Kinetic analysis of cytotoxic lymphocyte-target cell interaction as quantified by dual parameter flow cytometry

The kinetics of conjugate formation between leukemic cell lines (K562 and Daudi) and lymphokine-activated killer (LAK) cells was studied. A flow cytofluorometry method using double immunofluorescence staining was applied. During the first 15 min of incubation of LAK effectors with leukemic targets, a rapid binding occurred, followed by a plateau phase lasting until 30 min of observation. A considerable, yet not statistically significant, between-donor variability was noticed. A mathematical model of conjugate formation kinetics, based on the analogy to enzyme kinetics, was formulated and validated. Parameters of the model were related to the binding capacity of effector and target cells, and to the lifetime of conjugates and free cells. The concordance of theoretical curves with experimental data proved that the described model can be considered as a useful tool for the evaluation of kinetic and dynamic characterization of conjugate formation between leukemic targets and LAK effectors.