Remission-inducing effect of anti-TNF monoclonal antibody in TNBS colitis (original) (raw)
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Gastroenterology, 2011
The anti-tumor necrosis factor (TNF) antibodies infliximab, adalimumab, and certolizumab pegol have proven clinical efficacy in Crohn's disease. Here, we assessed the effects of anti-TNF antibodies on apoptosis in inflammatory bowel disease (IBD). METHODS: CD14 ϩ macrophages and CD4 ϩ T cells were isolated from peripheral blood and lamina propria mononuclear cells from patients with IBD and control patients. Cell surface markers and apoptosis were assessed by immunohistology and fluorescence-activated cell sorting techniques. RESULTS: Lamina propria CD14 ϩ macrophages showed significantly more frequent and higher membrane-bound TNF (mTNF) expression than CD4 ϩ T cells in IBD, whereas mTNF-dependent signaling proteins such as TNF receptor (TNFR) 2, TNFRassociated factor (TRAF) 2, and nuclear factor B were induced in IBD mucosal CD4 ϩ T cells. Most anti-TNF antibodies did not induce T-cell apoptosis in purified peripheral or mucosal CD4 ϩ T cells. However, in contrast to etanercept, administration of all clinically effective anti-TNF antibodies resulted in a significant induction of T-cell apoptosis in IBD when lamina propria CD4 ϩ T cells expressing TNFR2 ϩ were cocultured with mTNF ϩ CD14 ϩ intestinal macrophages. In contrast, no effects in control patients were noted. T-cell apoptosis in IBD occurred in vivo after treatment with adalimumab and infliximab, was critically dependent on TNFR2 signaling, and could be prevented via interleukin-6 signal transduction. Blockade of interleukin-6R signaling augmented anti-TNF-induced T-cell apoptosis in IBD. CON-CLUSIONS: Clinically effective anti-TNF antibodies are able to induce T-cell apoptosis in IBD only when mucosal TNFR2 ؉ T cells are cocultured with mTNF-expressing CD14 ؉ macrophages. The finding that anti-TNF antibodies induce apoptosis indirectly by targeting the mTNF/ TNFR2 pathway may have important implications for the development of new therapeutic strategies in IBD.
International Journal of Medical Sciences, 2000
Loss of epithelial barrier integrity is considered an early step in the pathogenesis of Crohn's disease (CD), and the rate of enterocyte apoptosis is one of the determinants of the intestinal barrier function. Tumor necrosis factor-α (TNF-α), one of the major proinflammatory mediators in CD, is one of the extrinsic signals which initiate apoptosis of enterocytes. The aim of this study was to investigate the early effects of experimental colitis on enterocyte apoptosis, and the effects of two anti-TNF treatments, infliximab (IFX) and etanercept (ETC). In addition, the importance of receptor I for TNF was tested in TNFR-1 -/mice. Circulating TNF-α levels were effectively reduced by IFX and ETC (p<0.01, both) at 3 and 6 h. Apoptosis of the ileal enterocytes, assessed by TUNEL staining, staining for Fas-ligand, and bax, increased at 3 and 6h. These alterations were prevented by both anti-TNF strategies, and in TNFR-1 -/animals. The anti-apoptotic protein Bcl-2 was expressed in the ileal epithelium under control conditions, but was suppressed in DNB-colitis. Expression of Bcl-2 was maintained in both anti-TNF treatments and TNFR-1 -/mice. DNB colitis induced a very early, rapid increase of enterocyte apoptosis. Both anti-TNF strategies, IFX and ETC, were equally effective in suppressing enterocyte apoptosis, most likely by inactivation of circulating TNF-α.
Proceedings of the National Academy of Sciences, 2003
Tumor necrosis factor ␣ (TNF-␣) is an important mediator of programmed cell death, and TNF-␣ blockade significantly improves disease severity in several inflammatory conditions, including Crohn's disease (CD), one of the idiopathic inflammatory bowel diseases. However, the precise mechanism(s) of action of anti-TNF-␣ therapy in CD remains poorly understood. SAMP1͞YitFc mice develop a spontaneous ileitis with similarities to human CD in regard to histological features as well as response to conventional treatments. In this report, we tested the novel hypothesis that the beneficial effects of anti-TNF-␣ therapy in CD are mediated by a mechanism that involves down-regulation of intestinal epithelial cell (IEC) apoptosis. Similar to the efficacy of monoclonal anti-TNF-␣ antibodies in human CD, a single injection of a chimeric anti-murine TNF-␣ antibody into SAMP1͞YitFc mice resulted in a marked suppression of intestinal inflammation and epithelial cell damage compared with mice injected with an isotype control antibody. These effects were associated with a significant reduction in apoptosis of freshly isolated IEC as assessed by propidium iodide staining and DNA laddering. In contrast, an increase in lamina propria mononuclear cell apoptosis was observed in anti-TNF-␣-treated mice compared with control. These results were confirmed in vivo by using the terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling-assay. In addition, neutralization of TNF-␣ reduced membrane bound FAS͞CD95 expression in IEC from SAMP1͞YitFc mice compared with control antibody. These data demonstrate a novel mechanism of action of anti-TNF-␣ therapy that involves homeostatic regulation of mucosal cell apoptosis, which results in the net decrease of chronic inflammation typically found in CD.
