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.
Strömberg
E
E
Department of Medical Microbiology and Immunology, Göteborg University Vaccine Research Institute (GUVAX), Göteborg University, Box 435, 405 30 Göteborg, Sweden.
Lundgren
A
A
Edebo
A
A
Lundin
S
S
Svennerholm
A-M
AM
Lindholm
C
C
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*