Figure 4.

Cell sorting and suppressive activity of inducible co‐stimulatory (ICOS)⁺ and ICOS⁻ regulatory T cells (T_regs). CD4⁺CD127^low+/−CD25⁺ T_regs were isolated by magnetic activated cell sorting (MACS), stained with anti‐CD4 and anti‐ICOS‐specific monoclonal antibodies and sorted into ICOS⁺ (P1) and ICOS⁻ T_regs (P2) (a). The suppressive activity of the different ICOS⁺ and ICOS⁻ T_reg subsets was estimated by suppression assays. Blood samples were obtained from non‐pregnant women (), healthy third‐trimester women (groups 4 and 5) (◆), pre‐eclampsia patients () and women with haemolysis elevated liver enzymes low platelet (HELLP) syndrome (). The figure shows the individual and median values of the maximum suppressive activity (T_reg/responder T cell (T_resp) = 1/2) (b,c) and of the ratio of T_reg/T_resp up to which the purified T_reg cells could be diluted to achieve a minimum suppressive activity of at least 15% (d,e). Compared to non‐pregnant and healthy third‐trimester women, the suppressive activity of both ICOS⁺ and ICOS⁻ T_regs was decreased significantly in pre‐eclampsia patients, but not in HELLP syndrome patients.