Fig. 6: ZC3H12D⁺NK cells harboring IL1β-mRNA in their nucleus function in antimetastasis.

a Migration of B220⁺CD11c⁺NK1.1⁺ cells derived from wild-type and Zc3h12d–/– mice to 10 ng/mL βactin-mRNA, gapdh-mRNA, IL1β-mRNA, and IL1β-stop-mRNA (n = 3 wells per group). b IFN-γ induction in B220⁺CD11c⁺NK1.1⁺ cells from TCM-stimulated wild-type and Zc3h12d–/– mice after incubation with IL1β-mRNA and IL1β-stop-mRNA. The IHC quantitative ratio of IFN-γ-positive cells (n = 3 wells per group). c Tumoricidal assay in vitro after coincubation of tumor cells with 10 ng/mL mRNA-primed B220⁺CD11c⁺NK1.1⁺ cells. The ratio of rhodamine-labeled E0771 cells that became Zombie⁺ dead cells in the assay. The dead E0771 cells increased after coculture with IL1β-mRNA- and IL1β-stop-mRNA-primed B220⁺CD11c⁺NK1.1⁺ cells from TCM-stimulated wild-type mice rather than cells from Zc3h12d–/– mice (n = 3 wells per group). d Tumoricidal assay system. Tumoricidal assay in vitro after coincubation of tumor cells with B220⁺CD11c⁺NK1.1⁺ cells after coculture with BMDMs primed with IL1β-mRNA (top). To exclude the direct effects of IL1β-mRNA on NK cells, BMDMs were washed with basal medium after priming. The ratio of rhodamine-labeled E0771 cells that became Zombie⁺ dead cells in the assay (bottom, n = 4 wells per group). e Antimetastatic assay system in vivo. IL1β-mRNA-primed B220⁺CD11c⁺NK1.1⁺ cells of TCM-stimulated mouse spleens and then applied to another TCM-stimulated mouse. Rhodamine-labeled tumor cells were injected to assess metastasis. f Metastatic LLC cell numbers in lungs with or without pretreated IL1β-mRNA-primed B220⁺CD11c⁺NK1.1⁺ cells from wild-type and Zc3h12d–/– mice are shown (n = 12 mice per group). B220⁺CD11c⁺NK1.1⁺ is shown as ^TriNK. In the graphs, averages ± SEM and the results of Student’s t-test (two-sided) or one-way ANOVA with Bonferroni correction are shown. The P values are shown in the figure. Source data are provided as a Source Data file.