Class 1 restriction by the AAV/HM1.24-generated CTL response. The cell key is the same as that in Figure 7. These experiments are similar to those discussed in Figure 5 except here the target cells were preincubated with either anti-isotype, anti–class 1 antibody (W6/32), anti–class 2 antibody (L243), or no antibody. Shown at the top are the CTL responses (as percentage of killing) of 3 donors (each experiment performed in quadruplicate) against the MM cells from 4 patients. The experimental labels at the bottom of the figure identify these CTL responses. At the bottom are 4 subfigures, each a compilation of the results from all 3 donors against one of the patients. Note that the addition of anti–class 1 antibody significantly inhibited killing, whereas the addition of the others did not. Also note that the CTLs generated from wild-type AAV-loading DCs did not kill the HM1.24-positive targets. All donors HLA matched to the primary MM cells, as indicated by the key to Figure 7, are used in place of the HM1.24-positive autologous PBL targets. Note that, again, only the anti–class 1 antibody inhibited killing, strongly suggesting class 1–restricted killing by these CTLs.