Figure 6. ILC1ls and ILTC1s exhibit potent cytotoxic activities against tumor cells.

(A–C) Lymphocyte populations were purified and cultured from pooled tumors of 20- to 24-week-old PyMT (A–C) and Prf1^−/−PyMT mice (C), incubated at a 1:1 ratio with AT-3 tumor cells and imaged in polydimethylsiloxane wells in the presence of propidium iodide (PI).

(A) Time-lapse montage showing the killing (marked by the red signal indicative of PI staining) of AT3 target cells (indicated by an asterisk) by ILC1l, TCRαβ⁺ ILTC1, TCRγδ⁺ ILTC1, cNK, TCRαβ⁺CD8α⁺NK1.1⁻ and TCRγδ⁺NK1.1⁻ cells (shown by arrowheads). Time (hours:minutes:seconds) is shown at the top of each image with the their initial co-appearance of target and effector cells in the well set at 0. Scale bar = 10 μm.

(B–C) Quantification of killing efficiency defined by number of wells with PI signal over total number of wells with background cell death subtracted. Wells containing one effector lymphocyte were included for quantification and only a single killing event per well was counted (n = 20–100). Filled and open bars represent killing efficiency of cells sorted from wild-type PyMT and Prf1^−/−PyMT mice, respectively (C). Data are pooled from two to three independent experiments. Error bars represent the mean ± SEM. Oneway ANOVA was used for statistical analysis. ****P<0.0001.

(D) Total tumor burden of Prf1^−/− PyMT and wild-type PyMT mice monitored between 8 and 15 weeks of age (n = 7–11). Error bars represent the mean ± SEM. Two-way ANOVA was used for statistical analysis. *P<0.05.

See also Figure S7, Movie S1, Movie S2, Movie S3, Movie S4, Movie S5 and Movie S6.