IL-17 is a protection effector against the adherent-invasive Escherichia coli in murine colitis.

Inflammatory bowel disease (IBD) is caused by aberrant immune responses to the gut microbiota. Among the gut microbiota, adherent-invasive Escherichia Coli (AIEC) is thought to be the pathogen through invading the intestinal epithelial cells and causing inflammation. IL-17 secretion increase, induced by enhanced bacterial adhesion to the intestine epithelium, could on one hand protect the mucosa, but on the other hand, over amount of IL-17 initializes inflammation reactions that in turn damages the mucosa. The relationship between IL-17 and AIEC is still unclear. In this study, we tried to elucidate the function of IL-17 in AIEC-mediated colitis. Wild type (WT) and IL-17 knockout (IL-17 KO) mice were inoculated with AIEC strain E. coli LF82 and treated with dextran sodium sulphate (DSS). Histological examination of the colon was performed. Mucosa damage was assessed and scored. IL-22 and IL-17 in colon tissues were detected by ELISA, qPCR and immunohistochemistry methods. Transient AIEC colonization in IL-17 KO mice resulted in increased intestinal epithelial damage, systemic bacterial burden and mortality compared with WT controls. Moreover, IL-17 is required for the induction of IL-22 in the experimental animal models during AIEC strain E. coli LF82 colonization. These results indicate IL-17 plays a protective role in AIEC strain E. coli LF82 induced colitis by promoting IL-22 secretion.

POU2F2-oriented network promotes human gastric cancer metastasis.

BACKGROUND AND AIMS: Aberrant upregulation of POU2F2 expression has been discovered in metastatic gastric cancer (GC). However, the mechanisms underlying the aberrant upregulation and the potential functions of POU2F2 remain uncertain. DESIGN: The role and mechanism of POU2F2 in GC metastasis were investigated in gastric epithelial cells, GC cell lines and an experimental metastasis animal model by gain of function and loss of function. Upstream and downstream targets of POU2F2 were selected by bioinformatics and identified by luciferase reporter assay, electrophoretic mobility shift assay and chromatin immunoprecipitation PCR. The influence of miR-218 on its putative target genes (POU2F2, ROBO1 and IKK-ß) and GC metastasis was further explored via in vitro and in vivo approaches. RESULTS: Increased POU2F2 expression was detected in metastatic GC cell lines and patient samples. POU2F2 was induced by the activation of nuclear factor (NF)-κB and, in turn, regulated ROBO1 transcription, thus functionally contributing to GC metastasis. Finally, miR-218 was found to suppress GC metastasis by simultaneously mediating multiple molecules in the POU2F2-oriented network. CONCLUSIONS: This study demonstrated that NF-κB and the SLIT2/ROBO1 interaction network with POU2F2 as the central part may exert critical effects on tumour metastasis. Blocking the activation of the POU2F2-oriented metastasis network using miR-218 precursors exemplified a promising approach that sheds light on new strategies for GC treatment.

Interleukin-17 plays a critical role in the acute rejection of intestinal transplantation.

