Gastric epithelial cells were damaged by gastric T cells through Fas/Fas Ligand-mediated interaction during Helicobacter pylori infection / 中华消化杂志

ABSTRACT

Objective To evaluate the expression of Fas Ligand (FasL) on gastric T cell during H.pylori infection and its cytotoxicity to gastric epithelial cells. Methods FasL protein expressions on mono nuclear cells of gastric mucosa with and without H.pylori infection were examined by immunohistochemistry assay. FasL mRNA expressions were detected in gastric T cell lines isolated from H.pylori infected and uninfected gastric biopsies by RT PCR. The function of FasL expressed by gastric T cells to induce apoptosis in Fas bearing cells was determined by a co culture bioassay (JAM), while the Fas mediated apoptosis of gastric epithelial cells induced by gastric T cells were also evaluated by the same assay. Results FasL was expressed by the mononuclear cells accumulated in gastric mucosa with H.pylori infection, whereas the few mononuclear cells presented in uninfected gastric tissues were negative for FasL. FasL mRNA was detected in gastric T cells isolated from H.pylori infected gastric biopises, while that of uninfected gastric T cell lines was either negative or weak positive. Gastric T cells were capable of inducing apoptosis of Fas positive jurkat cells, while this could be blocked by Fas blocking antibody, ZB4. Conclusions T cells presented in gastric mucosa during H.pylori infection could damage gastric epithelium through Fas/FasL interaction.