Construction of CD16⁺ clones of the YT line by transfection and selection of CD16⁺ and CD16⁻ variants of the NKL line.

(A) Stable transfection by electroporation of a plasmid containing the full-length human CD16 gene resulted in production of YT clones homogeneously expressing CD16. (B) Control YT cells transfected with the empty plasmid (YT mock cells) did not have detectable membrane CD16. YT CD16⁺ cells (C) and YT mock cells (D) expressed comparable levels of CD38. NKL cells were cloned by limiting dilution and selected as CD16⁺ (E) and CD16⁻ (F) sublines. Both sublines were stable over time, and they expressed comparable molecular densities of CD38 (G,H). Empty histograms show the staining obtained with an irrelevant isotype-matched control.