stringent follow up of patients in order to know the long-term outcomes of the disease.

Perils of total colonic aganglionosis presenting in neonatal age.

The purpose of this study is to review the cases of total colonic aganglionosis seen in the span of ten years at a pediatric surgery unit of a tertiary care public hospital in New Delhi. Medical records of twelve patients with total colonic aganglionosis were retrieved. Ten out of the twelve patients were males; seven were of the Muslim community. Average recorded birth weight was 2.2 kg. Ten patients presented with features of intestinal obstruction, while two presented with perforation peritonitis. Among the cases of obstruction, Hirschsprung's disease was suspected in eight cases (one was associated with Shah-Waardenburg syndrome), one case each was preoperatively diagnosed as ileal atresia and meconium ileus. Abdominal X-rays at presentation of all the neonates except in one with Shah-Waardenburg syndrome showed multiple air fluid levels. Contrast enema was done in five patients. It showed micro-colon in two patients, and typical question mark sign, dilated small bowel with transition zone in hepatic flexure and normal caliber colon in one each. All the patients underwent exploratory laparotomy. Intra-operatively, the transition zone was seen at distal ileum in ten cases and at hepatic flexure and transverse colon in one each. Biopsies of all the twelve patients eventually showed absence of ganglion cells in entire colon. Ileostomy was done in nine cases, colostomy in two and primary Kimura's procedure in one (this patient was discharged and lost to follow up). Left colonic patch with Swenson's pull through with ileostomy was done for one patient on colostomy. His stoma was closed; he was eventually discharged and lost to follow up. In the other patient with colostomy, the stoma was closed and an ileostomy was created. Of all the patients on ileostomy, three expired in the immediate postoperative period. Four were lost to follow up. Two underwent Kimura's procedure; and expired few months later. One patient on ileostomy is awaiting further treatment. The outcomes for total colonic aganglionosis in those presenting in neonatal age tend to be unsatisfactory in the developing countries.

Colonic patch and colonic SILT development are independent and differentially regulated events.

Intestinal lymphoid tissues have to simultaneously ensure protection against pathogens and tolerance towards commensals. Despite such vital functions, their development in the colon is poorly understood. Here, we show that the two distinct lymphoid tissues of the colon–colonic patches and colonic SILTs–can easily be distinguished based on anatomical location, developmental timeframe and cellular organization. Furthermore, whereas colonic patch development depended on CXCL13-mediated LTi cell clustering followed by LTα-mediated consolidation, early LTi clustering at SILT anlagen did not require CXCL13, CCR6 or CXCR3. Subsequent dendritic cell recruitment to and gp38+VCAM-1+ lymphoid stromal cell differentiation within SILTs required LTα; B cell recruitment and follicular dendritic cell differentiation depended on MyD88-mediated signalling, but not the microflora. In conclusion, our data demonstrate that different mechanisms, mediated mainly by programmed stimuli, induce the formation of distinct colonic lymphoid tissues, therefore suggesting that these tissues may have different functions.

Mo1747 Intestinal IL-10-Producing B Cells Induced by Commensal Bacteria May Contribute to Maintenance of Mucosal Homeostasis

