Another cell death induction system: TNF-alpha acts as a ligand for Fas in vaginal cells.

The death receptor Fas transduces apoptotic death signaling upon stimulation with the Fas ligand. We previously reported that Fas contributes to vaginal cell death observed during the estrus cycle and after estrogen deprivation, using the functional Fas-lacking lpr and lprcg mutant mouse. In the present study, we investigated whether the Fas ligand also plays a dominant role in vaginal cell death using the functional Fas ligand-lacking gld mutant mouse. Our results demonstrated that vaginal cells of gld mice do not show any abnormalities, suggesting the possible presence of another ligand for Fas. Through our investigation, we demonstrated TNF-α as a ligand for vaginal Fas. Here, we propose that TNF-α acts for the ligand for Fas in vaginal cells, suggesting a new cell death induction system.