ABSTRACT
The demonstration that interleukin-2 (IL-2) and IL-2- activated peripheral blood lymphocytes lymphokine-activated killer (LAK) cells are effective in reducing numbers of established metastases in experimental animal systems have recently paved new avenues to cancer immunotherapy. One of the prerequisites for improving adoptive immunotherapy with activated lymphocytes is a better understanding of the tumor-lymphocyte relationship and subsequent selection of lymphocytes with the strongest antitumor activity. It is essential to analyze positive and negative aspects of the conventional LAK therapy and to more accurately define characteristics of effector cells involved in LAK activity. The IL-2 activated lymphocytes acquire lytic activity against most tumor cell lines that are resistant to lysis by nonactivated lymphocytes. The degree of sensitivity of fresh tumor cells to IL-2-activated lymphocytes may vary considerably, with some tumors displaying resistance to lysis. Human adult nonlymphocytic leukemia is a serious clinical problem, despite progress in cancer chemotherapy. Chemotherapy-induced remissions are usually transient, and chemotherapy alone rarely cures the disease.
