The Role of Cytotoxicity in Allograft Rejection In Vivo

The discovery of cell-mediated immunity, and ultimately of cytotoxic T lymphocytes, emerged from attempts to understand the immunological basis and mechanism of two phenomena discovered early in the history of immunology: delayed hypersensitivity reactions, and allograft rejection. Both of these phenomena were presumed by many investigators to be immunological in nature, showing the properties of specificity and memory, but for many years were misunderstood and open to other interpretations.