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PubMed2005

Anti-interferon-inducible chemokine, CXCL10, reduces colitis by impairing T helper-1 induction and recruitment in mice.

BACKGROUND: Colitis in interleukin (IL)-10 mice is a CD4 T helper 1 (TH1)-mediated disease characterized by intermittent, transmural inflammation reminiscent of human Crohn's disease. In this study, we investigated the hypothesis that production of the CXC chemokine CXCL10 (interferon [IFN]gamma-inducible protein 10) enhances induction of inflammatory responses in draining lymph nodes (LNs) and promotes colonic TH1 cell recruitment. METHODS: Colitis was induced in B6 IL-10 mice. Mice were given anti-CXCL10 mAb in 2-week intervals before and after peak colitis. Colitis severity was graded and cytokine/chemokine levels were analyzed by real-time polymerase chain reaction. Cell yields were quantitated and effector cell recruitment was assessed by recovery of transferred D011.10 TH1 cells shortly (72 h) after transfer. RESULTS: Treatment with anti-CXCL10 during colitis development decreased clinical and histologic disease severity as well as cytokine/chemokine mRNA and accumulation of mononuclear cells in LNs and colon. Treatment of mice with severe colitis reduced colitis scores and cell yields to lesser degrees. Anti-CXCL10 specifically decreased recruitment of transferred TH1 cells into mesenteric LNs (MLNs) and colon of IL-10 mice by 75% (P<0.05). CONCLUSION: These results suggest that CXCL10 plays a dual role in colitis development by enhancing TH1 cell generation in inductive sites and promoting effector cell recruitment to inflamed tissue. Blockade of CXCL10 may be a useful adjunct to remission-inducing therapies in inflammatory bowel disease (IBD) by impairing disease recurrence through selective inhibition of effector cell generation and trafficking in vivo.

Animals↗
PubMed2005

Transfer of colitis by Galphai2-deficient T lymphocytes: impact of subpopulations and tissue origin.

To elucidate the potential cell population(s) involved in the induction of colitis in inhibitory G protein Galphai2(-/-) mice, Galphai2-deficient or competent bone marrow or splenic and mesenteric lymph node (MLN) T cells were transferred into immunodeficient mice. The mice were followed up to 23 weeks after transfer, recording changes in body weight. Colitis was graded on hematoxylin and eosin-stained colonic tissue, and production of serum interleukin-18 and colon-derived interferon-gamma was measured using ELISA. After adoptive transfer of Galphai2(-/-) bone marrow, severe colitis developed in irradiated wild type recipients, whereas irradiated Galphai2(-/-) mice increased their life span more than 3 times after transfer of wild type bone marrow, accompanied by significant amelioration of colitis. Neither purified Galphai2(-/-) CD4(+), nor CD8(+) splenic or MLN-derived T cells could induce colitis in recombination-activating gene V(RAG) 2(-/-) recipient mice, whereas transfer of splenic Galphai2(-/-) CD3(+) T cells induced severe colitis. In contrast, transfer of Galphai2(-/-) CD3(+) T cells from the MLN caused only minor histopathological changes in the intestinal mucosa. Finally, serum levels of interleukin-18 and interferon-gamma production from colonic tissue cultures correlated well with disease severity. Our results show that bone marrow transplantation can prolong the life of Galphai2(-/-) mice and ameliorate intestinal inflammation. Splenic CD4(+) or CD8(+) T cells on their own were poor inducers of colitis, whereas the combination of both was highly involved in the induction of intestinal inflammation. Furthermore, we show that the tissue origin of CD3(+) T cells is critical for their potency to induce colitis.

Animals↗
PubMed2003

Histopathological features of the terminal ileum in lymphocytic and collagenous colitis: a study of 32 cases and review of literature.

Biopsy specimens from the terminal ileum of 32 patients with the histopathological diagnosis of lymphocytic colitis or collagenous colitis and 11 control individuals were evaluated for the presence or absence of ileal mucosal abnormalities and for the number of intraepithelial lymphocytes, assessed by immunohistochemical stains for the pan T-cell marker, CD3. We found that the mean CD3 counts in patients with lymphocytic/collagenous colitis were significantly higher than those in the control group. Seven of 14 patients with collagenous colitis and 14 of 18 patients with lymphocytic colitis revealed an increase in intraepithelial T lymphocytes when compared with the control group (P =.001). Other notable changes included ileal villous atrophy in one case of lymphocytic colitis and in three cases of collagenous colitis and epithelial damage with thickened subepithelial collagen in two cases of collagenous colitis.

