T Cell-Mediated Cytotoxicity via Fas/Fas Ligand Signaling in Helicobacter pylori-Infected Gastric Corpus
| Autor: | Yoshikazu Kinoshita, Nobuyuki Moriyama, Makoto Watanabe, Hideaki Kazumori, Norihisa Ishimura, Toshihiko Okuyama, Ryo Fukuda, Takekazu Kaji, Hiroshi Suetsugu, Shunji Ishihara, Hiroshi Sato, Kyoichi Adachi, Kousaku Kawashima, Karim M. A. Rumi |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Adult
CD4-Positive T-Lymphocytes Cytotoxicity Immunologic Male Pathology medicine.medical_specialty Fas Ligand Protein T-Lymphocytes Apoptosis CD8-Positive T-Lymphocytes Fas ligand Cell Line Helicobacter Infections Immune system Antigen medicine Humans Cytotoxic T cell fas Receptor Aged Membrane Glycoproteins Helicobacter pylori biology Gastroenterology Epithelial Cells General Medicine Middle Aged Cytotoxicity Tests Immunologic Molecular biology Infectious Diseases Gastric Mucosa biology.protein Female Antibody T cell mediated cytotoxicity CD8 Signal Transduction |
| Zdroj: | Helicobacter. 6:283-293 |
| ISSN: | 1523-5378 1083-4389 |
| DOI: | 10.1046/j.1523-5378.2001.00043.x |
| Popis: | Background. Helicobacter pylori infection induces T helper-1 immune responses in inflamed mucosa. However, the role of T cell-mediated cytotoxicity in the induction of epithelial apoptosis is still unclear. The aim of this study was to investigate the involvement of the Fas/Fas ligand (Fas/Fas-L) system in the H. pylori-infected gastric corpus. Materials and Methods. Gastric fundic biopsy specimens were taken from patients with and without H. pylori infection. The expression of Fas and Fas-L was examined by immunohistochemistry and RT-PCR. Subsets of gastric infiltrating T cells in the biopsy specimens were studied by immunohistochemistry and flow cytometry. In histological sections, apoptosis was detected by the TUNEL method. We studied the in vitro expression of Fas-L in peripheral T cells after stimulation with H. pylori antigen and interferon-γ (IFN-γ). The Fas-mediated in vitro cytotoxicity of activated T cells was assessed by flow cytometry. Results. The numbers of CD4+ and CD8+ T cells were greater in H. pylori-infected subjects. Fas expression was abundantly increased on fundic gland epithelium, and Fas-L was detected on lamina propria mononuclear cells in H. pylori-infected mucosa. TUNEL-positive epithelial cells were also increased in H. pylori-infected subjects. H. pylori antigen and IFN-γ induced Fas-L mRNA expression in both CD4+ and CD8+ T cells. In cytotoxic assay, activated T cells induced apoptosis in AGS cells, which could be significantly inhibited by neutralizing Fas-L antibody. Conclusions. T cell-mediated cytotoxicity via Fas/Fas-L signaling may contribute to the induction of apoptosis in gastric epithelial cells during H. pylori infection. |
| Databáze: | OpenAIRE |
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