Absolute cell counts
LYSING
Absolute numbers of cells expressing CD45, CD3, CD4, and CD8 in peripheral blood were measured using BD TruCount tubes (BD Biosciences) according to the manufacturer’s instructions. Briefly, 50 μL of anticoagulated blood was added to TruCount tubes within three hours after extraction and thereafter fluorescently stained for CD45, CD3, CD4, and CD8 for 15 minutes at RT in the dark. Samples were then fixed with 1X BD FACS lysing solution before acquiring data on a BD Accuri flow cytometer (BD Biosciences).