Adult↗
PubMed2006

Prognostic significance of superficial fissuring ulceration in patients with severe "indeterminate" colitis.

Some colectomy specimens from patients with severe colitis contain superficial fissuring-type ulcers but do not have any other features of Crohn's disease (CD). This finding may cause difficulty with regard to distinguishing ulcerative colitis (UC) from CD and, thus, lead to a diagnosis of "indeterminate" colitis. The aim of this study was to evaluate the clinical and pathologic features, and outcome, of a cohort of patients with colitis and superficial fissuring ulcers, but without any other features that may suggest a diagnosis of CD. We retrospectively identified 21 patients (male-to-female ratio, 10/11; mean age, 38 years) with severe chronic active colitis, all of whom had at least one (range, 1-3) superficial fissuring ulcer in their colectomy specimens (but without any other features of CD), as well as a control group of 18 patients (male-to-female ratio, 10/8; mean age, 41 years) with equally severe disease, but without fissuring ulcers. Both groups were evaluated for a variety of clinical and pathologic features, such as clinical presentation, degree, extent, and duration of colitis, and follow-up information, such as the development of pouchitis, pouch fistulae, and any other features of CD. Overall, 81% of the study patients presented clinically with fulminant colitis and underwent an emergent or urgent colectomy, compared with only 41% of the control patients (P = 0.02). Nine (43%) study patients had active serositis in their colectomy specimens, whereas only 1 (6%) control patient had this finding (P = 0.002). However, no significant differences were noted in either the extent or severity of disease or the presence of active ("backwash") ileitis, between the study and control groups. Upon follow-up (mean, 42 months; range, 4-121 months), the study patients with superficial fissuring ulcers developed pouchitis significantly more often (68% vs. 20%, P = 0.007) than the control group following an ileal pouch-anal anastomosis (IPAA) procedure. One patient from each group developed an anal fissure and another from each group developed an anastomotic stricture. In addition, 1 study patient developed a pouch-cutaneous fistula, and 1 control patient developed an enterocutaneous fistula to a loop ileostomy. Finally, 1 control patient ultimately had her pouch excised because of recurrent intractable pouchitis. However, none of the other study or control patients developed any clinical or pathologic manifestations of CD. We conclude that superficial fissuring ulcers may occur in patients with severe chronic active UC, particularly those who present with fulminant disease. Affected individuals should not be considered to have CD or "indeterminate" colitis and should not be denied an IPAA procedure. Nevertheless, the presence of superficial fissuring-type ulcers in patients with severe chronic active UC denotes a subgroup with a higher risk of pouchitis following surgical resection.

Adult↗
PubMed1994

Topical anticolitic efficacy and selectivity of the glucocorticoid budesonide in a new model of acetic acid-induced acute colitis in the rat.

AIMS: To study the effect of local or parenteral administration of the glucocorticoid budesonide in the acetic acid-induced colitis model in the rat. METHODS: Colitis was induced in an exteriorized colonic segment by administration of 4% acetic acid for 15 s. Four days later, this colonic segment with colitis was examined using a morphological scoring system, and measurements of myeloperoxidase activity and of plasma exudation into the colonic segment. The experimental colitis showed morphological similarities to human ulcerative colitis, with 3-fold increase in myeloperoxidase activity and 6-fold increase in the plasma exudation. Budesonide in different doses administered for 3 days, starting one day after acetic acid instillation, prevented the development of colitis in a dose-dependent manner. The best effect of budesonide on the morphological score was achieved after local treatment at a dose of 10(-5) M twice daily (76% reduction compared with a control colitis group) and parenteral treatment with 0.75 mg/kg (80% reduction). These doses also normalized myeloperoxidase activity and significantly reduced the plasma exudation. The systemic effects of the drug were most pronounced in the group treated with parenteral budesonide. This group showed the greatest reduction in body weight and a significant reduction of the weight of adrenal glands and spleen (as compared to controls). Thymus weight in animals treated systemically was significantly lower than in locally treated animals. In the group treated with local budesonide the weight of adrenals was reduced. However, the weights of spleen and thymus were not reduced and the reduction of the body weight was even less than in the control group. CONCLUSION: Local treatment with budesonide at a dose of 10(-5) M (0.17 mg/kg if completely absorbed, but only 0.03 mg/kg with 15% bioavailability on colonic application) was as effective as parenteral treatment at a dose of 0.75 mg/kg in the attenuation of acetic acid-induced colitis in the rat, but resulted in minor systemic side-effects.

