- Email: [email protected]
Helicobacter pylori regulates expression of ID-1 and ID-3 but not ID-2
W898
55 +/- 12 years) with endoscopy-proven gastritis, with active H pylori infection confirmed by- both 13C-urea breath test and serdogy. At upper gastrointestinal endoscopy 6 biopsies were taken Presence/degree of gastric atrophy grade were assessed using a validated scoring systenl. Blood samples wei;e collected tbr measurement of homocysteine, vitamin B12 and folates (hyperhomocysteinemia: >15 micromol/L; vitamin B12 deficiency: <200 pg/ml; tolates deficiency: <5 ng/ml) Factors independently associated hy'perhomocysteinemia were also assessed by multiple logistic regession analysis. Results: 26 patients had gastritis with atrophy and 20 with only superficial gastritis. Eighleen out of 26 pts with AG (69.2%) showed hyperhomocysteinemla (mean value 16 +/- 6) with respect to 4 pts (20%) in tbe group with SG (mean value 8 +/- 4) in 14 (53.8%) subiects with atrophic gastritis a vnamin B12 deficiency was present (mean value 169+23); in the group with superficial gasmtis only one patmnt (5%) showed a vitaminic deficiency (mean value 357+27). Low folates we*e demonstrable in 6 patients in d'm group with AG (23%) and 4 patients in the group of SG (20%). The presence of atrophic gastritis (histologic grades b 4 vs. 0-1, or 5.3, 95% CL 1 2 3 2 5 2 6 , Chi-square=5.2 p=0.01) and low vitamin B12 (or 3.7, 95% C.I. 1 03-2208 Chi-square = 3 6 p < 0 05) were both predictors of hyperhomocysteinemia. None of the other valiables included in the analysis sbowed a significant association. Conclusion: These preliminary data suggest atrophic gastritis, rather titan the infection with H pylori alone, as a possible contributing lactor to hyI3erhomocystinemia, possibly" through ,Atamin B12 malabsorption
Imerleukin (IL) 17 Activates Mitogen-Activated Protein Kinases Leading to ID8 Production in Gastric Epithelial Cells Ladislava Sebkova, Antonia Pellicano, Giovanni Monteleone, Barbara Grazioli, Francesco Pugliano, Maria G hneneo, Giovanni Guamieri, Francesco Pallone, Francesco Luzza Background: IL-8 plays a major role in Helicobacter pylori-associated inflammatoi3, response. Previous studies demonstrated that IL-17 is a potent inducer of IL-8 sy"nthesis by epithelial cells. Furthermore, 1L-17 has been showed to be increased in human gastric mucosa colonized by H.pylori. Aim: To investigate the molecular mechanism of ll_-17-induced IL-8 production in gastric epnhelial cells. Specific aim was to explore the role of MAP kinases ERK, JNK, and p38. Methods: Human gastric cancer cells MKN28 were cultivated in complete medium at a concentration of 3.000.000 cells/ml until they rich confluence After that, MKN28 cells were serum deprived for 12 hours and then stimulated with graded doses of human recombinant 11-17 (0.1, 1, 10 ng/ml) for 15, 30, 60, and 120 minutes. In some experiments, MKN28 cells were treated with the specific ERK inhibitor PD98059 (10 micmM) for 30 minutes before stimulation with 1L-17. A similar protocol was used to btock JNK and p38 using the specific inhibitors 5P600125 (10 microM) and SB202190 (i0 micmM), respectively. Finally', total proteins and mRNA were. extracted from MKN28 cells. Tire level of total and phosphorytated fractions of ERK, JNK, and p38 was evalutated by Western blotting, using specilic antibodies. IL-8 levels were measured by semiquanritative RT-PCR and Southern Blotting. All experiments were performed in triplicate Results: The addition of IL-17, dosedependently activated ERK within 15 minutes The level of activation was maintained up to 30 minutes, declined at 60 minutes and sligthly augmented at 120 minutes. PhosphoD'lalion of JNK and p38 did not modify. The amount of lD8 mRNA significantly increased alter 30 minutes, reached the maximum at 60 minutes, and slightly decreased at 120 minutes. The addition of ERK inhibitor completely abolished 1L-8 mRNA tmnseription. Otherwise, JNK and p38 inhibitors did not change IL-8 expression. No detectable levels of ID8 mRNA were evident in unstimulated MRN28 cells. Conclusion: These findings indicate that, in gastric epithelial cells, ILq7-induced IL-8 expression is mediated by the activation of ERK MAP kinases
W896
Overexpressinn of Thioredoxin-I in Transgenic Mice Prevents Helicobacter]elisInduced Gastritis Kimio Kawasalq, Kazuichi Okazaki, Hazuki Yoshizawa Shmya Oohashi, Hiroyqaki "Iamaki, Toshiro Fukui, Minoru Matsuura, Masanori Asada, Ioshiki NLshi, Kazushige Uchida, Masaluro iwano, Masaya Ohana, Tsutomu Chiba Background gr Aims:Thioredoxin (TRX) is a redox-active protein which is induced by" oxidative stresses and sbows a variety" of bidogical acrivines including cytopmtectkm against oxidative stresses TRX] by itself can scavenge reactive oxygen species (ROSY such as singlet oxygen, hydmx):l radical and hydrogen peroxide TRX is constitutively expressed in the mrrmal gastric mucosa, and ov'erexpressed in gastric carcinoma or by an anti-ulcer drug, gcranylgeranylacetone However, it is still unclear whether TRX is involved in the protection ot Heficobactet-induced gastnris or not To clarify it we analyzed the gastric mucosa ot infected TRX-transgenic mice Methods:Trasgenic (TG) mice overexpmssing human TILX1 and wild-type (WT) mice were oM/y inoculated with H. fetis Three montbs after the inoculation, histologic examinations, Western blots and immunohistochemlcat findings for TRX, iNOS, COX2, TNF-c*, and IL- I [3 in the gastric mucosa were serially"studied. ImmunohistochemistU tkir 8-hydroxy-2'-deoxyguanosine (8-OHdG) was aim perfbrmed as a marker of omdauve DNA damage Resnlts:H:{dis was continuously identified in the stomach of 'vVrand TG-mice. Macroscopical/y, the gastric nmcosa was snhstantially thickened in the infected Wl'-mice 3 months later, but not m the infer'ted TG-mice Histologically, the infected WTmwe developed chronic gastritis with moderate to severe lymphocyte infdtration, loss of parietal and chief cells, and proliferation of mucus neck cells. In contrast, none of the infected TG-mice Md gastritis Western blot and real time PCR showed COX-2, iNOS, TNFo< and 1L-113expressior~s remarkably decreased in infected TG-mice compared with infected WT-mice hnnmnohistocbemistry for 8OHdG showed lower intensity in infected TG-mice compared with inkcted WT-mice Conclusions:TRX1 has a protective role against Hdicobaeter-induced gastritis via down regnlation of proinflammatory cytokines in H fells intected gastric mucosa as welt as ROS
