Publications by authors named "Bai-Sui Feng"

30 Publications

  • Page 1 of 1

Modulating oxidative stress counteracts specific antigen-induced regulatory T cell apoptosis in mice.

Eur J Immunol 2021 Apr 3. Epub 2021 Apr 3.

Guangdong Provincial Key Laboratory of Regional Immunity and Diseases, Shenzhen, China.

Regulatory T cells (Treg) are known to have a central role in orchestrating immune responses, but less is known about the destiny of regulatory T cells after being activated by specific antigens (Ags). This study aimed to investigate the role of superoxide dismutase, an active molecule in the regulation of oxidative stress in the body, in the prevention of Treg apoptosis induced by specific Ags. Ag-specific Tregs were isolated from the DO11.10 mouse intestine. A food allergy mouse model was developed with ovalbumin as the specific Ag and here, we observed that exposure to specific Ag induced Treg apoptosis through converting the precursor of TGF-β to its mature form inside the Tregs. Oxidative stress was induced in Tregs upon exposure to specific Ags, in which Smad3 bound the latency-associated peptide to induce its degradation, converting the TGF-β precursor to its mature form, TGF-β. Suppressing oxidative stress in Tregs alleviated the specific Ag-induced Treg apoptosis in in vitro experiments and suppressed experimental food allergy by preventing the specific Ag-induced Treg apoptosis in the intestine. In conclusion, exposure to specific Ags induces Treg apoptosis and it can be prevented by up-regulating superoxide dismutase or suppressing reactive oxidative species in Tregs. This article is protected by copyright. All rights reserved.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/eji.202049112DOI Listing
April 2021

FcγRI plays a critical role in patients with ulcerative colitis relapse.

Eur J Immunol 2021 02 16;51(2):459-470. Epub 2020 Nov 16.

Research Center of Allergy & Immunology, Shenzhen University School of Medicine, Shenzhen, China.

Ulcerative colitis (UC) is a disease that frequently relapses and affects more than 0.1% general population; the underlying mechanism is poorly understood. Published data show that polymorphonuclear neutrophils (PMN) contribute to the pathogenesis of UC. This study aims to identify antigen (Ag)-specific PMNs and investigate their role in UC relapse. In this study, the correlation between PMN activities and UC relapse was assessed in a group of UC patients. A UC mouse model was developed to expand the findings of UC patient study. The results showed that a positive correlation was detected between the high PMN activities and the food Ag-specific IgG amounts in colon biopsies of UC patients. UC patient-derived Ag-specific PMNs could be activated upon exposure to food specific Ag. The Ag/FcγRI complexes were detected on the surface of PMNs in UC patients. Re-exposure of sensitized PMNs to specific Ag triggered PMN activation and induced UC-like inflammation in the mouse colon. We conclude that FcγRI plays a critical role in UC relapse. Inhibition of FcγRI can efficiently inhibits experimental UC.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/eji.202048622DOI Listing
February 2021

Enolase-specific cross antibodies induce neutrophilic inflammation in the intestine.

J Leukoc Biol 2021 03 18;109(3):633-644. Epub 2020 Aug 18.

Research Center of Allergy & Immunology, Shenzhen University School of Medicine, Shenzhen, China.

The pathogenesis of ulcerative colitis (UC) is to be further investigated. House dust mites (HDM) are highly associated with the pathogenesis of immune inflammation in the body. This study aims to investigate the role of enolase (one of the HDM-derived proteins)-specific cross Abs in the induction of UC-like inflammation. The enolase specific IgG (EsIgG) was identified in UC patients by mass spectrometry. Mice were treated with EsIgG to induce inflammation in the colon mucosa. EsIgG was detected in the serum and the colon tissues of UC patients, which was positively correlated with the polymorphonuclear neutrophil (PMN) counts in the blood and colon tissues of UC patients. EsIgG formed immune complexes with the constitutive enolase in the UC colon epithelium that activated complement, induced epithelial cell apoptosis, compromised epithelial barrier functions, and resulted in UC-like inflammation in the mouse colon. In summary, UC patients have high serum levels of Abs against HDM-derived enolase and intestinal epithelial cell-derived enolase. These Abs attack the colonic epithelium to induce UC-like inflammation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/JLB.3A0620-128RDOI Listing
March 2021

Survivin Impairs the Apoptotic Machinery in CD4+ T Cells of Patients with Ulcerative Colitis.

J Innate Immun 2020 22;12(3):226-234. Epub 2019 Jul 22.

Research Center of Allergy and Immunology, Shenzhen University School of Medicine, Shenzhen, China,

Background: The increase in CD4+ T cell infiltration and overproduction of CD4+ T cell-associated cytokines have been observed in the inflamed colon mucosa of patients with ulcerative colitis (UC); the underlying mechanisms are not fully understood. Survivin plays a critical role in the interference with apoptotic machinery. This study aims to elucidate the role of survivin in the interference with the apoptotic machinery in CD4+ T cells of UC patients.

Methods: Peripheral blood samples were collected from UC patients (UC group) and healthy subjects (healthy group). The apoptotic status in CD4+ T cells was analyzed by flow cytometry.

Results: We observed that the expression of survivin was significantly higher in CD4+ T cells of UC patients than in healthy subjects. UC CD4+ T cells were resistant to apoptosis induction. A complex of survivin and c-Myc, the transcription factor of FasL, was detected in CD4+ T cells in UC patients, which prevented the binding of c-Myc to the FasL promoter and interfered with the expression of FasL. Increased expression of survivin prevented the activation-induced CD4+ T cells from apoptosis.

Conclusions: The data indicate that UC CD4+ T cells express high levels of survivin, which impairs the apoptotic machinery in CD4+ T cells and prevents the activation-induced CD4+ T cell apoptosis. Therefore, target therapy against survivin has translational potential in the treatment of UC patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1159/000500546DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7265744PMC
July 2019

Survivin induces defects in apoptosis in eosinophils in intestine with food allergy.

Innate Immun 2019 05 12;25(4):244-254. Epub 2019 Feb 12.