Acetates↗
PubMed1997

Neutralization of tumour necrosis factor (TNF) but not of IL-1 reduces inflammation in chronic dextran sulphate sodium-induced colitis in mice.

The cytokines TNF and IL-1 have been implicated as mediators of the inflammatory processes in patients with inflammatory bowel disease (IBD). To investigate the role of these cytokines in mucosal inflammation we used anti-cytokine strategies in a mouse model of acute and chronic colitis. Mice which received 5% dextran sulphate sodium (DSS) in their drinking water showed signs of acute colitis on day 4, with severe weight loss and bloody diarrhoea. Chronic colitis was established after four cycles of feeding 5% DSS for 7 days and water for 10 days, with the mice showing diarrhoea but no weight loss. In acute colitis, treatment with anti-IL-1 reagents, anti-TNF MoAb, or dexamethasone (DEX) led to aggravation. By contrast, in chronic colitis, treatment of mice with several IL-1 activity-inhibiting reagents failed to show significant effects, whereas anti-TNF MoAb or DEX significantly reduced the colitis. We conclude that in acute colitis IL-1 and TNF are beneficial, whereas in chronic colitis, TNF but not IL-1 seems to play a major role in perpetuation of chronic inflammation.

Acute Disease↗
PubMed1988

Mucin profiles in ulcerative colitis with dysplasia and carcinoma.

Mucin secretion was assessed in Crohn's colitis, in ulcerative colitis with regeneration, dysplasia and carcinoma and in non-colitic adenocarcinoma. The high iron diamine-alcian blue (HID-AB) and periodate borohydride-saponification periodic acid Schiff (PB-KOH-PAS) techniques were used to demonstrate sulphomucins and sialomucins, and O-acylated sialomucins respectively. There was mucosal hyperplasia and increased sialomucin secretion in Crohn's disease, quiescent and active ulcerative colitis. In colitis with carcinoma inflamed mucosa away from the tumour had increased sialomucins as had colitis with dysplasia. They did not differ statistically from each other or from colitic controls without cancer. Dysplastic crypts frequently secreted sulphomucins and the increased sialomucins were in transitional-like glands in the surface fronds or adjacent to the dysplasia. A comparative study of the HID-AB technique gave total correct qualitative allocation of individual quantitatively assessed crypts. Routine HID-AB staining did not aid the recognition of dysplasia in ulcerative colitis. With the PB-KOH-PAS technique colorectal adenocarcinoma showed a significant diminution in O-acylated sialomucins compared with its adjacent mucosa. Mucosal dysplasia in ulcerative colitis displayed a similar trend in O-acylated sialic acid variants, differing with respect to age-and sex-matched colitic controls. The PB-KOH-PAS technique may be of help in assessing mucin secretion in ulcerative colitis as a guide to the evolution of malignancy.

Adenocarcinoma↗
PubMed1998

Factors related to the presence of IgA class antineutrophil cytoplasmic antibodies in ulcerative colitis.

OBJECTIVES: Few studies have assessed the IgA antineutrophil cytoplasmic antibody (ANCA) positivity in ulcerative colitis patients and there is no information about factors related to its synthesis and its status after colectomy. The aims of the study were to assess the serum IgA ANCA prevalence in ulcerative colitis patients, both nonoperated and operated, and to determine the clinical factors related to this positivity. METHODS: Fifty-four ulcerative colitis patients, 63 ulcerative colitis colectomized patients (32 with Brooke's ileostomy and 31 with ileal pouch anal anastomosis), and 24 controls were studied. Antineutrophil cytoplasmic antibodies were detected by specific indirect immunofluorescent assays. RESULTS: The percentage of IgA ANCA was significantly higher in patients with ileal pouch anal anastomosis (45%) than in patients with Brooke's ileostomy (22%). There were no differences related to the presence of pouchitis in ileal pouch anal anastomosis patients. Patients with nonoperated extensive colitis (47%) had a significantly higher percentage of IgA ANCA than patients with proctitis (19%). Total percentage of ANCA (IgA and/or IgG) tended to be higher in ulcerative colitis and in patients with ileal pouch anal anastomosis than in patients with Brooke's ileostomy. However, in ileal pouch anal anastomosis patients, ANCA positivity was mainly due to exclusive IgA production. CONCLUSIONS: A substantial percentage of ulcerative colitis patients, and especially colectomized patients with ileal pouch anal anastomosis, had IgA ANCA, suggesting that ANCA production in ulcerative colitis might be stimulated by an immune reaction in the intestinal mucosa.

