Figure 5

CD13 expression in Treg-like cells in MT-50.1 and MT-50.4 cell populations. (a) Gating strategy of flow cytometry for sorting Treg-like cell population. We gated the cells using forward scatter (FSC) and side scatter (SCC), followed by the exclusion of dead cells, and then identified CD4⁺ cells. Among these CD4⁺ cells, we gated the CD25^highCD127⁻and the CD25^lowCD127⁻ cell subpopulations. (b) Flow cytometric analysis for expression of Foxp3 and CD13 in the CD4⁺CD25^highCD127⁻ Treg-like cells and the CD4⁺CD25^lowCD127⁻ non-Treg-like cells. Foxp3⁺ cells in the MT-50.4 cell population expressed high levels of CD13. (c) Measurement of secreted IL-10 and TGF-β concentrations by ELISA in the cell-free culture supernatant of the Treg-like and non-Treg-like cell subpopulations. A total of 4 × 10⁵/mL cells were cultured for 3 days. The TGF-β concentrations were below the detection limit (31.3 pg/mL) in culture supernatants of MT-50.1 cells. Data are shown as the mean ± SEM of three independent experiments. Significant differences are shown as **P < 0.01.