Evaluation of NK-to-target cell binding and evidence for T cell conjugates by flow cytometry.

A flow cytometric methodology was set up to assess the binding capability of peripheral blood NK and T cells to the K562 tumor cell line. Differential side scatter characteristics between effectors and targets were used to analyze conjugated and unconjugated cells. The previous labeling of NK and T cells with anti-Leu 11c and anti-Leu 4 monoclonal antibodies, allowed the distinction between unconjugated non-fluorescent and conjugated fluorescent targets and the percentual evaluation of bound anti-Leu 11c(+) and anti-Leu 4(+) cells.