Journal: bioRxiv
Article Title: Template-Directed RIG-I Agonist Assembly for Targeted Cancer Immunotherapy
doi: 10.1101/2022.12.08.519592
Figure Lengend Snippet: a-b) RIG-I activation by ss-ppp-miRNA-21 in HEK-Lucia™ RIG-I and HEK-Lucia™ Null control cells. Cells were transfected with ss-ppp-miRNA-21 or ss-miRNA-21 (4 μg/mL) along with varying concentrations of miRNA-21 mimic. Luciferase activity was measured in the supernatants after 48 h as per manufacturer’s recommendations. a) There was a dose-dependent RIG-I activation with increasing concentrations of the miR-21 mimic in the in HEK-Lucia™ RIG-I but not the HEK-Lucia™ Null cells, indicating RIG-I-specific activation that is miRNA-21 template dependent (n = 3; *, p < 0.05; **, p < 0.01). b) The response curves to the ss-ppp-miRNA-21 and ss-miRNA-21 resulted in the determination of an EC50 of 83.4 ng/mL for the miRNA-21 mimic when using ss-ppp-miRNA-21. By contrast, the calculated EC50 when using the 5’-ppp-deficient ss-miRNA-21 was 357.9 ng/mL, indicating that the presence of the 5’-ppp rendered the response more potent in this cell line (n = 3; **, p < 0.01; ***, p < 0.001). c) IFN-β expression by miRNA-21 transfected B16-F10 cells. B16-F10 cells (with or without transfection with a miRNA-21 mimic) were treated with indicated concentrations of ss-ppp-miRNA-21 or ss-miRNA-21 for 48 h. IFN-β concentrations in the culture supernatant were measured using ELISA. Transfection with a miRNA-21 mimic led to an increase in IFN-β secretion in the ss-ppp-miRNA-21 treated cells, relative to cells devoid of the mimic (n = 3; **, p < 0.01); d) IP-10/CXCL-10 concentration in the supernatants was quantified by ELISA in cells treated as in c. There was a highly but significant increase in IP-10/CXCL-10 secretion in cells transfected with the miRNA-21 mimic, when the cells were treated with ss-ppp-miRNA-21 relative to cells treated with ss-miRNA-21 (n = 3; ***, p < 0.001; ****, p < 0.0001). IP-10/CXCL-10 secretion in cells transfected with the miRNA-21 mimic, when the cells and treated with ss-ppp-miRNA-21 was higher than in cells treated with the ds-ppp-miRNA positive control (n = 4; p = 0.0001). e) Caspase-3/7 activation (dose dependent) in miRNA-21 mimic transfected B16-F10 cells. Cells were treated with ss-ppp-miRNA-21 or ss-miRNA-21 (4ug/mL) along with increasing concentrations of miRNA-21 mimic. After 48 h, cell death was measured by a CaspaseGlo assay. There was a dose-dependent increase in caspase 3/7 activation by ss-ppp-miRNA-21 in cells transfected with increasing concentrations of the miRNA-21 mimic (n = 4; *, p < 0.05; **, p < 0.01; ***, p < 0.001). f and g) western blot analysis of RIG-I; and phosphorylation of NF-kB (p65) protein. B16-F10 cells (with or without transfection with miRNA-21 mimic) were treated with ss-ppp-miRNA-21 (8 μg/mL) and respective controls. Whole cell lysates (50 μg) were analyzed over 8-20% SDS-PAGE and assayed using specific antibodies for indicated proteins. f) There was a moderate increase in RIG-I protein in cells treated with ds-ppp-miRNA-21. Protein induction was most notable in cells transfected with miRNA-21 mimic and treated with ss-ppp-miRNA-21. g) The abundance of phospho-P65 was increased in cells treated with ss-ppp-miRNA-21 relative to control treatments. This effect was seen both in cells transfected with miRNA-21 mimic prior to treatment with ss-ppp-miRNA-21 and cells that had not been transfected with the mimic. No differences in P65 protein were observed, indicating that the effect reflected protein phosphorylation.
Article Snippet: The RIG-I reporter cell line HEK-Lucia™ RIG-I cells (Catalog Code, hkl-hrigi, InvivoGen) and the control cell line HEK-Lucia™ Null cells (Catalog No. hkl-null, InvivoGen), and Mouse skin melanoma cells (B16-F10) were cultured in Dulbecco’s Modified Eagles Medium (DMEM, Gibco).
Techniques: Activation Assay, Transfection, Luciferase, Activity Assay, Expressing, Enzyme-linked Immunosorbent Assay, Concentration Assay, Positive Control, Caspase-Glo Assay, Western Blot, SDS Page