Adult↗
PubMed1999

The effects of migration on ulcerative colitis: a three-year prospective study among Europeans and first- and second- generation South Asians in Leicester (1991-1994).

OBJECTIVE: Our aim was to measure prospectively the incidence of ulcerative colitis in Leicester City and to compare this with a previous retrospective study in the same area. We also sought to compare the incidence and disease extent in the European community with that of the South Asian community and to compare the disease extent between first- and second-generation South Asian migrants. METHODS: A 3-yr prospective study of ulcerative colitis in the city of Leicester took place from October 1, 1991 to September 30, 1994 and included all cases resident in Leicester City and diagnosed as having ulcerative colitis, regardless of the extent and severity of the disease. RESULTS: Extensive colitis was commoner in second-generation migrants than in the first generation (chi2 = 4.3, p = 0.04) and was comparable to the European community. The annual average incidence of ulcerative colitis was 9.1/10(5) population/yr (95% confidence interval [CI] 7.1-11.3), which is similar to the previous retrospective study. However, the annual average incidence of ulcerative colitis in the European population was 7.0/10(5) population/yr (95% CI 5-9.5), whereas that of the South Asian population was 17.2/10(5) population/yr (95% CI 11.8-24.3), confirming that the risk of ulcerative colitis in this particular community is exceptionally high. CONCLUSIONS: These early results suggest that the disease pattern follows that of the indigenous population after only one generation and requires monitoring over the next decade. The incidence of ulcerative colitis in the South Asian population is high and continuing to rise.

Adult↗
PubMed2000

Epidemiology of ulcerative colitis in Israel: a survey of Israeli kibbutz settlements.

OBJECTIVE: The incidence of ulcerative colitis ranges from 3 to 15 cases per 100,000 persons per year with a prevalence of 50-80 cases per 100,000, and the disease is 3-5 times more common among Jews. In Israel, Ashkenazi Jews have a higher incidence than Sephardi Jews, but a lower incidence than Ashkenazi Jews in the United States or Northern Europe. The aim of this study was to examine the prevalence, mean annual incidence, and clinical patterns of ulcerative colitis in a stable population of communal settlements (kibbutz). METHODS: We repeated a community-based survey in 124,400 kibbutz residents, 10 yr after our first study. This population represents 2.5% of the Jewish population of Israel. All ulcerative colitis patients were located by contacting the kibbutz clinics of the 269 kibbutz settlements (100% compliance). Data were updated to December 31st, 1997, which was designated the point prevalence date, and included information on gender, age, origin, education, profession, extent of the inflammatory process, clinical spectrum of the disease, therapy, complications of the disease, and treatment. The mean annual incidence for the 10 yr was calculated from the prevalence data. Only cases with a definite diagnosis of ulcerative colitis made in a recognized gastroenterology unit were accepted into the study. RESULTS: There were 208 confirmed cases of ulcerative colitis disease, 113 women and 95 men (female:male ratio = 1.19). The prevalence rate rose from 121.0/100,000 in 1987 to 167.2/100,000 in 1997 (p < 0.001). The prevalence rates were higher in women than men. Prevalence was highest in Israeli-born members in 1987 but in European/American-born members in 1997. The average annual incidence rate for the 10-yr period was 5.04/100,000/yr. In 1987, 146 cases of ulcerative colitis were collected. During 10 yr of surveillance 17 patients left the kibbutz, 12 died, and 62 new cases were added. The mean age at presentation of the disease was lower in 1987 than in 1997, 46.14 +/- 11.10 and 51.43 +/- 16.67 yr, respectively. Prevalence was highest in men with >16 yr and in women with 9-10 yr of education, 259.3 and 242.9/100,000, respectively. CONCLUSIONS: The prevalence of ulcerative colitis in this Israeli population increased and has reached the upper range for European and American populations. The mean annual incidence rate of ulcerative colitis is in the lower range of that reported for the Western countries.