3 Research Center of Allergy & Immunology, Shenzhen University School of Medicine, China.

Survivin is an anti-apoptosis protein that may be associated with the development of eosinophilia; the latter is associated with the pathogenesis of many immune disorders. Here we report that less apoptotic eosinophils (Eos) were induced in those isolated from mice suffering from food allergy (FA) than those from naive mice after treating with cisplatin in vitro. Exposure to cisplatin induced more Fas ligand (FasL) expression in Eos isolated from naive mice than in those of FA mouse. Survivin was detected in the intestinal tissue extracts in much higher amounts in the FA group than in the naive group. Immunohistochemistry showed that epithelial cells were the major source of survivin in the intestine. Exposure to IL-4 or IL-13 up-regulated the expression of survivin in intestinal epithelial cells. Survivin interfered with the expression of FasL in Eos. Inhibition of survivin attenuated the eosinophilia-related inflammation in the intestine. In conclusion, intestinal epithelial cell-produced survivin induced defects in apoptosis in Eos to contribute to eosinophilia in the intestine. Inhibition of survivin can suppress the eosinophilia-related intestinal inflammation. The data suggest that survivin may be a novel target for the treatment of FA.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/1753425919829554DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6830885PMC
May 2019

Bcl2L12 mediates effects of protease-activated receptor-2 on the pathogenesis of Th2-dominated responses of patients with ulcerative colitis.

Arch Biochem Biophys 2018 11 11;657:8-14. Epub 2018 Sep 11.

The Affiliated ENT Hospital and Research Center of Allergy & Immunology, Shenzhen University School of Medicine, Shenzhen, China. Electronic address:

The immune dysregulation plays an important role in the pathogenesis of ulcerative colitis (UC). Bcl2 like protein-12 (Bcl2L12) and mast cells are involved in immune dysregulation of UC. This study aims to elucidate the role of Bcl2L12 in the contribution to the pathogenesis of T helper (Th)2-biased inflammation in UC patients. The results showed that Bcl2L12 was expressed by peripheral CD4 T cells that was associated with Th2 polarization in UC patients. Bcl2L12 mediated the protease-activated receptor-2 (PAR2)-induced IL-4 expression in CD4 cells. Activation of PAR2 increased expression of Bcl2L12 in CD4 T cells. Bcl2L12 mRNA decayed spontaneously in CD4 T cells after separated from UC patients which was prevented by activating PAR2. Bcl2L12 mediated the binding between GATA3 and the Il4 promoter in CD4 T cells. Mice with Bcl2L12 deficiency failed to induce Th2-biased inflammation in the colon mucosa. We conclude that CD4 T cells from UC patients expressed high levels of Bcl2L12; the latter plays an important role in the development of Th2-biased inflammation in the intestine. Bcl2L12 may be a novel therapeutic target in the treatment of Th2-biased inflammation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.abb.2018.09.003DOI Listing
November 2018

Bcl2L12 plays a critical role in the development of intestinal allergy.

Immunol Lett 2018 11 5;203:87-94. Epub 2018 Sep 5.

Research Center of Allergy & Immunology, Shenzhen University Faculty of Medicine, Shenzhen, China. Electronic address:

The skewed T helper (Th) 2 response plays a central role in the pathogenesis of allergic diseases, while its initiating factors remain elusive. Recent studies indicate that Bcl2 like protein-12 (Bcl2L12) is associated with the Th2-biased inflammation. This study is designed to test a hypothesis that Bcl2L12 plays a critical role in the initiation of allergic response. In this study, peripheral CD4 T cells were isolated from food allergy (FA) patients and healthy subjects; A mouse FA model was developed to test the role of Bcl2L12 in induction of allergic response in the intestine. The results showed that expression of Bcl2L12 by CD4 T cells was higher in FA patients and FA mice and positively correlated with expression of Th2 cytokines. CD4 T cells from FA patients showed a Bcl2L12-dependent tendency to differentiate into Th2 cells. Bcl2L12 played a crucial role in induction of allergic response in the intestine. Physical contact between Bcl2L12 and GATA3 facilitated GATA3 to bind Il4 promoter to promote expression of IL-4. Adoptive transfer with Bcl2L12-deficient CD4 T cells to Rag2¯¯ mice did not reconstitute the efficient CD4 T cell response as the mice could not be induced FA, while Rag2¯¯ mice received WT CD4 T cell transfer were induced FA. In conclusion, Bcl2L12 plays a crucial role in the induction of Th2 polarization and allergic response in the intestine. The Bcl2L12 in CD4 T cells may be a potential target for the treatment of FA.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.imlet.2018.09.001DOI Listing
November 2018

Vitamin D-deficiency induces eosinophil spontaneous activation.

Cell Immunol 2017 Dec 12;322:56-63. Epub 2017 Oct 12.

The Research Center of Allergy & Immunology, Shenzhen University School of Medicine, Shenzhen 518060, China. Electronic address:

Eosinophils (Eo) play a critical role in immunity and immune inflammation. The maintenance of Eo homeostasis is not fully understood yet. Vitamin D (VitD) is involved in the regulation of a large number of biochemical reactions. This study tests a hypothesis that VitD receptor (VDR) contributes to the homeostasis of Eos. In this study, EoL-1 cells (an Eo cell line) were cultured in the presence or absence of calcitriol. The Eo-mediators, including major basic protein (MBP), Eo peroxidase (EPX), Eo cationic protein (ECP) and Eo-derived neurotoxin (EDN), were assessed in the culture supernatant and in EoL-1 cells. We observed that, in a VitD deficient environment, EoL-1 cells produced high levels of the Eo-mediators, including MBP, EPX, ECP and EDN, which could be suppressed by the addition of calcitriol to the culture. EoL-1 cells expressed VitD receptor (VDR), which was up regulated by exposure to calcitriol. VDR formed complexes with the transcription factors of the Eo-mediators, which prevented the transcription factors to bind to the promoters of the Eo-mediators, and therefore prevented the Eo-mediated gene transcription. The Eo spontaneous activation was also found in the intestinal mucosa of VDR-deficient mice, in which the intestinal epithelial barrier dysfunction was observed. In conclusion, VDR contributes to the maintenance of the homeostasis of Eos by regulating the gene transcription of the Eo mediators. The VDR-deficiency is one of the causative factors inducing Eo spontaneous activation. This phenomenon may be taken into account in the management of the Eo-related diseases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.cellimm.2017.10.003DOI Listing
December 2017

Micro RNA-19a suppresses thrombospondin-1 in CD35 B cells in the intestine of mice with food allergy.

