Expression of PVR but not B7-H6 predicts cytotoxic targeting of primary AML samples by DOT cells. (A) Representative flow cytometry histograms of the expression of PVR, nectin-2, and B7-H6. Each row depicts a different AML sample donor. Gray histograms, isotype; black lines, sample. (B) Distribution of PVR, nectin-2, and B7-H6 expression on all primary AML samples analyzed. (C) Targeting of primary AML samples by DOT cells based on the expression of 1 of 3 ligands shown in panels A-B. (D) Targeting of primary AML samples by DOT cells based on the expression of PVR, nectin-2, or B7-H6. (E) Receiver operating characteristic curves that illustrate the predictive ability of the expression of each of the depicted ligand(s) to discriminate whether primary AML samples are targeted by DOT cells. (F) Fold change of percentage of CD69⁺ cells (left) or CD69 MFI (right) on DOT cells that were cultured alone, or in the presence of PVR⁻ or PVR⁺ primary AML samples. Each dot represents a different DOT cell/AML combination. Statistical analysis was performed using the Mann-Whitney U test for panels C-D, and Kruskal-Wallis followed by Dunn multiple comparisons test for panel E. AUC, area under the curve; w/o, without.