Journal: iScience

Article Title: TLR7-mediated inflammation drives PD-L1 upregulation and T cell exhaustion during influenza A virus infection

doi: 10.1016/j.isci.2026.114776

Figure Lengend Snippet: Reduced number of lung cells expressing PD-L1 in TLR7-KO mouse lungs following IAV infection WT C57BL/6 or TLR7-KO mice were intranasally infected with PR8 (50 PFUs) or mock infected with PBS. Flow cytometry was performed on lung tissue to measure the absolute numbers or frequencies of cells expressing PD-L1 at (A) 7 or (B) 14 days post infection. PD-L1 gating as a percentage of live cells at 7 dpi is shown. PD-L1 expression was specifically measured on CD45 − non-immune and CD45 + immune cells at (C) 7 or (D) 14 days post infection. Data are expressed as mean ± SEM (7 dpi: WT PBS n = 6, WT PR8 n = 8, TLR7-KO PBS n = 6, TLR7-KO PR8 n = 8; 14 dpi: WT PBS n = 6, WT PR8 n = 4, TLR7-KO PBS n = 6, TLR7-KO PR8 n = 6). Statistical analysis was conducted using two-way ANOVA test followed by Tukey’s post hoc test for multiple comparison test (∗ p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001, ∗∗∗∗ p < 0.0001).

Article Snippet: CD274 (Mm00452054_m1) , Life Technologies , Cat#4331182.

Techniques: Expressing, Infection, Flow Cytometry, Comparison

Journal: iScience

Article Title: TLR7-mediated inflammation drives PD-L1 upregulation and T cell exhaustion during influenza A virus infection

doi: 10.1016/j.isci.2026.114776

Figure Lengend Snippet: TLR7 stimulation boosts PD-L1 expression Splenocytes from naive WT C57BL/6 or TLR7-KO mice were exposed ex vivo for 24 h to imiquimod (IMQ, 10 μg/mL), PR8 virus (MOI of 1), or recombinant IFN-γ (0.1 ng/mL). Cells were then stained for PD-L1 and measured by flow cytometry. (A) Representative histograms of PD-L1 expression are shown. (B) Mean fluorescent intensities (MFIs) of B cells (B220+), T cells (CD3 + ), or dendritic cells (CD11c + ) expressing PD-L1 are shown. (C) Bone marrow-derived macrophages (BMDMs) were treated with IMQ (10 μg/mL) or IFN-γ (0.1 ng/mL) for 24 h and PD-L1 surface expression determined by flow cytometry. (D) Single cell lung suspensions from naive WT C57BL/6 or TLR7-KO mice were ex vivo exposed to imiquimod (IMQ, 10 μg/mL) or PR8 virus (MOI of 1) for 24 h. Gene expression of PD-L1 (CD274 mRNA) was measured and expressed relative to RPS18 housekeeping as a fold-change above non-treated controls of each mouse genotype. Data are expressed as mean ± SEM, n = 3–4 independent repeats. Statistical analysis was conducted using two-way ANOVA test followed by multiple comparison using Tukey’s post hoc test to compare differences between treatments and each genotype (∗ p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001, ∗∗∗∗ p < 0.0001) or Sidak’s post hoc test to compare differences between untreated groups for each respective genotype (# p < 0.05, ## p < 0.01, ### p < 0.001, #### p < 0.0001).

Article Snippet: CD274 (Mm00452054_m1) , Life Technologies , Cat#4331182.

Techniques: Expressing, Ex Vivo, Virus, Recombinant, Staining, Flow Cytometry, Derivative Assay, Single Cell, Gene Expression, Comparison

Journal: iScience

Article Title: TLR7-mediated inflammation drives PD-L1 upregulation and T cell exhaustion during influenza A virus infection

doi: 10.1016/j.isci.2026.114776

Figure Lengend Snippet: Soluble factors in WT-infected BALF promote PD-L1 upregulation on target cells (A) IFN-γ protein levels were measured in the bronchioalveolar fluid (BALF) of WT C57BL/6 or TLR7-KO mice infected with PR8 (50 PFUs) or mock infected with PBS after 7 days. (B) BMDM or alveolar MH-S macrophages were grown in BALF and surface expression of PD-L1 measured after 24 h by flow cytometry. (C) Simple linear regression tests were performed on lung mRNA expression of IFNG and CD274 from experimental mice. Data are expressed as mean ± SEM, n = 4–5 independent cell experiments, or n = 5–8 mice per experimental group. Statistical analysis was conducted using two-way ANOVA test followed by Tukey’s post hoc test for multiple comparison test (∗ p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001, ∗∗∗∗ p < 0.0001).

Article Snippet: CD274 (Mm00452054_m1) , Life Technologies , Cat#4331182.

Techniques: Infection, Expressing, Flow Cytometry, Comparison