Am J Transl Res 2016 15;8(12):5503-5511. Epub 2016 Dec 15.

The Research Center of Allergy & Immunology, Shenzhen University School of Medicine Shenzhen 518060, China.

Disruption of immune tolerance is associated in the pathogenesis of allergy. Thrombospondin-1 (TSP1) plays a role in the maintenance of immune tolerance, which is compromised in allergic disorders. Micro RNA (miR) is involved in the regulation of immune responses. This study tests a hypothesis that miR-17-92 cluster is involved in the regulation of TSP1 in the intestinal CD35 B cells. In this study, a food allergy mouse model was developed. The intestinal B cells were isolated to be analyzed for the expression of a miR-17-92 cluster and TSP1. The role of miR-19a in the suppression of TSP1 in B cells was tested in a cell culture model. We observed that the levels of TSP1 were significantly decreased; the levels of miR-19a were significantly increased in intestinal CD35 B cells of mice sensitized to ovalbumin (OVA) as compared with naïve controls. Exposure to interleukin (IL)-4 suppressed the expression of TSP1 in B cells, which was abolished by inhibition of miR-19a. miR-19a mediated the effects of IL-4 on repressing TSP1 expression in B cells. We conclude that IL-4 suppresses the expression of TSP1 in the intestinal CD35 B cells via up regulating miR-19a. The miR-19a may be a target to regulate the immune tolerant status in the body.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5209501PMC
December 2016

Induction of colitis in mice with food allergen-specific immune response.

Sci Rep 2016 09 8;6:32765. Epub 2016 Sep 8.

The Center of Allergy &Immunology, Shenzhen University School of Medicine, Shenzhen, China.

The pathogenesis of intestinal chronic inflammation is unclear. Food allergy plays an important role in the induction of intestinal inflammation. This study aims to test a hypothesis that food allergy initiates colitis. In this study, BALB/c mice were sensitized to a common food allergen, ovalbumin (OVA) with cholera toxin (CT) as an adjuvant. The colon epithelial barrier function was assessed with Ussing chamber technique. Expression of T cell immunoglobulin mucin domain molecule-4 (TIM4) in dendritic cells was evaluated by flow cytometry, RT-PCR and Western blotting. The results showed that allergen-related colitis was induced in mice as shown by heavy infiltration of inflammatory cells in the colon mucosa, loss of body weight of mice, increases in myeloperoxidase, tumor necrosis factor-α, interleukin-4, OVA-specific IgE in the colon tissue. The colon epithelial barrier function was markedly compromised in colitis group mice, which was mimicked by exposure the colon mucosa to CT in Ussing chamber. High frequency of TIM4(+) dendritic cells was detected in the colon mucosa of colitis mice. Exposure of dendritic cells to CT markedly increased the expression of TIM4. We conclude that IBD-like inflammation can be induced in the mouse colon by the food allergen-related immune response.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/srep32765DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5015191PMC
September 2016

Specific immunotherapy ameliorates ulcerative colitis.

Allergy Asthma Clin Immunol 2016 5;12:37. Epub 2016 Aug 5.

The Center of Allergy & Immunology, Shenzhen University School of Medicine, Shenzhen, China.

Background: Hypersensitivity reaction to certain allergens plays a role in the pathogenesis of inflammatory bowel disease (IBD). This study aims to observe the effect of specific immunotherapy in a group of IBD patients.

Methods: Patients with both ulcerative colitis (UC) and food allergy were recruited into this study. Food allergy was diagnosed by skin prick test and serum specific IgE. The patients were treated with specific immunotherapy (SIT) and Clostridium butyricum (CB) capsules.

Results: After treating with SIT and CB, the clinical symptoms of UC were markedly suppressed as shown by reduced truncated Mayo scores and medication scores. The serum levels of specific IgE, interleukin (IL)-4 and tumor necrosis factor (TNF)-α were also suppressed. Treating with SIT alone or CB alone did not show appreciable improvement of the clinical symptoms of UC.

Conclusions: UC with food allergy can be ameliorated by administration with SIT and butyrate-production probiotics.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s13223-016-0142-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4975874PMC
August 2016

Alternation of circadian clock modulates forkhead box protein-3 gene transcription in CD4 T cells in the intestine.

J Allergy Clin Immunol 2016 11 8;138(5):1446-1449.e10. Epub 2016 Jun 8.

Hangzhou Zheda Dixun Biological Gene Engineering Co, LTD, Hangzhou, China. Electronic address:

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jaci.2016.04.035DOI Listing
November 2016

Flagellin modulates IgE expression in B cells to initiate food allergy in mice.

Am J Transl Res 2016 15;8(6):2748-57. Epub 2016 Jun 15.

The Research Center of Allergy & Immunology, Shenzhen University School of Medicine Shenzhen 518060, China.

The initiation mechanism of IgE expression has not been fully understood. Flagellin (FGN) is an important microbial factor in the regulation of immune responses in the intestine. This study tests a hypothesis that FGN plays a crucial role in the isotype switching of IgE in B cells and the initiation of food allergy. In this study, the expression of IgE in B cells was analyzed by real time RT-PCR, Western blotting and chromatin immunoprecipitation. A mouse model was developed to assess the role of Toll like receptor-5 in the development of IgE-mediated allergic reaction in the intestinal mucosa. The results showed that exposure to FGN suppressed the expression of Bcl6 in B cells via increasing the levels of histone deacetylase (HDAC) 7; the latter up regulated the levels of methylated H3K9 and H3K27, down regulated RNA polymerase II and STAT3 (signal transducer and activator of transcription 3) at the Bcl6 promoter locus. Exposure to FGN and IL-4 markedly increased the expression of IgE in B cells via activating p300, H3K4, Pol II and STAT6 at the IgE promoter locus. As compared with the sensitized wild mice, the sensitized TLR5-deficient mice showed no detectable OVA-specific IgE in the serum; mast cells in the intestinal mucosa were not activated, no apparent allergic symptoms were evoked after the specific antigen challenge. In conclusion, FGN facilitates the initiation of food allergy in mice by triggering IgE transcription in B cells in a Th2 polarization environment via activating HDAC7 and suppressing Bcl6 expression.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4931168PMC
July 2016

Role of interleukin-22 in inflammatory bowel disease.

