Figure 1.

Tracking FoxP3‐expressing cells using a combination of CD25⁺ CD127^lo markers in either magnetically sorted regulatory T (Treg) cells or bulk peripheral blood mononuclear cells (PBMC). (a) Representative dot plots of the gating strategy for magnetically purified Treg cells. Following identification of lymphocytes based on forward and side scatter, CD3⁺ CD4⁺ T cells were selected from live lymphocytes and CD127^lo T cells were gated from this population; 1000 events were collected from the CD127^lo gate to detect cells that were positive for CD25 and FoxP3 expression. (b, c) Magnetic sorting of Treg cells resulted in a significant increase in the desired population in both HIV ⁺ (n = 16) and HIV ^– (n = 6) participants. (d–f) There was a positive correlation between CD127^lo CD25⁺ and FoxP3⁺ irrespective of whether staining was done with bulk PBMCs (r = 0·94; P < 0·0001; d), partially purified Treg cells (r = 0·86; P < 0·0001; e) or fully purified Treg cells (r = 0·71; P = 0·0002; f) Horizontal bars represent the median. Values were compared using Kruskal–Wallis test followed by Dunn's multiple comparison test.(*P <0·05; **P <0·001; ***P <0·0001) Each dot represents a single individual and correlation was assessed using Spearman test.