Figure 3

Role of NK-cell receptors in killing mock- and H-1PV-infected colon carcinoma cells. HT29 and Colo 32 cells (d-e) were infected with H-1PV (MOI = 5 RU/cell) or mock-treated (a-b) for 24 h and used as targets (T) for IL-2-activated NK effector (E) cells (E:T=10:1) in 4-h chromium release assays. Prior to their co-incubation with target cells, the effector cells (E) were incubated for 1h with 10 μg/ml blocking antibodies specific to the indicated receptor or with the unrelated MOPC-21 IgG1 isotype. Figure 3 c shows results from uninfected SW480 cells. Data are expressed as percentages of target cell killing and represent means (with SD bars) of triplicate values from one representative donor. The statistical significance of differences in target-cell lysis was calculated with Student’s t test (*p, <0.05; **, p<0.01; ***, p<0.001).