Journal: PLOS Pathogens
Article Title: Basal IFNλ2/3 signaling is required for ISG expression and viral control in human intestinal epithelial cells
doi: 10.1371/journal.ppat.1013857
Figure Lengend Snippet: (A, B) T84 WT cells were seeded, and media was replaced the following day. After 48 h, supernatants (conditioned media) were collected and used as a reference control for antiviral activity. IRF3 KO cells were treated with recombinant IFNλ2 or IFNλ3 (0.01–20 ng/mL) or with WT conditioned media for 24 h and then infected with VSV-Luc for 7 h. (A) Schematic representation of the experimental workflow was created in BioRender Keser,Y. (2025) https://BioRender.com/ip2l074 . (B) 7hpi luciferase activity was measured to assess VSV-Luc infection in IRF3 KO cells treated with recombinant IFNλ2 or IFNλ3. (C–F) IFNλ2/3 KO cells were chronically supplemented for two weeks with IFNλ2 (5 ng/mL), IFNλ3 (1 ng/mL), or both. Cells were then trypsinized, reseeded in the absence of any IFN treatment and collected 48 h later for ISG analysis, or used for antiviral assays. (C) Schematic representation of chronic IFNλ2/3 supplementation and subsequent experimental steps. Created in BioRender Keser,Y. (2025) https://BioRender.com/3775duy . (D) Western blot analysis of IRF7, RIG-I, and STAT1 in WT cells and IFNλ2/3 KO cells under the indicated supplementation conditions or non-treated (NT). Protein abundance was quantified relative to actin. Representative images are shown. (E) qRT-PCR analysis of ISGs (MX1, IFIT1, OAS1) in WT cells and IFNλ2/3 cells maintained with IFNλ2, IFNλ3, IFNλ2 + 3, or non-treated. Relative expression was normalized to TBP. (F) VSV-Luc infection was measured by luciferase assayed 7 hpi in hours in WT and IFNλ2/3 cells maintained with IFNλ2, IFNλ3, IFNλ2 + 3, or non-treated. (G–I) IFNλ2/3 KO cells were chronically supplemented with IFNλ2 (5 ng/mL), IFNλ3 (1 ng/mL), or IFNλ2 + 3 for two weeks, reseeded in the absence of any IFNs, and next day, acutely stimulated with IFNλ1–3 (20 ng/mL of each) for 1 h or 24 h. (G) Schematic representation of chronic supplementation followed by acute IFNλ stimulation, was created in BioRender Keser,Y. (2025) https://BioRender.com/beodbxz . (H) Western blot analysis of p-STAT1 and total STAT1 in WT and IFNλ2/3 cells maintained with IFNλ2, IFNλ3, IFNλ2 + 3, or non-treated (NT). Protein abundance was quantified relative to actin, loading control. Representative images are shown. (I) qRT-PCR analysis of ISGs (MX1, IFIT1, OAS1) 24 h after acute IFNλ1–3 stimulation in WT and ΔIFNλ2/3 cells supplemented as indicated. Relative expression was normalized to TBP. Data represent n ≥ 3 biological replicates. Statistical significance was determined using two-way ANOVA (P < 0.05 *, P < 0.01 **, P < 0.001 ***, P < 0.0001 ****, ns = not significant). Error bars represent standard deviation, with the mean shown at the center.
Article Snippet: Wild type (WT) T84 (ATCC CCL-248) as well as T84 knock-out (KO) cells were cultured in a 50:50 mixture of Dulbecco’s Modified Eagle’s Medium (DMEM) and F12 (Gibco #11320033).
Techniques: Control, Activity Assay, Recombinant, Infection, Luciferase, Western Blot, Quantitative Proteomics, Quantitative RT-PCR, Expressing, Standard Deviation