Figure 1.

CD4⁺ T cells upregulated programmed death ligand 1 (PD‐L1) expression in Gastric cancer mesenchymal stem cells (GC‐MSCs). (A) CD4⁺ T cells were collected from PBMCs of healthy people. (B) GC‐MSCs were incubated with CD4⁺ T cells for 24 hours. Expression of PD‐L1 in GC‐MSCs was determined by immunofluorescent staining. PD‐L1 (red). Cell nuclei were counterstained with Hoechst33342 (blue) in the same view in each section. Scale bar = 100 μm. (C) After CD4⁺ T cells were co‐cultured with GC‐MSCs for 24 hours, protein expression of PD‐L1 in GC‐MSCs was determined by western blotting. (D) Gene expression of PD‐L1 in GC‐MSCs was confirmed using qRT‐PCR. The level of PD‐L1 was normalized to β‐actin. ***P < .001