AIM: To investigate the role of interleukin (IL)-17 in small bowel allograft rejection. METHODS: We detected the expression of helper T cell 17 (Th17) cells in biopsy specimens from 3 cases of living small bowel transplantation in our department through immunofluorescence stain. We then established a rat heterotopic small bowel transplantation model. The rats were sacrificed on the 1(st), 2(nd), 3(rd), 5(th), and 7(th) d after small bowel transplantation. The degrees of transplantation rejection in rat intestine graft were examined through hematoxylin eosin (HE) stain, and the expression of Th17 cells in rat intestine graft were detected through immunofluorescence stain. In addition, the recipient rats undergoing intestinal transplantation were administrated with mouse-anti-rat IL-17 monoclonal antibody (mAb), and the survival of rats was analyzed. The recipient rats which received mouse-anti-rat IL-17 mAb treatment were sacrificed on the 1(st), 2(nd), 3(rd), 5(th), and 7(th) d after small bowel transplantation. The degrees of transplantation rejection and the expression of Th17 cells in rat intestine graft were detected through HE and immunofluorescence stain. The expression of IL-17, IL-1ß, tumor necroses factor receptor-α (TNF-α), IL-6, and IL-8 in the intestine graft or serum were also detected. RESULTS: The expressions of Th17 cells ran parallel with the degree of acute rejection in human intestine grafts. The intestine graft rejection of rats was aggravated with prolonged duration after intestinal transplantation, and the expressions of Th17 cells were also correlated with the degree of acute rejection in rat intestine grafts. Administration of mouse-anti-rat IL-17 mAb prolonged the survival of rats after small bowel transplantation (P < 0.001). Furthermore, we found that the administration of mouse-anti-rat IL-17 mAb significantly decreased the intensity of CD4+IL-17+ Th17 cells in intestine grafts on the 2(nd), 3(rd), 5(th), and the 7(th) d (97.22 ± 4.05 vs 12.45 ± 2.02 on the 7(th) d, P < 0.0001), and suppressed the severity of acute rejection. The expression of IL-17 in the intestine graft declined after mouse-anti-rat IL-17 mAb administration on the 2(nd), 3(rd), 5(th), and the 7(th) d (0.88 ± 0.03 vs 0.35 ± 0.02 on the 7(th) d, P < 0.0001). We also detected the IL-17 serum level and found that the IL-17 level reduced from the 1(st) d to the 7(th) d (6.52 ± 0.18 ng/mL vs 2.04 ± 0.15 ng/mL on the 7(th) d, P < 0.0001). No significant difference in the level of IL-17 mRNA in the intestine graft was identified between the two groups. The levels of IL-1ß, TNF-α, IL-6, and IL-8 mRNA in the intestine graft after the administration of mouse-anti-rat IL-17 mAb were also tested. We found that on the 3(rd), 5(th), and 7(th) d after intestinal transplantation, administration of mouse-anti-rat IL-17 mAb significantly inhibited the levels of IL-1ß (12.11 ± 1.16 vs 1.27 ± 0.15 on the 7(th) d, P < 0.001), TNF-α (27.37 ± 2.60 vs 1.06 ± 0.26 on the 7(th) d, P < 0.001), IL-6 (21.43 ± 1.79 vs 1.90 ± 0.32 on the 7(th) d, P < 0.001), and IL-8 (20.44 ± 1.44 vs 1.34 ± 0.20 on the 7(th) d, P < 0.001) mRNA in the intestine graft. CONCLUSION: IL-17 may act as a promising and potent target for inhibiting acute rejection after small bowel transplantation.

Generation of rat monoclonal antibodies against human RANTES.

RANTES (or regulated upon activation, normal T cell expressed and secreted) belongs to the rapidly growing chemokine family. It is mainly produced by T cells, epithelial cells, monocytes, fibroblasts, and mesanglial cells. Increased RANTES expression has been associated with a wide range of inflammatory disorders and pathologies. Mouse RANTES is the homolog molecule of human RANTES. The two have considerable homology in both sequence and structure. Using hRANTES as immunogen and the technique of rat B lymphocyte hybridoma, we raised two hybridoma cell lines secreting monoclonal antibodies (MAbs) to hRANTES, designated no. 1 and no. 2. Both MAbs can bind the hRANTES in FCM, Western blot analysis, and immunocytochemistry. No. 1 also worked well in immunohistochemistry of rat transplanted intestine, which may recognize the same epitope on human RANTES and rat RANTES. Thus, successful production of rat anti-human RANTES MAbs may provide a useful tool in further exploration of the biological function and pathological significance of RANTES and may provide a new method to judge early rejection after small bowel transplantation.

Diagnosis and treatment of acute rejection in the first case of human living-related small bowel transplantation with a long-term survival in China.

AIM: To report the comprehensive diagnosis and treatment of acute rejection in the first case of living-related small bowel transplantation with a long-term survival in China. METHODS: A 18-year-old boy with short gut syndrome underwent living-related small bowel transplantation, with the graft taken from his father (44-year old). A segment of 150-cm distal small bowel was resected from the donor. The ileo-colic artery and vein from the donor were anastomosed to the infrarenal aorta and vena cava of the recipient respectively. The intestinal continuity was restored with an end-to-end anastomosis between the recipient jejunum and donor ileum, and the distal end was fistulized. FK506, MMF and prednisone were initially used for post-transplant immunosuppression. Endoscopic observation and mucosal biopsies of the graft were carried out through the terminal ileum enterostomy; serum was collected to detect the levels of IL-2R, IL-4, IL-6 and IL-8. The change of the graft secretion and absorption was observed. RESULTS: Acute rejection was diagnosed promptly and cured. The patient was in good health, 5 years after living-related small bowel transplantation. CONCLUSION: The correct diagnosis and treatment of acute rejection are the key to the long-term survival after living-related small bowel transplantation.