World J Gastroenterol 2014 Dec;20(48):18177-88

Lin-Jing Li, Chen Gong, Mei-Hua Zhao, Bai-Sui Feng, Department of Gastroenterology, the Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou 450000, Henan Province, China.

Inflammatory bowel disease (IBD) is a chronic inflammatory disease thought to be mediated by the microbiota of the intestinal lumen and inappropriate immune responses. Aberrant immune responses can cause secretion of harmful cytokines that destroy the epithelium of the gastrointestinal tract, leading to further inflammation. Interleukin (IL)-22 is a member of the IL-10 family of cytokines that was recently discovered to be mainly produced by both adaptive and innate immune cells. Several cytokines and many of the transcriptional factors and T regulatory cells are known to regulate IL-22 expression through activation of signal transducer and activator of transcription 3 signaling cascades. This cytokine induces antimicrobial molecules and proliferative and antiapoptotic pathways, which help prevent tissue damage and aid in its repair. All of these processes play a beneficial role in IBD by enhancing intestinal barrier integrity and epithelial innate immunity. In this review, we discuss recent progress in the involvement of IL-22 in the pathogenesis of IBD, as well as its therapeutic potential.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3748/wjg.v20.i48.18177DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4277955PMC
December 2014

Dysregulation of mucosal immune response in pathogenesis of inflammatory bowel disease.

World J Gastroenterol 2014 Mar;20(12):3255-64

Xiao-Rong Xu, Chang-Qin Liu, Bai-Sui Feng, Zhan-Ju Liu, Department of Gastroenterology, Shanghai Tenth People's Hospital, Tongji University, Shanghai 200072, China.

Inflammatory bowel disease (IBD) includes Crohn's disease and ulcerative colitis. The exact etiology and pathology of IBD remain unknown. Available evidence suggests that an abnormal immune response against the microorganisms in the intestine is responsible for the disease in genetically susceptible individuals. Dysregulation of immune response in the intestine plays a critical role in the pathogenesis of IBD, involving a wide range of molecules including cytokines. On the other hand, besides T helper (Th) 1 and Th2 cell immune responses, other subsets of T cells, namely Th17 and regulatory T cells, are likely associated with disease progression. Studying the interactions between various constituents of the innate and adaptive immune systems will certainly open new horizons of the knowledge about the immunologic mechanisms in IBD.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3748/wjg.v20.i12.3255DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3964397PMC
March 2014

Prolactin mediates psychological stress-induced dysfunction of regulatory T cells to facilitate intestinal inflammation.

Gut 2014 Dec 18;63(12):1883-92. Epub 2014 Feb 18.

Shenzhen Key Laboratory of Allergy & Immunology, Shenzhen University School of Medicine and State Key Laboratory of Respiratory Disease for Allergy at Shenzhen University, Shenzhen, China.

Objective: The dysfunction of immune regulation plays a critical role in the pathogenesis of a number of chronic inflammatory disorders, such as IBD. A close relationship between psychological stress and intestinal inflammation has been noted; the underlying mechanism remains elusive. This study aims to elucidate a pathological pathway between psychological stress and the dysfunction of regulatory T cells (Treg), and its effect on facilitating intestinal inflammation.

Design: A restraint stress model was employed to induce psychological stress in mice. The functions of Tregs were determined by assessing the immune suppressor effects in the intestine. A mouse model of intestinal inflammation was established using a low dose of trinitrobenzene sulfonic acid (TNBS) or dextran sulfate sodium (DSS) together with the challenge of chronic stress.

Results: After treating mice with restraint stress, the suppressor function of intestinal Treg was compromised, although the frequency of Treg was not changed in the intestine. Further observation revealed that stress induced Tregs in the intestine to differentiate into foxhead box P3(+) interleukin (IL)-17(+) tumour necrosis factor (TNF)-α(+) T cells. We also observed that exposure to stress-derived prolactin induced dendritic cells (DC) to produce IL-6 and IL-23 in vitro and in vivo, which played a critical role in altering Treg's phenotypes. Treating mice with chronic stress facilitated the initiation of intestinal inflammation by a low dose of TNBS or DSS, which was abolished by pretreatment with an inhibitor of prolactin, the cabergoline.

Conclusions: Psychological stress-derived prolactin alters DC and Treg's properties to contribute to intestinal inflammation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1136/gutjnl-2013-306083DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4251191PMC
December 2014

Food-cooking processes modulate allergenic properties of hen's egg white proteins.

Int Arch Allergy Immunol 2013 25;160(2):134-42. Epub 2012 Sep 25.

State Key Laboratory of Respiratory Disease for Allergy, School of Medicine, Shenzhen University, Shenzhen, PR China.

Background And Objective: Reducing the allergenicity of food allergens can suppress the clinical symptoms of food allergy. The objective of the present study was to investigate the effects of processing on the allergenic properties of hen's egg white proteins.

Methods: Eggs were processed by traditional Chinese cooking, including steaming, water boiling, frying, spicing and tea boiling. The contents of processed egg protein were assessed by sodium dodecyl sulfate polyacrylamide gel electrophoresis; the allergenicity was evaluated by Western blotting, enzyme-linked immunosorbent assay and enzyme allergosorbent test inhibition. Circular dichroism spectrum analysis of four major egg allergens from various egg products was performed as well. A mouse model of food allergy was developed to test the allergenicity of processed egg protein in vivo.