Adolescent↗
PubMed2000

Treatment of experimental colitis by oral tolerance induction: a central role for suppressor lymphocytes.

OBJECTIVE: Inflammatory bowel diseases (IBD) are immune-mediated disorders wherein an imbalance between proinflammatory (Th1) and antiinflammatory (Th2) cytokines is thought to play a role in the pathogenesis. The aim of this study was to test whether induction of oral tolerance to proteins extracted from inflammatory colon alleviates experimental colitis, and whether oral tolerization mediated by suppressor cells can induce immune tolerance. METHODS: Colitis was induced in rats by intracolonic instillation of trinitrobenzenesulfonic acid (TNBS). Rats received five oral doses of colonic proteins extracted from TNBS-colitis colonic wall. Splenocytes harvested from tolerized and control rats were transplanted into irradiated naive rats. RESULTS: Feeding of colitis-extracted proteins ameliorated colonic inflammation, as shown by reduction of colonic ulcerations, as well as decreased diarrhea, intestine and peritoneal adhesions, wall thickness, and edema. A marked reduction of the fraction of injured colonic area and colon weight, and decrease in colon weight, were observed in tolerized rats versus controls. Histological parameters for colitis were markedly improved in tolerized animals that showed significant reduction in inflammatory response and mucosal ulcerations. Tolerized rats developed an increase in TGFbeta1 and a decrease in IFNgamma serum levels. TNBS-induced colitis was significantly attenuated in naive recipients of splenocytes from tolerized rats, compared with rats that received splenocytes from control donors. CONCLUSIONS: Induction of oral tolerance to colitis-extracted proteins downregulates the anticolon immune response, thereby ameliorating experimental colitis. Suppressor lymphocytes mediate the tolerance by induction of a shift from a proinflammatory to an antiinflammatory immune response.

Administration, Oral↗
PubMed2000

Birth outcomes of women with ulcerative colitis: a nationwide Danish cohort study.

OBJECTIVE: Our study aimed to compare the birth outcomes in offspring of women with ulcerative colitis with controls without the disease. METHODS: A cohort study of 1531 newborns to mothers with ulcerative colitis, and 9092 controls, based on linkage between the Danish National Registry of Patients and the Danish Birth Registry from 1982 to 1992. RESULTS: Among the births to women with ulcerative colitis, 569 took place before and 962 after the first hospitalization for ulcerative colitis. We found no increased risk of either low birth weight or intrauterine growth retardation for newborns born before or after the mothers' first hospitalization. The risk of preterm birth was increased when birth occurred after the mothers' first hospitalization (odds ratio = 1.4, 95% confidence interval = 1.1-1.9), and particularly when the first hospitalization for ulcerative colitis took place during pregnancy (odds ratio = 3.4, 95% confidence interval = 1.8-6.4). CONCLUSIONS: In the offspring of women with ulcerative colitis, we found no increased risk of low birth weight or signs of intrauterine growth retardation. The risk of preterm birth was increased in the offspring of women with ulcerative colitis, particularly when the first hospitalization for ulcerative colitis occurred during pregnancy.

Adult↗
PubMed2001

Hemostatic imbalance in active and quiescent ulcerative colitis.