W899 Microarray Analysis of Epithelial Gene Expression Profiles during Gastric Helicobacter pylori Infection ivlichael Hoecker, Am3~aWalduck, Christian Wunder, Stelan Juettner, Bertram Wiedemnann, Thomas F. Meyer, Michael Naumann Background/Aims: Heficobacter pylori (H. pylori) represents a crucial determinant in the pathogenesis of Benign and neoplastic gasn'ic diseases, molecular mechanisms underlying its pathogenic action, however, are largely mxclear COX-2 is the inducible key enzyme of arachidonic metabolism and its prostanoid metabolites have been recognized as central mediators in inflammation and cancer Expression of the cox-2 gene is upregnlated during gastric H. pyloti infection, while pathobiological consequences of enhanced cox-2 gene expression in this setting are poorly understood. Methods: To identfly mucosal gene profiles regtllated by H. pylori through COX-2-dependent and -independent mechanisms in vivn, we analyzed epithelial gene expression at different time points (&19 weeks) of H. pylon infection using cDNA microarray techniques and an established rodent infection model. To evaluate the importance of COX-2 for H. pylon-triggered gene expression, subgroups of animals were treated with the COX-2-specific inhibitor NS398. Regulation of selected genes was confirmed by mrmunohistochemistty and/or real time PCR analysis. Results: H. pylori affected the expression of approximately 380 epithelial genes, comprising regulators of gastric acid secretion, apoptosis, angiogenesis and mucosal defense as well as transcription factors and signal transductinn molecules. Subgroups of H. pylori-responsive genes showed timedependent coregnlation in their expression patterns, indicating involvement in common pathobiological processes In addition, a substantial number of H. pylori target genes were identified to be up- or down-regulated through COX-2-dependent mechanisms. Similarly, in the non-iniectad mucosa, COX-2 appears to control the expression of a subset of genes Conclusions: Our study uncovers H. pylori-triggered epithehal gane expression profiles and their dynamics at different time points of infectkm. In addition, several novel H. pylori target genes, which have not been linked to gastric pathobiology yet, were identified. Moreover, regulation of dowmstream target genes through (a) COX-2-depen&tu pathway appears to represent an important mechanism for H. pylori-trlggered effects in the gastric mucosa. These data provide novel insights into potential mechanisms underlying the pathogenic action of H. pylori in the stomach and may help to develop new therapentic and/m" diagnostic strategies.
W897 Heat Shock Protein 60 of Helieobacter Pylori Induces tntlammatory Responses Through The TolbLike Receptor-Triggered Pathway in Cultured Human Gastric Epithelial Cells Ryuta Takcnaka, Kenji Yokota, Motowo Mizuno, Yoshihito Ft~linami, Tatsuya Toyokawa, SakLko Hitaoka Shinichiou Hon, Chiho Makidono, Susumu Take, Hiroyukl Okada, Rei}i Oguma, Yasushi Shiraton Background and aims: Contact between Helicobacler pylori and gastric epithelial cells results in activaBon ot nuclear factor (NF)-KB that is followed by' interleukin (IL)-8 production and induces the mucosal intihration of inflammatory cells. However, a host cell receptor(s) and its figand on 8. D, loti revolved in the 11-8 prodnctinn have not been fully understood. The aim of this study was to examine the interaction of Toll-like receptors (TLBs; host receptors for patbogens in the innate inuumniy) and heat shock protein (HSD 60 (an immune-potent suriace antigen of H pyloti) during H. pylon-induced ll.-8 production in Kato II1 human gastric epithelial cells Metbods: Recombinant HSP60 of H. pylori was prepared as a glutathione S-transferase fusion protein Cnhured Kato 1II cells were reacted with the recombinam HSP60 with or without preincubation with mouse monoclona! anti-TLR2 or anti-TLR4 antibodies Expression of IL~8 mRNA and secretion of ID8 protein was analyzed by Northern blotung and immunoassay, respectively. To e~mfine NF-gB activation, ceils were stained by inlmunolluorescence using an i-NF-KB p65 antibody, and nuclear tmnslocation of p65 protein was evaluated using a conlocaI laser scanning microscope Results: Recombinant H. pylori HSP60 induced iL-8 mRNA expression and [L-8 secretion in dose* and time-dependent manners in Kato ii1 gastric epithelial cells Anti-TLR2 antibody inhibited HSP60-induced IL-8 secretion by 75%, whereas anti-TLR4 antibody reduced by 30% HSP60 induced nuclear translocation of p65, and prelreatmen~ with anti-TLR2 and anti-TLR4 antibodies inhibited the NF~KBnuclear translocaUon. (ionclusion: ttSP60 of 1f. pylori activates NF-gB and induces II.-8 production through TLR2 and 4-trigered pathways in gastric epithelial cells. These findings suggest that the interaction of HSP60 of tt. Wlori and TLRs on host ceils is involved in tim development of gastritis due to H. }~vloti infi-:ction.
