Correlation of FOXP3 with CD4 count and viral load.

<p><i>Panel A</i>: CD4 count was negatively correlated with day 1 FOXP3 percentage in the HIV infected group. <i>Panel B</i>: The control group showed no correlation between CD4 count and FOXP3 percentage. Panel C: FOXP3 percentage stratified by CD4 count. <i>Panel D</i>: FOXP3 percentage was positively correlated with viral load.</p

Representative plot illustrating CD25 gating strategy.

<p>Lymphocytes were gated according to forward and side scatter. CD3 positive lymphocytes were selected. CD25 expression on the x-axis was plotted against CD4 on the y-axis. A gate was set according to CD25 expression on the CD4⁻ population. This gave a percentage of CD3⁺CD4⁺CD25⁺ lymphocytes as a percentage of CD3⁺ (figure in top-right quadrant). This percentage was then used to calculate the percentage of CD3⁺CD4⁺CD25⁺ lymphocytes as a percentage of the CD3⁺CD4⁺ population (CD4 population being top-left and right quadrants added together).</p

FOXP3 expression after T cell receptor stimulation.

<p><i>Panel A</i>: FOXP3 expression as a percentage of T lymphocytes at baseline and after 4 days of cell culture, with and without T cell receptor stimulation with anti-CD3. <i>Panel B</i>: Proliferation of total CD4⁺ T cells and FOXP3⁺ expression in proliferated CD4⁺ T cells following T cell receptor stimulation with aCD3. <i>Panel C</i>: Representative plot of FOXP3⁺ expression in proliferated T cells (left-hand plot) following anti-CD3 stimulation compared with an unstimulated sample(right-hand plot). The small plots above show ancestry – lymphocytes were gated; followed by exclusion of events with high CFSE; followed by selection of CD3⁺CD4⁺ T cells. Proliferation is demonstrated by halving of CFSE fluorescence in cells that have divided (large plots below). In the anti-CD3 stimulated sample, FOXP3 expression is noted in cells which have proliferated (top-left quadrant) as well as those that have not proliferated (top-right quadrant).</p

FOXP3 expression at baseline in HIV infected patients.

<p><i>Panel A</i>: Subgroup analysis of the HIV and HIV/TB coinfected groups showed no difference in FOXP3 expression as a percentage of CD3⁺CD4⁺ T lymphocytes between the HIV and HIV/TB co-infected groups. <i>Panel B</i>: Representative plots of baseline FOXP3 expression in CD3⁺CD4⁺ lymphocytes plotted against CD25 for a control and an HIV positive sample. <i>Panel C</i>: Expression of FOXP3, CD25, CTLA-4 and GITR as a percentage of the CD3⁺CD4⁺ population. <i>Panel D</i>: Absolute numbers of total and FOXP3 expressing CD4⁺ T cells at baseline.</p