Extended Data Fig. 3: MALT1 cleaves ROQUIN1/2 to stabilize Cd274 mRNA.
a, E0771-VEC or E0771-MALT1 cells were transduced with respective shRNA to knock down the indicated gene. Cancer cell survival rates after CD8+ T cells killing were showed. b, Survival rates of E0771 cells transduced to singly express MALT1, REGNASE1 (3X FLAG-tagged), or simultaneously express MALT1 and REGNASE1 after CD8+ T cells killing at E:T ratio of 1. c, Survival rates of E0771 cells transduced with lentiviruses to singly KD endogenous MALT1 or REGNASE1, or simultaneously KD both MALT1 and REGNASE1 after CD8+ T cells killing at E:T ratio of 1. d, e, Similar experiments were performed as in (c), with the KD of ROQUIN1 (d) and ROQUIN2 (e) being tested. f, MFI of PD-L1 from E0771 cells which were transduced with lentiviruses to singly KD endogenous MALT1 or REGNASE1, or simultaneously KD both MALT1 and REGNASE1 after CD8+ T cells killing. g, h, Similar experiments were performed as in (f), with the KD of ROQUIN1 (g) and ROQUIN2 (h) being tested. i, The relative mRNA levels of Tnfrsf4, Tnf, Tnfaip3, and Cd274 in E0771-CTRL-KD, E0771-ROQUIN1-KD, and E0771-ROQUIN2-KD cells were determined by qPCR. Gapdh was control. j, E0771 cells overexpressing VEC or MALT1 were immunoblotted with α-MALT1 and α-ROQUIN1/2 antibodies. β-actin was used as control. The experiment was independently repeated three times with similar results. k, The relative mRNA levels of Tnfrsf4, Tnf, Tnfaip3, and Cd274 in E0771-VEC and E0771-MALT1 cells were determined by qPCR. Gapdh was used as control. l, E0771-VEC or E0771-MALT1 cells were transduced with respective shRNA to knock down the indicated gene. Cancer cell survival rates after CD8+ T cells killing at E:T ratio of 3 were showed. m, The relative protein level of PD-L1 at different time points post actinomycin D treatment were detected by FACS. For a, c–e, and l, n = 6 biological independent samples; for b, n = 12 biological independent samples; for f-i, k, and m, n = 3 biological independent samples. For a-i, and k-m, data represent mean ± SD. For a-i, one-way ANOVA analysis; for k-m, two-way ANOVA analysis.
