Functional differences among KIR2DL1 alleles observed in vitro are confirmed in vivo. YT-Indy cells expressing different alleles of KIR2DL1 were mixed with 721.221-Cw6 at a 10:1 (E/T) ratio and injected subcutaneously into NOD-scid IL2Rγnull mice. A total of 30 mice, 5 mice for each group, were given injections. After the tumors reached 20% of body mass in the positive control group (mice injected with only target cells), the mice were humanely killed, dissected, and photographed. The image of a representative tumor from each group is shown. (A) Vector, *00301, *00401, *006, and *010 are tumors from mice given injections of YT-Indy transfected with empty vector, KIR2DL1*00301, KIR2DL1*00401, KIR2DL1*006, or KIR2DL1*010, together with 721.221 expressing HLA-Cw6. Cw6 was a tumor from a mouse given only 721.221 expressing HLA-Cw6. Tumor mass (B) and tumor volume (C) were also measured. The experiment was repeated 3 times. *P = .08, **P < .05, ***P < .01. Error bars represent SD.
