NK-specific killing mediated by each antibody was tested using a primary in vitro autologous model, in which NL-LucR.WITO.ecto–infected primary CD4+ T cells were used as targets (T) and autologous purified and IL-15–stimulated NK cells as effectors (E). The percentage specific killing is reported on the y axes and the mAb dilutions on the x axes. Blue, red, purple, black, and green titration curves represent killing at 2, 3, 4, and 6 hours and overnight, respectively. CH65 (an anti-influenza monoclonal antibody) was used as negative control (83). The results show the average of 2 replicates from a single experiment.