AGA
Abstracts
W900
He|icobacter Pylori Regulates Expression of 1D-1 and ID-3 but Not ID-2 Barbara Ada Manzo, Mona Bajaj-Elliott, John C. Atherton, Rachel J. Thomas, ian R. Sanderson, James W Wilson
Helicobacter pylori (H.p.) can induce both apoptosis and proliferation of gastric epithelial cells. The balance between these two processes during bacterial infection depends on both host and microbial determinants and underlay the, nsk of developing cancer Id (Inhibitor of differentiation/DNA binding) helix-loop-helix proteins are critically Mated to cell cycle progression, diflerentiation and apoptosis. These eflects are mediated by inhibiting the DNA binding of basic HLH transcription factors, such as the ubiquitous E47 and tissue-specific factors like myoD. We hypothesised that H,p. could regulate ld expression in gastric epithelial cells tollowing infection. AGS cells were co-cuhured with Hp. 60190 wild type strain (lx 10~ l~actena/cell) fl'om 2 to 48 hours. RT-PCR analysis revealed down-regulation for ld-1 and Id-3 mDNA levels, which occurred over the first 6 hours of exposure to H.p_ In contrast, Id-2 mRNA levels remained constant. In agreement with transcriptional data, Western blot analysis showed that protein levels were strongly and rapidly" downmgnlated by the bacteria; again ld-2 protein levels were unaltered. Culture of AGS ceils in presence of H.p. resulted in the
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accmnulation of cells in the GI phase of the cell cycle (60% after 24 hours compared with 40% iu control cultures), as assessed by"FACS analysis. No significant apoptosis was observed. Iu conclusion, H.p. results m decreased Id-1 and ld-3 e~xpressinn in AGS cells in vitro, which is associated with arrest of the cells in G1 phase of the cell cycle. These results indicate that Hp can alter the expression of key regulatory transeription t~mtorscontrolling gene expression in the cell cycle
Two samples were used to assess PMN cell infiltration (Sydney system) and H.pylori status. Epithelial cells were isolated from biopsies by means of EDTA/EGTA lot I 0 toni. The isolated cells were counted and viability was measured. Total proteins and RNA were extracted from freshly isolated epithelial cells, pERK~RK, pJNK/JNK, and pp38/p38 were analysed by Western blotting. Transcripts of IL-8 and beta-actin were measured by RT-PCR and Southeru blotting. Results: Levels ofJNK, ERK, and p38 were equal m afi tested samples, irrespectwe of H.pylon. However, the amount of phosphorylated ERK, JNK, and p38 in gastric epithelial cells from H.pylori-infected patients (u = 11) was significantly higher compared to that fi'om uninfected patients. Accordingly, levels of 1L-8 transcripts in gastric epithelial cells and the degree of PMN cell infiltration in the gastric mucosa were increased in H.pyIori-nitected samples. Conclusion: Findings of this study indicate that H.pylori infection is associated with the activation of ERK, JNK, and p38 in human gastric epithehal cells. These MAP kinases may have a role in H.pylori-mduced IL-8 production.
W901 Distinct Inhibitory Role of Helicobacter t~'lori for The Expression of The Secretory Leukocyte Protease Inhibitor in The Stomach and Duodenum Tbnmas Wex, Gerhard Ti~iber, blanfi'ed Nilnis, Michael Vieth, Albert Roessner, Peter Ma/krtbeiner Background: Secretory leukocyte protease inhibitor (SLPI) has been implicated as a componetu of the first line deknse ot epithelia nichiding the intestinal and gastric mucus,a. In order to study the etlect of gasmc H.pylori nitection on SLPI expression, 29 heahhy volunteers (ttV) who were grouped accordingly to their H.pylon status (H.pylori-positive, n = 10 ; H.pylori-negative following successful eradication therapy, n = 9 ; and H.pylori-negative individuals, n = 10) were analyzed. Methods: SLPI expression was analyzed using biopsies by quantitative RT-PCR, ELISA and immunohistochemisrty. Results: SLPI expression differed significamly with respect to location (antrum > corpus > bulbus) and H.pylori-status (H.pylori+ < H.pylori- = H.pylori-eradicated). SLPI levels were reduced by 67% in the antrum of Hp-positive individuals, whereas other regions and both control groups did not reveals diftkrences in SI21 levels. Interestingly, the location-dependent differences were accompanied by corresponding SLPI-mRNA levels, whereas the amounts of SLPI-mRNA did not differ with respect to the H.pylori status, implying regulation at a posttranslational level. Immunohlstochemistel revealed high SLPI expression in epithelial ceils of the gastric surface mucosa and deep loveolar glands in H.pylori-negative I-W. In accordance to ELISA, SLP1expression was strongly reduced in the epithelium of H~pylori+ HV. SLP1 levels in sera were similar in all groups. The successhil eradication of H.pylori resulted in the normalization of SLPI expression provnig that the gastnc H.pylori infection is the primary cause [br diutinished antral SLPI expression, Conclusion: SLPI represents a protective factor of the gastric mucosa that is strongly reduced locally in the antrum during H.pylori infection, This work was supported in part by the ~utsche Forsehungsgememschafi, Germany (We2170/ 3-1)
W904 Efl'ects of Helicobacter Pylor/Infection on The Link Between Regenerating Gene Expression and Serum Gastrin Levels in Mongolian Gerbils Hirokazu Fukni, Tsutomu Chiba, Robert M. Gema Background & Aims: Although regenerating gene (Peg) protein is reported to have a trophic eflect on gastric epithelial cells, its nivoh,emem in human gastric diseases is not dear. We have recently shown that both gastrin and gastric mucusal inflammation enhance Reg gene expression in the hindic mucosa in rats. This study was designed to clarify whether Reg protein is involved m Helicobacter pylon (H, pylon)-niduced gastritis and whether Reg germ expression is linked to serum gastnn levels in this condition. Methods: Mongolian gerbils weighing 30-50 g were nioculated with an H. pylori strain CA20 isolated from a gastric cancer patient. Four weeks later, some of the gerbils with H. pflori infection were eradicated by lansoprazole, amoxicillni and darithromycin (10, 3 and 30 mg/kg body weight, respectively). Both infected and unifected gerbils were sacrificed at 1, 2, 4, 6, 8,12, 24, and 36 weeks after inoculation. The gerbils which had undergone H, pylori eradication were sacrificed at 6 and 8 weeks after inoculation. The time courses of changes in serum gastrin levels, gastric acidity and histopathological factors were examined ni each groups. In addition, the time courses of changes in Peg gene expression were examined by Northern blot, and immunostainnig for Reg protein were carried out. Results: Four weeks after H. pyloti infection, gastritis started spreading to the lundic mucosa and gastric acidity started reducing. Serum gastrin levels and Reg mRNA expression in the fundns were significantly increased 6 weeks after infection. Peg mRNA expression in the hindus correlated significamly with both serum gastrin levels and the severity of fundic mucosal inflammation. After H. pylori eradication, serum gastrin levels and fundic mucosa[ inflammation were normalized and the increase m Peg mRNA expression was abolished. Although Reg protein-positive ceils were hardly detected in the normal fundic mucosa, the number of Reg protein-positive cells was increased in H. pylorMnfected gerbils at more than 12 weeks after inoculation. Conclusions: The increase in Reg geue expression in fundic mucosa is associated with hypergastrinemia and hindic mucosal mflammation and may be involved in development of H. pylori-induced gastritis.
