FAS AND PERFORIN PATHWAYS AS MAJOR MECHANISMS OF T-CELL-MEDIATED CYTOTOXICITY

Two molecular mechanisms of T cell-mediated cytotoxicity, one perforin -based, the other Fas-based, have been demonstrated. To determine the extent of their contribution to T cell-mediated cytotoxicity, a range of effector cells from normal control or perforin-deficient mice were tested against a panel of target cells with various levels of Fas expr ession. All cytotoxicity observed was due to either of these mechanism s, and no third mechanism was detected. Thus, the perforin- and Fas-ba sed mechanisms may account for all T cell-mediated cytotoxicity in sho rt-term in vitro assays.