Journal: Frontiers in Cell and Developmental Biology
Article Title: Prolonged TNF-α stimulation induces a PD-1–associated exhaustion-like phenotype in mesenchymal stromal cells
doi: 10.3389/fcell.2026.1680076
Figure Lengend Snippet: Prolonged TNF-α stimulation induces an exhaustion-like phenotype in MSCs. (A) Time-course expression of Tgf-β , Il-10 , and Fasl in MSCs stimulated with TNF-α (10 ng/mL) for up to 48 h. An initial upregulation at the indicated time points was observed, followed by significant downregulation. (B) Immune checkpoint genes ( Pd-1 and Ctla-4 ) were progressively upregulated over time. (C) Immunofluorescence revealed decreased numbers of TGF-β + and IL-10 + MSCs and increased PD-1 + MSCs with prolonged TNF-α stimulation (Scale bar = 20 µm). (D) Expression of Tradd , Ikkα , and Nf-κb remained elevated throughout stimulation. (E) Western blot analysis showed sustained phosphorylation of p65 in MSCs treated with TNF-α. Quantification was performed by densitometric analysis of independent biological replicates (n = 3), each derived from separately prepared MSC cultures. (F) Prolonged TNF-α stimulation led to an increased number of ROS-positive MSCs, indicating elevated intracellular oxidative stress (Scale bar = 100 µm). ROS positivity was defined using a fixed fluorescence intensity threshold, and all samples were processed in parallel, under identical acquisition settings. ROS data are presented as supportive evidence rather than definitive mechanistic proof. Data represent mean ± SD of independent biological replicates derived from separately prepared MSC cultures (n = 4–5). One-way ANOVA with Tukey’s post-hoc test was used. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001.
Article Snippet: To assess the role of TNF-α secreted by M1 macrophages, a TNF-α neutralizing antibody (Cell Signaling Technology, MA, United States) was added to the MSC culture medium at a final concentration of 1 μg/mL during co-culture experiment.
Techniques: Expressing, Immunofluorescence, Western Blot, Phospho-proteomics, Derivative Assay, Fluorescence