W902 H. pylon Binds CD74 on Gastric Epithelial Cells and Causes IL-8 Secretion Ellen J. Beswick, Xuejung Fan, Victor E. Reyes BACKGROUND: Gastric epithelial cells express the class II MHC-associated invariam chain (Ii, CD74) on the cetl surface. Since Ii is phosphorylated, and an isoform of Ii (IiCS)is modibed by choudoritin sulfate, which binds H. pylon, we hypothesized that Ii expressed by gastric epithelial cells mediates H. pylnri attachment and this interaction leads to epithelial cell responses associated with the inthmmatory response. METHODS: The presence of the invariant chain and the chondroitin sullate isoform on the surface of N87 and tetal gastric epithelial cells was determined and quantita~ed by confocal microscopy and flow cytometry, respectively, tt. pylori binding to the nivariant chain was investigated using cell lysates from a B cell line (P3HR1) that expresses it, but not class II MHC molecules that was used as a source of li to assess its binding to H. pylori. The preseuce of li among the cell proteins that bound to H. pylon was determined by SDS@AGE, autoradiogmphy, and Western Blotting. The role of chondroitin sufiate in H. pylori attachment was investigated by staining bacteria and measuring attachment to gastnc epithelial ceils before and after enzymatic removal of choudroitni sulfate, or blocking attachment by coating bacteria with chondroitin sultate Expression of inflammatory cytokines induced by H. pylori or crosslinking antibodies to Ii and IiCS was determined by ELISA. RESULTS: The mvariant chain and the chondroitin sultate isoform are expressed on bofh N87 and fetal gastric- epithelial cells surfaces at similar levels, up to 5 x 104 molecules per cell. Detailed analysis of cells by confocal microscopy revealed both of these nmlecules on the apical surtace of gastric epithelial cells. H. pylori was tbund to bind li from cell lysates Interestingly, the attachment of H. pylori to gastric epithelial cells was ~'educed upon removal of cbondmitin sulfate from cells or by competitive inhibition with chondmitin suflate, which suggests a role tbr the IiCS in H, pylori binding. This interaction may have biologmal cortsequences since IG8 was induced following crosslinking of li or IiCS wtth antibodies. CONCLUSIONS: The resuhs indicate that the nivariant chain and the chondroitni sulfate modified isoform are present on gastric epithelial cells and may play a role in H pylori attachment to the host gastric epithelium and the resulting nitlammatory response.
W905 Transformation of Helicobacter Pylori Affects The Expression of Tlrs and IL-8 Mrna Joon Yong Park, Dong Son Hart, Jni Bae Kim, Hang Lak Lee, Yin Chun Li, Joo Hymn Sohn, Ho Soon Choi, joon Son Hahm Background : Helicobacter pylori induces gastric mucosal inflammation without direct invasion. The interaction between the bacteria and gastric mucosa would have the main role in initiating an immune response in gastric mucosa. Helicobacter pylori exists in two forms; a spiral form and a coccoid form. The coccoid form H. pylon is alive and metabolically active but noncuhurable. The role of the coccoid form in pathogenesis of gastric diseases remains unclear. We investigated the H. pylori infection-induced expression of Toll-like receptors 2, 3, 4, 5 and Ik-8 mRNA, and the eltect of coccoid transformation of H. pylori on the expression of TLRs mRNA from the AGS cell line. Methods : After 3 days of culture on Brucella agar with 5% horse serum in a microaerophilic atmosphere, Helicohacter pylon were stored in Brani-heart infusion broth, containing 10% horse serum, for 3 days to obtain spiral forms of H. pylori and 7 days for coccoid torms of H. pylon. Both forms of H. pylori were added to the human gastric epithelial cell line, AGS and cultured for 24 hours RTPCP,s for TLR2, 3, 4, 5 and IL-8 were performed utter a 24-hour cuhure of AGS. Results : Both torms of H. pylori did not induce the difference in expression of TLR 2, 3 and 4. mRNA (TLR2/lB-actm 0.72 vs. 0.75, TLP,3//3-actin 0.31 vs. 0.29, TLR4/~-actin 0.87 vs. 0.89). However, decreased expression of TLR5 was detected in coccoid form H. pyloriinfected AGS while the TLR5 expression was increased by spiral form H. pylori infection (TkRS/13-actin 0.58 vs. 0.032). Additionally, 1L-8 mRNA expression was less potent in coccoid-lorm H. pylori-infected AGS (IL-8/~-actin 021 vs 0.71). Conclusions : The transformation of H. pylon changes the pathogenicity of the bacteria and the immune reaction of gastric mucosa. Decreased expression of TLR5 and 1L-8 mPcNAwithout any change of TLR4 expression was shown in coccoid tbrm H. pylori-infected AGS. Decreased expression of flagellin induced by structural change of flagella &mug the transfom~ation would affect the immune reaction of gastric mucosa,
W903 Activation of MAP-Kinases and Increased Levels of interleakin 8 in Ex Vivo Human Gastric Epithelial Cells Associates with Helicobacter Pylori Infection Ladislava Sebkova, Antonia Pellicano, Giovanni Monteleone, Barbara Grazinli, Francesco I%~ghano, Maria G. Imeneo, Francesco Pallone, Francesco Luzza Background MAP kinases are a tamily of ubiquitous, highly' conserved, cell sigualing molecules. They can be activated by a wide variety of extracellular stimuli like IL-1, TNF-alpha, and pathogens and transmit signals from the cell surtace to the nucleus to regulate gene expression. These signaling pathways may induce the production of 1L-8, a chemotactic factor ol polymorphonuclear (PMN) celts. Epithelial cells are the first barrier against bacterial infections and a major source of 1L-8 H.pylori-associated gastritis is characterized by massive mucosal infiltration ot PMN cells, confirmnig an important role of IL-8 in this iutlammatoD, response. Aim: To evaluate the activation of MAP kinases ERK, JNK, and p38 m gastric epithelial cells trom pat*cuts ,alth H.pylori int}ction and its relationship with 1L-8 expression. Methods : 19 patients (10M; 23-62 yrs, median 42) who underwem gastroscopy for dyspeptic complaims were studied. During endoscopy, s~x biopsies were obtained from each patient.
