Reversible Inhibition of Lymphocyte-mediated Cytotoxicity by Cytochalasin B

ALLOGRAFT immunity is characterized by the appearance of sensitized lymphocytes which are specifically able in vitro to destroy target cells carrying the sensitizing alloantigens. These cytotoxic lymphocytes represent thymus-derived effector cells^1,2 and are quite distinct from alloantibody-producing cells, which are also formed during induction of allograft immunity³. Although contact between viable cytotoxic lymphocytes and target cells is necessary for destruction, the events which lead to target cell lysis are still unknown⁵.