Increased frequency of activated T-cells in the Helicobacter pylori-infected antrum and duodenum.
Helicobacter pylori colonize the human stomach and duodenum. The infection has been shown to induce a strong T-cell response in the stomach, whereas the response within the duodenum has been poorly characterized. Furthermore, it remains to be elucidated whether the T-cell response may contribute to ulcer formation in the host. In this study, the frequency of different T-cell subsets, their degree of activation and expression of co-stimulatory receptors in biopsies from the duodenum as well as the antrum were studied by immunohistochemistry and flow cytometry. It was also evaluated whether there are differences in the T-cell responses between duodenal ulcer patients and asymptomatic carriers that might explain why only 10-15% of the infected subjects develop duodenal ulcers. The frequencies of CD4+, CD8+ and CD45RO+, i.e. memory T-cells, were significantly increased in the antrum, and the number of CD25+ cells was considerably higher in both the antrum and duodenum of duodenal ulcer patients and asymptomatic carriers as compared to uninfected individuals. Interestingly, the levels of immunosuppressive CTLA-4+ cells were significantly higher in the duodenum of duodenal ulcer patients, as compared to the asymptomatic carriers. H. pylori cause activation of T-cells in the duodenum as well as in the stomach. Our observation of higher levels of CTLA-4+ cells in the duodenum of duodenal ulcer patients than in the asymptomatic carriers suggests that a suppressive T-cell response may be related to the development of duodenal ulcers.
Department of Medical Microbiology and Immunology, Göteborg University Vaccine Research Institute (GUVAX), Göteborg University, Box 435, 405 30 Göteborg, Sweden.
E
E
Strömberg
A
A
Lundgren
A
A
Edebo
S
S
Lundin
A-M
AM
Svennerholm
C
C
Lindholm
D000328:Adult; D000368:Aged; D001706:Biopsy; D004386:Duodenum / Q000276:immunology / Q000382:microbiology*; D005260:Female; D005434:Flow Cytometry; D016481:Helicobacter Infections / Q000276:immunology / Q000503:physiopathology; D016480:Helicobacter pylori / Q000276:immunology / Q000472:pathogenicity*; D006801:Humans; D007150:Immunohistochemistry; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D011706:Pyloric Antrum / Q000276:immunology / Q000382:microbiology*; D016176:T-Lymphocyte Subsets / Q000276:immunology*