Results: Protein degradation was significant following tea boiling and spiced-tea boiling. The total allergenic potential of water-boiled egg and fried egg was relatively higher than that of steamed egg, spiced egg and tea-boiled egg. Challenge with proteins from raw egg, water-boiled egg and fried egg induced skewed T-helper 2 pattern responses (Th2 responses) in the intestine of mice sensitized to egg proteins; however, when the mice sensitized to egg proteins were challenged with proteins from steamed egg, spiced egg and tea-boiled egg, respectively, only weak Th2 responses were induced in their intestine.

Conclusion: Processing by steaming, spicing, or tea boiling can weaken the allergenicity of egg proteins.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1159/000339396DOI Listing
March 2013

Interleukin (IL)-23 suppresses IL-10 in inflammatory bowel disease.

J Biol Chem 2012 Jan 12;287(5):3591-7. Epub 2011 Dec 12.

Department of Gastroenterology, Shanghai Tenth People's Hospital, Tongji University, Shanghai 200072, China.

Interleukin (IL)-10 plays an important role in immune regulation in the intestine. Immune deregulation is suggested in the pathogenesis of inflammatory bowel disease (IBD). This study aims to elucidate the role of IL-23 in the suppression of IL-10 in the IBD intestinal mucosa. Surgically removed colon specimens were obtained from 16 IBD patients. The expressions of IL-10, IL-23, and IgA in the specimens were examined at the protein and gene transcriptional levels. The gene transcription of IL-10 was assessed by chromatin immunoprecipitation assay and promoter accessibility assay. The levels of IgA and IL-10 were significantly lower, whereas the levels of IL-23 were higher, in IBD specimens than in normal controls. The levels of IgA and IL-10 were negatively correlated with the infiltration of inflammatory cells in the IBD mucosa. The production of IL-10 by lamina propria mononuclear cells was lower in the IBD group than in the control group, and these levels could be enhanced by blocking IL-23. The gene transcription of IL-10 was significantly suppressed in CD4(+) T cells of IBD mucosa; this phenomenon could be replicated in vitro by adding IL-23 in the culture of polarized Th2 cells. Overexpression of IL-23 in the intestinal mucosa suppresses the production of IL-10, which weakens the defensive barrier by reducing the production of IgA in the gut.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1074/jbc.M111.304949DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3271012PMC
January 2012

Intestinal epithelial cell-derived integrin αβ6 plays an important role in the induction of regulatory T cells and inhibits an antigen-specific Th2 response.

J Leukoc Biol 2011 Oct 1;90(4):751-9. Epub 2011 Jul 1.

Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada.

Toleroge nic DCs and Tregs are believed to play a critical role in oral tolerance. However, the mechanisms of the generation of tolerogenic DCs and activation of Tregs in the gut remain poorly understood. This study aims to dissect the molecular mechanisms by which IECs and protein antigen induce functional tolerogenic DCs and Tregs. Expression of αvβ6 by gut epithelial cell-derived exosomes, its coupling with food antigen, and their relationship with the development of functional tolerogenic DCs and Tregs were examined by using in vitro and in vivo approaches. The results show that IECs up-regulated the integrin αvβ6 upon uptake of antigens. The epithelial cell-derived exosomes entrapped and transported αvβ6 and antigens to the extracellular environment. The uptake of antigens alone induced DCs to produce LTGFβ, whereas exosomes carrying αvβ6/antigen resulted in the production of abundant, active TGF-β in DCs that conferred to DCs the tolerogenic properties. Furthermore, αvβ6/OVA-carrying, exosome-primed DCs were found to promote the production of active TGF-β in Tregs. Thus, in vivo administration of αvβ6/OVA-laden exosomes induced the generation of Tregs and suppressed skewed Th2 responses toward food antigen in the intestine. Our study provides important molecular insights into the molecular mechanisms of Treg development by demonstrating an important role of IEC-derived exosomes carrying αvβ6 and food antigen in the induction of tolerogenic DCs and antigen-specific Tregs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1189/jlb.1210696DOI Listing
October 2011

[Effects of S-adenosylmethionine on gastric cancer cell lines SGC-7901 and BGC-823].

Zhonghua Yi Xue Za Zhi 2010 Jun;90(22):1559-64

Department of Gastroenterology, First Hospital Affiliated to Zhengzhou University, Zhengzhou 450052, China.

Objective: To observe the effects of S-adenosylmethionine (SAM) on cell proliferation, cell cycles, apoptosis and invasive capacity of gastric cancer cell lines SGC-7901 and BGC-823 and detect the methylation status and expression of c-myc and urokinase-type plasminogen activator (uPA).

Methods: The effect of SAM on proliferation of SGC-7901 and BGC-823 cells were determined by MTT assay. SGC-7901 and BGC-823 cells were treated with different concentrations of SAM (0, 2, 4 mmol/L) for 72 h. Then flow cytometry was used to detect the change of cell cycles and apoptosis; Transwell assay to detect the invasion; RT-PCR and Western blot to detect the expression of c-myc and uPA; and MSP to detect the methylation of c-myc and uPA.

Results: SAM displayed a growth-inhibiting effect on SGC-7901 and BGC-823 cells in a dose- and time-dependent manner after exposure to SAM at different concentrations (0.5 - 32 mmol/L) for 24, 48 and 72 h, cell proliferation were significantly restrained (all P < 0.05); 72 h IC50 SGC-7901 5.40 mmol/L and BGC-823 4.01 mmol/L. After treating SGC-7901 and BGC-823 with different concentrations of SAM, the cell percentages of G0/G1 phase significantly increased (P < 0.05 and P < 0.01) while the cell proliferation indices significantly decreased (P < 0.05 and P < 0.01). Compared with control group (0.33 +/- 0.09), the cell apoptosis of 2 mmol/L (5.79 +/- 0.75) and 4 mmol/L groups (10.19 +/- 0.60) of SGC-7901 were obviously reduced (all P < 0.01). Compared with control group (0.95 +/- 0.19), the cell apoptosis of 2 mmol/L (6.23 +/- 0.75) and 4 mmol/L groups (11.82 +/- 1.14) of BGC-823 were obviously reduced (all P < 0.01). The cell invasive capacity were significantly restrained (P < 0.01). The invasion inhibition ratio of 2 mmol/L and 4 mmol/L groups of SGC-7901 were 51.07% and 80.69% respectively. The invasion inhibition ratio of 2 mmol/L and 4 mmol/L groups of BGC-823 were 48.57% and 84.10% respectively. The expressions of c-myc and uPA significantly decreased (P < 0.05 and P < 0.01). There was no expression of c-myc in 2 mmol/L group of BGC-823. The methylation of c-myc and uPA genes in two cell lines were reversed after SAM treatment.