Background We demonstrated that wild-type B cells produce Interleukin (IL)-10 following Toll-like receptor (TLR) stimulation and inhibit the production of pro-inflammatory cytokines by T cells and macrophages (MΦ) In Vitro (DDW 2011). However, the In Vivo development and roles of intestinal IL-10-producing B cells in response to gut bacteria are poorly understood. In addition, commensal bacteria have been implicated in the pathogenesis of the inflammatory bowel diseases (IBD) and the regulation of mucosal homeostasis. We hypothesize that commensal microbiota are essential for IL-10 secretion by intestinal B cells.Methods Germ-free (GF) IL-10EGFP reporter (Vert-X) mice were transferred to specific pathogen-free (SPF) conditions and colonized with SPF feces. Mice were studied on days 0, 3 and 7 postcolonization, and populations of IL-10-producing GFP+ cells were analyzed in the colon lamina propria (LP), mesenteric lymph nodes (MLN) and spleen using flow cytometry (FACS) and immunohistochemistry (IHC). To induce chronic colitis, SPF Vert-X mice were cyclically administered 2% dextran sulfate sodium (DSS) solution for 7 day periods. Colonic LP IL10-producing GFP+ cells were identified by FACS.Results 1.5 ± 0.7% of total colonic LP cells in GFVert-Xmicewere GFP+, with the number expanding following bacteria colonization and with chronic inflammation (Table), while those in the spleen and MLN did not significantly change. Of note, the number of GFP+ B cells in the colonic LP greatly expanded following bacterial colonization (1.7-fold from baseline on day 3, and 3.3-fold on day 7, vs. 11.2fold in SPF mice). IHC demonstrated that GFP+ B cells were concentrated in the colonic patches rather than the LP. The ratio of GFP+ colonic Foxp3+CD4+ cells /total GFP+ cells did not change significantly after bacterial colonization (32.6 ± 9.6 % on GF, 32.4 ± 18.9 % on day 3, and 36.8 ± 8.6 % on day 7, vs. 19.7 ± 1.7 % in SPF mice), nor did the numbers of GFP+ MΦ and dendritic cells change. Following chronic DSS administration, the percentage of intestinal GFP+ cells increased (Table). Although CD4+ T cells were predominant among enteric IL-10-producing cells in chronic colitis, the ratio of B cells to total intestinal GFP+ cell increased during chronic inflammation (Table). Summary Commensal bacteria and chronic intestinal inflammation stimulate IL-10 secretion by intestinal B cells, whichmay contribute tomaintainingmucosal homeostasis and help regulate intestinal inflammation. IL-10 producing GFP+ cells in the colonic lymphocytes following bacterial colonization and chronic mucosal inflammation

CD4+FoxP3+ Regulatory T Cells from Gαi2−/− Mice Are Functionally Active In Vitro, but Do Not Prevent Colitis

BackgroundMice deficient in the inhibitory G protein subunit Gαi2 spontaneously develop a T helper 1 dominated colitis. We examined whether a defect in CD4+FoxP3+ regulatory T cells (Treg) underpins the pathogenesis of colitis in the Gαi2−/− (Gαi2-deficient) colitis model.Methodology/Principal FindingsUsing flow cytometry, we found that thymus and colonic lamina propria, but not spleen and mesenteric lymph nodes, of colitic Gαi2−/− mice contained increased frequencies of Treg, whereas FoxP3 expression intensity was similar in Gαi2−/− compared to Gαi2+/− or Gαi2+/+ wild type (WT) mice. The frequency of CD4+FoxP3+ T cells expressing CD103 was significantly increased in Gαi2−/− compared to WT mice. Treg in colons from WT mice clustered in the T cell areas of colonic lymphoid patches (CLP), with relatively few Treg in the lamina propria, as demonstrated by immunohistochemistry. In Gαi2−/− mice, CLP were not observed but lamina propria Treg were increased in number and frequency within the CD4+ infiltrate, compared to WT mice. Using an in vitro co-culture system and flow cytometric analysis of cell division we could demonstrate that the in vitro suppressive function of WT and Gαi2−/− CD4+FoxP3+ regulatory T cells (WT-Treg and KO-Treg) was indistinguishable, but that T effector cells (CD4+25− T cells) from Gαi2−/− mice were less readily suppressed than WT effectors (WT-Teff) by Treg from either source. However, neither WT nor Gαi2−/− Treg was able to suppress colitis induced by adoptive transfer of Gαi2−/− effector T cells (KO-Teff) to RAG2−/− recipients. The enhanced inflammatory activity of Gαi2−/− effectors was accompanied by increased expression of an effector/memory T cell phenotype and increased cytokine secretion, especially IL-4, IL-6 and IFN-γ.ConclusionsThere is an increased frequency of Gαi2−/− Treg in the colon, and they demonstrate no endogenous functional defect. However, Gαi2−/− T effector cells are dramatically less susceptible to suppression in vitro, and in vivo, despite increased effective numbers of Treg, they cannot prevent disease.

