FIG 6.
RIG-I-Q10E and MAVS-K136A resist destruction and restore innate immune activation during SARS-CoV-2 infection. (A, B) Immunoblotting analysis of WCLs of Caco-2 cells stably expressing RIG-I-WT or RIG-I-Q10E with the indicated antibodies (A). Total RNA extracted from Caco-2 cells stably expressing RIG-I-WT or RIG-I-Q10E infected with SARS-CoV-2 (MOI = 1) was analyzed by RT-qPCR with primers specific for the indicated genes (B). (C) Immunoblotting analysis of WCLs of Caco-2 cells stably expressing MAVS-WT or MAVS-K136R with the indicated antibodies. (D) Total RNA extracted from Caco-2 cells stably expressing MAVS-WT or MAVS-K136R infected with SARS-CoV-2 (MOI = 1) was analyzed by RT-qPCR with primers specific for the indicated genes. (E) Immunoblotting analysis of WCLs of Caco-2 cells stably expressing RIG-I-WT and MAVS-WT or RIG-I-Q10E and MAVS-K136R with the indicated antibodies. (F) Total RNA extracted from Caco-2 cells stably expressing RIG-I-WT and RIG-I-Q10E or MAVS-WT and MAVS-K136R infected with SARS-CoV-2 (MOI = 1) was analyzed by RT-qPCR with primers specific for the indicated genes. (G) Immunoblotting analysis of WCLs of Caco-2 cells stably expressing RIG-I-WT and RIG-I-Q10E or MAVS-WT and MAVS-K136R infected with SARS-CoV-2 for 72 h, with the indicated antibodies. (H, I) SARS-CoV-2 replication in Caco-2 cells stably expressing RIG-I-WT, RIG-I-Q10E, MAVS-WT, MAVS-K136R, RIG-I-WT, and MAVS-WT or RIG-I-Q10E and MAVS-K136R was analyzed by RT-qPCR for SARS-CoV-2 S and RdRp RNA (H) or determined by plaque assay (I) at 72 h postinfection. Data are means ± SD. Significance was calculated using Student’s two-tailed, unpaired t test. *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001. See also Fig. S5.