Induction and distribution of intestinal immune responses after administration of recombinant cholera toxin B subunit in the ileal pouches of colectomized patients

Vaccination in Inflammatory Bowel Disease: Utility and Future Perspective

Inflammatory bowel disease (IBD) is an immune-mediated disease, which often require lifetime treatment with immunomodulators and immunosuppressive drugs. Both IBD and its treatments are associated with an increased risk of infectious disease and mortality. Several of these diseases are vaccine preventable and could be avoided, reducing morbidity and mortality. However, vaccination rates among patients with IBD are lower than in the general population and both patients and doctors are not fully aware of the problem. Education campaigns and well planned vaccination schemes are necessary to improve vaccination coverage in patients with IBD. Immunomodulators and immunosuppressive drugs may reduce the seroprotection levels. For this reason, new vaccination schemes are being studied in patients with IBD. It is therefore important to understand which and when vaccines can be administrated based on immunocompetence or immunosuppression of patients. Usually, live-attenuated vaccines should be avoided in immunosuppressed patients, so assessing vaccination status and planning vaccination before immunosuppressive treatments are pivotal to reduce infection risk. The aim of this review is to increase the awareness of the problem and provide a quick reference for vaccination plan tailoring, especially for gastroenterologists and primary care physicians, who have the skills and knowledge to implement vaccination strategies.

Selective upregulation of endothelial E-selectin in response to Helicobacter pylori-induced gastritis

Helicobacter pylori is one of the most common bacterial pathogens, infecting up to 50% of the world's population. The host is not able to clear the infection, leading to life-long chronic inflammation with continuous infiltration of lymphocytes and granulocytes. The migration of leukocytes from the blood into inflamed tissue is dependent on adhesion molecules expressed on the vascular endothelium. The aim of this study was to characterize the effect of H. pylori-induced gastritis with regard to the expression of endothelial adhesion molecules in the gastric mucosa and compare this to other types of chronic mucosal inflammations. Our results demonstrate an increased level of expression of the adhesion molecule E-selectin, but not of intracellular adhesion molecule 1, vascular adhesion molecule 1, or vascular adhesion protein 1, in H. pylori-induced gastritis but not in gastritis induced by acetylsalicylic acid or pouchitis. The upregulated E-selectin expression was determined to be localized to the gastric mucosa rather than being a systemic response to the infection. Moreover, the H. pylori type IV secretion system encoded by the cag pathogenicity island (cagPAI) was found to be an important determinant for the upregulation of human endothelial E-selectin expression in vitro, and this process is probably dependent on the CagL protein, mediating binding to alpha5beta1 integrins. Thus, endothelial E-selectin expression induced by H. pylori probably contributes to the large influx of neutrophils and macrophages seen in infected individuals, and our results suggest that this process may be more pronounced in patients infected with cagPAI-positive H. pylori strains and may thereby contribute to tissue damage in these individuals.

Priming and expression of immune responses in the gastric mucosa

This review deals with the induction and expression of immune responses in the human stomach following mucosal immunisation. As prerequisites for developing a Helicobacter pylori vaccine, the role of gastric inflammation, in particular inflammation induced by H. pylori infection, as well as lymphocyte homing within the common mucosal immune system, and the importance of immunisation route are discussed.