Human natural killer cells: correlation of a lytic assay with a visual binding assay

Different populations of human effector cells were examined for their ability to bind and to lyse K562 target cells as monitored by a fluorochrome-labeled batch system binding assay and a 6-hour chromium release assay respectively. Binding and cytolysis were found to increase, or decrease, concomitantly with null cell purification, and both were abrogated by trypsin treatment of effectors. At 4 degrees C, cytolysis was abolished whereas binding was only decreased. When binding and cytolysis data were correlated, the nylon wool nonadherent cells (i.e., T and null cells) were found to be the most efficient (i.e., fewer bound effectors per target cell lysed) while mononuclear cells were the least efficient with respect to natural killing. These findings support the current hypotheses of spontaneous killer ontogeny and peripheral blood compartmentalization. Furthermore, this study confirms observations made for mononuclear and enriched T plus null cell populations in single conjugate in agarose assays and extends those to the null cell population--a population relatively enriched for large granular lymphocytes.