Journal: Journal for Immunotherapy of Cancer
Article Title: Colorectal cancer-specific IFNβ delivery overcomes dysfunctional dsRNA-mediated type I interferon signaling to increase the abscopal effect of radiotherapy
doi: 10.1136/jitc-2023-008515
Figure Lengend Snippet: Radiotherapy (RT) enhanced cytosolic dsRNA accumulation for TLR3-mediated type I IFN production. (A) HCT116 cells were irradiated for 24 hours, and then RNA was extracted for electrophoresis (7.5% polyacrylamide gel electrophoresis). HCT116 cells were irradiated for 24 and 48 hours, and the content of cytosolic dsRNA was measured by dsRNA ELISA kit (n=3). *p<0.05, **p<0.01. One-way ANOVA test. (B) SW480 cells were irradiated with 5 Gy for 24 hours, and the level of dsRNA was observed by immunofluorescence staining. *p<0.05 Unpaired t-test. (C) SW480 cells were treated with conditioned medium for 24 hours and then examined by qRT-PCR (n=3). The conditioned medium was collected from irradiated cells and then incubated with RNase A and RNase III for 2 hours. The level of IFNβ1 was analyzed by qRT-PCR (n=3). ***p<0.001. One-way ANOVA test. (D) SW480 cells were treated with conditioned medium for 24 hours and then examined by qRT-PCR (n=3). The conditioned medium was collected from irradiated cells and then incubated with RNase A and RNase III for 2 hours. The level of CXCL10 was analyzed by qRT-PCR (n=3). **p<0.01. One-way ANOVA test. (E) Representative images of cytosolic dsRNA in pre-neoCRT biopsies and post-neoCRT surgical tissues. (F) The correlation between cytosolic dsRNA and tumor IFNβ expression was measured (non-linear regression model, p=0.0012, r =0.2794, n=131). (G) SW480 cells were infected with lentivirus carrying shRNA against RIG1, MDA5 and MAVS. The knockdown efficacy was examined by western blotting. (H) SW480 shNC , SW480 shRIG1 , SW480 shTLR3 , SW480 shMDA5 and SW480 shMAVS cells were irradiated with 5 Gy. After 24 hours, the cells were harvested, and the mRNA levels of IFNβ1 and CXCL10 were examined by qRT-PCR (n=3). *p<0.05, **p<0.01. One-way ANOVA test. (I) HCT116 cells were infected with lentivirus carrying shRNA against TLR3. The knockdown efficacy was measured by immunoblotting. HCT116 shNC , HCT116 shTLR3#1 and HCT116 shTLR3#2 cells were irradiated with 5 and 10 Gy. After 24 hours, the cells were harvested, and the mRNA levels of IFNβ1 and CXCL10 were examined by qRT-PCR (n=3). **p<0.01, ***p<0.001. One-way ANOVA test. (J) HCT116 shNC and HCT116 shTLR3 cells were with or without irradiation with 5 Gy. After 24 hours, CFSE-labeled SupT1 T cells were seeded in the upper wells, and the migrated T cells were examined by flow cytometry (n=3). **p<0.01, ***p<0.001. One-way ANOVA test. (K) HCT116 isogenic TLR3 knockout cells (HCT116-TLR3 KO ) constructed with TLR3 gRNA and HCT115-WT cells constructed with non-targeting (NT) gRNA. HCT116-WT and HCT116-TLR3 KO cells were irradiated with 5 Gy and harvested after 24 hours. The levels of IFNβ1 were analyzed by qRT-PCR (n=3). *p<0.05. One-way ANOVA test. ANOVA, analysis of variance; CFSE, Carboxyfluorescein succinimidyl ester; qRT-PCR, quantitated by real-time PCR.
Article Snippet: HCT116 cells were treated with 2.5 μg/mL poly (I:C) (Sigma, Missouri, USA) or 10 μM selective TLR3 inhibitor CU-CPT4a (Tocris, Pennsylvania, USA) for 24 hours.
Techniques: Irradiation, Electrophoresis, Polyacrylamide Gel Electrophoresis, Enzyme-linked Immunosorbent Assay, Immunofluorescence, Staining, Quantitative RT-PCR, Incubation, Expressing, Infection, shRNA, Knockdown, Western Blot, Labeling, Flow Cytometry, Knock-Out, Construct, Real-time Polymerase Chain Reaction