Fig. 6: ARIH1 promotes anti-tumor immunity via PD-L1 degradation.
From: ARIH1 signaling promotes anti-tumor immunity by targeting PD-L1 for proteasomal degradation
a Immunoblot of PD-L1 and ARIH1 (HA) in H1975 cells transfected with HA-ARIH1 (WT or Y392C); HA-tagged empty vector (HA-EV) was transfected as a negative control. b Co-IP analysis for the interaction of K48-ubiquitin, ARIH1 (HA), and PD-L1 in HEK293T cells transfected with Flag-PD-L1 and HA-ARIH1 (WT or Y392C) in the presence of 10 μM MG132 for 6 h. c 4T1 cells were infected with an empty vector (CTRL) or two different ARIH1-overexpressing lentiviral preparations (OE#1 and OE#2). ARIH1 and PD-L1 levels were determined by immunoblotting. d–f Tumor growth (d, e) of CTRL (n = 10) and ARIH1-OE cells (n = 11) in BALB/c mice and final tumor weights (f). Data represent means ± SEM, ***P < 0.001 (P = 0.0001), ****P < 0.0001. g, h Flow cytometry analysis for the tumor levels of CD8+ T cells (g) and CD8+GzmB+ T cells (h). Data represent means ± SEM, CTRL (n = 10) and ARIH1-OE (n = 5), ***P < 0.001 (P = 0.0006), **P < 0.01 (P = 0.0046). i–k 4T1 tumor xenograft growth in BALB/c mice (I, j) and final tumor weights (k) following treatment with ES-072 and/or anti-CTLA4 (n = 6-7). Vehicle = sodium carboxymethyl (CMC-Na). ES = ES-072. Data represent means ± SEM, *P < 0.05 (P = 0.01), **P < 0.01 (P = 0.0013), ***P < 0.001 (P = 0.0001), ****P < 0.0001. l, m Flow cytometry analysis for the tumor levels of CD8+ T cells (l) (n = 4–7) and CD8+GzmB+ T cells (m) (n = 4–7). Data represent means ± SEM. l **P < 0.01 (P = 0.0017), ***P < 0.001 (P = 0.0001), ****P < 0.0001. m *P < 0.05 (P = 0.0286), **P < 0.01 (P = 0.0012), ***P < 0.001 (P = 0.00099). n Immunobloting of the indicated tumor lysates. Source data are provided as a Source Data file.
