Mesangial Cells Exhibit Features of Antigen-Presenting Cells and Activate CD4+ T Cell Responses
MMCs activate CD4+ T cells by MHC-II presentation. (a) Flow cytometric analysis of MHC-II molecules expressed on MMCs that were cultured for 48 h with IFN-γ stimulation. (b) IFN-γ-treated MMCs or LPS-treated DCs were incubated with or without ovalbumin (OVA, 1 mg/ml). Subsequently, antigen-pulsed MMCs or DCs were cocultured with naïve CD4+ T cells (OT-II). Additionally, OT-II T cell preparations were incubated with ovalbumin (1 mg/ml) alone. Two days after stimulation, antigen-specific proliferation was analysed with an EdU assay and detected by FCM. The results are expressed as fold changes in EdU-positive CD4+ T cells (OT-II). (c) MMCs were treated with IFN-γ for 48 h, extensively washed, irradiated, and cocultured with naïve CD4+ OT-II T cells and ovalbumin (1 mg/ml) for 48 h. Cytokine expression was analysed via ELISA to determine the expression of IFN-γ, IL-4, IL-10, and IL-17 in the culture supernatant. The data in (b) and (c) were analysed by one-way analysis of variance (ANOVA) followed by Tukey’s HSD post hoc test. The error bars represent the , and the graphs are representative of at least three independent experiments with similar results; .