W906 Somatostatin Inhibits LPS-induced Dendritic Cell Maturation John Y, Kao, Sivaprakash Rathinavehi, Juanita L, Merchant Background: Dendritic cells (DCs) are the most potent antigen presenting cells (APC) that modulate host immune responses to foreign pathogens. CD40 expression on DCs plays an important role in their activation and is essential for induction of antigen-speci tic Tcell respmtses. We recendy showed that somatostatin (SST) mediates IL-4 resolution of Helicobacter-induced gastitis (Gastro 122(4):A22, 2002). Aim: On this basis, we examined
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AGA Abstracts
55 +/- 12 years) with endoscopy-proven gastritis, with active H pylori infection confirmed by- both 13C-urea breath test and serdogy. At upper gastrointestinal endoscopy 6 biopsies were taken Presence/degree of gastric atrophy grade were assessed using a validated scoring systenl. Blood samples wei;e collected tbr measurement of homocysteine, vitamin B12 and folates (hyperhomocysteinemia: >15 micromol/L; vitamin B12 deficiency: <200 pg/ml; tolates deficiency: <5 ng/ml) Factors independently associated hy'perhomocysteinemia were also assessed by multiple logistic regession analysis. Results: 26 patients had gastritis with atrophy and 20 with only superficial gastritis. Eighleen out of 26 pts with AG (69.2%) showed hyperhomocysteinemla (mean value 16 +/- 6) with respect to 4 pts (20%) in tbe group with SG (mean value 8 +/- 4) in 14 (53.8%) subiects with atrophic gastritis a vnamin B12 deficiency was present (mean value 169+23); in the group with superficial gasmtis only one patmnt (5%) showed a vitaminic deficiency (mean value 357+27). Low folates we*e demonstrable in 6 patients in d'm group with AG (23%) and 4 patients in the group of SG (20%). The presence of atrophic gastritis (histologic grades b 4 vs. 0-1, or 5.3, 95% CL 1 2 3 2 5 2 6 , Chi-square=5.2 p=0.01) and low vitamin B12 (or 3.7, 95% C.I. 1 03-2208 Chi-square = 3 6 p < 0 05) were both predictors of hyperhomocysteinemia. None of the other valiables included in the analysis sbowed a significant association. Conclusion: These preliminary data suggest atrophic gastritis, rather titan the infection with H pylori alone, as a possible contributing lactor to hyI3erhomocystinemia, possibly" through ,Atamin B12 malabsorption
Imerleukin (IL) 17 Activates Mitogen-Activated Protein Kinases Leading to ID8 Production in Gastric Epithelial Cells Ladislava Sebkova, Antonia Pellicano, Giovanni Monteleone, Barbara Grazioli, Francesco Pugliano, Maria G hneneo, Giovanni Guamieri, Francesco Pallone, Francesco Luzza Background: IL-8 plays a major role in Helicobacter pylori-associated inflammatoi3, response. Previous studies demonstrated that IL-17 is a potent inducer of IL-8 sy"nthesis by epithelial cells. Furthermore, 1L-17 has been showed to be increased in human gastric mucosa colonized by H.pylori. Aim: To investigate the molecular mechanism of ll_-17-induced IL-8 production in gastric epnhelial cells. Specific aim was to explore the role of MAP kinases ERK, JNK, and p38. Methods: Human gastric cancer cells MKN28 were cultivated in complete medium at a concentration of 3.000.000 cells/ml until they rich confluence After that, MKN28 cells were serum deprived for 12 hours and then stimulated with graded doses of human recombinant 11-17 (0.1, 1, 10 ng/ml) for 15, 30, 60, and 120 minutes. In some experiments, MKN28 cells were treated with the specific ERK inhibitor PD98059 (10 micmM) for 30 minutes before stimulation with 1L-17. A similar protocol was used to btock JNK and p38 using the specific inhibitors 5P600125 (10 microM) and SB202190 (i0 micmM), respectively. Finally', total proteins and mRNA were. extracted from MKN28 cells. Tire level of total and phosphorytated fractions of ERK, JNK, and p38 was evalutated by Western blotting, using specilic antibodies. IL-8 levels were measured by semiquanritative RT-PCR and Southern Blotting. All experiments were performed in triplicate Results: The addition of IL-17, dosedependently activated ERK within 15 minutes The level of activation was maintained up to 30 minutes, declined at 60 minutes and sligthly augmented at 120 minutes. PhosphoD'lalion of JNK and p38 did not modify. The amount of lD8 mRNA significantly increased alter 30 minutes, reached the maximum at 60 minutes, and slightly decreased at 120 minutes. The addition of ERK inhibitor completely abolished 1L-8 mRNA tmnseription. Otherwise, JNK and p38 inhibitors did not change IL-8 expression. No detectable levels of ID8 mRNA were evident in unstimulated MRN28 cells. Conclusion: These findings indicate that, in gastric epithelial cells, ILq7-induced IL-8 expression is mediated by the activation of ERK MAP kinases
W896
Overexpressinn of Thioredoxin-I in Transgenic Mice Prevents Helicobacter]elisInduced Gastritis Kimio Kawasalq, Kazuichi Okazaki, Hazuki Yoshizawa Shmya Oohashi, Hiroyqaki "Iamaki, Toshiro Fukui, Minoru Matsuura, Masanori Asada, Ioshiki NLshi, Kazushige Uchida, Masaluro iwano, Masaya Ohana, Tsutomu Chiba Background gr Aims:Thioredoxin (TRX) is a redox-active protein which is induced by" oxidative stresses and sbows a variety" of bidogical acrivines including cytopmtectkm against oxidative stresses TRX] by itself can scavenge reactive oxygen species (ROSY such as singlet oxygen, hydmx):l radical and hydrogen peroxide TRX is constitutively expressed in the mrrmal gastric mucosa, and ov'erexpressed in gastric carcinoma or by an anti-ulcer drug, gcranylgeranylacetone However, it is still unclear whether TRX is involved in the protection ot Heficobactet-induced gastnris or not To clarify it we analyzed the gastric mucosa ot infected TRX-transgenic mice Methods:Trasgenic (TG) mice overexpmssing human TILX1 and wild-type (WT) mice were oM/y inoculated with H. fetis Three montbs after the inoculation, histologic examinations, Western blots and immunohistochemlcat findings for TRX, iNOS, COX2, TNF-c*, and IL- I [3 in