Figure 2.

Oral contraception alters the number of and Helios expression in CD4⁺ Treg cells in peripheral blood. Peripheral blood drawn at early-, mid-, and late-cycle phases from naturally cycling women (N), women using oral contraception (OC), and men was analyzed by flow cytometry to analyze CD3⁺CD4⁺CD25⁺FOXP3⁺CD127^−/lo Treg cells (A). Panels show the number of Treg cells (B), the number of Ki67⁺ Treg cells (C), the mean fluorescence intensity of FOXP3 in Treg cells (D), the number of Helios⁺ Treg cells (E), the mean fluorescence intensity of Helios in Helios⁺ Treg cells (F), the number of CTLA4⁺ Treg cells (G), and the mean fluorescence intensity of CTLA4 in CTLA4⁺ Treg cells (H). Data are shown by group as estimated marginal means (left side, bar graphs) calculated by linear mixed model analysis (Model 1, all participants). Individual data points are also shown for each woman at each cycle phase in the N and OC groups (right side), with mean ± SE of the mean indicated. The effects of participant group, female sex, OC use, and cycle phase were assessed by linear mixed model analysis and pairwise comparison (n = 10-17 participants/group). ^a,b,cDifferent superscripts indicate differences between participant group (Model 1). ǂSignificant effect of sex (Model 1). ^ϕSignificant effect of cycle phase (Model 2). *Significant effect of OC at specific cycle phases (Model 2). All Ps < 0.05.