Fig. 9. IFN-γ and p21^Cip1-dependent senescence induction in B cells of λ-MYC mice during ICB.

a–c Fresh frozen cryostat sections of representative lymph nodes of λ-MYC or λ-MYC.p21^Cip1−/− mice. λ-MYC mice were controls (Ctr) or treated with anti-CTLA-4 and anti-PD-1 mAbs (ICB) or anti-CTLA-4, anti-PD-1 and anti-IFN-γ mAbs (ICB/anti-IFN-γ), or λ-MYC.p21^Cip1−/− mice were treated with ICB (ICB/p21^Cip1−/−). pHP1γ (red), nuclei (white) (a). H3K9me3 (red), nuclei (white) (b). Representative microscopic images of SA-β-gal activity at pH5.5 and percentage of SA-β-gal positive tumour cells in each tumour (c). The colour evaluation and calculation of the SA-β-gal⁺ cells are described in Supplementary Fig. 2 and Methods. Scale bars 2 μm (a, b), 1000 μm (c). The SA-β-gal data are representative for three individual tumours. Immune fluorescence was performed in one to two representative tumours from Fig. 8c.