Conclusions: SAM can induce the apoptosis of SGC-7901 and BGC-823, block the cell cycles at G0/G1 phase and suppress the proliferation and invasion of these two cell lines. SAM can reverse the methylation of c-myc and uPA in these two cell lines and reduce their expression. SAM may act as a methyl donor to restrain the development and progression of tumor when hypomethylation is widely present in cancer.
View Article and Find Full Text PDF

Download full-text PDF

Source
June 2010

Inhibitory effect of S-adenosylmethionine on the growth of human gastric cancer cells in vivo and in vitro.

Chin J Cancer 2010 Aug;29(8):752-60

Department of Gastroenterology, the First Affiliated Hospital of Zhengzhou University, Key-Disciplines Laboratory Clinical-Medicine, Zhengzhou, Henan 450052, P. R. China.

Background And Objective: S-adenosylmethionine (SAM), the most important methyl donor in human body, is generally used to treat cholestasis in clinic. In recent years, SAM has been found to have inhibitory effects on breast cancer, liver cancer and colon carcinoma. This study was to investigate the inhibitory effects of SAM on human gastric cancer cells in vivo and in vitro, and the antitumor mechanisms.

Methods: The effects of SAM on the proliferation of gastric cancer SGC-7901 and MKN-45 cells were determined by MTT assay. After SGC-7901 and MKN-45 cells were treated with 0, 2, and 4 mmol/L SAM for 72 h, the expression and methylation of c-myc and urokinase type plasminogen activator (uPA) were detected by reverse transcription-polymerase chain reaction (RT-PCR) and methylation-specific PCR (MSP). Tumor xenografts were established by injecting SGC-7901 cells subcutaneously in BALB/c nude mice. The mice were randomized into low concentration group [192 µmol/(kg · day)], high concentration group [768 µmol/(kg · day)], and control group [normal saline (NS)], and received peritoneal injection of relative reagents for 15 days. The tumor size was measured, the protein and mRNA expression of c-myc and uPA were detected by immunohistochemistry and RT-PCR, and the methylation of c-myc and uPA genes was detected by MSP.

Results: SAM inhibited the growth of SGC-7901 and MKN-45 cells obviously and the effects were enhanced with the increase of SAM concentration and treatment time. The mRNA expression of c-myc and uPA in SGC-7901 cells and that of uPA in MKN-45 cells significantly decreased. The c-myc and uPA genes in SGC-7901 cells and uPA gene in MKN-45 cells were partly or completely methylated after SAM treatment. The tumor volume was significantly lower in low concentration group [(618.51 ± 149.27) mm³] and high concentration group [(444.32 ± 118.51) mm³] than in control group [(1018.22 ± 223.07) mm³] (both P < 0.01). The inhibitory rates of tumor growth were 39.26% in low concentration group and 56.36% in high concentration group. The protein and mRNA expressions of c-myc and uPA were remarkably reduced (all P < 0.01), and the hypomethylation of c-myc and uPA genes were reversed after SAM treatment.

Conclusions: SAM can inhibit the growth of human gastric cancer cells both in vivo and in vitro. The mechanism may be that SAM can reverse the hypomethylation of c-myc and uPA genes, reduce their expression, and then inhibit tumor growth.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.5732/cjc.010.10046DOI Listing
August 2010

Glucuronoxylomannan promotes the generation of antigen-specific T regulatory cell that suppresses the antigen-specific Th2 response upon activation.

J Cell Mol Med 2009 Aug;13(8B):1765-1774

Brain Body Institute and Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada.

T regulatory cells (Treg) have the capability to suppress the skewed immune response, but the generation of antigen (Ag)-specific Treg for therapeutic purpose is a challenge; the mechanism of Ag-specific Treg activation remains obscure. Here, we report that glucuronoxylomannan (GXM) is capable of promoting the development of human tolerogenic dendritic cells (DC). GXM-pulsed DCs increased the expression of forkhead box P3 (Foxp3) in naïve human CD4(+)CD25(-) T cells via activating Fc gamma receptor IIb and activator protein-1 and promoting the expression of transforming growth factor beta in dendritic cells. Furthermore, the conjugated complex of house dust mite Ag, Dermatophagoides pteronyssinus (Der p) 1, and GXM-pulsed DCs to drive the naïve human CD4(+)CD25(-) T cells to develop into the Der p 1-specific Tregs, which efficiently suppressed the Ag-specific Th2 responses. We conclude that GXM-conjugated specific Ag have the capacity to up-regulate the tolerogenic property of DCs and promote the generation of Ag-specific Tregs; the latter can be activated upon the re-exposure to specific Ag and suppress the skewed Ag-specific T helper (Th)2 responses.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/j.1582-4934.2008.00583.xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6529965PMC
August 2009

Expression of integrin alphavbeta6 in the intestinal epithelial cells of patients with inflammatory bowel disease.

N Am J Med Sci 2009 Sep;1(4):200-4

Brain Body Institute, McMaster University, Hamilton, ON, Canada.

Background And Aims: The prevalence of inflammatory bowel disease (IBD) is about 0.05% in industrialized countries. The pathogenesis of IBD remains to be further understood. The present study aims to elucidate the expression of integrin αvβ6 in the intestinal mucosa of patients with IBD.

Materials And Methods: Colonic biopsy was obtained from a group of IBD patients. The expression of αvβ6 in the intestinal mucosa was detected by Western blotting. Human colonic epithelial cell line T84 cells were stimulated by microbial antigen flagellin. The expression of αvβ6 in T84 cells was evaluated by quantitative RT-PCR and Western blotting.

