Selective induction of autocytotoxic activity through the CD3 molecule.

In the present study we show that when certain major histocompatibility complex-alloreactive CD8+ T cell clones with natural killer-like activity are stimulated through their CD3 molecules, in the absence of significant cross-linkage (as provided by Fab' fragments of OKT3 antibodies) they lose their interleukin 2 response. This is attributable to an induction of a nonspecific autocytolytic activity. These results suggest that activation of this process in some cytotoxic cells leads to an overall decrease in CTL activity and constitutes a possible mechanism of suppression of the immune response.