Cell-mediated immunity to hapten modified self- and non-self antigens

Abstract

CELL-mediated lysis of cells infected by certain viruses or coupled with haptenic groups has been reported to occur only in situations in which the target cell and cytotoxic effector cell are either syngeneic or semi-allogeneic and cannot be observed when they are allogeneic^1–4. Thus, spleen cells from random-bred chickens bearing Rous sarcomas are very cytotoxic to autochthonous tumour cells but show little cytotoxicity on allogeneic tumour cells. Mouse cells infected with lymphocytic choriomeningitis virus (LCM) are only lysed by sensitised thymus-derived cells (T cells) syngeneic or semi-allogeneic to the target cells². Similarly, spleen cells sensitised in vitro to tirinitrophenyl (TNP) coupled syngeneic spleen cells were reported to lyse only syngeneic but not allogeneic hapten-coupled target cells³. Since in all these models the induction of cell-mediated cytotoxicity was carried out in a syngeneic situation, it is clear that the phenomenon is not a result of the induction step, but is mediated through the effector step of cell-mediated cytotoxicity. It was concluded from these results that the cytotoxic effector cells recognise the modified self antigen^2–4 rather than the determinants introduced into the cell membrane (the virus or the hapten). I report here, however, results which show that TNP-specific cytotoxicity mediated by cytotoxic T cells (T killer cells) can be detected under appropriate assay conditions.