OBJECTIVE: In healthy conditions, factors inducing or inhibiting coagulation and factors inducing or inhibiting fibrinolysis are in balance. In ulcerative colitis, hypercoagulation is presumed, which may explain part of the clinical features of this disease. Therapy strategies affecting hemostasis may improve the course of ulcerative colitis. This study was conducted to evaluate the balance of coagulation and fibrinolysis in the course of treatment of active ulcerative colitis. METHODS: Patients with active ulcerative colitis were studied by serial determination of markers of the coagulation cascade (thrombin-antithrombin complexes and fibrin degradation products [FbDP]) and the fibrinolytic cascade (fibrinogen degradation products [FgDP]). Parameters of inflammation were also measured (C-reactive protein [CRP], erythrocyte sedimentation rate [ESR], albumin, platelet count, and fibrinogen). Disease activity was assessed by endoscopic and histopathological scores. Follow-up measurement was performed in the course of treatment at the third or fourth month after baseline. Measurements were compared with healthy controls. RESULTS: Thirty-three patients and 22 healthy controls were included. During active ulcerative colitis, inflammatory parameters (CRP, ESR, platelet count) and hemostatic parameters (thrombin-antithrombin complexes, fibrinogen, FgDP, and FbDP) were elevated in comparison with healthy controls. Albumin was decreased and antithrombin-III remained unchanged. During treatment, disease activity decreased significantly endoscopically and histopathologically (p < 0.001). CRP, ESR, platelet count, and fibrinogen also decreased significantly. The hemostatic balance, expressed as the ratio between the plasmin-dependent generation of FgDP and coagulation-dependent generation of FbDP, increased from 0.69 to 1.12 during treatment, mainly because of a decrease of FbDP. In healthy controls, this ratio was CONCLUSIONS: The coagulation and fibrinolytic cascades were activated in active ulcerative colitis, with a hemostatic imbalance in favor of coagulation. This hypercoagulability persisted in 20% (7/33) of patients with ulcerative colitis in remission. The decrease of FbDP and the increase in the FgDP/FbDP ratio during reconvalescence of ulcerative colitis showed that the coagulation cascade was more activated than the fibrinolytic cascade in active disease.

Adult↗
PubMed1994

The true extent of ulcerative colitis? A radiological, endoscopic and histological study.

Twenty-six radiological, endoscopic and histological examinations of the large bowel were performed in 25 patients with ulcerative colitis. Extensive colitis was observed in 42% of the radiological, in 38% of the endoscopic, and in 27% of the histological examinations. Agreement as to the extent of the colitis between all three examination methods was reached in 53% of the cases. The endoscopic extent of colitis varied between left-sided and extensive in 41% of the patients during a 7-year median follow-up. The frequent change in the extent of ulcerative colitis and the considerable disagreement between radiography, colonoscopy and histology in evaluating the extent of colitis justify the question, "Does a true, unambiguous extent of colitis really exist?" It is more likely that the extent of colitis is just a function of time and the examination method used.

Adolescent↗
PubMed2006

Colitis-induced oxidative damage of the colon and skeletal muscle is ameliorated by regular exercise in rats: the anxiolytic role of exercise.

Epidemiological studies have shown that exercise protects the gastrointestinal tract, reducing the risk of diverticulosis, gastrointestinal haemorrhage and inflammatory bowel disease, while many digestive complaints occurring during exercise are attributed to the adverse effects of exercise on the colon. In order to assess the effects of regular exercise on the pathogenesis of colitis, Sprague-Dawley rats of both sexes were either kept sedentary or given exercise on a running wheel (0.4 km h(-1), 30 min for 3 days week(-1)). At the end of 6 weeks, under anaesthesia, either saline or acetic acid (4%, 1 ml) was given intracolonically. Holeboard tests were performed for the evaluation of anxiety at 24 h before and 48 h after induction of colitis. Increased 'freezing time' in the colitis-induced sedentary group, representing increased anxiety, was reduced in the exercised colitis group (P < 0.05). On the third day following the colonic instillation, the rats were decapitated under brief ether anesthesia and the distal 8 cm of the colons were removed. In the sedentary colitis group, macroscopic and microscopic damage scores, malondialdehyde level and myeloperoxidase activity were increased when compared to the control group (P < 0.01-0.001), while exercise prior to colitis reduced all the measurements with respect to sedentary colitis group (P < 0.05-0.001). The results demonstrate that low-intensity, repetitive exercise protects against oxidative colonic injury, and that this appears to involve the anxiolytic effect of exercise, suggesting that exercise may have a therapeutic value in reducing stress-related exacerbation of colitis.

Animals↗
PubMed2004

Preventive effects of Escherichia coli strain Nissle 1917 on acute and chronic intestinal inflammation in two different murine models of colitis.