the gastric mucosa were serially"studied. ImmunohistochemistU tkir 8-hydroxy-2'-deoxyguanosine (8-OHdG) was aim perfbrmed as a marker of omdauve DNA damage Resnlts:H:{dis was continuously identified in the stomach of 'vVrand TG-mice. Macroscopical/y, the gastric nmcosa was snhstantially thickened in the infected Wl'-mice 3 months later, but not m the infer'ted TG-mice Histologically, the infected WTmwe developed chronic gastritis with moderate to severe lymphocyte infdtration, loss of parietal and chief cells, and proliferation of mucus neck cells. In contrast, none of the infected TG-mice Md gastritis Western blot and real time PCR showed COX-2, iNOS, TNFo< and 1L-113expressior~s remarkably decreased in infected TG-mice compared with infected WT-mice hnnmnohistocbemistry for 8OHdG showed lower intensity in infected TG-mice compared with inkcted WT-mice Conclusions:TRX1 has a protective role against Hdicobaeter-induced gastritis via down regnlation of proinflammatory cytokines in H fells intected gastric mucosa as welt as ROS
W899 Microarray Analysis of Epithelial Gene Expression Profiles during Gastric Helicobacter pylori Infection ivlichael Hoecker, Am3~aWalduck, Christian Wunder, Stelan Juettner, Bertram Wiedemnann, Thomas F. Meyer, Michael Naumann Background/Aims: Heficobacter pylori (H. pylori) represents a crucial determinant in the pathogenesis of Benign and neoplastic gasn'ic diseases, molecular mechanisms underlying its pathogenic action, however, are largely mxclear COX-2 is the inducible key enzyme of arachidonic metabolism and its prostanoid metabolites have been recognized as central mediators in inflammation and cancer Expression of the cox-2 gene is upregnlated during gastric H. pyloti infection, while pathobiological consequences of enhanced cox-2 gene expression in this setting are poorly understood. Methods: To identfly mucosal gene profiles regtllated by H. pylori through COX-2-dependent and -independent mechanisms in vivn, we analyzed epithelial gene expression at different time points (&19 weeks) of H. pylon infection using cDNA microarray techniques and an established rodent infection model. To evaluate the importance of COX-2 for H. pylon-triggered gene expression, subgroups of animals were treated with the COX-2-specific inhibitor NS398. Regulation of selected genes was confirmed by mrmunohistochemistty and/or real time PCR analysis. Results: H. pylori affected the expression of approximately 380 epithelial genes, comprising regulators of gastric acid secretion, apoptosis, angiogenesis and mucosal defense as well as transcription factors and signal transductinn molecules. Subgroups of H. pylori-responsive genes showed timedependent coregnlation in their expression patterns, indicating involvement in common pathobiological processes In addition, a substantial number of H. pylori target genes were identified to be up- or down-regulated through COX-2-dependent mechanisms. Similarly, in the non-iniectad mucosa, COX-2 appears to control the expression of a subset of genes Conclusions: Our study uncovers H. pylori-triggered epithehal gane expression profiles and their dynamics at different time points of infectkm. In addition, several novel H. pylori target genes, which have not been linked to gastric pathobiology yet, were identified. Moreover, regulation of dowmstream target genes through (a) COX-2-depen&tu pathway appears to represent an important mechanism for H. pylori-trlggered effects in the gastric mucosa. These data provide novel insights into potential mechanisms underlying the pathogenic action of H. pylori in the stomach and may help to develop new therapentic and/m" diagnostic strategies.
W897 Heat Shock Protein 60 of Helieobacter Pylori Induces tntlammatory Responses Through The TolbLike Receptor-Triggered Pathway in Cultured Human Gastric Epithelial Cells Ryuta Takcnaka, Kenji Yokota, Motowo Mizuno, Yoshihito Ft~linami, Tatsuya Toyokawa, SakLko Hitaoka Shinichiou Hon, Chiho Makidono, Susumu Take, Hiroyukl Okada, Rei}i Oguma, Yasushi Shiraton Background and aims: Contact between Helicobacler pylori and gastric epithelial cells results in activaBon ot nuclear factor (NF)-KB that is followed by' interleukin (IL)-8 production and induces the mucosal intihration of inflammatory cells. However, a host cell receptor(s) and its figand on 8. D, loti revolved in the 11-8 prodnctinn have not been fully understood. The aim of this study was to examine the interaction of Toll-like receptors (TLBs; host receptors for patbogens in the innate inuumniy) and heat shock protein (HSD 60 (an immune-potent suriace antigen of H pyloti) during H. pylon-induced ll.-8 production in Kato II1 human gastric epithelial cells Metbods: Recombinant HSP60 of H. pylori was prepared as a glutathione S-transferase fusion protein Cnhured Kato 1II cells were reacted with the recombinam HSP60 with or without preincubation with mouse monoclona! anti-TLR2 or anti-TLR4 antibodies Expression of IL~8 mRNA and secretion of ID8 protein was analyzed by Northern blotung and immunoassay, respectively. To e~mfine NF-gB activation, ceils were stained by inlmunolluorescence using an i-NF-KB p65 antibody, and nuclear tmnslocation of p65 protein was evaluated using a conlocaI laser scanning microscope Results: Recombinant H. pylori HSP60 induced iL-8 mRNA expression and [L-8 secretion in dose* and time-dependent manners in Kato ii1 gastric epithelial cells Anti-TLR2 antibody inhibited HSP60-induced IL-8 secretion by 75%, whereas anti-TLR4 antibody reduced by 30% HSP60 induced nuclear translocation of p65, and prelreatmen~ with anti-TLR2 and anti-TLR4 antibodies inhibited the NF~KBnuclear translocaUon. (ionclusion: ttSP60 of 1f. pylori activates NF-gB and induces II.-8 production through TLR2 and 4-trigered pathways in gastric epithelial cells. These findings suggest that the interaction of HSP60 of tt. Wlori and TLRs on host ceils is involved in tim development of gastritis due to H. }~vloti infi-:ction.
