Cytotoxic cellular mediators of the immune response to neoplasia: a review.

Immunotherapy in the management of neoplastic disease has recently been a major focus of scientific attention. Studies in vitro and in animal systems have provided the basis for the first trials of cellular immunotherapy for neoplasia in humans. Work over the past ten years has identified several distinct populations of lymphocytes active in lysing neoplastic cells, including major histocompatibility complex (MHC)-restricted and non-restricted cytotoxic T lymphocytes (CTL), natural killer (NK) cells, the natural cell-mediated cytotoxicity (NCMC) population, and the lymphokine-activated killer (LAK) phenomenon. This paper reviews the current understanding of the distinguishing cell surface phenotypes, recognition structures, mechanisms of neoplastic target cell lysis, activation requirements, and ontogeny of each of these cell groups.