The interaction of mucosal lymphocytes and intestinal epithelial cells is thought to be important in

We have demonstrated that intestinal epithelial cells produce interleukin 7 (IL-7), and IL-7 serves as a potent regulatory factor for proliferation of intestinal mucosal lymphocytes expressing functional IL-7 receptor. To clarify the mechanism by which locally produced IL-7 regulates the mucosal lymphocytes, we investigated IL-7 transgenic mice. Here we report that transgenic mice expressing murine IL-7 cDNA driver by the SRα promoter developed chronic colitis in concert with the expression of SRα/IL-7 transgene in the colonic mucosa. IL-7 transgenic but not littermate mice developed chronic colitis at 4–12 wk of age, with histopathological similarity to ulcerative colitis in humans. Southern blot hybridization and competitive PCR demonstrated that the expression of IL-7 messenger RNA was increased in the colonic mucosal lymphocytes but not in the colonic epithelial cells. IL-7 protein accumulation was decreased in the goblet cell–depleted colonic epithelium in the transgenic mice. Immunohistochemical and cytokine production analysis showed that lymphoid infiltrates in the lamina propria were dominated by T helper cell type 1 CD4+ T cells. Flow cytometric analysis demonstrated that CD4+ intraepithelial T cells were increased, but T cell receptor γ/δ T cells and CD8α/α cells were not increased in the area of chronic inflammation. Increased IL-7 receptor expression in mucosal lymphocytes was demonstrated in the transgenic mice. These findings suggest that chronic inflammation in the colonic mucosa may be mediated by dysregulation of colonic epithelial cell–derived IL-7, and this murine model of chronic colitis may contribute to the understanding of the pathogenesis of human inflammatory bowel disease.

BackgroundAlthough recent guidelines for endoscopic submucosal dissection (ESD) as treatment for early gastric cancer (EGC) recommend noninterruption of low-dose aspirin (LDA) perioperatively, this strategy is controversial. It was our practice to interrupt LDA therapy 5–7 days before to ESD until December 2010, when we instituted the new guidelines and performed ESD without interrupting LDA therapy. Our purpose in this study was to confirm the validity of noninterrupted use of LDA in patients undergoing ESD for EGC.MethodsWe studied 78 consecutive patients with 94 EGCs who were routinely taking LDA and were treated by ESD at Hiroshima University Hospital between April 2005 and June 2012. The patients were of two groups: those in whom LDA was interrupted perioperatively (53 patients with 66 EGCs) and those in whom LDA was continued perioperatively (25 patients with 28 EGCs).ResultsThe complete resection rate was 92.4 % (61/66) in the LDA-interrupted group and 100 % (28/28) in the LDA-continued group. Incidences of poor bleeding control during the procedure and bleeding after procedure were 10.6 % (7/66) and 4.8 % (3/66), respectively, in the LDA-interrupted group and 7.1 % (2/28) and 3.6 % (1/28) in the LDA-continued group. Two patients in the interrupted-LDA group suffered cerebrovascular infarction before ESD, and 2 patients in this group suffered acute myocardial infarction after ESD.ConclusionsOur data suggest that continued use of LDA does not increase the risk of bleeding during or after ESD for EGC and does decrease the risk of ischemic events.

The present data indicated that the activation of Valpha14 NKT cells by OCH plays a pivotal role in mediating intestinal inflammation via altered mucosal T-helper type 1/type 2 responses. Therapeutic strategies that are designed to activate specifically Valpha14 NKT cells may prove to be beneficial in treating intestinal inflammation.

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Background and study aims: Colitis-associated cancer/dysplasia (CC/D) can affect the life expectancy of patients with ulcerative colitis (UC). Although the utility of magnifying chromocolonoscopy has been shown, the use of optical magnification with narrow band imaging (NBI) for distinguishing CC/D from non-neoplastic lesions in patients with UC has not been reported. We evaluated whether endoscopic findings are distinguishing and thus assessed the clinical usefulness of NBI magnification for differentiating UC-associated lesions. Patients and methods: The study involved 27 patients diagnosed and treated at Hiroshima University Hospital between September 2005 and March 2015: a neoplasia group (16 lesions) and a non-neoplasia group (17 lesions). The neoplasias comprised 9 dysplastic lesions, 5 intramucosal carcinomas, and 2 submucosal carcinomas, and 17 non-neoplastic lesions. Targeted biopsy samples of suspicious lesions detected by conventional colonoscopy were classified pathologically as neoplastic or non-neoplastic, and NBI magnifying colonoscopy findings (i. e., the surface [unclear/regular/irregular/amorphous] and vascular [same as the background mucosa/regular/irregular/avascular] patterns) of the 2 lesion types were compared. Results: Irregular/amorphous surface patterns were significantly more common in neoplastic lesions than in non-neoplastic lesions (81 % [13/16] vs. 18 % [3/17], respectively, P < 0.001). Irregular/avascular vessel pattern tended to be more common in neoplastic lesions (75 % [12/16] vs. 41 % [7/17], respectively). The surface pattern correctly predicted 82 % of neoplastic lesions, and the vessel pattern correctly predicted 67 % of non-neoplastic lesions. The 2 endoscopic findings together correctly predicted 91 % of neoplastic lesions. Conclusion: Surface pattern, determined by magnifying colonoscopy with NBI, is useful for differenting between UC-associated neoplastic and non-neoplastic lesions.

These results suggest that molecular mechanisms of genomic instability are not necessarily independent and may not be fully defined by either the MSI or CIN pathways in sporadic gastric cancers.

Cytotoxic T-lymphocyte-antigen 4 (CTLA-4) is an essential negative regulator expressed on regulatory T cells (Tregs) and activated T cells. Germline heterozygous mutations in CTLA4 lead to haploinsufficiency of CTLA-4, resulting in the development of an autosomal dominant immune dysregulation syndrome with incomplete penetrance. We report here a Japanese patient with this disorder who has a novel heterozygous single nucleotide insertion, 76_77insT (p. L28SfsX40), in the CTLA4 gene. Peripheral blood mononuclear cells from the patient showed decreased frequency of CTLA-4(high) cells in CD4(+)FOXP3(+) cells following CD3/CD28 stimulation. The patient experienced hypogammaglobulinemia, recurrent pneumonia, esophageal candidiasis, cytomegalovirus-positive chronic gastritis, chronic and severe diarrhea, and type 1 diabetes mellitus. Moreover, the patient developed multifocal gastric cancer, histologically poorly and well-differentiated adenocarcinomas, associated with chronic atrophic gastritis and intestinal metaplasia. Previously, 23 symptomatic cases with heterozygous CTLA4 mutations have been reported. Including the case presented here, 3 of the 24 cases (12.5%) developed gastric cancer. Notably, 2 of 3 patients presented similarly multifocal adenocarcinomas associated with atrophic gastritis and intestinal metaplasia. Predisposition to gastric cancer has been also reported in CVID patients. These clinical observations suggest that gastric cancer is a disease commonly associated with autosomal dominant immune dysregulation syndrome due to CTLA4 mutation.