Figure 4.

Purified regulatory T (Treg) cells release soluble CD25 (sCD25). Immune cell types were purified from peripheral blood mononuclear cells (PBMCs; n = 4) using magnetic antibody cell sorting beads. Unfractionated PBMCs, CD4⁺ CD127^low CD25^high Treg cells, CD4⁺ T cells, CD8⁺ T cells, CD14⁺ monocytes, CD20⁺ B cells, and PBMCs as well as CD20⁺ B cells from CLL blood were cultured for 2 days in a 96-well plate. Cells were cultured without stimulation (a) or with anti-CD3 stimulation (b). Mann–Whitney U-test was used to analyse differences among groups.