STRENGTH OF BINDING BETWEEN LEUKEMIC BLASTS AND CYTOTOXIC LYMPHOCYTES

Strength of binding (Sb), a new parameter defined by the ratio of bind ing capacity and dissociation rate constants, was estimated and used f or the characterization of conjugate formation between leukemic blasts and cytotoxic lymphocytes, Lymphokine activated killer (LAK) cells, i .e., interleukin-a activated peripheral blood lymphocytes (PBL) displa yed significantly (P < 0.001) higher Sb with leukemic blasts when comp ared to fresh, nonactivated PBL. Interaction of both fresh PBL and Wt effector cells with acute myeloid leukemia (AML) blasts was characteri zed by a significantly (P < 0.05) lower Sb when compared to the K562 c ell line, Interaction of WC effector cells with leukemic cell-lines of lymphoid origin (Daudi, Raji, and HuT78) was characterized by a signi ficantly (P < 0.005) lower Sb than with K562 myeloid cell line, Sb for the interaction of natural killer (NK)-derived CD16(+)/CK56(+) LAK wi th leukemic blasts was significantly (P < 0.001) higher than that of T -cell-derived CD3(+)LAK, We conclude that calculation of Sb provides a relatively simple and independent way to evaluate systems of interact ing cells at a single time and may be used to compare results between different cell systems and laboratories. (C) 1996 Wiley-Liss, Inc.