Fas ligand mediates activation-induced cell death in human T lymphocytes.

TLDR

Activation‑induced cell death (AICD) occurs in previously activated human T cells upon CD3/TCR stimulation, and Fas engagement by antibodies or recombinant Fas‑ligand also triggers cytolysis. The study aims to demonstrate that CD3/TCR‑induced AICD and Fas‑mediated cytolysis are causally linked. Stimulation of activated T cells upregulates Fas‑ligand expression, causing lysis of Fas‑positive targets, and Fas‑ligand antagonists block AICD, confirming that AICD is mediated by Fas/Fas‑ligand interactions.

Abstract

A significant proportion of previously activated human T cells undergo apoptosis when triggered through the CD3/T cell receptor complex, a process termed activation-induced cell death (AICD). Ligation of Fas on activated T cells by either Fas antibodies or recombinant human Fas-ligand (Fas-L) also results in cytolysis. We demonstrate that these two pathways of apoptosis are causally related. Stimulation of previously activated T cells resulted in the expression of Fas-L mRNA and lysis of Fas-positive target cells. Fas-L antagonists inhibited AICD of T cell clones and staphylococcus enterotoxin B (SEB)-specific T cell lines. The data indicate AICD in previously stimulated T cells is mediated by Fas/Fas-L interactions.