Results: The levels of αvβ6 in the intestinal mucosa were much lower than it in normal control subjects. The serum levels of myeloperoxidase (MPO) were higher in IBD patients that were negatively correlated with the levels of αvβ6 in the intestinal mucosa. The expression of αvβ6 was detectable in T84 cells at naοve status that could be upregulated by exposure to microbial antigen flagellin. Pretreatment with MPO dramatically suppressed the expression of αvβ6 in T84 cells.

Conclusions: We conclude that the expression of αvβ6 was suppressed in IBD intestinal mucosa, which could be resulted from the high levels of MPO.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4297/najms.2009.4200DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3364666PMC
September 2009

Investigation of the role of cholera toxin in assisting the initiation of the antigen-specific Th2 response.

Immunol Invest 2008 ;37(8):782-97

Department of Gastroenterology, Zhengzhou University School of Medicine, Zhengzhou, China.

Skewed Th2 polarization and tissue mastocytosis are the main features of allergy; but how the antigen-specific Th2 polarization initiated remains unclear. The present study shows that cholera toxin (CT) activates mouse bone marrow mast cells (BMMC) to release interleukin (IL)-4. The activation process involved in Toll-like receptor 4, nucleotide oligomerisation domain 1, activate signal transducer and activator of transcription 6 (STAT6), and IL-4. Activated mast cell-derived IL-4 in synergy with co-existing antigen information provided by dendritic cells drives naive CD4+ T cells to differentiate into antigen-specific Th2 cells. The finding demonstrates that concurrent exposure to microbial products, such as CT, and antigen-loaded dendritic cells plays a critical role in the initiation of antigen-specific Th2 response in the body; this notion is supported by the concurrent adoptive transfer with CT-pulsed BMMCs and antigen-loaded BMDCs that induced antigen-specific Th2 response and hypersensitivity reaction in the intestine.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/08820130802403341DOI Listing
January 2009

Fc gamma receptor signaling in mast cells links microbial stimulation to mucosal immune inflammation in the intestine.

Am J Pathol 2008 Dec 30;173(6):1647-56. Epub 2008 Oct 30.

Brain Body Institute, McMaster University, Ontario, Canada.

Microbes and microbial products are closely associated with the pathogenesis of inflammatory bowel disease (IBD); however, the mechanisms behind this connection remain unclear. It has been previously reported that flagellin-specific antibodies are increased in IBD patient sera. As mastocytosis is one of the pathological features of IBD, we hypothesized that flagellin-specific immune responses might activate mast cells that then contribute to the initiation and maintenance of intestinal inflammation. Thirty-two colonic biopsy samples were collected from IBD patients. A flagellin/flagellin-specific IgG/Fc gamma receptor I complex was identified on biopsied mast cells using both immunohistochemistry and co-immunoprecipitation experiments; this complex was shown to co-localize on the surfaces of mast cells in the colonic mucosa of patients with IBD. In addition, an ex vivo study showed flagellin-IgG was able to bind to human mast cells. These cells were found to be sensitized to flagellin-specific IgG; re-exposure to flagellin induced the mast cells to release inflammatory mediators. An animal model of IBD was then used to examine flagellin-specific immune responses in the intestine. Mice could be sensitized to flagellin, and repeated challenges with flagellin induced an IBD-like T helper 1 pattern of intestinal inflammation that could be inhibited by pretreatment with anti-Fc gamma receptor I antibodies. Therefore, flagellin-specific immune responses activate mast cells in the intestine and play important roles in the pathogenesis of intestinal immune inflammation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2353/ajpath.2008.080487DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2626377PMC
December 2008

Disruption of T-cell immunoglobulin and mucin domain molecule (TIM)-1/TIM4 interaction as a therapeutic strategy in a dendritic cell-induced peanut allergy model.

J Allergy Clin Immunol 2008 Jul 10;122(1):55-61, 61.e1-7. Epub 2008 Jun 10.

Brain-Body Institute, McMaster University, Hamilton, Ontario, Canada.

Background: Recent reports indicate that dendritic cell (DC)-derived T-cell immunoglobulin and mucin domain molecule (TIM)-4 plays an important role in the initiation of T(H)2 polarization. This study aims to elucidate the mechanisms of peanut allergy mediated by microbial products and DCs and the relationship between peanut allergy and TIM4.

Methods: Mouse bone marrow-derived DCs (BMDCs) were generated and exposed to cholera toxin (CT) or/and peanut extract (PE) for 24 hours and then adoptively transferred to naive mice. After re-exposure to specific antigen PE, the mice were killed; intestinal allergic status was determined.

Results: Increased expression of TIM4 and costimulatory molecules was detected in BMDCs after concurrent exposure to CT and PE. Adoptively transferred CT/PE-conditioned BMDCs resulted in the increases in serum PE-specific IgE and skewed T(H)2 polarization in the intestine. Oral challenge with specific antigen PE induced mast cell activation in the intestine. Treating with Toll-like receptor 4 small interfering RNA abolished increased expression of TIM4 and costimulatory molecules by BMDCs. Pretreatment with anti-TIM1 or anti-TIM4 antibody abolished PE-specific T(H)2 polarization and allergy in the intestine.

Conclusion: Concurrent exposure to microbial product CT and food antigen PE increases TIM4 expression in DCs and promotes DC maturation, which plays an important role in the initiation of PE-specific T(H)2 polarization and allergy in the intestine. Modulation of TIM4 production in DCs represents a novel therapeutic approach for the treatment of peanut allergy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jaci.2008.04.036DOI Listing
July 2008

TIM-4 expressed by mucosal dendritic cells plays a critical role in food antigen-specific Th2 differentiation and intestinal allergy.

Gastroenterology 2007 Nov 2;133(5):1522-33. Epub 2007 Aug 2.

Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada.

Background & Aims: Food allergy accounts for significant morbidity. The etiology and immune mechanisms of food allergy, however, have remained poorly understood. In this study, we aimed to determine the role of T-cell immunoglobulin-domain and mucin-domain (TIM)-4, a recently identified member of cell surface molecules, in the pathogenesis of intestinal allergy in a murine model.

