Human T cell clones use a CD3-associated surface antigen recognition structure to exhibit both NK-like and allogeneic cytotoxic reactivity.

In the present study, we developed human non-MHC-restricted CTL clones from human peripheral blood mononuclear cells activated in vitro with recombinant IL 2 and subsequently expended with PHA. The CD3/Ti+ clones were selected for their ability to exhibit non-MHC-restricted CTL reactivity by killing various tumor cell lines in culture, including the line K562 which does not express MHC antigens. We report that, at least for some of the NK-like T cell clones, it is possible to establish an allo-CTL activity, and that the CD3-associated surface antigen recognition structure might be involved in both reactivities.