IL-22 bridges the lymphotoxin pathway with the maintenance of colonic lymphoid structures during infection with Citrobacter rodentium

Colonic patches (CLPs) and isolated lymphoid follicles (ILFs) are two main lymphoid structures in the colon. Lymphoid tissue-inducer cells (LTi cells) are indispensable for the development of ILFs. LTi cells also produce interleukin 17 (IL-17) and IL-22, signature cytokines secreted by IL-17-producing helper T cells. Here we report that IL-22 acted downstream of the lymphotoxin pathway and regulated the organization and maintenance of mature CLPs and ILFs in the colon during infection with Citrobacter rodentium. Lymphotoxin (LTα(1)β(2)) regulated the production of IL-22 during infection with C. rodentium, but the lymphotoxin-like protein LIGHT did not. IL-22 signaling was sufficient to restore the organization of CLPs and ILFs and host defense against infection with C. rodentium in mice lacking lymphotoxin signals, which suggests that IL-22 connects the lymphotoxin pathway to mucosal epithelial defense mechanisms.

Dendritic cells patrol epithelium and the lumen of the crypts associated with the organized lymphoid tissue of the colon. (161.1)

Abstract Antigen capture and presentation by the gut dendritic cells (DCs) is a complicated process that often involves a direct sampling of the antigens from the lumen. Peyer’s patches (PP) and colonic patches (CP) contain two distinct population of DCs that are thought to participate in the antigen uptake and transport of antigens from the lumen. One group of the DCs sample the lumen by extending the transepithelial dendrites from the lamina propria. The other group of DCs is localized in the intraepithelial compartment itself. In our study we have shown, by intravital imaging of the colon, that the previously reported population of intraepithelial DCs belongs to the fraction of highly motile CD11c+ cells that circulate between crypts and the T-cell and B-cell zones of the CP. We observed that these CD11c+ cells come from the T-cell zone and make a brief contact with the lumen before retreating. Upon examination of the expression profiles of different chemokines we found that CCL20 is expressed on the apical portion of the colonic patch-associated epithelial cells. Administration of anti-CCL20 antibodies blocked homing of CD11c+ cells to the intraepithelial compartment. Motile CD11c+ cells were also able to uptake fluorescent particles and Salmonella bacteria from the lumen and rapidly transport them to the T- and B-cell zones. Thus intraepithelial DCs might play an important role in antigen uptake and trafficking in the gut lymphoid compartments.

Routine surveillance cystoscopy for patients with augmentation and substitution cystoplasty for benign urological conditions: is it necessary?

To evaluate screening cystoscopy as the long-term follow up in patients with an enterocystoplasty for > or =10 years. We performed a prospective analysis of 92 consecutive patients who attended our endoscopy suite for regular check cystoscopy as per standard follow-up. This is performed for all patients with cystoplasty performed at our institute after 10 years. The data were recorded on patient demographics, original diagnosis and type of cystoplasty. In all, 53 of these patients consented to undergo bladder biopsies at the same time. The median (range) follow-up was 15 (10-33) years. No cancer was identified with either surveillance cystoscopy or on routine biopsies. Chronic inflammation was identified in 25 biopsies (27%). Villous atrophy was present in 12 (55%) ileal patch and three (12.5%) colonic patch biopsies. During this study, the first and only case of malignancy in a cystoplasty at our institution was diagnosed in a symptomatic patient. She had intermittent haematuria and recurrent urinary tract infections (UTIs). She previously had a normal surveillance cystoscopy. We feel that it is not necessary to perform yearly check cystoscopies in patients with augmented bladders at least in the first 15 years, as cancer has not yet been detected with surveillance cystoscopy in this patient group. However, if the patient develops haematuria or other worrisome symptoms including suprapubic pain and recurrent unexplained UTIs a full evaluation, including cystoscopy and computerized tomography should be undertaken.