Methods: We report that TIM-4 as well as costimulatory molecules were up-regulated in intestinal mucosal dendritic cells by in vitro or in vivo exposure to Staphylococcus enterotoxin B (SEB). SEB-conditioned intestinal dendritic cells loaded with a food macromolecule ovalbumin (OVA) induced potent OVA-specific T-helper (Th)2 lymphocyte responses in vitro and such Th2 responses were inhibited completely by TIM-4 blockade.

Results: In vivo exposure to both SEB and OVA resulted in OVA-specific Th2 differentiation and intestinal allergic responses including increased serum immunoglobulin E and Th2 cytokine levels, activation of OVA-specific Th2 cells detected both ex vivo and in situ, and mast cell degranulation. Of importance, in vivo abrogation of TIM-4 or its cognate ligand TIM-1 by using a polyclonal antibody remarkably dampened Th2 differentiation and intestinal allergy.

Conclusions: Our study thus identifies TIM-4 as a novel molecule critically required for the development of intestinal allergy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1053/j.gastro.2007.08.006DOI Listing
November 2007

Mast cells play a crucial role in Staphylococcus aureus peptidoglycan-induced diarrhea.

Am J Pathol 2007 Aug 28;171(2):537-47. Epub 2007 Jun 28.

Department of Pathology, McMaster University, Hamilton, Ontario, Canada.

Bacterium-induced diarrhea results in 2 to 2.5 million deaths in the world each year. The mechanism needs to be further understood. Staphylococcus aureus infection has a close relation with diarrhea; its cell wall component peptidoglycan (PGN) has strong biological activity on immune cells and possibly plays a role in S. aureus-induced diarrhea. The present study showed that oral PGN-induced diarrhea in mice in a dose-dependent manner. Intestinal epithelial cells absorbed PGN via the intracellular pathway. Intestinal mast cells were activated after PGN gavage. Toll-like receptor (TLR)2 expression was detected in mast cells in the intestine as well as in the murine mast cell line p815 cells. Blocking TLR2 or nucleotide-binding oligomerization domain (NOD)1 with related antibodies or RNA interference abolished PGN-induced p815 cell activation. The mast cell mediator histamine and serotonin had synergistic effects in PGN-induced diarrhea. In summary, oral PGN can induce diarrhea in mice, and TLR2 and NOD1 mediate the PGN-induced mast cell activation that plays a critical role in diarrhea induction. Blockade of TLR2 or NOD1 or treating mice with a mast cell stabilizer can efficiently inhibit PGN-induced-diarrhea, providing potential therapeutic significance.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2353/ajpath.2007.061274DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1934528PMC
August 2007

Bacterial peptidoglycan breaks down intestinal tolerance via mast cell activation: the role of TLR2 and NOD2.

Immunol Cell Biol 2007 Oct 12;85(7):538-45. Epub 2007 Jun 12.

Pathology & Molecular Medicine, McMaster University, Hamilton, ON, Canada.

Intestinal microbes are believed to be involved in the pathogenesis of inflammatory bowel disease. Microbes and their products are generally well tolerated by intestinal epithelial cells in the intestinal tract of healthy individuals. It is of significance to understand what breaks down the established tolerance leading to intestinal barrier dysfunction and intestinal inflammation. T84 monolayer transported peptidoglycan (PGN) was determined by enzyme-linked immune assay. Mast cell line HMC-1 cell activation in response to PGN stimulation was observed with electron microscopy and measurement of histamine release. T84 monolayer barrier function was determined by recording the transepithelial electric resistance (TER) and measuring the permeability in response to PGN-induced HMC-1 cell activation. Expression of Toll-like receptor (TLR) 2 and nucleotide-binding oligomerization domain (NOD) 2 were determined by immunocytochemistry, real-time reverse transcription (RT)-PCR and Western blot. Exposure to PGN alone did not alter TER and permeability of T84 monolayers. T84 monolayers transported PGN from the apical chamber to the basal chamber of transwell system. TLR2 expressed on the surface of HMC-1 cells. HMC-1 cells absorbed PGN. HMC-1 cells released histamine in response to the PGN stimulation, which was blocked by pretreatment with antibodies or small interfering RNA against TLR2 or NOD2. In a co-culture system, T84 monolayer transported PGN activated HMC-1 cells and increased the horseradish peroxidase flux. TLR2 mediated the PGN-absorption in HMC-1 cells. Blockade of TLR2 or NOD2 abolished PGN-induced HMC-1 cell activation and T84 monolayer barrier dysfunction. T84 monolayer transported PGN activates HMC-1 cells to release chemical mediators to induce T84 monolayer dysfunction that are mediated by TLR2 and NOD2.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/sj.icb.7100079DOI Listing
October 2007

[Construction of the enhanced green fluorescent protein eukaryotic expression vector carrying CagA of Helicobacter pylori].

Zhonghua Yi Xue Za Zhi 2007 Feb;87(8):570-2

Department of Digestive Medicine, Institute of Clinical Medical Research of Universities Henan China, the First Affiliated Hospital, Zhengzhou University, Zhengzhou 450052, China.

Objective: To construct a eukaryotic green fluorescent protein expressing vector containing the fragment of cytotoxin associated gene A (CagA) of Helicobacter pylori (Hp) so as to lay a foundation for the research of gene vaccine of gastric cancer. pEGFP-C3-CagA.

Methods: The fragment of gene CagA was amplified from Hp using PCR. The amplified product was examined by electrophoresis and sequence determination. This fragment was inserted into pGEM-T plasmid and pEGFP-C3 fluorescent expression vector. The recombined plasmid pEGFP-C3-CagA was transfected into the gastric carcinoma cells of the strain BGC823 by lipoplasty method. Fluorescence microscopy was used to observe the expression of pEGFP-C3-CagA under.

Results: CagA was inserted in the plasmid correctly. It was verified by DNA sequencing and restriction enzyme. The enhanced green fluorescent protein eukaryotic expression vector carrying CagA of Helicobacter pylori (pEGFP-C3-CagA) was recombined correctly and transfected in gastric carcinoma cell strain BGC823. Green fluorescence was observed in transfected gastric carcinoma cell.

Conclusion: Construction of the enhanced green fluorescent protein eukaryotic expression vector carrying CagA was successful.
View Article and Find Full Text PDF

Download full-text PDF

Source
February 2007