AGA
Abstracts
W900
He|icobacter Pylori Regulates Expression of 1D-1 and ID-3 but Not ID-2 Barbara Ada Manzo, Mona Bajaj-Elliott, John C. Atherton, Rachel J. Thomas, ian R. Sanderson, James W Wilson
Helicobacter pylori (H.p.) can induce both apoptosis and proliferation of gastric epithelial cells. The balance between these two processes during bacterial infection depends on both host and microbial determinants and underlay the, nsk of developing cancer Id (Inhibitor of differentiation/DNA binding) helix-loop-helix proteins are critically Mated to cell cycle progression, diflerentiation and apoptosis. These eflects are mediated by inhibiting the DNA binding of basic HLH transcription factors, such as the ubiquitous E47 and tissue-specific factors like myoD. We hypothesised that H,p. could regulate ld expression in gastric epithelial cells tollowing infection. AGS cells were co-cuhured with Hp. 60190 wild type strain (lx 10~ l~actena/cell) fl'om 2 to 48 hours. RT-PCR analysis revealed down-regulation for ld-1 and Id-3 mDNA levels, which occurred over the first 6 hours of exposure to H.p_ In contrast, Id-2 mRNA levels remained constant. In agreement with transcriptional data, Western blot analysis showed that protein levels were strongly and rapidly" downmgnlated by the bacteria; again ld-2 protein levels were unaltered. Culture of AGS ceils in presence of H.p. resulted in the
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accmnulation of cells in the GI phase of the cell cycle (60% after 24 hours compared with 40% iu control cultures), as assessed by"FACS analysis. No significant apoptosis was observed. Iu conclusion, H.p. results m decreased Id-1 and ld-3 e~xpressinn in AGS cells in vitro, which is associated with arrest of the cells in G1 phase of the cell cycle. These results indicate that Hp can alter the expression of key regulatory transeription t~mtorscontrolling gene expression in the cell cycle
Two samples were used to assess PMN cell infiltration (Sydney system) and H.pylori status. Epithelial cells were isolated from biopsies by means of EDTA/EGTA lot I 0 toni. The isolated cells were counted and viability was measured. Total proteins and RNA were extracted from freshly isolated epithelial cells, pERK~RK, pJNK/JNK, and pp38/p38 were analysed by Western blotting. Transcripts of IL-8 and beta-actin were measured by RT-PCR and Southeru blotting. Results: Levels ofJNK, ERK, and p38 were equal m afi tested samples, irrespectwe of H.pylon. However, the amount of phosphorylated ERK, JNK, and p38 in gastric epithelial cells from H.pylori-infected patients (u = 11) was significantly higher compared to that fi'om uninfected patients. Accordingly, levels of 1L-8 transcripts in gastric epithelial cells and the degree of PMN cell infiltration in the gastric mucosa were increased in H.pyIori-nitected samples. Conclusion: Findings of this study indicate that H.pylori infection is associated with the activation of ERK, JNK, and p38 in human gastric epithehal cells. These MAP kinases may have a role in H.pylori-mduced IL-8 production.
W901 Distinct Inhibitory Role of Helicobacter t~'lori for The Expression of The Secretory Leukocyte Protease Inhibitor in The Stomach and Duodenum Tbnmas Wex, Gerhard Ti~iber, blanfi'ed Nilnis, Michael Vieth, Albert Roessner, Peter Ma/krtbeiner Background: Secretory leukocyte protease inhibitor (SLPI) has been implicated as a componetu of the first line deknse ot epithelia nichiding the intestinal and gastric mucus,a. In order to study the etlect of gasmc H.pylori nitection on SLPI expression, 29 heahhy volunteers (ttV) who were grouped accordingly to their H.pylon status (H.pylori-positive, n = 10 ; H.pylori-negative following successful eradication therapy, n = 9 ; and H.pylori-negative individuals, n = 10) were analyzed. Methods: SLPI expression was analyzed using biopsies by quantitative RT-PCR, ELISA and immunohistochemisrty. Results: SLPI expression differed significamly with respect to location (antrum > corpus > bulbus) and H.pylori-status (H.pylori+ < H.pylori- = H.pylori-eradicated). SLPI levels were reduced by 67% in the antrum of Hp-positive individuals, whereas other regions and both control groups did not reveals diftkrences in SI21 levels. Interestingly, the location-dependent differences were accompanied by corresponding SLPI-mRNA levels, whereas the amounts of SLPI-mRNA did not differ with respect to the H.pylori status, implying regulation at a posttranslational level. Immunohlstochemistel revealed high SLPI expression in epithelial ceils of the gastric surface mucosa and deep loveolar glands in H.pylori-negative I-W. In accordance to ELISA, SLP1expression was strongly reduced in the epithelium of H~pylori+ HV. SLP1 levels in sera were similar in all groups. The successhil eradication of H.pylori resulted in the normalization of SLPI expression provnig that the gastnc H.pylori infection is the primary cause [br diutinished antral SLPI expression, Conclusion: SLPI represents a protective factor of the gastric mucosa that is strongly reduced locally in the antrum during H.pylori infection, This work was supported in part by the ~utsche Forsehungsgememschafi, Germany (We2170/ 3-1)
W904 Efl'ects of Helicobacter Pylor/Infection on The Link Between Regenerating Gene Expression and Serum Gastrin Levels in Mongolian Gerbils Hirokazu Fukni, Tsutomu Chiba, Robert M. Gema Background & Aims: Although regenerating gene (Peg) protein is reported to have a trophic eflect on gastric epithelial cells, its nivoh,emem in human gastric diseases is not dear. We have recently shown that both gastrin and gastric mucusal inflammation enhance Reg gene expression in the hindic mucosa in rats. This study was designed to clarify whether Reg protein is involved m Helicobacter pylon (H, pylon)-niduced gastritis and whether Reg germ expression is linked to serum gastnn levels in this condition. Methods: Mongolian gerbils weighing 30-50 g were nioculated with an H. pylori strain CA20 isolated from a gastric cancer patient. Four weeks later, some of the gerbils with H. pflori infection were eradicated by lansoprazole, amoxicillni and darithromycin (10, 3 and 30 mg/kg body weight, respectively). Both infected and unifected gerbils were sacrificed at 1, 2, 4, 6, 8,12, 24, and 36 weeks after inoculation. The gerbils which had undergone H, pylori eradication were sacrificed at 6 and 8 weeks after inoculation. The time courses of changes in serum gastrin levels, gastric acidity and histopathological factors were examined ni each groups. In addition, the time courses of changes in Peg gene expression were examined by Northern blot, and immunostainnig for Reg protein were carried out. Results: Four weeks after H. pyloti infection, gastritis started spreading to the lundic mucosa and gastric acidity started reducing. Serum gastrin levels and Reg mRNA expression in the fundns were significantly increased 6 weeks after infection. Peg mRNA expression in the hindus correlated significamly with both serum gastrin levels and the severity of fundic mucosal inflammation. After H. pylori eradication, serum gastrin levels and fundic mucosa[ inflammation were normalized and the increase m Peg mRNA expression was abolished. Although Reg protein-positive ceils were hardly detected in the normal fundic mucosa, the number of Reg protein-positive cells was increased in H. pylorMnfected gerbils at more than 12 weeks after inoculation. Conclusions: The increase in Reg geue expression in fundic mucosa is associated with hypergastrinemia and hindic mucosal mflammation and may be involved in development of H. pylori-induced gastritis.