Clinical & Experimental Immunology, 2012
Inflammatory bowel disease (IBD) can be treated effectively by anti-tumour necrosis factor (TNF) therapy. We set out to investigate the unclear immunoregulatory mechanisms of the treatment. Thirty-four patients with IBD treated with anti-TNF were included. Lymphocytes from peripheral blood and intestinal biopsies were analysed by flow cytometry. Regulation of antigen-stimulated proliferation was analysed by blocking of interleukin (IL)-10, transforming growth factor (TGF)-b or depletion of CD25 + cells in peripheral blood mononuclear cell cultures. No changes in CD4 + CD25 + , CD25 + TNF-RII + or CD4 + CD25 + forkhead box protein 3 (FoxP3 + ) T cells could be observed in peripheral blood after, in comparison to before, 6 weeks of treatment. The suppressive ability of CD4 + CD25 + cells did not change. There was an initial decrease of CD4 + CD25 + cells in intestinal mucosa after 2 weeks of treatment, followed by an increase of these cells from weeks 2 to 6 of treatment (P < 0·05). This was accompanied by an increased percentage of CD69 + cells among these cells after 6 weeks of treatment compared to before treatment (P < 0·01). There was also an increase of mucosal T helper type1 cells from weeks 2 to 6 (P < 0·05). In addition, CD25 + TNF-RII + cells in the mucosa were decreased after 6 weeks of treatment compared to before treatment (P < 0·05). Before treatment, peripheral blood mononuclear cell baseline proliferation was increased when IL-10 was blocked (P < 0·01), but not after. In CD25 + cell-depleted cultures proliferation increased after treatment (P < 0·05). Our data indicate that anti-TNF treatment leads to an induction of effector T cells. Anti-TNF therapy has no significant impact on regulatory T cells in IBD, although the composition of regulatory T cell subsets may change during treatment.
Amelioration of severe TNBS induced colitis by novel AP-1 and NF- κ B inhibitors in rats
TheScientificWorldJournal, 2014
AP-1 and NF-κ B inhibitors, namely, DTCM-G and DHMEQ, were investigated in male Wistar rats with severe colitis, induced by TNBS. The animals were randomized into 3 groups. The control group received 0.5 mL of 0.5% of the vehicle i.p., the DTCM-G group received 22.5 mg/kg body weight DTCM-G in 0.5% i.p., and the DHMEQ group received 15 mg/kg body weight DHMEQ i.p., all twice daily for 5 days. The body weight losses and mortality rates were significantly higher in the control group than those in DTCM-G-treated and DHMEQ-treated groups. The endoscopic inflammation scores in the control, DTCM-G-treated, and DHMEQ-treated groups were 6.3 ± 0.7, 1.0 ± 0.3, and 0.7 ± 0.3, respectively (P = 0.004 and 0.02, resp.). The inflammation scores as assessed by the macroscopic appearance were 4.3 ± 0.8, 0.7 ± 0.3, and 1.2 ± 0.4 in the control, DTCM-G-treated, and DHMEQ-treated groups, respectively (P = 0.01 and 0.009, resp.). The histopathological inflammation scores were 6.4 ± 0.7, 2.0 ± 1.0, and ...
Anti-TNF Treatment in Inflammatory Bowel Disease
Annals of Gastroenterology, 2007
Crohn’s disease and ulcerative colitis are chronic inflammatory disorders of the gastrointestinal tract. Although the primary etiological defect stil remains unknown, in the last decade impotant progress has been made concerning the immunological basis of the disease. Genetic, environmental and microbial factors result in repeated activation of mucosal immune response. Tumor necrosis factor alpha (TNF-alpha) is one of the central cytokines in the underlying pathogenesis of mucosal inflammation in inflammatory bowel disease (IBD) and has been the primary target of biologic therapies.
Proceedings of the National Academy of Sciences of the United States of America, 2003
Tumor necrosis factor alpha (TNF-alpha) is an important mediator of programmed cell death, and TNF-alpha blockade significantly improves disease severity in several inflammatory conditions, including Crohn's disease (CD), one of the idiopathic inflammatory bowel diseases. However, the precise mechanism(s) of action of anti-TNF-alpha therapy in CD remains poorly understood. SAMP1/YitFc mice develop a spontaneous ileitis with similarities to human CD in regard to histological features as well as response to conventional treatments. In this report, we tested the novel hypothesis that the beneficial effects of anti-TNF-alpha therapy in CD are mediated by a mechanism that involves down-regulation of intestinal epithelial cell (IEC) apoptosis. Similar to the efficacy of monoclonal anti-TNF-alpha antibodies in human CD, a single injection of a chimeric anti-murine TNF-alpha antibody into SAMP1/YitFc mice resulted in a marked suppression of intestinal inflammation and epithelial cell da...