Escherichia coli strain Nissle 1917 (EcN) is as effective in maintaining remission in ulcerative colitis as is treatment with mesalazine. This study aims to evaluate murine models of acute and chronic intestinal inflammation to study the antiinflammatory effect of EcN in vivo. Acute colitis was induced in mice with 2% dextran-sodium sulfate (DSS) in drinking water. EcN was administered from day -2 to day +7. Chronic colitis was induced by transfer of CD4(+) CD62L(+) T lymphocytes from BALB/c mice in SCID mice. EcN was administered three times/week from week 1 to week 8 after cell transfer. Mesenteric lymph node (MLN) cytokine secretion (of gamma interferon [IFN-gamma], interleukin 5 [IL-5], IL-6, and IL-10) was measured by enzyme-linked immunosorbent assay. Histologic sections of the colon were analyzed by using a score system ranging from 0 to 4. Intestinal contents and homogenized MLN were cultured, and the number of E. coli-like colonies was determined. EcN was identified by repetitive extragenic palindromic (REP) PCR. EcN administration to DSS-treated mice reduced the secretion of proinflammatory cytokines (IFN-gamma, 32,477 +/- 6,377 versus 9,734 +/- 1,717 [P = 0.004]; IL-6, 231 +/- 35 versus 121 +/- 17 [P = 0.02]) but had no effect on the mucosal inflammation. In the chronic experimental colitis of the transfer model, EcN ameliorated the intestinal inflammation (histology score, 2.7 +/- 0.2 versus 1.9 +/- 0.3 [P = 0.02]) and reduced the secretion of proinflammatory cytokines. Translocation of EcN and resident E. coli into MLN was observed in the chronic colitis model but not in healthy controls. Administration of EcN ameliorated acute and chronic experimental colitis by modifying proinflammatory cytokine secretion but had no influence on the acute DSS-induced colitis. In this model, preexisting colitis was necessary for translocation of EcN and resident E. coli into MLN.

Acute Disease↗
PubMed1998

Resident enteric bacteria are necessary for development of spontaneous colitis and immune system activation in interleukin-10-deficient mice.

Mice with targeted deletion of the gene for interleukin-10 (IL-10) spontaneously develop enterocolitis when maintained in conventional conditions but develop only colitis when kept in specific-pathogen-free (SPF) environments. This study tested the hypothesis that enteric bacteria are necessary for the development of spontaneous colitis and immune system activation in IL-10-deficient mice. IL-10-deficient mice were maintained in either SPF conditions or germfree conditions or were populated with bacteria known to cause colitis in other rodent models. IL-10-deficient mice kept in SPF conditions developed colitis in all segments of the colon (cecum and proximal and distal colon). These mice exhibited immune system activation as evidenced by increased expression of CD44 on CD4(+) T cells; increased mesenteric lymph node cell numbers; and increased production of immunoglobulin A (IgA), IgG1, and IL-12 p40 from colon fragment cultures. Mice populated with bacterial strains, including Bacteroides vulgatus, known to induce colitis in other rodent models had minimal colitis. Germfree IL-10-deficient mice had no evidence of colitis or immune system activation. We conclude therefore that resident enteric bacteria are necessary for the development of spontaneous colitis and immune system activation in IL-10-deficient mice.

Animals↗
PubMed2001

Different subsets of enteric bacteria induce and perpetuate experimental colitis in rats and mice.

Resident bacteria are incriminated in the pathogenesis of experimental colitis and inflammatory bowel diseases. We investigated the relative roles of various enteric bacteria populations in the induction and perpetuation of experimental colitis. HLA-B27 transgenic rats received antibiotics (ciprofloxacin, metronidazole, or vancomycin-imipenem) in drinking water or water alone in either prevention or treatment protocols. Mice were treated similarly with metronidazole or vancomycin-imipenem before or after receiving 5% dextran sodium sulfate (DSS). Germfree transgenic rats were colonized with specific-pathogen-free enteric bacteria grown overnight either in anaerobic or aerobic atmospheres. Nontransgenic rats colonized with anaerobic bacteria served as negative controls. Although preventive metronidazole significantly attenuated colitis in transgenic rats and DSS-treated mice, it had no therapeutic benefit once colitis was established. Ciprofloxacin also partially prevented but did not treat colitis in B27 transgenic rats. In both animal models vancomycin-imipenem most effectively prevented and treated colitis. Germfree transgenic rats reconstituted with enteric bacteria grown under anaerobic conditions had more aggressive colitis than those associated with aerobic bacteria. These results suggest that a subset of resident luminal bacteria induces colitis, but that a complex interaction of commensal aerobic and anaerobic bacteria provides the constant antigenic drive for chronic immune-mediated colonic inflammation.

Animals↗