Effector Mechanisms of Cell-Mediated Immunity to Xenogeneic Cell Antigens

Abstract

The effector cells in mouse and rat spleen performing cell-mediated lysis of xenogeneic target cells in vitro have been identified. In mice injected with either a rat or human cell line, the cytotoxic effector cells are shown to be thymus-derived lymphocytes. Repeated challenge of mice with the human cell line also gives rise to antibody, which induces normal spleen cells to become cytotoxic, indicating that two effector mechanisms of cell-mediated lysis may operate in this model.In the rat, cell-mediated lysis of a mouse and of a human cell line is brought about by thymus-derived lymphocytes as well as thymus independent cells, as shown by a T cell-specific antiserum. In confirmation of this, antibody, which renders normal spleen cells cytotoxic, is consistently found in the serum of rats injected with these two cell lines.