W902 H. pylon Binds CD74 on Gastric Epithelial Cells and Causes IL-8 Secretion Ellen J. Beswick, Xuejung Fan, Victor E. Reyes BACKGROUND: Gastric epithelial cells express the class II MHC-associated invariam chain (Ii, CD74) on the cetl surface. Since Ii is phosphorylated, and an isoform of Ii (IiCS)is modibed by choudoritin sulfate, which binds H. pylon, we hypothesized that Ii expressed by gastric epithelial cells mediates H. pylnri attachment and this interaction leads to epithelial cell responses associated with the inthmmatory response. METHODS: The presence of the invariant chain and the chondroitin sullate isoform on the surface of N87 and tetal gastric epithelial cells was determined and quantita~ed by confocal microscopy and flow cytometry, respectively, tt. pylori binding to the nivariant chain was investigated using cell lysates from a B cell line (P3HR1) that expresses it, but not class II MHC molecules that was used as a source of li to assess its binding to H. pylori. The preseuce of li among the cell proteins that bound to H. pylon was determined by SDS@AGE, autoradiogmphy, and Western Blotting. The role of chondroitin sufiate in H. pylori attachment was investigated by staining bacteria and measuring attachment to gastnc epithelial ceils before and after enzymatic removal of choudroitni sulfate, or blocking attachment by coating bacteria with chondroitin sultate Expression of inflammatory cytokines induced by H. pylori or crosslinking antibodies to Ii and IiCS was determined by ELISA. RESULTS: The mvariant chain and the chondroitin sultate isoform are expressed on bofh N87 and fetal gastric- epithelial cells surfaces at similar levels, up to 5 x 104 molecules per cell. Detailed analysis of cells by confocal microscopy revealed both of these nmlecules on the apical surtace of gastric epithelial cells. H. pylori was tbund to bind li from cell lysates Interestingly, the attachment of H. pylori to gastric epithelial cells was ~'educed upon removal of cbondmitin sulfate from cells or by competitive inhibition with chondmitin suflate, which suggests a role tbr the IiCS in H, pylori binding. This interaction may have biologmal cortsequences since IG8 was induced following crosslinking of li or IiCS wtth antibodies. CONCLUSIONS: The resuhs indicate that the nivariant chain and the chondroitni sulfate modified isoform are present on gastric epithelial cells and may play a role in H pylori attachment to the host gastric epithelium and the resulting nitlammatory response.
W905 Transformation of Helicobacter Pylori Affects The Expression of Tlrs and IL-8 Mrna Joon Yong Park, Dong Son Hart, Jni Bae Kim, Hang Lak Lee, Yin Chun Li, Joo Hymn Sohn, Ho Soon Choi, joon Son Hahm Background : Helicobacter pylori induces gastric mucosal inflammation without direct invasion. The interaction between the bacteria and gastric mucosa would have the main role in initiating an immune response in gastric mucosa. Helicobacter pylori exists in two forms; a spiral form and a coccoid form. The coccoid form H. pylon is alive and metabolically active but noncuhurable. The role of the coccoid form in pathogenesis of gastric diseases remains unclear. We investigated the H. pylori infection-induced expression of Toll-like receptors 2, 3, 4, 5 and Ik-8 mRNA, and the eltect of coccoid transformation of H. pylori on the expression of TLRs mRNA from the AGS cell line. Methods : After 3 days of culture on Brucella agar with 5% horse serum in a microaerophilic atmosphere, Helicohacter pylon were stored in Brani-heart infusion broth, containing 10% horse serum, for 3 days to obtain spiral forms of H. pylori and 7 days for coccoid torms of H. pylon. Both forms of H. pylori were added to the human gastric epithelial cell line, AGS and cultured for 24 hours RTPCP,s for TLR2, 3, 4, 5 and IL-8 were performed utter a 24-hour cuhure of AGS. Results : Both torms of H. pylori did not induce the difference in expression of TLR 2, 3 and 4. mRNA (TLR2/lB-actm 0.72 vs. 0.75, TLP,3//3-actin 0.31 vs. 0.29, TLR4/~-actin 0.87 vs. 0.89). However, decreased expression of TLR5 was detected in coccoid form H. pyloriinfected AGS while the TLR5 expression was increased by spiral form H. pylori infection (TkRS/13-actin 0.58 vs. 0.032). Additionally, 1L-8 mRNA expression was less potent in coccoid-lorm H. pylori-infected AGS (IL-8/~-actin 021 vs 0.71). Conclusions : The transformation of H. pylon changes the pathogenicity of the bacteria and the immune reaction of gastric mucosa. Decreased expression of TLR5 and 1L-8 mPcNAwithout any change of TLR4 expression was shown in coccoid tbrm H. pylori-infected AGS. Decreased expression of flagellin induced by structural change of flagella &mug the transfom~ation would affect the immune reaction of gastric mucosa,
W903 Activation of MAP-Kinases and Increased Levels of interleakin 8 in Ex Vivo Human Gastric Epithelial Cells Associates with Helicobacter Pylori Infection Ladislava Sebkova, Antonia Pellicano, Giovanni Monteleone, Barbara Grazinli, Francesco I%~ghano, Maria G. Imeneo, Francesco Pallone, Francesco Luzza Background MAP kinases are a tamily of ubiquitous, highly' conserved, cell sigualing molecules. They can be activated by a wide variety of extracellular stimuli like IL-1, TNF-alpha, and pathogens and transmit signals from the cell surtace to the nucleus to regulate gene expression. These signaling pathways may induce the production of 1L-8, a chemotactic factor ol polymorphonuclear (PMN) celts. Epithelial cells are the first barrier against bacterial infections and a major source of 1L-8 H.pylori-associated gastritis is characterized by massive mucosal infiltration ot PMN cells, confirmnig an important role of IL-8 in this iutlammatoD, response. Aim: To evaluate the activation of MAP kinases ERK, JNK, and p38 m gastric epithelial cells trom pat*cuts ,alth H.pylori int}ction and its relationship with 1L-8 expression. Methods : 19 patients (10M; 23-62 yrs, median 42) who underwem gastroscopy for dyspeptic complaims were studied. During endoscopy, s~x biopsies were obtained from each patient.
W906 Somatostatin Inhibits LPS-induced Dendritic Cell Maturation John Y, Kao, Sivaprakash Rathinavehi, Juanita L, Merchant Background: Dendritic cells (DCs) are the most potent antigen presenting cells (APC) that modulate host immune responses to foreign pathogens. CD40 expression on DCs plays an important role in their activation and is essential for induction of antigen-speci tic Tcell respmtses. We recendy showed that somatostatin (SST) mediates IL-4 resolution of Helicobacter-induced gastitis (Gastro 122(4):A22, 2002). Aim: On this basis, we examined
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AGA Abstracts