Fig. 2.

Loss of NK cell IFNAR1 impairs NK cell function, may impact adaptive immune regulation of tumorigenesis and increases lung metastasis. 1 × 10⁵ EO771.LMB cells were injected into the fourth mammary fat pad (IMFP) of control^iCre and Ifnar^−/−NKp46 C57BL/6 mice at day 0 and subsequent alterations to circulating and primary tumor cells assessed. Peripheral blood (PB) was taken at day 7 for FACS analysis and for intracellular staining (ICS) of monocytes was performed at endpoint. a Primary tumor weights (mg) of control (n = 7) and Ifnar^−/−NKp46 mice (n = 7) mice at experimental endpoint. Flow cytometric analysis of b absolute number (cell #) of primary tumor NK cells (n = 6/group). c PB CD69⁺ NK (NK1.1⁺) cell frequency (%). Primary tumor d CD69⁺ (e. representative plots shown) and f IFNγ⁺ NK cell frequency (%) and g IFNAR1 expression, represented as MFI (n = 5/group). Flow cytometric analysis of h CD8⁺ T cell IFNAR1 (MFI; n = 5/group) and i. PB CD69⁺ CD8⁺ T cells, j primary tumor CD69⁺ CD8⁺ T cells, k CD8⁺ IFNγ⁺ T cells, l. PB CD69⁺ CD4⁺ T cells and m primary tumor CD4⁺ IFNγ⁺ T cells, expressed as frequency (%). n RT-qPCR of mCherry (EO771.LMB) DNA expression in the lungs post-intravenous (IV) injection of EO771.LMB cells into WT (n = 9), control^iCre (n = 5) and Ifnar^−/−NKp46 (n = 8) mice at day 24. Representative fluorescence imaging of mCherry (EO771.LMB) in lungs shown for each group. All PB analysis (n = 7/group) and primary tumor analysis (n = 6/group). p values * < 0.05, ** < 0.005, *** < 0.0005. **** < 0.0001 determined by Student’s t test. Errors bars, SEM