Anti-Lyt-1 monoclonal antibody inhibits induction of anti-self-TNP but not of alloreactive cytotoxic T lymphocytes.

The role of Lyt-1+ T cells in the induction of anti-self + TNP and anti-allogeneic CTL was investigated by the use of monoclonal antibodies directed against these molecules. When present during the 5 days of in vitro induction of CTL, anti-Lyt-1.1 mAb partially inhibited the induction of anti-self + TNP CTL but did not affect the induction of alloreactive CTL. The inhibitory effect was dose-dependent, Lyt-1 allotype-specific, and directed at the responding cells. The inhibition could be abolished by the addition of interleukin 2-containing supernatants. These results suggest that under some experimental conditions, Lyt-1-specific mAb can be shown to affect a T cell function, probably a helper function. Possible differences in the induction mechanisms of anti-self + TNP and alloreactive CTL are discussed.